Replace boost by the standalone asio library

50 files changed, 15058 insertions, 0 deletions

diff --git a/lib/asio/detail/impl/buffer_sequence_adapter.ipp b/lib/asio/detail/impl/buffer_sequence_adapter.ipp
new file mode 100644
index 0000000..323c8ad
--- /dev/null
+++ b/lib/asio/detail/impl/buffer_sequence_adapter.ipp
@@ -0,0 +1,118 @@
+//
+// detail/impl/buffer_sequence_adapter.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_BUFFER_SEQUENCE_ADAPTER_IPP
+#define ASIO_DETAIL_IMPL_BUFFER_SEQUENCE_ADAPTER_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_WINDOWS_RUNTIME)
+
+#include <robuffer.h>
+#include <windows.storage.streams.h>
+#include <wrl/implements.h>
+#include "asio/detail/buffer_sequence_adapter.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class winrt_buffer_impl :
+  public Microsoft::WRL::RuntimeClass<
+    Microsoft::WRL::RuntimeClassFlags<
+      Microsoft::WRL::RuntimeClassType::WinRtClassicComMix>,
+    ABI::Windows::Storage::Streams::IBuffer,
+    Windows::Storage::Streams::IBufferByteAccess>
+{
+public:
+  explicit winrt_buffer_impl(const asio::const_buffer& b)
+  {
+    bytes_ = const_cast<byte*>(static_cast<const byte*>(b.data()));
+    length_ = b.size();
+    capacity_ = b.size();
+  }
+
+  explicit winrt_buffer_impl(const asio::mutable_buffer& b)
+  {
+    bytes_ = static_cast<byte*>(b.data());
+    length_ = 0;
+    capacity_ = b.size();
+  }
+
+  ~winrt_buffer_impl()
+  {
+  }
+
+  STDMETHODIMP Buffer(byte** value)
+  {
+    *value = bytes_;
+    return S_OK;
+  }
+
+  STDMETHODIMP get_Capacity(UINT32* value)
+  {
+    *value = capacity_;
+    return S_OK;
+  }
+
+  STDMETHODIMP get_Length(UINT32 *value)
+  {
+    *value = length_;
+    return S_OK;
+  }
+
+  STDMETHODIMP put_Length(UINT32 value)
+  {
+    if (value > capacity_)
+      return E_INVALIDARG;
+    length_ = value;
+    return S_OK;
+  }
+
+private:
+  byte* bytes_;
+  UINT32 length_;
+  UINT32 capacity_;
+};
+
+void buffer_sequence_adapter_base::init_native_buffer(
+    buffer_sequence_adapter_base::native_buffer_type& buf,
+    const asio::mutable_buffer& buffer)
+{
+  std::memset(&buf, 0, sizeof(native_buffer_type));
+  Microsoft::WRL::ComPtr<IInspectable> insp
+    = Microsoft::WRL::Make<winrt_buffer_impl>(buffer);
+  buf = reinterpret_cast<Windows::Storage::Streams::IBuffer^>(insp.Get());
+}
+
+void buffer_sequence_adapter_base::init_native_buffer(
+    buffer_sequence_adapter_base::native_buffer_type& buf,
+    const asio::const_buffer& buffer)
+{
+  std::memset(&buf, 0, sizeof(native_buffer_type));
+  Microsoft::WRL::ComPtr<IInspectable> insp
+    = Microsoft::WRL::Make<winrt_buffer_impl>(buffer);
+  Platform::Object^ buf_obj = reinterpret_cast<Platform::Object^>(insp.Get());
+  buf = reinterpret_cast<Windows::Storage::Streams::IBuffer^>(insp.Get());
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_WINDOWS_RUNTIME)
+
+#endif // ASIO_DETAIL_IMPL_BUFFER_SEQUENCE_ADAPTER_IPP
diff --git a/lib/asio/detail/impl/descriptor_ops.ipp b/lib/asio/detail/impl/descriptor_ops.ipp
new file mode 100644
index 0000000..1af643f
--- /dev/null
+++ b/lib/asio/detail/impl/descriptor_ops.ipp
@@ -0,0 +1,474 @@
+//
+// detail/impl/descriptor_ops.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_DESCRIPTOR_OPS_IPP
+#define ASIO_DETAIL_IMPL_DESCRIPTOR_OPS_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <cerrno>
+#include "asio/detail/descriptor_ops.hpp"
+#include "asio/error.hpp"
+
+#if !defined(ASIO_WINDOWS) \
+  && !defined(ASIO_WINDOWS_RUNTIME) \
+  && !defined(__CYGWIN__)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+namespace descriptor_ops {
+
+int open(const char* path, int flags, asio::error_code& ec)
+{
+  errno = 0;
+  int result = error_wrapper(::open(path, flags), ec);
+  if (result >= 0)
+    ec = asio::error_code();
+  return result;
+}
+
+int close(int d, state_type& state, asio::error_code& ec)
+{
+  int result = 0;
+  if (d != -1)
+  {
+    errno = 0;
+    result = error_wrapper(::close(d), ec);
+
+    if (result != 0
+        && (ec == asio::error::would_block
+          || ec == asio::error::try_again))
+    {
+      // According to UNIX Network Programming Vol. 1, it is possible for
+      // close() to fail with EWOULDBLOCK under certain circumstances. What
+      // isn't clear is the state of the descriptor after this error. The one
+      // current OS where this behaviour is seen, Windows, says that the socket
+      // remains open. Therefore we'll put the descriptor back into blocking
+      // mode and have another attempt at closing it.
+#if defined(__SYMBIAN32__)
+      int flags = ::fcntl(d, F_GETFL, 0);
+      if (flags >= 0)
+        ::fcntl(d, F_SETFL, flags & ~O_NONBLOCK);
+#else // defined(__SYMBIAN32__)
+      ioctl_arg_type arg = 0;
+      ::ioctl(d, FIONBIO, &arg);
+#endif // defined(__SYMBIAN32__)
+      state &= ~non_blocking;
+
+      errno = 0;
+      result = error_wrapper(::close(d), ec);
+    }
+  }
+
+  if (result == 0)
+    ec = asio::error_code();
+  return result;
+}
+
+bool set_user_non_blocking(int d, state_type& state,
+    bool value, asio::error_code& ec)
+{
+  if (d == -1)
+  {
+    ec = asio::error::bad_descriptor;
+    return false;
+  }
+
+  errno = 0;
+#if defined(__SYMBIAN32__)
+  int result = error_wrapper(::fcntl(d, F_GETFL, 0), ec);
+  if (result >= 0)
+  {
+    errno = 0;
+    int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK));
+    result = error_wrapper(::fcntl(d, F_SETFL, flag), ec);
+  }
+#else // defined(__SYMBIAN32__)
+  ioctl_arg_type arg = (value ? 1 : 0);
+  int result = error_wrapper(::ioctl(d, FIONBIO, &arg), ec);
+#endif // defined(__SYMBIAN32__)
+
+  if (result >= 0)
+  {
+    ec = asio::error_code();
+    if (value)
+      state |= user_set_non_blocking;
+    else
+    {
+      // Clearing the user-set non-blocking mode always overrides any
+      // internally-set non-blocking flag. Any subsequent asynchronous
+      // operations will need to re-enable non-blocking I/O.
+      state &= ~(user_set_non_blocking | internal_non_blocking);
+    }
+    return true;
+  }
+
+  return false;
+}
+
+bool set_internal_non_blocking(int d, state_type& state,
+    bool value, asio::error_code& ec)
+{
+  if (d == -1)
+  {
+    ec = asio::error::bad_descriptor;
+    return false;
+  }
+
+  if (!value && (state & user_set_non_blocking))
+  {
+    // It does not make sense to clear the internal non-blocking flag if the
+    // user still wants non-blocking behaviour. Return an error and let the
+    // caller figure out whether to update the user-set non-blocking flag.
+    ec = asio::error::invalid_argument;
+    return false;
+  }
+
+  errno = 0;
+#if defined(__SYMBIAN32__)
+  int result = error_wrapper(::fcntl(d, F_GETFL, 0), ec);
+  if (result >= 0)
+  {
+    errno = 0;
+    int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK));
+    result = error_wrapper(::fcntl(d, F_SETFL, flag), ec);
+  }
+#else // defined(__SYMBIAN32__)
+  ioctl_arg_type arg = (value ? 1 : 0);
+  int result = error_wrapper(::ioctl(d, FIONBIO, &arg), ec);
+#endif // defined(__SYMBIAN32__)
+
+  if (result >= 0)
+  {
+    ec = asio::error_code();
+    if (value)
+      state |= internal_non_blocking;
+    else
+      state &= ~internal_non_blocking;
+    return true;
+  }
+
+  return false;
+}
+
+std::size_t sync_read(int d, state_type state, buf* bufs,
+    std::size_t count, bool all_empty, asio::error_code& ec)
+{
+  if (d == -1)
+  {
+    ec = asio::error::bad_descriptor;
+    return 0;
+  }
+
+  // A request to read 0 bytes on a stream is a no-op.
+  if (all_empty)
+  {
+    ec = asio::error_code();
+    return 0;
+  }
+
+  // Read some data.
+  for (;;)
+  {
+    // Try to complete the operation without blocking.
+    errno = 0;
+    signed_size_type bytes = error_wrapper(::readv(
+          d, bufs, static_cast<int>(count)), ec);
+
+    // Check if operation succeeded.
+    if (bytes > 0)
+      return bytes;
+
+    // Check for EOF.
+    if (bytes == 0)
+    {
+      ec = asio::error::eof;
+      return 0;
+    }
+
+    // Operation failed.
+    if ((state & user_set_non_blocking)
+        || (ec != asio::error::would_block
+          && ec != asio::error::try_again))
+      return 0;
+
+    // Wait for descriptor to become ready.
+    if (descriptor_ops::poll_read(d, 0, ec) < 0)
+      return 0;
+  }
+}
+
+bool non_blocking_read(int d, buf* bufs, std::size_t count,
+    asio::error_code& ec, std::size_t& bytes_transferred)
+{
+  for (;;)
+  {
+    // Read some data.
+    errno = 0;
+    signed_size_type bytes = error_wrapper(::readv(
+          d, bufs, static_cast<int>(count)), ec);
+
+    // Check for end of stream.
+    if (bytes == 0)
+    {
+      ec = asio::error::eof;
+      return true;
+    }
+
+    // Retry operation if interrupted by signal.
+    if (ec == asio::error::interrupted)
+      continue;
+
+    // Check if we need to run the operation again.
+    if (ec == asio::error::would_block
+        || ec == asio::error::try_again)
+      return false;
+
+    // Operation is complete.
+    if (bytes > 0)
+    {
+      ec = asio::error_code();
+      bytes_transferred = bytes;
+    }
+    else
+      bytes_transferred = 0;
+
+    return true;
+  }
+}
+
+std::size_t sync_write(int d, state_type state, const buf* bufs,
+    std::size_t count, bool all_empty, asio::error_code& ec)
+{
+  if (d == -1)
+  {
+    ec = asio::error::bad_descriptor;
+    return 0;
+  }
+
+  // A request to write 0 bytes on a stream is a no-op.
+  if (all_empty)
+  {
+    ec = asio::error_code();
+    return 0;
+  }
+
+  // Write some data.
+  for (;;)
+  {
+    // Try to complete the operation without blocking.
+    errno = 0;
+    signed_size_type bytes = error_wrapper(::writev(
+          d, bufs, static_cast<int>(count)), ec);
+
+    // Check if operation succeeded.
+    if (bytes > 0)
+      return bytes;
+
+    // Operation failed.
+    if ((state & user_set_non_blocking)
+        || (ec != asio::error::would_block
+          && ec != asio::error::try_again))
+      return 0;
+
+    // Wait for descriptor to become ready.
+    if (descriptor_ops::poll_write(d, 0, ec) < 0)
+      return 0;
+  }
+}
+
+bool non_blocking_write(int d, const buf* bufs, std::size_t count,
+    asio::error_code& ec, std::size_t& bytes_transferred)
+{
+  for (;;)
+  {
+    // Write some data.
+    errno = 0;
+    signed_size_type bytes = error_wrapper(::writev(
+          d, bufs, static_cast<int>(count)), ec);
+
+    // Retry operation if interrupted by signal.
+    if (ec == asio::error::interrupted)
+      continue;
+
+    // Check if we need to run the operation again.
+    if (ec == asio::error::would_block
+        || ec == asio::error::try_again)
+      return false;
+
+    // Operation is complete.
+    if (bytes >= 0)
+    {
+      ec = asio::error_code();
+      bytes_transferred = bytes;
+    }
+    else
+      bytes_transferred = 0;
+
+    return true;
+  }
+}
+
+int ioctl(int d, state_type& state, long cmd,
+    ioctl_arg_type* arg, asio::error_code& ec)
+{
+  if (d == -1)
+  {
+    ec = asio::error::bad_descriptor;
+    return -1;
+  }
+
+  errno = 0;
+  int result = error_wrapper(::ioctl(d, cmd, arg), ec);
+
+  if (result >= 0)
+  {
+    ec = asio::error_code();
+
+    // When updating the non-blocking mode we always perform the ioctl syscall,
+    // even if the flags would otherwise indicate that the descriptor is
+    // already in the correct state. This ensures that the underlying
+    // descriptor is put into the state that has been requested by the user. If
+    // the ioctl syscall was successful then we need to update the flags to
+    // match.
+    if (cmd == static_cast<long>(FIONBIO))
+    {
+      if (*arg)
+      {
+        state |= user_set_non_blocking;
+      }
+      else
+      {
+        // Clearing the non-blocking mode always overrides any internally-set
+        // non-blocking flag. Any subsequent asynchronous operations will need
+        // to re-enable non-blocking I/O.
+        state &= ~(user_set_non_blocking | internal_non_blocking);
+      }
+    }
+  }
+
+  return result;
+}
+
+int fcntl(int d, int cmd, asio::error_code& ec)
+{
+  if (d == -1)
+  {
+    ec = asio::error::bad_descriptor;
+    return -1;
+  }
+
+  errno = 0;
+  int result = error_wrapper(::fcntl(d, cmd), ec);
+  if (result != -1)
+    ec = asio::error_code();
+  return result;
+}
+
+int fcntl(int d, int cmd, long arg, asio::error_code& ec)
+{
+  if (d == -1)
+  {
+    ec = asio::error::bad_descriptor;
+    return -1;
+  }
+
+  errno = 0;
+  int result = error_wrapper(::fcntl(d, cmd, arg), ec);
+  if (result != -1)
+    ec = asio::error_code();
+  return result;
+}
+
+int poll_read(int d, state_type state, asio::error_code& ec)
+{
+  if (d == -1)
+  {
+    ec = asio::error::bad_descriptor;
+    return -1;
+  }
+
+  pollfd fds;
+  fds.fd = d;
+  fds.events = POLLIN;
+  fds.revents = 0;
+  int timeout = (state & user_set_non_blocking) ? 0 : -1;
+  errno = 0;
+  int result = error_wrapper(::poll(&fds, 1, timeout), ec);
+  if (result == 0)
+    ec = (state & user_set_non_blocking)
+      ? asio::error::would_block : asio::error_code();
+  else if (result > 0)
+    ec = asio::error_code();
+  return result;
+}
+
+int poll_write(int d, state_type state, asio::error_code& ec)
+{
+  if (d == -1)
+  {
+    ec = asio::error::bad_descriptor;
+    return -1;
+  }
+
+  pollfd fds;
+  fds.fd = d;
+  fds.events = POLLOUT;
+  fds.revents = 0;
+  int timeout = (state & user_set_non_blocking) ? 0 : -1;
+  errno = 0;
+  int result = error_wrapper(::poll(&fds, 1, timeout), ec);
+  if (result == 0)
+    ec = (state & user_set_non_blocking)
+      ? asio::error::would_block : asio::error_code();
+  else if (result > 0)
+    ec = asio::error_code();
+  return result;
+}
+
+int poll_error(int d, state_type state, asio::error_code& ec)
+{
+  if (d == -1)
+  {
+    ec = asio::error::bad_descriptor;
+    return -1;
+  }
+
+  pollfd fds;
+  fds.fd = d;
+  fds.events = POLLPRI | POLLERR | POLLHUP;
+  fds.revents = 0;
+  int timeout = (state & user_set_non_blocking) ? 0 : -1;
+  errno = 0;
+  int result = error_wrapper(::poll(&fds, 1, timeout), ec);
+  if (result == 0)
+    ec = (state & user_set_non_blocking)
+      ? asio::error::would_block : asio::error_code();
+  else if (result > 0)
+    ec = asio::error_code();
+  return result;
+}
+
+} // namespace descriptor_ops
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // !defined(ASIO_WINDOWS)
+       //   && !defined(ASIO_WINDOWS_RUNTIME)
+       //   && !defined(__CYGWIN__)
+
+#endif // ASIO_DETAIL_IMPL_DESCRIPTOR_OPS_IPP
diff --git a/lib/asio/detail/impl/dev_poll_reactor.hpp b/lib/asio/detail/impl/dev_poll_reactor.hpp
new file mode 100644
index 0000000..4cd8aaf
--- /dev/null
+++ b/lib/asio/detail/impl/dev_poll_reactor.hpp
@@ -0,0 +1,91 @@
+//
+// detail/impl/dev_poll_reactor.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_DEV_POLL_REACTOR_HPP
+#define ASIO_DETAIL_IMPL_DEV_POLL_REACTOR_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_DEV_POLL)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename Time_Traits>
+void dev_poll_reactor::add_timer_queue(timer_queue<Time_Traits>& queue)
+{
+  do_add_timer_queue(queue);
+}
+
+template <typename Time_Traits>
+void dev_poll_reactor::remove_timer_queue(timer_queue<Time_Traits>& queue)
+{
+  do_remove_timer_queue(queue);
+}
+
+template <typename Time_Traits>
+void dev_poll_reactor::schedule_timer(timer_queue<Time_Traits>& queue,
+    const typename Time_Traits::time_type& time,
+    typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  if (shutdown_)
+  {
+    scheduler_.post_immediate_completion(op, false);
+    return;
+  }
+
+  bool earliest = queue.enqueue_timer(time, timer, op);
+  scheduler_.work_started();
+  if (earliest)
+    interrupter_.interrupt();
+}
+
+template <typename Time_Traits>
+std::size_t dev_poll_reactor::cancel_timer(timer_queue<Time_Traits>& queue,
+    typename timer_queue<Time_Traits>::per_timer_data& timer,
+    std::size_t max_cancelled)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  op_queue<operation> ops;
+  std::size_t n = queue.cancel_timer(timer, ops, max_cancelled);
+  lock.unlock();
+  scheduler_.post_deferred_completions(ops);
+  return n;
+}
+
+template <typename Time_Traits>
+void dev_poll_reactor::move_timer(timer_queue<Time_Traits>& queue,
+    typename timer_queue<Time_Traits>::per_timer_data& target,
+    typename timer_queue<Time_Traits>::per_timer_data& source)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  op_queue<operation> ops;
+  queue.cancel_timer(target, ops);
+  queue.move_timer(target, source);
+  lock.unlock();
+  scheduler_.post_deferred_completions(ops);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_DEV_POLL)
+
+#endif // ASIO_DETAIL_IMPL_DEV_POLL_REACTOR_HPP
diff --git a/lib/asio/detail/impl/dev_poll_reactor.ipp b/lib/asio/detail/impl/dev_poll_reactor.ipp
new file mode 100644
index 0000000..1ca376c
--- /dev/null
+++ b/lib/asio/detail/impl/dev_poll_reactor.ipp
@@ -0,0 +1,446 @@
+//
+// detail/impl/dev_poll_reactor.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_DEV_POLL_REACTOR_IPP
+#define ASIO_DETAIL_IMPL_DEV_POLL_REACTOR_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_DEV_POLL)
+
+#include "asio/detail/dev_poll_reactor.hpp"
+#include "asio/detail/assert.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+dev_poll_reactor::dev_poll_reactor(asio::execution_context& ctx)
+  : asio::detail::execution_context_service_base<dev_poll_reactor>(ctx),
+    scheduler_(use_service<scheduler>(ctx)),
+    mutex_(),
+    dev_poll_fd_(do_dev_poll_create()),
+    interrupter_(),
+    shutdown_(false)
+{
+  // Add the interrupter's descriptor to /dev/poll.
+  ::pollfd ev = { 0, 0, 0 };
+  ev.fd = interrupter_.read_descriptor();
+  ev.events = POLLIN | POLLERR;
+  ev.revents = 0;
+  ::write(dev_poll_fd_, &ev, sizeof(ev));
+}
+
+dev_poll_reactor::~dev_poll_reactor()
+{
+  shutdown();
+  ::close(dev_poll_fd_);
+}
+
+void dev_poll_reactor::shutdown()
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  shutdown_ = true;
+  lock.unlock();
+
+  op_queue<operation> ops;
+
+  for (int i = 0; i < max_ops; ++i)
+    op_queue_[i].get_all_operations(ops);
+
+  timer_queues_.get_all_timers(ops);
+
+  scheduler_.abandon_operations(ops);
+} 
+
+void dev_poll_reactor::notify_fork(
+    asio::execution_context::fork_event fork_ev)
+{
+  if (fork_ev == asio::execution_context::fork_child)
+  {
+    detail::mutex::scoped_lock lock(mutex_);
+
+    if (dev_poll_fd_ != -1)
+      ::close(dev_poll_fd_);
+    dev_poll_fd_ = -1;
+    dev_poll_fd_ = do_dev_poll_create();
+
+    interrupter_.recreate();
+
+    // Add the interrupter's descriptor to /dev/poll.
+    ::pollfd ev = { 0, 0, 0 };
+    ev.fd = interrupter_.read_descriptor();
+    ev.events = POLLIN | POLLERR;
+    ev.revents = 0;
+    ::write(dev_poll_fd_, &ev, sizeof(ev));
+
+    // Re-register all descriptors with /dev/poll. The changes will be written
+    // to the /dev/poll descriptor the next time the reactor is run.
+    for (int i = 0; i < max_ops; ++i)
+    {
+      reactor_op_queue<socket_type>::iterator iter = op_queue_[i].begin();
+      reactor_op_queue<socket_type>::iterator end = op_queue_[i].end();
+      for (; iter != end; ++iter)
+      {
+        ::pollfd& pending_ev = add_pending_event_change(iter->first);
+        pending_ev.events |= POLLERR | POLLHUP;
+        switch (i)
+        {
+        case read_op: pending_ev.events |= POLLIN; break;
+        case write_op: pending_ev.events |= POLLOUT; break;
+        case except_op: pending_ev.events |= POLLPRI; break;
+        default: break;
+        }
+      }
+    }
+    interrupter_.interrupt();
+  }
+}
+
+void dev_poll_reactor::init_task()
+{
+  scheduler_.init_task();
+}
+
+int dev_poll_reactor::register_descriptor(socket_type, per_descriptor_data&)
+{
+  return 0;
+}
+
+int dev_poll_reactor::register_internal_descriptor(int op_type,
+    socket_type descriptor, per_descriptor_data&, reactor_op* op)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  op_queue_[op_type].enqueue_operation(descriptor, op);
+  ::pollfd& ev = add_pending_event_change(descriptor);
+  ev.events = POLLERR | POLLHUP;
+  switch (op_type)
+  {
+  case read_op: ev.events |= POLLIN; break;
+  case write_op: ev.events |= POLLOUT; break;
+  case except_op: ev.events |= POLLPRI; break;
+  default: break;
+  }
+  interrupter_.interrupt();
+
+  return 0;
+}
+
+void dev_poll_reactor::move_descriptor(socket_type,
+    dev_poll_reactor::per_descriptor_data&,
+    dev_poll_reactor::per_descriptor_data&)
+{
+}
+
+void dev_poll_reactor::start_op(int op_type, socket_type descriptor,
+    dev_poll_reactor::per_descriptor_data&, reactor_op* op,
+    bool is_continuation, bool allow_speculative)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  if (shutdown_)
+  {
+    post_immediate_completion(op, is_continuation);
+    return;
+  }
+
+  if (allow_speculative)
+  {
+    if (op_type != read_op || !op_queue_[except_op].has_operation(descriptor))
+    {
+      if (!op_queue_[op_type].has_operation(descriptor))
+      {
+        if (op->perform())
+        {
+          lock.unlock();
+          scheduler_.post_immediate_completion(op, is_continuation);
+          return;
+        }
+      }
+    }
+  }
+
+  bool first = op_queue_[op_type].enqueue_operation(descriptor, op);
+  scheduler_.work_started();
+  if (first)
+  {
+    ::pollfd& ev = add_pending_event_change(descriptor);
+    ev.events = POLLERR | POLLHUP;
+    if (op_type == read_op
+        || op_queue_[read_op].has_operation(descriptor))
+      ev.events |= POLLIN;
+    if (op_type == write_op
+        || op_queue_[write_op].has_operation(descriptor))
+      ev.events |= POLLOUT;
+    if (op_type == except_op
+        || op_queue_[except_op].has_operation(descriptor))
+      ev.events |= POLLPRI;
+    interrupter_.interrupt();
+  }
+}
+
+void dev_poll_reactor::cancel_ops(socket_type descriptor,
+    dev_poll_reactor::per_descriptor_data&)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  cancel_ops_unlocked(descriptor, asio::error::operation_aborted);
+}
+
+void dev_poll_reactor::deregister_descriptor(socket_type descriptor,
+    dev_poll_reactor::per_descriptor_data&, bool)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  // Remove the descriptor from /dev/poll.
+  ::pollfd& ev = add_pending_event_change(descriptor);
+  ev.events = POLLREMOVE;
+  interrupter_.interrupt();
+
+  // Cancel any outstanding operations associated with the descriptor.
+  cancel_ops_unlocked(descriptor, asio::error::operation_aborted);
+}
+
+void dev_poll_reactor::deregister_internal_descriptor(
+    socket_type descriptor, dev_poll_reactor::per_descriptor_data&)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  // Remove the descriptor from /dev/poll. Since this function is only called
+  // during a fork, we can apply the change immediately.
+  ::pollfd ev = { 0, 0, 0 };
+  ev.fd = descriptor;
+  ev.events = POLLREMOVE;
+  ev.revents = 0;
+  ::write(dev_poll_fd_, &ev, sizeof(ev));
+
+  // Destroy all operations associated with the descriptor.
+  op_queue<operation> ops;
+  asio::error_code ec;
+  for (int i = 0; i < max_ops; ++i)
+    op_queue_[i].cancel_operations(descriptor, ops, ec);
+}
+
+void dev_poll_reactor::cleanup_descriptor_data(
+    dev_poll_reactor::per_descriptor_data&)
+{
+}
+
+void dev_poll_reactor::run(long usec, op_queue<operation>& ops)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  // We can return immediately if there's no work to do and the reactor is
+  // not supposed to block.
+  if (usec == 0 && op_queue_[read_op].empty() && op_queue_[write_op].empty()
+      && op_queue_[except_op].empty() && timer_queues_.all_empty())
+    return;
+
+  // Write the pending event registration changes to the /dev/poll descriptor.
+  std::size_t events_size = sizeof(::pollfd) * pending_event_changes_.size();
+  if (events_size > 0)
+  {
+    errno = 0;
+    int result = ::write(dev_poll_fd_,
+        &pending_event_changes_[0], events_size);
+    if (result != static_cast<int>(events_size))
+    {
+      asio::error_code ec = asio::error_code(
+          errno, asio::error::get_system_category());
+      for (std::size_t i = 0; i < pending_event_changes_.size(); ++i)
+      {
+        int descriptor = pending_event_changes_[i].fd;
+        for (int j = 0; j < max_ops; ++j)
+          op_queue_[j].cancel_operations(descriptor, ops, ec);
+      }
+    }
+    pending_event_changes_.clear();
+    pending_event_change_index_.clear();
+  }
+
+  // Calculate timeout.
+  int timeout;
+  if (usec == 0)
+    timeout = 0;
+  else
+  {
+    timeout = (usec < 0) ? -1 : ((usec - 1) / 1000 + 1);
+    timeout = get_timeout(timeout);
+  }
+  lock.unlock();
+
+  // Block on the /dev/poll descriptor.
+  ::pollfd events[128] = { { 0, 0, 0 } };
+  ::dvpoll dp = { 0, 0, 0 };
+  dp.dp_fds = events;
+  dp.dp_nfds = 128;
+  dp.dp_timeout = timeout;
+  int num_events = ::ioctl(dev_poll_fd_, DP_POLL, &dp);
+
+  lock.lock();
+
+  // Dispatch the waiting events.
+  for (int i = 0; i < num_events; ++i)
+  {
+    int descriptor = events[i].fd;
+    if (descriptor == interrupter_.read_descriptor())
+    {
+      interrupter_.reset();
+    }
+    else
+    {
+      bool more_reads = false;
+      bool more_writes = false;
+      bool more_except = false;
+
+      // Exception operations must be processed first to ensure that any
+      // out-of-band data is read before normal data.
+      if (events[i].events & (POLLPRI | POLLERR | POLLHUP))
+        more_except =
+          op_queue_[except_op].perform_operations(descriptor, ops);
+      else
+        more_except = op_queue_[except_op].has_operation(descriptor);
+
+      if (events[i].events & (POLLIN | POLLERR | POLLHUP))
+        more_reads = op_queue_[read_op].perform_operations(descriptor, ops);
+      else
+        more_reads = op_queue_[read_op].has_operation(descriptor);
+
+      if (events[i].events & (POLLOUT | POLLERR | POLLHUP))
+        more_writes = op_queue_[write_op].perform_operations(descriptor, ops);
+      else
+        more_writes = op_queue_[write_op].has_operation(descriptor);
+
+      if ((events[i].events & (POLLERR | POLLHUP)) != 0
+            && !more_except && !more_reads && !more_writes)
+      {
+        // If we have an event and no operations associated with the
+        // descriptor then we need to delete the descriptor from /dev/poll.
+        // The poll operation can produce POLLHUP or POLLERR events when there
+        // is no operation pending, so if we do not remove the descriptor we
+        // can end up in a tight polling loop.
+        ::pollfd ev = { 0, 0, 0 };
+        ev.fd = descriptor;
+        ev.events = POLLREMOVE;
+        ev.revents = 0;
+        ::write(dev_poll_fd_, &ev, sizeof(ev));
+      }
+      else
+      {
+        ::pollfd ev = { 0, 0, 0 };
+        ev.fd = descriptor;
+        ev.events = POLLERR | POLLHUP;
+        if (more_reads)
+          ev.events |= POLLIN;
+        if (more_writes)
+          ev.events |= POLLOUT;
+        if (more_except)
+          ev.events |= POLLPRI;
+        ev.revents = 0;
+        int result = ::write(dev_poll_fd_, &ev, sizeof(ev));
+        if (result != sizeof(ev))
+        {
+          asio::error_code ec(errno,
+              asio::error::get_system_category());
+          for (int j = 0; j < max_ops; ++j)
+            op_queue_[j].cancel_operations(descriptor, ops, ec);
+        }
+      }
+    }
+  }
+  timer_queues_.get_ready_timers(ops);
+}
+
+void dev_poll_reactor::interrupt()
+{
+  interrupter_.interrupt();
+}
+
+int dev_poll_reactor::do_dev_poll_create()
+{
+  int fd = ::open("/dev/poll", O_RDWR);
+  if (fd == -1)
+  {
+    asio::error_code ec(errno,
+        asio::error::get_system_category());
+    asio::detail::throw_error(ec, "/dev/poll");
+  }
+  return fd;
+}
+
+void dev_poll_reactor::do_add_timer_queue(timer_queue_base& queue)
+{
+  mutex::scoped_lock lock(mutex_);
+  timer_queues_.insert(&queue);
+}
+
+void dev_poll_reactor::do_remove_timer_queue(timer_queue_base& queue)
+{
+  mutex::scoped_lock lock(mutex_);
+  timer_queues_.erase(&queue);
+}
+
+int dev_poll_reactor::get_timeout(int msec)
+{
+  // By default we will wait no longer than 5 minutes. This will ensure that
+  // any changes to the system clock are detected after no longer than this.
+  const int max_msec = 5 * 60 * 1000;
+  return timer_queues_.wait_duration_msec(
+      (msec < 0 || max_msec < msec) ? max_msec : msec);
+}
+
+void dev_poll_reactor::cancel_ops_unlocked(socket_type descriptor,
+    const asio::error_code& ec)
+{
+  bool need_interrupt = false;
+  op_queue<operation> ops;
+  for (int i = 0; i < max_ops; ++i)
+    need_interrupt = op_queue_[i].cancel_operations(
+        descriptor, ops, ec) || need_interrupt;
+  scheduler_.post_deferred_completions(ops);
+  if (need_interrupt)
+    interrupter_.interrupt();
+}
+
+::pollfd& dev_poll_reactor::add_pending_event_change(int descriptor)
+{
+  hash_map<int, std::size_t>::iterator iter
+    = pending_event_change_index_.find(descriptor);
+  if (iter == pending_event_change_index_.end())
+  {
+    std::size_t index = pending_event_changes_.size();
+    pending_event_changes_.reserve(pending_event_changes_.size() + 1);
+    pending_event_change_index_.insert(std::make_pair(descriptor, index));
+    pending_event_changes_.push_back(::pollfd());
+    pending_event_changes_[index].fd = descriptor;
+    pending_event_changes_[index].revents = 0;
+    return pending_event_changes_[index];
+  }
+  else
+  {
+    return pending_event_changes_[iter->second];
+  }
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_DEV_POLL)
+
+#endif // ASIO_DETAIL_IMPL_DEV_POLL_REACTOR_IPP
diff --git a/lib/asio/detail/impl/epoll_reactor.hpp b/lib/asio/detail/impl/epoll_reactor.hpp
new file mode 100644
index 0000000..f990059
--- /dev/null
+++ b/lib/asio/detail/impl/epoll_reactor.hpp
@@ -0,0 +1,89 @@
+//
+// detail/impl/epoll_reactor.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_EPOLL_REACTOR_HPP
+#define ASIO_DETAIL_IMPL_EPOLL_REACTOR_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#if defined(ASIO_HAS_EPOLL)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename Time_Traits>
+void epoll_reactor::add_timer_queue(timer_queue<Time_Traits>& queue)
+{
+  do_add_timer_queue(queue);
+}
+
+template <typename Time_Traits>
+void epoll_reactor::remove_timer_queue(timer_queue<Time_Traits>& queue)
+{
+  do_remove_timer_queue(queue);
+}
+
+template <typename Time_Traits>
+void epoll_reactor::schedule_timer(timer_queue<Time_Traits>& queue,
+    const typename Time_Traits::time_type& time,
+    typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op)
+{
+  mutex::scoped_lock lock(mutex_);
+
+  if (shutdown_)
+  {
+    scheduler_.post_immediate_completion(op, false);
+    return;
+  }
+
+  bool earliest = queue.enqueue_timer(time, timer, op);
+  scheduler_.work_started();
+  if (earliest)
+    update_timeout();
+}
+
+template <typename Time_Traits>
+std::size_t epoll_reactor::cancel_timer(timer_queue<Time_Traits>& queue,
+    typename timer_queue<Time_Traits>::per_timer_data& timer,
+    std::size_t max_cancelled)
+{
+  mutex::scoped_lock lock(mutex_);
+  op_queue<operation> ops;
+  std::size_t n = queue.cancel_timer(timer, ops, max_cancelled);
+  lock.unlock();
+  scheduler_.post_deferred_completions(ops);
+  return n;
+}
+
+template <typename Time_Traits>
+void epoll_reactor::move_timer(timer_queue<Time_Traits>& queue,
+    typename timer_queue<Time_Traits>::per_timer_data& target,
+    typename timer_queue<Time_Traits>::per_timer_data& source)
+{
+  mutex::scoped_lock lock(mutex_);
+  op_queue<operation> ops;
+  queue.cancel_timer(target, ops);
+  queue.move_timer(target, source);
+  lock.unlock();
+  scheduler_.post_deferred_completions(ops);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_EPOLL)
+
+#endif // ASIO_DETAIL_IMPL_EPOLL_REACTOR_HPP
diff --git a/lib/asio/detail/impl/epoll_reactor.ipp b/lib/asio/detail/impl/epoll_reactor.ipp
new file mode 100644
index 0000000..65584a4
--- /dev/null
+++ b/lib/asio/detail/impl/epoll_reactor.ipp
@@ -0,0 +1,787 @@
+//
+// detail/impl/epoll_reactor.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_EPOLL_REACTOR_IPP
+#define ASIO_DETAIL_IMPL_EPOLL_REACTOR_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_EPOLL)
+
+#include <cstddef>
+#include <sys/epoll.h>
+#include "asio/detail/epoll_reactor.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+
+#if defined(ASIO_HAS_TIMERFD)
+# include <sys/timerfd.h>
+#endif // defined(ASIO_HAS_TIMERFD)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+epoll_reactor::epoll_reactor(asio::execution_context& ctx)
+  : execution_context_service_base<epoll_reactor>(ctx),
+    scheduler_(use_service<scheduler>(ctx)),
+    mutex_(ASIO_CONCURRENCY_HINT_IS_LOCKING(
+          REACTOR_REGISTRATION, scheduler_.concurrency_hint())),
+    interrupter_(),
+    epoll_fd_(do_epoll_create()),
+    timer_fd_(do_timerfd_create()),
+    shutdown_(false),
+    registered_descriptors_mutex_(mutex_.enabled())
+{
+  // Add the interrupter's descriptor to epoll.
+  epoll_event ev = { 0, { 0 } };
+  ev.events = EPOLLIN | EPOLLERR | EPOLLET;
+  ev.data.ptr = &interrupter_;
+  epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, interrupter_.read_descriptor(), &ev);
+  interrupter_.interrupt();
+
+  // Add the timer descriptor to epoll.
+  if (timer_fd_ != -1)
+  {
+    ev.events = EPOLLIN | EPOLLERR;
+    ev.data.ptr = &timer_fd_;
+    epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, timer_fd_, &ev);
+  }
+}
+
+epoll_reactor::~epoll_reactor()
+{
+  if (epoll_fd_ != -1)
+    close(epoll_fd_);
+  if (timer_fd_ != -1)
+    close(timer_fd_);
+}
+
+void epoll_reactor::shutdown()
+{
+  mutex::scoped_lock lock(mutex_);
+  shutdown_ = true;
+  lock.unlock();
+
+  op_queue<operation> ops;
+
+  while (descriptor_state* state = registered_descriptors_.first())
+  {
+    for (int i = 0; i < max_ops; ++i)
+      ops.push(state->op_queue_[i]);
+    state->shutdown_ = true;
+    registered_descriptors_.free(state);
+  }
+
+  timer_queues_.get_all_timers(ops);
+
+  scheduler_.abandon_operations(ops);
+}
+
+void epoll_reactor::notify_fork(
+    asio::execution_context::fork_event fork_ev)
+{
+  if (fork_ev == asio::execution_context::fork_child)
+  {
+    if (epoll_fd_ != -1)
+      ::close(epoll_fd_);
+    epoll_fd_ = -1;
+    epoll_fd_ = do_epoll_create();
+
+    if (timer_fd_ != -1)
+      ::close(timer_fd_);
+    timer_fd_ = -1;
+    timer_fd_ = do_timerfd_create();
+
+    interrupter_.recreate();
+
+    // Add the interrupter's descriptor to epoll.
+    epoll_event ev = { 0, { 0 } };
+    ev.events = EPOLLIN | EPOLLERR | EPOLLET;
+    ev.data.ptr = &interrupter_;
+    epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, interrupter_.read_descriptor(), &ev);
+    interrupter_.interrupt();
+
+    // Add the timer descriptor to epoll.
+    if (timer_fd_ != -1)
+    {
+      ev.events = EPOLLIN | EPOLLERR;
+      ev.data.ptr = &timer_fd_;
+      epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, timer_fd_, &ev);
+    }
+
+    update_timeout();
+
+    // Re-register all descriptors with epoll.
+    mutex::scoped_lock descriptors_lock(registered_descriptors_mutex_);
+    for (descriptor_state* state = registered_descriptors_.first();
+        state != 0; state = state->next_)
+    {
+      ev.events = state->registered_events_;
+      ev.data.ptr = state;
+      int result = epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, state->descriptor_, &ev);
+      if (result != 0)
+      {
+        asio::error_code ec(errno,
+            asio::error::get_system_category());
+        asio::detail::throw_error(ec, "epoll re-registration");
+      }
+    }
+  }
+}
+
+void epoll_reactor::init_task()
+{
+  scheduler_.init_task();
+}
+
+int epoll_reactor::register_descriptor(socket_type descriptor,
+    epoll_reactor::per_descriptor_data& descriptor_data)
+{
+  descriptor_data = allocate_descriptor_state();
+
+  ASIO_HANDLER_REACTOR_REGISTRATION((
+        context(), static_cast<uintmax_t>(descriptor),
+        reinterpret_cast<uintmax_t>(descriptor_data)));
+
+  {
+    mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+    descriptor_data->reactor_ = this;
+    descriptor_data->descriptor_ = descriptor;
+    descriptor_data->shutdown_ = false;
+    for (int i = 0; i < max_ops; ++i)
+      descriptor_data->try_speculative_[i] = true;
+  }
+
+  epoll_event ev = { 0, { 0 } };
+  ev.events = EPOLLIN | EPOLLERR | EPOLLHUP | EPOLLPRI | EPOLLET;
+  descriptor_data->registered_events_ = ev.events;
+  ev.data.ptr = descriptor_data;
+  int result = epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, descriptor, &ev);
+  if (result != 0)
+  {
+    if (errno == EPERM)
+    {
+      // This file descriptor type is not supported by epoll. However, if it is
+      // a regular file then operations on it will not block. We will allow
+      // this descriptor to be used and fail later if an operation on it would
+      // otherwise require a trip through the reactor.
+      descriptor_data->registered_events_ = 0;
+      return 0;
+    }
+    return errno;
+  }
+
+  return 0;
+}
+
+int epoll_reactor::register_internal_descriptor(
+    int op_type, socket_type descriptor,
+    epoll_reactor::per_descriptor_data& descriptor_data, reactor_op* op)
+{
+  descriptor_data = allocate_descriptor_state();
+
+  ASIO_HANDLER_REACTOR_REGISTRATION((
+        context(), static_cast<uintmax_t>(descriptor),
+        reinterpret_cast<uintmax_t>(descriptor_data)));
+
+  {
+    mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+    descriptor_data->reactor_ = this;
+    descriptor_data->descriptor_ = descriptor;
+    descriptor_data->shutdown_ = false;
+    descriptor_data->op_queue_[op_type].push(op);
+    for (int i = 0; i < max_ops; ++i)
+      descriptor_data->try_speculative_[i] = true;
+  }
+
+  epoll_event ev = { 0, { 0 } };
+  ev.events = EPOLLIN | EPOLLERR | EPOLLHUP | EPOLLPRI | EPOLLET;
+  descriptor_data->registered_events_ = ev.events;
+  ev.data.ptr = descriptor_data;
+  int result = epoll_ctl(epoll_fd_, EPOLL_CTL_ADD, descriptor, &ev);
+  if (result != 0)
+    return errno;
+
+  return 0;
+}
+
+void epoll_reactor::move_descriptor(socket_type,
+    epoll_reactor::per_descriptor_data& target_descriptor_data,
+    epoll_reactor::per_descriptor_data& source_descriptor_data)
+{
+  target_descriptor_data = source_descriptor_data;
+  source_descriptor_data = 0;
+}
+
+void epoll_reactor::start_op(int op_type, socket_type descriptor,
+    epoll_reactor::per_descriptor_data& descriptor_data, reactor_op* op,
+    bool is_continuation, bool allow_speculative)
+{
+  if (!descriptor_data)
+  {
+    op->ec_ = asio::error::bad_descriptor;
+    post_immediate_completion(op, is_continuation);
+    return;
+  }
+
+  mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+  if (descriptor_data->shutdown_)
+  {
+    post_immediate_completion(op, is_continuation);
+    return;
+  }
+
+  if (descriptor_data->op_queue_[op_type].empty())
+  {
+    if (allow_speculative
+        && (op_type != read_op
+          || descriptor_data->op_queue_[except_op].empty()))
+    {
+      if (descriptor_data->try_speculative_[op_type])
+      {
+        if (reactor_op::status status = op->perform())
+        {
+          if (status == reactor_op::done_and_exhausted)
+            if (descriptor_data->registered_events_ != 0)
+              descriptor_data->try_speculative_[op_type] = false;
+          descriptor_lock.unlock();
+          scheduler_.post_immediate_completion(op, is_continuation);
+          return;
+        }
+      }
+
+      if (descriptor_data->registered_events_ == 0)
+      {
+        op->ec_ = asio::error::operation_not_supported;
+        scheduler_.post_immediate_completion(op, is_continuation);
+        return;
+      }
+
+      if (op_type == write_op)
+      {
+        if ((descriptor_data->registered_events_ & EPOLLOUT) == 0)
+        {
+          epoll_event ev = { 0, { 0 } };
+          ev.events = descriptor_data->registered_events_ | EPOLLOUT;
+          ev.data.ptr = descriptor_data;
+          if (epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev) == 0)
+          {
+            descriptor_data->registered_events_ |= ev.events;
+          }
+          else
+          {
+            op->ec_ = asio::error_code(errno,
+                asio::error::get_system_category());
+            scheduler_.post_immediate_completion(op, is_continuation);
+            return;
+          }
+        }
+      }
+    }
+    else if (descriptor_data->registered_events_ == 0)
+    {
+      op->ec_ = asio::error::operation_not_supported;
+      scheduler_.post_immediate_completion(op, is_continuation);
+      return;
+    }
+    else
+    {
+      if (op_type == write_op)
+      {
+        descriptor_data->registered_events_ |= EPOLLOUT;
+      }
+
+      epoll_event ev = { 0, { 0 } };
+      ev.events = descriptor_data->registered_events_;
+      ev.data.ptr = descriptor_data;
+      epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, descriptor, &ev);
+    }
+  }
+
+  descriptor_data->op_queue_[op_type].push(op);
+  scheduler_.work_started();
+}
+
+void epoll_reactor::cancel_ops(socket_type,
+    epoll_reactor::per_descriptor_data& descriptor_data)
+{
+  if (!descriptor_data)
+    return;
+
+  mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+  op_queue<operation> ops;
+  for (int i = 0; i < max_ops; ++i)
+  {
+    while (reactor_op* op = descriptor_data->op_queue_[i].front())
+    {
+      op->ec_ = asio::error::operation_aborted;
+      descriptor_data->op_queue_[i].pop();
+      ops.push(op);
+    }
+  }
+
+  descriptor_lock.unlock();
+
+  scheduler_.post_deferred_completions(ops);
+}
+
+void epoll_reactor::deregister_descriptor(socket_type descriptor,
+    epoll_reactor::per_descriptor_data& descriptor_data, bool closing)
+{
+  if (!descriptor_data)
+    return;
+
+  mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+  if (!descriptor_data->shutdown_)
+  {
+    if (closing)
+    {
+      // The descriptor will be automatically removed from the epoll set when
+      // it is closed.
+    }
+    else if (descriptor_data->registered_events_ != 0)
+    {
+      epoll_event ev = { 0, { 0 } };
+      epoll_ctl(epoll_fd_, EPOLL_CTL_DEL, descriptor, &ev);
+    }
+
+    op_queue<operation> ops;
+    for (int i = 0; i < max_ops; ++i)
+    {
+      while (reactor_op* op = descriptor_data->op_queue_[i].front())
+      {
+        op->ec_ = asio::error::operation_aborted;
+        descriptor_data->op_queue_[i].pop();
+        ops.push(op);
+      }
+    }
+
+    descriptor_data->descriptor_ = -1;
+    descriptor_data->shutdown_ = true;
+
+    descriptor_lock.unlock();
+
+    ASIO_HANDLER_REACTOR_DEREGISTRATION((
+          context(), static_cast<uintmax_t>(descriptor),
+          reinterpret_cast<uintmax_t>(descriptor_data)));
+
+    scheduler_.post_deferred_completions(ops);
+
+    // Leave descriptor_data set so that it will be freed by the subsequent
+    // call to cleanup_descriptor_data.
+  }
+  else
+  {
+    // We are shutting down, so prevent cleanup_descriptor_data from freeing
+    // the descriptor_data object and let the destructor free it instead.
+    descriptor_data = 0;
+  }
+}
+
+void epoll_reactor::deregister_internal_descriptor(socket_type descriptor,
+    epoll_reactor::per_descriptor_data& descriptor_data)
+{
+  if (!descriptor_data)
+    return;
+
+  mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+  if (!descriptor_data->shutdown_)
+  {
+    epoll_event ev = { 0, { 0 } };
+    epoll_ctl(epoll_fd_, EPOLL_CTL_DEL, descriptor, &ev);
+
+    op_queue<operation> ops;
+    for (int i = 0; i < max_ops; ++i)
+      ops.push(descriptor_data->op_queue_[i]);
+
+    descriptor_data->descriptor_ = -1;
+    descriptor_data->shutdown_ = true;
+
+    descriptor_lock.unlock();
+
+    ASIO_HANDLER_REACTOR_DEREGISTRATION((
+          context(), static_cast<uintmax_t>(descriptor),
+          reinterpret_cast<uintmax_t>(descriptor_data)));
+
+    // Leave descriptor_data set so that it will be freed by the subsequent
+    // call to cleanup_descriptor_data.
+  }
+  else
+  {
+    // We are shutting down, so prevent cleanup_descriptor_data from freeing
+    // the descriptor_data object and let the destructor free it instead.
+    descriptor_data = 0;
+  }
+}
+
+void epoll_reactor::cleanup_descriptor_data(
+    per_descriptor_data& descriptor_data)
+{
+  if (descriptor_data)
+  {
+    free_descriptor_state(descriptor_data);
+    descriptor_data = 0;
+  }
+}
+
+void epoll_reactor::run(long usec, op_queue<operation>& ops)
+{
+  // This code relies on the fact that the scheduler queues the reactor task
+  // behind all descriptor operations generated by this function. This means,
+  // that by the time we reach this point, any previously returned descriptor
+  // operations have already been dequeued. Therefore it is now safe for us to
+  // reuse and return them for the scheduler to queue again.
+
+  // Calculate timeout. Check the timer queues only if timerfd is not in use.
+  int timeout;
+  if (usec == 0)
+    timeout = 0;
+  else
+  {
+    timeout = (usec < 0) ? -1 : ((usec - 1) / 1000 + 1);
+    if (timer_fd_ == -1)
+    {
+      mutex::scoped_lock lock(mutex_);
+      timeout = get_timeout(timeout);
+    }
+  }
+
+  // Block on the epoll descriptor.
+  epoll_event events[128];
+  int num_events = epoll_wait(epoll_fd_, events, 128, timeout);
+
+#if defined(ASIO_ENABLE_HANDLER_TRACKING)
+  // Trace the waiting events.
+  for (int i = 0; i < num_events; ++i)
+  {
+    void* ptr = events[i].data.ptr;
+    if (ptr == &interrupter_)
+    {
+      // Ignore.
+    }
+# if defined(ASIO_HAS_TIMERFD)
+    else if (ptr == &timer_fd_)
+    {
+      // Ignore.
+    }
+# endif // defined(ASIO_HAS_TIMERFD)
+    else
+    {
+      unsigned event_mask = 0;
+      if ((events[i].events & EPOLLIN) != 0)
+        event_mask |= ASIO_HANDLER_REACTOR_READ_EVENT;
+      if ((events[i].events & EPOLLOUT))
+        event_mask |= ASIO_HANDLER_REACTOR_WRITE_EVENT;
+      if ((events[i].events & (EPOLLERR | EPOLLHUP)) != 0)
+        event_mask |= ASIO_HANDLER_REACTOR_ERROR_EVENT;
+      ASIO_HANDLER_REACTOR_EVENTS((context(),
+            reinterpret_cast<uintmax_t>(ptr), event_mask));
+    }
+  }
+#endif // defined(ASIO_ENABLE_HANDLER_TRACKING)
+
+#if defined(ASIO_HAS_TIMERFD)
+  bool check_timers = (timer_fd_ == -1);
+#else // defined(ASIO_HAS_TIMERFD)
+  bool check_timers = true;
+#endif // defined(ASIO_HAS_TIMERFD)
+
+  // Dispatch the waiting events.
+  for (int i = 0; i < num_events; ++i)
+  {
+    void* ptr = events[i].data.ptr;
+    if (ptr == &interrupter_)
+    {
+      // No need to reset the interrupter since we're leaving the descriptor
+      // in a ready-to-read state and relying on edge-triggered notifications
+      // to make it so that we only get woken up when the descriptor's epoll
+      // registration is updated.
+
+#if defined(ASIO_HAS_TIMERFD)
+      if (timer_fd_ == -1)
+        check_timers = true;
+#else // defined(ASIO_HAS_TIMERFD)
+      check_timers = true;
+#endif // defined(ASIO_HAS_TIMERFD)
+    }
+#if defined(ASIO_HAS_TIMERFD)
+    else if (ptr == &timer_fd_)
+    {
+      check_timers = true;
+    }
+#endif // defined(ASIO_HAS_TIMERFD)
+    else
+    {
+      // The descriptor operation doesn't count as work in and of itself, so we
+      // don't call work_started() here. This still allows the scheduler to
+      // stop if the only remaining operations are descriptor operations.
+      descriptor_state* descriptor_data = static_cast<descriptor_state*>(ptr);
+      if (!ops.is_enqueued(descriptor_data))
+      {
+        descriptor_data->set_ready_events(events[i].events);
+        ops.push(descriptor_data);
+      }
+      else
+      {
+        descriptor_data->add_ready_events(events[i].events);
+      }
+    }
+  }
+
+  if (check_timers)
+  {
+    mutex::scoped_lock common_lock(mutex_);
+    timer_queues_.get_ready_timers(ops);
+
+#if defined(ASIO_HAS_TIMERFD)
+    if (timer_fd_ != -1)
+    {
+      itimerspec new_timeout;
+      itimerspec old_timeout;
+      int flags = get_timeout(new_timeout);
+      timerfd_settime(timer_fd_, flags, &new_timeout, &old_timeout);
+    }
+#endif // defined(ASIO_HAS_TIMERFD)
+  }
+}
+
+void epoll_reactor::interrupt()
+{
+  epoll_event ev = { 0, { 0 } };
+  ev.events = EPOLLIN | EPOLLERR | EPOLLET;
+  ev.data.ptr = &interrupter_;
+  epoll_ctl(epoll_fd_, EPOLL_CTL_MOD, interrupter_.read_descriptor(), &ev);
+}
+
+int epoll_reactor::do_epoll_create()
+{
+#if defined(EPOLL_CLOEXEC)
+  int fd = epoll_create1(EPOLL_CLOEXEC);
+#else // defined(EPOLL_CLOEXEC)
+  int fd = -1;
+  errno = EINVAL;
+#endif // defined(EPOLL_CLOEXEC)
+
+  if (fd == -1 && (errno == EINVAL || errno == ENOSYS))
+  {
+    fd = epoll_create(epoll_size);
+    if (fd != -1)
+      ::fcntl(fd, F_SETFD, FD_CLOEXEC);
+  }
+
+  if (fd == -1)
+  {
+    asio::error_code ec(errno,
+        asio::error::get_system_category());
+    asio::detail::throw_error(ec, "epoll");
+  }
+
+  return fd;
+}
+
+int epoll_reactor::do_timerfd_create()
+{
+#if defined(ASIO_HAS_TIMERFD)
+# if defined(TFD_CLOEXEC)
+  int fd = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC);
+# else // defined(TFD_CLOEXEC)
+  int fd = -1;
+  errno = EINVAL;
+# endif // defined(TFD_CLOEXEC)
+
+  if (fd == -1 && errno == EINVAL)
+  {
+    fd = timerfd_create(CLOCK_MONOTONIC, 0);
+    if (fd != -1)
+      ::fcntl(fd, F_SETFD, FD_CLOEXEC);
+  }
+
+  return fd;
+#else // defined(ASIO_HAS_TIMERFD)
+  return -1;
+#endif // defined(ASIO_HAS_TIMERFD)
+}
+
+epoll_reactor::descriptor_state* epoll_reactor::allocate_descriptor_state()
+{
+  mutex::scoped_lock descriptors_lock(registered_descriptors_mutex_);
+  return registered_descriptors_.alloc(ASIO_CONCURRENCY_HINT_IS_LOCKING(
+        REACTOR_IO, scheduler_.concurrency_hint()));
+}
+
+void epoll_reactor::free_descriptor_state(epoll_reactor::descriptor_state* s)
+{
+  mutex::scoped_lock descriptors_lock(registered_descriptors_mutex_);
+  registered_descriptors_.free(s);
+}
+
+void epoll_reactor::do_add_timer_queue(timer_queue_base& queue)
+{
+  mutex::scoped_lock lock(mutex_);
+  timer_queues_.insert(&queue);
+}
+
+void epoll_reactor::do_remove_timer_queue(timer_queue_base& queue)
+{
+  mutex::scoped_lock lock(mutex_);
+  timer_queues_.erase(&queue);
+}
+
+void epoll_reactor::update_timeout()
+{
+#if defined(ASIO_HAS_TIMERFD)
+  if (timer_fd_ != -1)
+  {
+    itimerspec new_timeout;
+    itimerspec old_timeout;
+    int flags = get_timeout(new_timeout);
+    timerfd_settime(timer_fd_, flags, &new_timeout, &old_timeout);
+    return;
+  }
+#endif // defined(ASIO_HAS_TIMERFD)
+  interrupt();
+}
+
+int epoll_reactor::get_timeout(int msec)
+{
+  // By default we will wait no longer than 5 minutes. This will ensure that
+  // any changes to the system clock are detected after no longer than this.
+  const int max_msec = 5 * 60 * 1000;
+  return timer_queues_.wait_duration_msec(
+      (msec < 0 || max_msec < msec) ? max_msec : msec);
+}
+
+#if defined(ASIO_HAS_TIMERFD)
+int epoll_reactor::get_timeout(itimerspec& ts)
+{
+  ts.it_interval.tv_sec = 0;
+  ts.it_interval.tv_nsec = 0;
+
+  long usec = timer_queues_.wait_duration_usec(5 * 60 * 1000 * 1000);
+  ts.it_value.tv_sec = usec / 1000000;
+  ts.it_value.tv_nsec = usec ? (usec % 1000000) * 1000 : 1;
+
+  return usec ? 0 : TFD_TIMER_ABSTIME;
+}
+#endif // defined(ASIO_HAS_TIMERFD)
+
+struct epoll_reactor::perform_io_cleanup_on_block_exit
+{
+  explicit perform_io_cleanup_on_block_exit(epoll_reactor* r)
+    : reactor_(r), first_op_(0)
+  {
+  }
+
+  ~perform_io_cleanup_on_block_exit()
+  {
+    if (first_op_)
+    {
+      // Post the remaining completed operations for invocation.
+      if (!ops_.empty())
+        reactor_->scheduler_.post_deferred_completions(ops_);
+
+      // A user-initiated operation has completed, but there's no need to
+      // explicitly call work_finished() here. Instead, we'll take advantage of
+      // the fact that the scheduler will call work_finished() once we return.
+    }
+    else
+    {
+      // No user-initiated operations have completed, so we need to compensate
+      // for the work_finished() call that the scheduler will make once this
+      // operation returns.
+      reactor_->scheduler_.compensating_work_started();
+    }
+  }
+
+  epoll_reactor* reactor_;
+  op_queue<operation> ops_;
+  operation* first_op_;
+};
+
+epoll_reactor::descriptor_state::descriptor_state(bool locking)
+  : operation(&epoll_reactor::descriptor_state::do_complete),
+    mutex_(locking)
+{
+}
+
+operation* epoll_reactor::descriptor_state::perform_io(uint32_t events)
+{
+  mutex_.lock();
+  perform_io_cleanup_on_block_exit io_cleanup(reactor_);
+  mutex::scoped_lock descriptor_lock(mutex_, mutex::scoped_lock::adopt_lock);
+
+  // Exception operations must be processed first to ensure that any
+  // out-of-band data is read before normal data.
+  static const int flag[max_ops] = { EPOLLIN, EPOLLOUT, EPOLLPRI };
+  for (int j = max_ops - 1; j >= 0; --j)
+  {
+    if (events & (flag[j] | EPOLLERR | EPOLLHUP))
+    {
+      try_speculative_[j] = true;
+      while (reactor_op* op = op_queue_[j].front())
+      {
+        if (reactor_op::status status = op->perform())
+        {
+          op_queue_[j].pop();
+          io_cleanup.ops_.push(op);
+          if (status == reactor_op::done_and_exhausted)
+          {
+            try_speculative_[j] = false;
+            break;
+          }
+        }
+        else
+          break;
+      }
+    }
+  }
+
+  // The first operation will be returned for completion now. The others will
+  // be posted for later by the io_cleanup object's destructor.
+  io_cleanup.first_op_ = io_cleanup.ops_.front();
+  io_cleanup.ops_.pop();
+  return io_cleanup.first_op_;
+}
+
+void epoll_reactor::descriptor_state::do_complete(
+    void* owner, operation* base,
+    const asio::error_code& ec, std::size_t bytes_transferred)
+{
+  if (owner)
+  {
+    descriptor_state* descriptor_data = static_cast<descriptor_state*>(base);
+    uint32_t events = static_cast<uint32_t>(bytes_transferred);
+    if (operation* op = descriptor_data->perform_io(events))
+    {
+      op->complete(owner, ec, 0);
+    }
+  }
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_EPOLL)
+
+#endif // ASIO_DETAIL_IMPL_EPOLL_REACTOR_IPP
diff --git a/lib/asio/detail/impl/eventfd_select_interrupter.ipp b/lib/asio/detail/impl/eventfd_select_interrupter.ipp
new file mode 100644
index 0000000..c56e89a
--- /dev/null
+++ b/lib/asio/detail/impl/eventfd_select_interrupter.ipp
@@ -0,0 +1,165 @@
+//
+// detail/impl/eventfd_select_interrupter.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2008 Roelof Naude (roelof.naude at gmail dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_EVENTFD_SELECT_INTERRUPTER_IPP
+#define ASIO_DETAIL_IMPL_EVENTFD_SELECT_INTERRUPTER_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_EVENTFD)
+
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#if __GLIBC__ == 2 && __GLIBC_MINOR__ < 8
+# include <asm/unistd.h>
+#else // __GLIBC__ == 2 && __GLIBC_MINOR__ < 8
+# include <sys/eventfd.h>
+#endif // __GLIBC__ == 2 && __GLIBC_MINOR__ < 8
+#include "asio/detail/cstdint.hpp"
+#include "asio/detail/eventfd_select_interrupter.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+eventfd_select_interrupter::eventfd_select_interrupter()
+{
+  open_descriptors();
+}
+
+void eventfd_select_interrupter::open_descriptors()
+{
+#if __GLIBC__ == 2 && __GLIBC_MINOR__ < 8
+  write_descriptor_ = read_descriptor_ = syscall(__NR_eventfd, 0);
+  if (read_descriptor_ != -1)
+  {
+    ::fcntl(read_descriptor_, F_SETFL, O_NONBLOCK);
+    ::fcntl(read_descriptor_, F_SETFD, FD_CLOEXEC);
+  }
+#else // __GLIBC__ == 2 && __GLIBC_MINOR__ < 8
+# if defined(EFD_CLOEXEC) && defined(EFD_NONBLOCK)
+  write_descriptor_ = read_descriptor_ =
+    ::eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
+# else // defined(EFD_CLOEXEC) && defined(EFD_NONBLOCK)
+  errno = EINVAL;
+  write_descriptor_ = read_descriptor_ = -1;
+# endif // defined(EFD_CLOEXEC) && defined(EFD_NONBLOCK)
+  if (read_descriptor_ == -1 && errno == EINVAL)
+  {
+    write_descriptor_ = read_descriptor_ = ::eventfd(0, 0);
+    if (read_descriptor_ != -1)
+    {
+      ::fcntl(read_descriptor_, F_SETFL, O_NONBLOCK);
+      ::fcntl(read_descriptor_, F_SETFD, FD_CLOEXEC);
+    }
+  }
+#endif // __GLIBC__ == 2 && __GLIBC_MINOR__ < 8
+
+  if (read_descriptor_ == -1)
+  {
+    int pipe_fds[2];
+    if (pipe(pipe_fds) == 0)
+    {
+      read_descriptor_ = pipe_fds[0];
+      ::fcntl(read_descriptor_, F_SETFL, O_NONBLOCK);
+      ::fcntl(read_descriptor_, F_SETFD, FD_CLOEXEC);
+      write_descriptor_ = pipe_fds[1];
+      ::fcntl(write_descriptor_, F_SETFL, O_NONBLOCK);
+      ::fcntl(write_descriptor_, F_SETFD, FD_CLOEXEC);
+    }
+    else
+    {
+      asio::error_code ec(errno,
+          asio::error::get_system_category());
+      asio::detail::throw_error(ec, "eventfd_select_interrupter");
+    }
+  }
+}
+
+eventfd_select_interrupter::~eventfd_select_interrupter()
+{
+  close_descriptors();
+}
+
+void eventfd_select_interrupter::close_descriptors()
+{
+  if (write_descriptor_ != -1 && write_descriptor_ != read_descriptor_)
+    ::close(write_descriptor_);
+  if (read_descriptor_ != -1)
+    ::close(read_descriptor_);
+}
+
+void eventfd_select_interrupter::recreate()
+{
+  close_descriptors();
+
+  write_descriptor_ = -1;
+  read_descriptor_ = -1;
+
+  open_descriptors();
+}
+
+void eventfd_select_interrupter::interrupt()
+{
+  uint64_t counter(1UL);
+  int result = ::write(write_descriptor_, &counter, sizeof(uint64_t));
+  (void)result;
+}
+
+bool eventfd_select_interrupter::reset()
+{
+  if (write_descriptor_ == read_descriptor_)
+  {
+    for (;;)
+    {
+      // Only perform one read. The kernel maintains an atomic counter.
+      uint64_t counter(0);
+      errno = 0;
+      int bytes_read = ::read(read_descriptor_, &counter, sizeof(uint64_t));
+      if (bytes_read < 0 && errno == EINTR)
+        continue;
+      bool was_interrupted = (bytes_read > 0);
+      return was_interrupted;
+    }
+  }
+  else
+  {
+    for (;;)
+    {
+      // Clear all data from the pipe.
+      char data[1024];
+      int bytes_read = ::read(read_descriptor_, data, sizeof(data));
+      if (bytes_read < 0 && errno == EINTR)
+        continue;
+      bool was_interrupted = (bytes_read > 0);
+      while (bytes_read == sizeof(data))
+        bytes_read = ::read(read_descriptor_, data, sizeof(data));
+      return was_interrupted;
+    }
+  }
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_EVENTFD)
+
+#endif // ASIO_DETAIL_IMPL_EVENTFD_SELECT_INTERRUPTER_IPP
diff --git a/lib/asio/detail/impl/handler_tracking.ipp b/lib/asio/detail/impl/handler_tracking.ipp
new file mode 100644
index 0000000..5a4ff6f
--- /dev/null
+++ b/lib/asio/detail/impl/handler_tracking.ipp
@@ -0,0 +1,358 @@
+//
+// detail/impl/handler_tracking.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_HANDLER_TRACKING_IPP
+#define ASIO_DETAIL_IMPL_HANDLER_TRACKING_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_CUSTOM_HANDLER_TRACKING)
+
+// The handler tracking implementation is provided by the user-specified header.
+
+#elif defined(ASIO_ENABLE_HANDLER_TRACKING)
+
+#include <cstdarg>
+#include <cstdio>
+#include "asio/detail/handler_tracking.hpp"
+
+#if defined(ASIO_HAS_BOOST_DATE_TIME)
+# include "asio/time_traits.hpp"
+#elif defined(ASIO_HAS_CHRONO)
+# include "asio/detail/chrono.hpp"
+# include "asio/detail/chrono_time_traits.hpp"
+# include "asio/wait_traits.hpp"
+#endif // defined(ASIO_HAS_BOOST_DATE_TIME)
+
+#if defined(ASIO_WINDOWS_RUNTIME)
+# include "asio/detail/socket_types.hpp"
+#elif !defined(ASIO_WINDOWS)
+# include <unistd.h>
+#endif // !defined(ASIO_WINDOWS)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+struct handler_tracking_timestamp
+{
+  uint64_t seconds;
+  uint64_t microseconds;
+
+  handler_tracking_timestamp()
+  {
+#if defined(ASIO_HAS_BOOST_DATE_TIME)
+    boost::posix_time::ptime epoch(boost::gregorian::date(1970, 1, 1));
+    boost::posix_time::time_duration now =
+      boost::posix_time::microsec_clock::universal_time() - epoch;
+#elif defined(ASIO_HAS_CHRONO)
+    typedef chrono_time_traits<chrono::system_clock,
+        asio::wait_traits<chrono::system_clock> > traits_helper;
+    traits_helper::posix_time_duration now(
+        chrono::system_clock::now().time_since_epoch());
+#endif
+    seconds = static_cast<uint64_t>(now.total_seconds());
+    microseconds = static_cast<uint64_t>(now.total_microseconds() % 1000000);
+  }
+};
+
+struct handler_tracking::tracking_state
+{
+  static_mutex mutex_;
+  uint64_t next_id_;
+  tss_ptr<completion>* current_completion_;
+};
+
+handler_tracking::tracking_state* handler_tracking::get_state()
+{
+  static tracking_state state = { ASIO_STATIC_MUTEX_INIT, 1, 0 };
+  return &state;
+}
+
+void handler_tracking::init()
+{
+  static tracking_state* state = get_state();
+
+  state->mutex_.init();
+
+  static_mutex::scoped_lock lock(state->mutex_);
+  if (state->current_completion_ == 0)
+    state->current_completion_ = new tss_ptr<completion>;
+}
+
+void handler_tracking::creation(execution_context&,
+    handler_tracking::tracked_handler& h,
+    const char* object_type, void* object,
+    uintmax_t /*native_handle*/, const char* op_name)
+{
+  static tracking_state* state = get_state();
+
+  static_mutex::scoped_lock lock(state->mutex_);
+  h.id_ = state->next_id_++;
+  lock.unlock();
+
+  handler_tracking_timestamp timestamp;
+
+  uint64_t current_id = 0;
+  if (completion* current_completion = *state->current_completion_)
+    current_id = current_completion->id_;
+
+  write_line(
+#if defined(ASIO_WINDOWS)
+      "@asio|%I64u.%06I64u|%I64u*%I64u|%.20s@%p.%.50s\n",
+#else // defined(ASIO_WINDOWS)
+      "@asio|%llu.%06llu|%llu*%llu|%.20s@%p.%.50s\n",
+#endif // defined(ASIO_WINDOWS)
+      timestamp.seconds, timestamp.microseconds,
+      current_id, h.id_, object_type, object, op_name);
+}
+
+handler_tracking::completion::completion(
+    const handler_tracking::tracked_handler& h)
+  : id_(h.id_),
+    invoked_(false),
+    next_(*get_state()->current_completion_)
+{
+  *get_state()->current_completion_ = this;
+}
+
+handler_tracking::completion::~completion()
+{
+  if (id_)
+  {
+    handler_tracking_timestamp timestamp;
+
+    write_line(
+#if defined(ASIO_WINDOWS)
+        "@asio|%I64u.%06I64u|%c%I64u|\n",
+#else // defined(ASIO_WINDOWS)
+        "@asio|%llu.%06llu|%c%llu|\n",
+#endif // defined(ASIO_WINDOWS)
+        timestamp.seconds, timestamp.microseconds,
+        invoked_ ? '!' : '~', id_);
+  }
+
+  *get_state()->current_completion_ = next_;
+}
+
+void handler_tracking::completion::invocation_begin()
+{
+  handler_tracking_timestamp timestamp;
+
+  write_line(
+#if defined(ASIO_WINDOWS)
+      "@asio|%I64u.%06I64u|>%I64u|\n",
+#else // defined(ASIO_WINDOWS)
+      "@asio|%llu.%06llu|>%llu|\n",
+#endif // defined(ASIO_WINDOWS)
+      timestamp.seconds, timestamp.microseconds, id_);
+
+  invoked_ = true;
+}
+
+void handler_tracking::completion::invocation_begin(
+    const asio::error_code& ec)
+{
+  handler_tracking_timestamp timestamp;
+
+  write_line(
+#if defined(ASIO_WINDOWS)
+      "@asio|%I64u.%06I64u|>%I64u|ec=%.20s:%d\n",
+#else // defined(ASIO_WINDOWS)
+      "@asio|%llu.%06llu|>%llu|ec=%.20s:%d\n",
+#endif // defined(ASIO_WINDOWS)
+      timestamp.seconds, timestamp.microseconds,
+      id_, ec.category().name(), ec.value());
+
+  invoked_ = true;
+}
+
+void handler_tracking::completion::invocation_begin(
+    const asio::error_code& ec, std::size_t bytes_transferred)
+{
+  handler_tracking_timestamp timestamp;
+
+  write_line(
+#if defined(ASIO_WINDOWS)
+      "@asio|%I64u.%06I64u|>%I64u|ec=%.20s:%d,bytes_transferred=%I64u\n",
+#else // defined(ASIO_WINDOWS)
+      "@asio|%llu.%06llu|>%llu|ec=%.20s:%d,bytes_transferred=%llu\n",
+#endif // defined(ASIO_WINDOWS)
+      timestamp.seconds, timestamp.microseconds,
+      id_, ec.category().name(), ec.value(),
+      static_cast<uint64_t>(bytes_transferred));
+
+  invoked_ = true;
+}
+
+void handler_tracking::completion::invocation_begin(
+    const asio::error_code& ec, int signal_number)
+{
+  handler_tracking_timestamp timestamp;
+
+  write_line(
+#if defined(ASIO_WINDOWS)
+      "@asio|%I64u.%06I64u|>%I64u|ec=%.20s:%d,signal_number=%d\n",
+#else // defined(ASIO_WINDOWS)
+      "@asio|%llu.%06llu|>%llu|ec=%.20s:%d,signal_number=%d\n",
+#endif // defined(ASIO_WINDOWS)
+      timestamp.seconds, timestamp.microseconds,
+      id_, ec.category().name(), ec.value(), signal_number);
+
+  invoked_ = true;
+}
+
+void handler_tracking::completion::invocation_begin(
+    const asio::error_code& ec, const char* arg)
+{
+  handler_tracking_timestamp timestamp;
+
+  write_line(
+#if defined(ASIO_WINDOWS)
+      "@asio|%I64u.%06I64u|>%I64u|ec=%.20s:%d,%.50s\n",
+#else // defined(ASIO_WINDOWS)
+      "@asio|%llu.%06llu|>%llu|ec=%.20s:%d,%.50s\n",
+#endif // defined(ASIO_WINDOWS)
+      timestamp.seconds, timestamp.microseconds,
+      id_, ec.category().name(), ec.value(), arg);
+
+  invoked_ = true;
+}
+
+void handler_tracking::completion::invocation_end()
+{
+  if (id_)
+  {
+    handler_tracking_timestamp timestamp;
+
+    write_line(
+#if defined(ASIO_WINDOWS)
+        "@asio|%I64u.%06I64u|<%I64u|\n",
+#else // defined(ASIO_WINDOWS)
+        "@asio|%llu.%06llu|<%llu|\n",
+#endif // defined(ASIO_WINDOWS)
+        timestamp.seconds, timestamp.microseconds, id_);
+
+    id_ = 0;
+  }
+}
+
+void handler_tracking::operation(execution_context&,
+    const char* object_type, void* object,
+    uintmax_t /*native_handle*/, const char* op_name)
+{
+  static tracking_state* state = get_state();
+
+  handler_tracking_timestamp timestamp;
+
+  unsigned long long current_id = 0;
+  if (completion* current_completion = *state->current_completion_)
+    current_id = current_completion->id_;
+
+  write_line(
+#if defined(ASIO_WINDOWS)
+      "@asio|%I64u.%06I64u|%I64u|%.20s@%p.%.50s\n",
+#else // defined(ASIO_WINDOWS)
+      "@asio|%llu.%06llu|%llu|%.20s@%p.%.50s\n",
+#endif // defined(ASIO_WINDOWS)
+      timestamp.seconds, timestamp.microseconds,
+      current_id, object_type, object, op_name);
+}
+
+void handler_tracking::reactor_registration(execution_context& /*context*/,
+    uintmax_t /*native_handle*/, uintmax_t /*registration*/)
+{
+}
+
+void handler_tracking::reactor_deregistration(execution_context& /*context*/,
+    uintmax_t /*native_handle*/, uintmax_t /*registration*/)
+{
+}
+
+void handler_tracking::reactor_events(execution_context& /*context*/,
+    uintmax_t /*native_handle*/, unsigned /*events*/)
+{
+}
+
+void handler_tracking::reactor_operation(
+    const tracked_handler& h, const char* op_name,
+    const asio::error_code& ec)
+{
+  handler_tracking_timestamp timestamp;
+
+  write_line(
+#if defined(ASIO_WINDOWS)
+      "@asio|%I64u.%06I64u|.%I64u|%s,ec=%.20s:%d\n",
+#else // defined(ASIO_WINDOWS)
+      "@asio|%llu.%06llu|.%llu|%s,ec=%.20s:%d\n",
+#endif // defined(ASIO_WINDOWS)
+      timestamp.seconds, timestamp.microseconds,
+      h.id_, op_name, ec.category().name(), ec.value());
+}
+
+void handler_tracking::reactor_operation(
+    const tracked_handler& h, const char* op_name,
+    const asio::error_code& ec, std::size_t bytes_transferred)
+{
+  handler_tracking_timestamp timestamp;
+
+  write_line(
+#if defined(ASIO_WINDOWS)
+      "@asio|%I64u.%06I64u|.%I64u|%s,ec=%.20s:%d,bytes_transferred=%I64u\n",
+#else // defined(ASIO_WINDOWS)
+      "@asio|%llu.%06llu|.%llu|%s,ec=%.20s:%d,bytes_transferred=%llu\n",
+#endif // defined(ASIO_WINDOWS)
+      timestamp.seconds, timestamp.microseconds,
+      h.id_, op_name, ec.category().name(), ec.value(),
+      static_cast<uint64_t>(bytes_transferred));
+}
+
+void handler_tracking::write_line(const char* format, ...)
+{
+  using namespace std; // For sprintf (or equivalent).
+
+  va_list args;
+  va_start(args, format);
+
+  char line[256] = "";
+#if defined(ASIO_HAS_SECURE_RTL)
+  int length = vsprintf_s(line, sizeof(line), format, args);
+#else // defined(ASIO_HAS_SECURE_RTL)
+  int length = vsprintf(line, format, args);
+#endif // defined(ASIO_HAS_SECURE_RTL)
+
+  va_end(args);
+
+#if defined(ASIO_WINDOWS_RUNTIME)
+  wchar_t wline[256] = L"";
+  mbstowcs_s(0, wline, sizeof(wline) / sizeof(wchar_t), line, length);
+  ::OutputDebugStringW(wline);
+#elif defined(ASIO_WINDOWS)
+  HANDLE stderr_handle = ::GetStdHandle(STD_ERROR_HANDLE);
+  DWORD bytes_written = 0;
+  ::WriteFile(stderr_handle, line, length, &bytes_written, 0);
+#else // defined(ASIO_WINDOWS)
+  ::write(STDERR_FILENO, line, length);
+#endif // defined(ASIO_WINDOWS)
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_ENABLE_HANDLER_TRACKING)
+
+#endif // ASIO_DETAIL_IMPL_HANDLER_TRACKING_IPP
diff --git a/lib/asio/detail/impl/kqueue_reactor.hpp b/lib/asio/detail/impl/kqueue_reactor.hpp
new file mode 100644
index 0000000..136d167
--- /dev/null
+++ b/lib/asio/detail/impl/kqueue_reactor.hpp
@@ -0,0 +1,93 @@
+//
+// detail/impl/kqueue_reactor.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2005 Stefan Arentz (stefan at soze dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_KQUEUE_REACTOR_HPP
+#define ASIO_DETAIL_IMPL_KQUEUE_REACTOR_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_KQUEUE)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename Time_Traits>
+void kqueue_reactor::add_timer_queue(timer_queue<Time_Traits>& queue)
+{
+  do_add_timer_queue(queue);
+}
+
+// Remove a timer queue from the reactor.
+template <typename Time_Traits>
+void kqueue_reactor::remove_timer_queue(timer_queue<Time_Traits>& queue)
+{
+  do_remove_timer_queue(queue);
+}
+
+template <typename Time_Traits>
+void kqueue_reactor::schedule_timer(timer_queue<Time_Traits>& queue,
+    const typename Time_Traits::time_type& time,
+    typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op)
+{
+  mutex::scoped_lock lock(mutex_);
+
+  if (shutdown_)
+  {
+    scheduler_.post_immediate_completion(op, false);
+    return;
+  }
+
+  bool earliest = queue.enqueue_timer(time, timer, op);
+  scheduler_.work_started();
+  if (earliest)
+    interrupt();
+}
+
+template <typename Time_Traits>
+std::size_t kqueue_reactor::cancel_timer(timer_queue<Time_Traits>& queue,
+    typename timer_queue<Time_Traits>::per_timer_data& timer,
+    std::size_t max_cancelled)
+{
+  mutex::scoped_lock lock(mutex_);
+  op_queue<operation> ops;
+  std::size_t n = queue.cancel_timer(timer, ops, max_cancelled);
+  lock.unlock();
+  scheduler_.post_deferred_completions(ops);
+  return n;
+}
+
+template <typename Time_Traits>
+void kqueue_reactor::move_timer(timer_queue<Time_Traits>& queue,
+    typename timer_queue<Time_Traits>::per_timer_data& target,
+    typename timer_queue<Time_Traits>::per_timer_data& source)
+{
+  mutex::scoped_lock lock(mutex_);
+  op_queue<operation> ops;
+  queue.cancel_timer(target, ops);
+  queue.move_timer(target, source);
+  lock.unlock();
+  scheduler_.post_deferred_completions(ops);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_KQUEUE)
+
+#endif // ASIO_DETAIL_IMPL_KQUEUE_REACTOR_HPP
diff --git a/lib/asio/detail/impl/kqueue_reactor.ipp b/lib/asio/detail/impl/kqueue_reactor.ipp
new file mode 100644
index 0000000..73986e0
--- /dev/null
+++ b/lib/asio/detail/impl/kqueue_reactor.ipp
@@ -0,0 +1,566 @@
+//
+// detail/impl/kqueue_reactor.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2005 Stefan Arentz (stefan at soze dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_KQUEUE_REACTOR_IPP
+#define ASIO_DETAIL_IMPL_KQUEUE_REACTOR_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_KQUEUE)
+
+#include "asio/detail/kqueue_reactor.hpp"
+#include "asio/detail/scheduler.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+#if defined(__NetBSD__)
+# define ASIO_KQUEUE_EV_SET(ev, ident, filt, flags, fflags, data, udata) \
+    EV_SET(ev, ident, filt, flags, fflags, data, \
+      reinterpret_cast<intptr_t>(static_cast<void*>(udata)))
+#else
+# define ASIO_KQUEUE_EV_SET(ev, ident, filt, flags, fflags, data, udata) \
+    EV_SET(ev, ident, filt, flags, fflags, data, udata)
+#endif
+
+namespace asio {
+namespace detail {
+
+kqueue_reactor::kqueue_reactor(asio::execution_context& ctx)
+  : execution_context_service_base<kqueue_reactor>(ctx),
+    scheduler_(use_service<scheduler>(ctx)),
+    mutex_(ASIO_CONCURRENCY_HINT_IS_LOCKING(
+          REACTOR_REGISTRATION, scheduler_.concurrency_hint())),
+    kqueue_fd_(do_kqueue_create()),
+    interrupter_(),
+    shutdown_(false),
+    registered_descriptors_mutex_(mutex_.enabled())
+{
+  struct kevent events[1];
+  ASIO_KQUEUE_EV_SET(&events[0], interrupter_.read_descriptor(),
+      EVFILT_READ, EV_ADD, 0, 0, &interrupter_);
+  if (::kevent(kqueue_fd_, events, 1, 0, 0, 0) == -1)
+  {
+    asio::error_code error(errno,
+        asio::error::get_system_category());
+    asio::detail::throw_error(error);
+  }
+}
+
+kqueue_reactor::~kqueue_reactor()
+{
+  close(kqueue_fd_);
+}
+
+void kqueue_reactor::shutdown()
+{
+  mutex::scoped_lock lock(mutex_);
+  shutdown_ = true;
+  lock.unlock();
+
+  op_queue<operation> ops;
+
+  while (descriptor_state* state = registered_descriptors_.first())
+  {
+    for (int i = 0; i < max_ops; ++i)
+      ops.push(state->op_queue_[i]);
+    state->shutdown_ = true;
+    registered_descriptors_.free(state);
+  }
+
+  timer_queues_.get_all_timers(ops);
+
+  scheduler_.abandon_operations(ops);
+}
+
+void kqueue_reactor::notify_fork(
+    asio::execution_context::fork_event fork_ev)
+{
+  if (fork_ev == asio::execution_context::fork_child)
+  {
+    // The kqueue descriptor is automatically closed in the child.
+    kqueue_fd_ = -1;
+    kqueue_fd_ = do_kqueue_create();
+
+    interrupter_.recreate();
+
+    struct kevent events[2];
+    ASIO_KQUEUE_EV_SET(&events[0], interrupter_.read_descriptor(),
+        EVFILT_READ, EV_ADD, 0, 0, &interrupter_);
+    if (::kevent(kqueue_fd_, events, 1, 0, 0, 0) == -1)
+    {
+      asio::error_code ec(errno,
+          asio::error::get_system_category());
+      asio::detail::throw_error(ec, "kqueue interrupter registration");
+    }
+
+    // Re-register all descriptors with kqueue.
+    mutex::scoped_lock descriptors_lock(registered_descriptors_mutex_);
+    for (descriptor_state* state = registered_descriptors_.first();
+        state != 0; state = state->next_)
+    {
+      if (state->num_kevents_ > 0)
+      {
+        ASIO_KQUEUE_EV_SET(&events[0], state->descriptor_,
+            EVFILT_READ, EV_ADD | EV_CLEAR, 0, 0, state);
+        ASIO_KQUEUE_EV_SET(&events[1], state->descriptor_,
+            EVFILT_WRITE, EV_ADD | EV_CLEAR, 0, 0, state);
+        if (::kevent(kqueue_fd_, events, state->num_kevents_, 0, 0, 0) == -1)
+        {
+          asio::error_code ec(errno,
+              asio::error::get_system_category());
+          asio::detail::throw_error(ec, "kqueue re-registration");
+        }
+      }
+    }
+  }
+}
+
+void kqueue_reactor::init_task()
+{
+  scheduler_.init_task();
+}
+
+int kqueue_reactor::register_descriptor(socket_type descriptor,
+    kqueue_reactor::per_descriptor_data& descriptor_data)
+{
+  descriptor_data = allocate_descriptor_state();
+
+  ASIO_HANDLER_REACTOR_REGISTRATION((
+        context(), static_cast<uintmax_t>(descriptor),
+        reinterpret_cast<uintmax_t>(descriptor_data)));
+
+  mutex::scoped_lock lock(descriptor_data->mutex_);
+
+  descriptor_data->descriptor_ = descriptor;
+  descriptor_data->num_kevents_ = 0;
+  descriptor_data->shutdown_ = false;
+
+  return 0;
+}
+
+int kqueue_reactor::register_internal_descriptor(
+    int op_type, socket_type descriptor,
+    kqueue_reactor::per_descriptor_data& descriptor_data, reactor_op* op)
+{
+  descriptor_data = allocate_descriptor_state();
+
+  ASIO_HANDLER_REACTOR_REGISTRATION((
+        context(), static_cast<uintmax_t>(descriptor),
+        reinterpret_cast<uintmax_t>(descriptor_data)));
+
+  mutex::scoped_lock lock(descriptor_data->mutex_);
+
+  descriptor_data->descriptor_ = descriptor;
+  descriptor_data->num_kevents_ = 1;
+  descriptor_data->shutdown_ = false;
+  descriptor_data->op_queue_[op_type].push(op);
+
+  struct kevent events[1];
+  ASIO_KQUEUE_EV_SET(&events[0], descriptor, EVFILT_READ,
+      EV_ADD | EV_CLEAR, 0, 0, descriptor_data);
+  if (::kevent(kqueue_fd_, events, 1, 0, 0, 0) == -1)
+    return errno;
+
+  return 0;
+}
+
+void kqueue_reactor::move_descriptor(socket_type,
+    kqueue_reactor::per_descriptor_data& target_descriptor_data,
+    kqueue_reactor::per_descriptor_data& source_descriptor_data)
+{
+  target_descriptor_data = source_descriptor_data;
+  source_descriptor_data = 0;
+}
+
+void kqueue_reactor::start_op(int op_type, socket_type descriptor,
+    kqueue_reactor::per_descriptor_data& descriptor_data, reactor_op* op,
+    bool is_continuation, bool allow_speculative)
+{
+  if (!descriptor_data)
+  {
+    op->ec_ = asio::error::bad_descriptor;
+    post_immediate_completion(op, is_continuation);
+    return;
+  }
+
+  mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+  if (descriptor_data->shutdown_)
+  {
+    post_immediate_completion(op, is_continuation);
+    return;
+  }
+
+  if (descriptor_data->op_queue_[op_type].empty())
+  {
+    static const int num_kevents[max_ops] = { 1, 2, 1 };
+
+    if (allow_speculative
+        && (op_type != read_op
+          || descriptor_data->op_queue_[except_op].empty()))
+    {
+      if (op->perform())
+      {
+        descriptor_lock.unlock();
+        scheduler_.post_immediate_completion(op, is_continuation);
+        return;
+      }
+
+      if (descriptor_data->num_kevents_ < num_kevents[op_type])
+      {
+        struct kevent events[2];
+        ASIO_KQUEUE_EV_SET(&events[0], descriptor, EVFILT_READ,
+            EV_ADD | EV_CLEAR, 0, 0, descriptor_data);
+        ASIO_KQUEUE_EV_SET(&events[1], descriptor, EVFILT_WRITE,
+            EV_ADD | EV_CLEAR, 0, 0, descriptor_data);
+        if (::kevent(kqueue_fd_, events, num_kevents[op_type], 0, 0, 0) != -1)
+        {
+          descriptor_data->num_kevents_ = num_kevents[op_type];
+        }
+        else
+        {
+          op->ec_ = asio::error_code(errno,
+              asio::error::get_system_category());
+          scheduler_.post_immediate_completion(op, is_continuation);
+          return;
+        }
+      }
+    }
+    else
+    {
+      if (descriptor_data->num_kevents_ < num_kevents[op_type])
+        descriptor_data->num_kevents_ = num_kevents[op_type];
+
+      struct kevent events[2];
+      ASIO_KQUEUE_EV_SET(&events[0], descriptor, EVFILT_READ,
+          EV_ADD | EV_CLEAR, 0, 0, descriptor_data);
+      ASIO_KQUEUE_EV_SET(&events[1], descriptor, EVFILT_WRITE,
+          EV_ADD | EV_CLEAR, 0, 0, descriptor_data);
+      ::kevent(kqueue_fd_, events, descriptor_data->num_kevents_, 0, 0, 0);
+    }
+  }
+
+  descriptor_data->op_queue_[op_type].push(op);
+  scheduler_.work_started();
+}
+
+void kqueue_reactor::cancel_ops(socket_type,
+    kqueue_reactor::per_descriptor_data& descriptor_data)
+{
+  if (!descriptor_data)
+    return;
+
+  mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+  op_queue<operation> ops;
+  for (int i = 0; i < max_ops; ++i)
+  {
+    while (reactor_op* op = descriptor_data->op_queue_[i].front())
+    {
+      op->ec_ = asio::error::operation_aborted;
+      descriptor_data->op_queue_[i].pop();
+      ops.push(op);
+    }
+  }
+
+  descriptor_lock.unlock();
+
+  scheduler_.post_deferred_completions(ops);
+}
+
+void kqueue_reactor::deregister_descriptor(socket_type descriptor,
+    kqueue_reactor::per_descriptor_data& descriptor_data, bool closing)
+{
+  if (!descriptor_data)
+    return;
+
+  mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+  if (!descriptor_data->shutdown_)
+  {
+    if (closing)
+    {
+      // The descriptor will be automatically removed from the kqueue when it
+      // is closed.
+    }
+    else
+    {
+      struct kevent events[2];
+      ASIO_KQUEUE_EV_SET(&events[0], descriptor,
+          EVFILT_READ, EV_DELETE, 0, 0, 0);
+      ASIO_KQUEUE_EV_SET(&events[1], descriptor,
+          EVFILT_WRITE, EV_DELETE, 0, 0, 0);
+      ::kevent(kqueue_fd_, events, descriptor_data->num_kevents_, 0, 0, 0);
+    }
+
+    op_queue<operation> ops;
+    for (int i = 0; i < max_ops; ++i)
+    {
+      while (reactor_op* op = descriptor_data->op_queue_[i].front())
+      {
+        op->ec_ = asio::error::operation_aborted;
+        descriptor_data->op_queue_[i].pop();
+        ops.push(op);
+      }
+    }
+
+    descriptor_data->descriptor_ = -1;
+    descriptor_data->shutdown_ = true;
+
+    descriptor_lock.unlock();
+
+    ASIO_HANDLER_REACTOR_DEREGISTRATION((
+          context(), static_cast<uintmax_t>(descriptor),
+          reinterpret_cast<uintmax_t>(descriptor_data)));
+
+    scheduler_.post_deferred_completions(ops);
+
+    // Leave descriptor_data set so that it will be freed by the subsequent
+    // call to cleanup_descriptor_data.
+  }
+  else
+  {
+    // We are shutting down, so prevent cleanup_descriptor_data from freeing
+    // the descriptor_data object and let the destructor free it instead.
+    descriptor_data = 0;
+  }
+}
+
+void kqueue_reactor::deregister_internal_descriptor(socket_type descriptor,
+    kqueue_reactor::per_descriptor_data& descriptor_data)
+{
+  if (!descriptor_data)
+    return;
+
+  mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+  if (!descriptor_data->shutdown_)
+  {
+    struct kevent events[2];
+    ASIO_KQUEUE_EV_SET(&events[0], descriptor,
+        EVFILT_READ, EV_DELETE, 0, 0, 0);
+    ASIO_KQUEUE_EV_SET(&events[1], descriptor,
+        EVFILT_WRITE, EV_DELETE, 0, 0, 0);
+    ::kevent(kqueue_fd_, events, descriptor_data->num_kevents_, 0, 0, 0);
+
+    op_queue<operation> ops;
+    for (int i = 0; i < max_ops; ++i)
+      ops.push(descriptor_data->op_queue_[i]);
+
+    descriptor_data->descriptor_ = -1;
+    descriptor_data->shutdown_ = true;
+
+    descriptor_lock.unlock();
+
+    ASIO_HANDLER_REACTOR_DEREGISTRATION((
+          context(), static_cast<uintmax_t>(descriptor),
+          reinterpret_cast<uintmax_t>(descriptor_data)));
+
+    // Leave descriptor_data set so that it will be freed by the subsequent
+    // call to cleanup_descriptor_data.
+  }
+  else
+  {
+    // We are shutting down, so prevent cleanup_descriptor_data from freeing
+    // the descriptor_data object and let the destructor free it instead.
+    descriptor_data = 0;
+  }
+}
+
+void kqueue_reactor::cleanup_descriptor_data(
+    per_descriptor_data& descriptor_data)
+{
+  if (descriptor_data)
+  {
+    free_descriptor_state(descriptor_data);
+    descriptor_data = 0;
+  }
+}
+
+void kqueue_reactor::run(long usec, op_queue<operation>& ops)
+{
+  mutex::scoped_lock lock(mutex_);
+
+  // Determine how long to block while waiting for events.
+  timespec timeout_buf = { 0, 0 };
+  timespec* timeout = usec ? get_timeout(usec, timeout_buf) : &timeout_buf;
+
+  lock.unlock();
+
+  // Block on the kqueue descriptor.
+  struct kevent events[128];
+  int num_events = kevent(kqueue_fd_, 0, 0, events, 128, timeout);
+
+#if defined(ASIO_ENABLE_HANDLER_TRACKING)
+  // Trace the waiting events.
+  for (int i = 0; i < num_events; ++i)
+  {
+    void* ptr = reinterpret_cast<void*>(events[i].udata);
+    if (ptr != &interrupter_)
+    {
+      unsigned event_mask = 0;
+      switch (events[i].filter)
+      {
+      case EVFILT_READ:
+        event_mask |= ASIO_HANDLER_REACTOR_READ_EVENT;
+        break;
+      case EVFILT_WRITE:
+        event_mask |= ASIO_HANDLER_REACTOR_WRITE_EVENT;
+        break;
+      }
+      if ((events[i].flags & (EV_ERROR | EV_OOBAND)) != 0)
+        event_mask |= ASIO_HANDLER_REACTOR_ERROR_EVENT;
+      ASIO_HANDLER_REACTOR_EVENTS((context(),
+            reinterpret_cast<uintmax_t>(ptr), event_mask));
+    }
+  }
+#endif // defined(ASIO_ENABLE_HANDLER_TRACKING)
+
+  // Dispatch the waiting events.
+  for (int i = 0; i < num_events; ++i)
+  {
+    void* ptr = reinterpret_cast<void*>(events[i].udata);
+    if (ptr == &interrupter_)
+    {
+      interrupter_.reset();
+    }
+    else
+    {
+      descriptor_state* descriptor_data = static_cast<descriptor_state*>(ptr);
+      mutex::scoped_lock descriptor_lock(descriptor_data->mutex_);
+
+      if (events[i].filter == EVFILT_WRITE
+          && descriptor_data->num_kevents_ == 2
+          && descriptor_data->op_queue_[write_op].empty())
+      {
+        // Some descriptor types, like serial ports, don't seem to support
+        // EV_CLEAR with EVFILT_WRITE. Since we have no pending write
+        // operations we'll remove the EVFILT_WRITE registration here so that
+        // we don't end up in a tight spin.
+        struct kevent delete_events[1];
+        ASIO_KQUEUE_EV_SET(&delete_events[0],
+            descriptor_data->descriptor_, EVFILT_WRITE, EV_DELETE, 0, 0, 0);
+        ::kevent(kqueue_fd_, delete_events, 1, 0, 0, 0);
+        descriptor_data->num_kevents_ = 1;
+      }
+
+      // Exception operations must be processed first to ensure that any
+      // out-of-band data is read before normal data.
+#if defined(__NetBSD__)
+      static const unsigned int filter[max_ops] =
+#else
+      static const int filter[max_ops] =
+#endif
+        { EVFILT_READ, EVFILT_WRITE, EVFILT_READ };
+      for (int j = max_ops - 1; j >= 0; --j)
+      {
+        if (events[i].filter == filter[j])
+        {
+          if (j != except_op || events[i].flags & EV_OOBAND)
+          {
+            while (reactor_op* op = descriptor_data->op_queue_[j].front())
+            {
+              if (events[i].flags & EV_ERROR)
+              {
+                op->ec_ = asio::error_code(
+                    static_cast<int>(events[i].data),
+                    asio::error::get_system_category());
+                descriptor_data->op_queue_[j].pop();
+                ops.push(op);
+              }
+              if (op->perform())
+              {
+                descriptor_data->op_queue_[j].pop();
+                ops.push(op);
+              }
+              else
+                break;
+            }
+          }
+        }
+      }
+    }
+  }
+
+  lock.lock();
+  timer_queues_.get_ready_timers(ops);
+}
+
+void kqueue_reactor::interrupt()
+{
+  interrupter_.interrupt();
+}
+
+int kqueue_reactor::do_kqueue_create()
+{
+  int fd = ::kqueue();
+  if (fd == -1)
+  {
+    asio::error_code ec(errno,
+        asio::error::get_system_category());
+    asio::detail::throw_error(ec, "kqueue");
+  }
+  return fd;
+}
+
+kqueue_reactor::descriptor_state* kqueue_reactor::allocate_descriptor_state()
+{
+  mutex::scoped_lock descriptors_lock(registered_descriptors_mutex_);
+  return registered_descriptors_.alloc(ASIO_CONCURRENCY_HINT_IS_LOCKING(
+        REACTOR_IO, scheduler_.concurrency_hint()));
+}
+
+void kqueue_reactor::free_descriptor_state(kqueue_reactor::descriptor_state* s)
+{
+  mutex::scoped_lock descriptors_lock(registered_descriptors_mutex_);
+  registered_descriptors_.free(s);
+}
+
+void kqueue_reactor::do_add_timer_queue(timer_queue_base& queue)
+{
+  mutex::scoped_lock lock(mutex_);
+  timer_queues_.insert(&queue);
+}
+
+void kqueue_reactor::do_remove_timer_queue(timer_queue_base& queue)
+{
+  mutex::scoped_lock lock(mutex_);
+  timer_queues_.erase(&queue);
+}
+
+timespec* kqueue_reactor::get_timeout(long usec, timespec& ts)
+{
+  // By default we will wait no longer than 5 minutes. This will ensure that
+  // any changes to the system clock are detected after no longer than this.
+  const long max_usec = 5 * 60 * 1000 * 1000;
+  usec = timer_queues_.wait_duration_usec(
+      (usec < 0 || max_usec < usec) ? max_usec : usec);
+  ts.tv_sec = usec / 1000000;
+  ts.tv_nsec = (usec % 1000000) * 1000;
+  return &ts;
+}
+
+} // namespace detail
+} // namespace asio
+
+#undef ASIO_KQUEUE_EV_SET
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_KQUEUE)
+
+#endif // ASIO_DETAIL_IMPL_KQUEUE_REACTOR_IPP
diff --git a/lib/asio/detail/impl/null_event.ipp b/lib/asio/detail/impl/null_event.ipp
new file mode 100644
index 0000000..22ade40
--- /dev/null
+++ b/lib/asio/detail/impl/null_event.ipp
@@ -0,0 +1,74 @@
+//
+// detail/impl/null_event.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_NULL_EVENT_IPP
+#define ASIO_DETAIL_IMPL_NULL_EVENT_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_WINDOWS_RUNTIME)
+# include <thread>
+#elif defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+# include "asio/detail/socket_types.hpp"
+#else
+# include <unistd.h>
+# if defined(__hpux)
+#  include <sys/time.h>
+# endif
+# if !defined(__hpux) || defined(__SELECT)
+#  include <sys/select.h>
+# endif
+#endif
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+void null_event::do_wait()
+{
+#if defined(ASIO_WINDOWS_RUNTIME)
+  std::this_thread::sleep_until((std::chrono::steady_clock::time_point::max)());
+#elif defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  ::Sleep(INFINITE);
+#else
+  ::pause();
+#endif
+}
+
+void null_event::do_wait_for_usec(long usec)
+{
+#if defined(ASIO_WINDOWS_RUNTIME)
+  std::this_thread::sleep_for(std::chrono::microseconds(usec));
+#elif defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  ::Sleep(usec / 1000);
+#elif defined(__hpux) && defined(__SELECT)
+  timespec ts;
+  ts.tv_sec = usec / 1000000;
+  ts.tv_nsec = (usec % 1000000) * 1000;
+  ::pselect(0, 0, 0, 0, &ts, 0);
+#else
+  timeval tv;
+  tv.tv_sec = usec / 1000000;
+  tv.tv_usec = usec % 1000000;
+  ::select(0, 0, 0, 0, &tv);
+#endif
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_IMPL_NULL_EVENT_IPP
diff --git a/lib/asio/detail/impl/pipe_select_interrupter.ipp b/lib/asio/detail/impl/pipe_select_interrupter.ipp
new file mode 100644
index 0000000..13931ab
--- /dev/null
+++ b/lib/asio/detail/impl/pipe_select_interrupter.ipp
@@ -0,0 +1,124 @@
+//
+// detail/impl/pipe_select_interrupter.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_PIPE_SELECT_INTERRUPTER_IPP
+#define ASIO_DETAIL_IMPL_PIPE_SELECT_INTERRUPTER_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if !defined(ASIO_WINDOWS_RUNTIME)
+#if !defined(ASIO_WINDOWS)
+#if !defined(__CYGWIN__)
+#if !defined(__SYMBIAN32__)
+#if !defined(ASIO_HAS_EVENTFD)
+
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include "asio/detail/pipe_select_interrupter.hpp"
+#include "asio/detail/socket_types.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+pipe_select_interrupter::pipe_select_interrupter()
+{
+  open_descriptors();
+}
+
+void pipe_select_interrupter::open_descriptors()
+{
+  int pipe_fds[2];
+  if (pipe(pipe_fds) == 0)
+  {
+    read_descriptor_ = pipe_fds[0];
+    ::fcntl(read_descriptor_, F_SETFL, O_NONBLOCK);
+    write_descriptor_ = pipe_fds[1];
+    ::fcntl(write_descriptor_, F_SETFL, O_NONBLOCK);
+
+#if defined(FD_CLOEXEC)
+    ::fcntl(read_descriptor_, F_SETFD, FD_CLOEXEC);
+    ::fcntl(write_descriptor_, F_SETFD, FD_CLOEXEC);
+#endif // defined(FD_CLOEXEC)
+  }
+  else
+  {
+    asio::error_code ec(errno,
+        asio::error::get_system_category());
+    asio::detail::throw_error(ec, "pipe_select_interrupter");
+  }
+}
+
+pipe_select_interrupter::~pipe_select_interrupter()
+{
+  close_descriptors();
+}
+
+void pipe_select_interrupter::close_descriptors()
+{
+  if (read_descriptor_ != -1)
+    ::close(read_descriptor_);
+  if (write_descriptor_ != -1)
+    ::close(write_descriptor_);
+}
+
+void pipe_select_interrupter::recreate()
+{
+  close_descriptors();
+
+  write_descriptor_ = -1;
+  read_descriptor_ = -1;
+
+  open_descriptors();
+}
+
+void pipe_select_interrupter::interrupt()
+{
+  char byte = 0;
+  signed_size_type result = ::write(write_descriptor_, &byte, 1);
+  (void)result;
+}
+
+bool pipe_select_interrupter::reset()
+{
+  for (;;)
+  {
+    char data[1024];
+    signed_size_type bytes_read = ::read(read_descriptor_, data, sizeof(data));
+    if (bytes_read < 0 && errno == EINTR)
+      continue;
+    bool was_interrupted = (bytes_read > 0);
+    while (bytes_read == sizeof(data))
+      bytes_read = ::read(read_descriptor_, data, sizeof(data));
+    return was_interrupted;
+  }
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // !defined(ASIO_HAS_EVENTFD)
+#endif // !defined(__SYMBIAN32__)
+#endif // !defined(__CYGWIN__)
+#endif // !defined(ASIO_WINDOWS)
+#endif // !defined(ASIO_WINDOWS_RUNTIME)
+
+#endif // ASIO_DETAIL_IMPL_PIPE_SELECT_INTERRUPTER_IPP
diff --git a/lib/asio/detail/impl/posix_event.ipp b/lib/asio/detail/impl/posix_event.ipp
new file mode 100644
index 0000000..4b46ab0
--- /dev/null
+++ b/lib/asio/detail/impl/posix_event.ipp
@@ -0,0 +1,59 @@
+//
+// detail/impl/posix_event.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_POSIX_EVENT_IPP
+#define ASIO_DETAIL_IMPL_POSIX_EVENT_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_PTHREADS)
+
+#include "asio/detail/posix_event.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+posix_event::posix_event()
+  : state_(0)
+{
+#if (defined(__MACH__) && defined(__APPLE__)) \
+      || (defined(__ANDROID__) && (__ANDROID_API__ < 21))
+  int error = ::pthread_cond_init(&cond_, 0);
+#else // (defined(__MACH__) && defined(__APPLE__))
+      // || (defined(__ANDROID__) && (__ANDROID_API__ < 21))
+  ::pthread_condattr_t attr;
+  ::pthread_condattr_init(&attr);
+  int error = ::pthread_condattr_setclock(&attr, CLOCK_MONOTONIC);
+  if (error == 0)
+    error = ::pthread_cond_init(&cond_, &attr);
+#endif // (defined(__MACH__) && defined(__APPLE__))
+       // || (defined(__ANDROID__) && (__ANDROID_API__ < 21))
+
+  asio::error_code ec(error,
+      asio::error::get_system_category());
+  asio::detail::throw_error(ec, "event");
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_PTHREADS)
+
+#endif // ASIO_DETAIL_IMPL_POSIX_EVENT_IPP
diff --git a/lib/asio/detail/impl/posix_mutex.ipp b/lib/asio/detail/impl/posix_mutex.ipp
new file mode 100644
index 0000000..27272b5
--- /dev/null
+++ b/lib/asio/detail/impl/posix_mutex.ipp
@@ -0,0 +1,46 @@
+//
+// detail/impl/posix_mutex.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_POSIX_MUTEX_IPP
+#define ASIO_DETAIL_IMPL_POSIX_MUTEX_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_PTHREADS)
+
+#include "asio/detail/posix_mutex.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+posix_mutex::posix_mutex()
+{
+  int error = ::pthread_mutex_init(&mutex_, 0);
+  asio::error_code ec(error,
+      asio::error::get_system_category());
+  asio::detail::throw_error(ec, "mutex");
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_PTHREADS)
+
+#endif // ASIO_DETAIL_IMPL_POSIX_MUTEX_IPP
diff --git a/lib/asio/detail/impl/posix_thread.ipp b/lib/asio/detail/impl/posix_thread.ipp
new file mode 100644
index 0000000..69bd16f
--- /dev/null
+++ b/lib/asio/detail/impl/posix_thread.ipp
@@ -0,0 +1,84 @@
+//
+// detail/impl/posix_thread.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_POSIX_THREAD_IPP
+#define ASIO_DETAIL_IMPL_POSIX_THREAD_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_PTHREADS)
+
+#include "asio/detail/posix_thread.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+posix_thread::~posix_thread()
+{
+  if (!joined_)
+    ::pthread_detach(thread_);
+}
+
+void posix_thread::join()
+{
+  if (!joined_)
+  {
+    ::pthread_join(thread_, 0);
+    joined_ = true;
+  }
+}
+
+std::size_t posix_thread::hardware_concurrency()
+{
+#if defined(_SC_NPROCESSORS_ONLN)
+  long result = sysconf(_SC_NPROCESSORS_ONLN);
+  if (result > 0)
+    return result;
+#endif // defined(_SC_NPROCESSORS_ONLN)
+  return 0;
+}
+
+void posix_thread::start_thread(func_base* arg)
+{
+  int error = ::pthread_create(&thread_, 0,
+        asio_detail_posix_thread_function, arg);
+  if (error != 0)
+  {
+    delete arg;
+    asio::error_code ec(error,
+        asio::error::get_system_category());
+    asio::detail::throw_error(ec, "thread");
+  }
+}
+
+void* asio_detail_posix_thread_function(void* arg)
+{
+  posix_thread::auto_func_base_ptr func = {
+      static_cast<posix_thread::func_base*>(arg) };
+  func.ptr->run();
+  return 0;
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_PTHREADS)
+
+#endif // ASIO_DETAIL_IMPL_POSIX_THREAD_IPP
diff --git a/lib/asio/detail/impl/posix_tss_ptr.ipp b/lib/asio/detail/impl/posix_tss_ptr.ipp
new file mode 100644
index 0000000..54b58bd
--- /dev/null
+++ b/lib/asio/detail/impl/posix_tss_ptr.ipp
@@ -0,0 +1,46 @@
+//
+// detail/impl/posix_tss_ptr.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_POSIX_TSS_PTR_IPP
+#define ASIO_DETAIL_IMPL_POSIX_TSS_PTR_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_PTHREADS)
+
+#include "asio/detail/posix_tss_ptr.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+void posix_tss_ptr_create(pthread_key_t& key)
+{
+  int error = ::pthread_key_create(&key, 0);
+  asio::error_code ec(error,
+      asio::error::get_system_category());
+  asio::detail::throw_error(ec, "tss");
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_PTHREADS)
+
+#endif // ASIO_DETAIL_IMPL_POSIX_TSS_PTR_IPP
diff --git a/lib/asio/detail/impl/reactive_descriptor_service.ipp b/lib/asio/detail/impl/reactive_descriptor_service.ipp
new file mode 100644
index 0000000..f9505ca
--- /dev/null
+++ b/lib/asio/detail/impl/reactive_descriptor_service.ipp
@@ -0,0 +1,222 @@
+//
+// detail/impl/reactive_descriptor_service.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_REACTIVE_DESCRIPTOR_SERVICE_IPP
+#define ASIO_DETAIL_IMPL_REACTIVE_DESCRIPTOR_SERVICE_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if !defined(ASIO_WINDOWS) \
+  && !defined(ASIO_WINDOWS_RUNTIME) \
+  && !defined(__CYGWIN__)
+
+#include "asio/error.hpp"
+#include "asio/detail/reactive_descriptor_service.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+reactive_descriptor_service::reactive_descriptor_service(
+    asio::io_context& io_context)
+  : service_base<reactive_descriptor_service>(io_context),
+    reactor_(asio::use_service<reactor>(io_context))
+{
+  reactor_.init_task();
+}
+
+void reactive_descriptor_service::shutdown()
+{
+}
+
+void reactive_descriptor_service::construct(
+    reactive_descriptor_service::implementation_type& impl)
+{
+  impl.descriptor_ = -1;
+  impl.state_ = 0;
+}
+
+void reactive_descriptor_service::move_construct(
+    reactive_descriptor_service::implementation_type& impl,
+    reactive_descriptor_service::implementation_type& other_impl)
+{
+  impl.descriptor_ = other_impl.descriptor_;
+  other_impl.descriptor_ = -1;
+
+  impl.state_ = other_impl.state_;
+  other_impl.state_ = 0;
+
+  reactor_.move_descriptor(impl.descriptor_,
+      impl.reactor_data_, other_impl.reactor_data_);
+}
+
+void reactive_descriptor_service::move_assign(
+    reactive_descriptor_service::implementation_type& impl,
+    reactive_descriptor_service& other_service,
+    reactive_descriptor_service::implementation_type& other_impl)
+{
+  destroy(impl);
+
+  impl.descriptor_ = other_impl.descriptor_;
+  other_impl.descriptor_ = -1;
+
+  impl.state_ = other_impl.state_;
+  other_impl.state_ = 0;
+
+  other_service.reactor_.move_descriptor(impl.descriptor_,
+      impl.reactor_data_, other_impl.reactor_data_);
+}
+
+void reactive_descriptor_service::destroy(
+    reactive_descriptor_service::implementation_type& impl)
+{
+  if (is_open(impl))
+  {
+    ASIO_HANDLER_OPERATION((reactor_.context(),
+          "descriptor", &impl, impl.descriptor_, "close"));
+
+    reactor_.deregister_descriptor(impl.descriptor_, impl.reactor_data_,
+        (impl.state_ & descriptor_ops::possible_dup) == 0);
+
+    asio::error_code ignored_ec;
+    descriptor_ops::close(impl.descriptor_, impl.state_, ignored_ec);
+
+    reactor_.cleanup_descriptor_data(impl.reactor_data_);
+  }
+}
+
+asio::error_code reactive_descriptor_service::assign(
+    reactive_descriptor_service::implementation_type& impl,
+    const native_handle_type& native_descriptor, asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ec = asio::error::already_open;
+    return ec;
+  }
+
+  if (int err = reactor_.register_descriptor(
+        native_descriptor, impl.reactor_data_))
+  {
+    ec = asio::error_code(err,
+        asio::error::get_system_category());
+    return ec;
+  }
+
+  impl.descriptor_ = native_descriptor;
+  impl.state_ = descriptor_ops::possible_dup;
+  ec = asio::error_code();
+  return ec;
+}
+
+asio::error_code reactive_descriptor_service::close(
+    reactive_descriptor_service::implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ASIO_HANDLER_OPERATION((reactor_.context(),
+          "descriptor", &impl, impl.descriptor_, "close"));
+
+    reactor_.deregister_descriptor(impl.descriptor_, impl.reactor_data_,
+        (impl.state_ & descriptor_ops::possible_dup) == 0);
+
+    descriptor_ops::close(impl.descriptor_, impl.state_, ec);
+
+    reactor_.cleanup_descriptor_data(impl.reactor_data_);
+  }
+  else
+  {
+    ec = asio::error_code();
+  }
+
+  // The descriptor is closed by the OS even if close() returns an error.
+  //
+  // (Actually, POSIX says the state of the descriptor is unspecified. On
+  // Linux the descriptor is apparently closed anyway; e.g. see
+  //   http://lkml.org/lkml/2005/9/10/129
+  // We'll just have to assume that other OSes follow the same behaviour.)
+  construct(impl);
+
+  return ec;
+}
+
+reactive_descriptor_service::native_handle_type
+reactive_descriptor_service::release(
+    reactive_descriptor_service::implementation_type& impl)
+{
+  native_handle_type descriptor = impl.descriptor_;
+
+  if (is_open(impl))
+  {
+    ASIO_HANDLER_OPERATION((reactor_.context(),
+          "descriptor", &impl, impl.descriptor_, "release"));
+
+    reactor_.deregister_descriptor(impl.descriptor_, impl.reactor_data_, false);
+    reactor_.cleanup_descriptor_data(impl.reactor_data_);
+    construct(impl);
+  }
+
+  return descriptor;
+}
+
+asio::error_code reactive_descriptor_service::cancel(
+    reactive_descriptor_service::implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    return ec;
+  }
+
+  ASIO_HANDLER_OPERATION((reactor_.context(),
+        "descriptor", &impl, impl.descriptor_, "cancel"));
+
+  reactor_.cancel_ops(impl.descriptor_, impl.reactor_data_);
+  ec = asio::error_code();
+  return ec;
+}
+
+void reactive_descriptor_service::start_op(
+    reactive_descriptor_service::implementation_type& impl,
+    int op_type, reactor_op* op, bool is_continuation,
+    bool is_non_blocking, bool noop)
+{
+  if (!noop)
+  {
+    if ((impl.state_ & descriptor_ops::non_blocking) ||
+        descriptor_ops::set_internal_non_blocking(
+          impl.descriptor_, impl.state_, true, op->ec_))
+    {
+      reactor_.start_op(op_type, impl.descriptor_,
+          impl.reactor_data_, op, is_continuation, is_non_blocking);
+      return;
+    }
+  }
+
+  reactor_.post_immediate_completion(op, is_continuation);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // !defined(ASIO_WINDOWS)
+       //   && !defined(ASIO_WINDOWS_RUNTIME)
+       //   && !defined(__CYGWIN__)
+
+#endif // ASIO_DETAIL_IMPL_REACTIVE_DESCRIPTOR_SERVICE_IPP
diff --git a/lib/asio/detail/impl/reactive_serial_port_service.ipp b/lib/asio/detail/impl/reactive_serial_port_service.ipp
new file mode 100644
index 0000000..c907835
--- /dev/null
+++ b/lib/asio/detail/impl/reactive_serial_port_service.ipp
@@ -0,0 +1,152 @@
+//
+// detail/impl/reactive_serial_port_service.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2008 Rep Invariant Systems, Inc. (info@repinvariant.com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_REACTIVE_SERIAL_PORT_SERVICE_IPP
+#define ASIO_DETAIL_IMPL_REACTIVE_SERIAL_PORT_SERVICE_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_SERIAL_PORT)
+#if !defined(ASIO_WINDOWS) && !defined(__CYGWIN__)
+
+#include <cstring>
+#include "asio/detail/reactive_serial_port_service.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+reactive_serial_port_service::reactive_serial_port_service(
+    asio::io_context& io_context)
+  : service_base<reactive_serial_port_service>(io_context),
+    descriptor_service_(io_context)
+{
+}
+
+void reactive_serial_port_service::shutdown()
+{
+  descriptor_service_.shutdown();
+}
+
+asio::error_code reactive_serial_port_service::open(
+    reactive_serial_port_service::implementation_type& impl,
+    const std::string& device, asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ec = asio::error::already_open;
+    return ec;
+  }
+
+  descriptor_ops::state_type state = 0;
+  int fd = descriptor_ops::open(device.c_str(),
+      O_RDWR | O_NONBLOCK | O_NOCTTY, ec);
+  if (fd < 0)
+    return ec;
+
+  int s = descriptor_ops::fcntl(fd, F_GETFL, ec);
+  if (s >= 0)
+    s = descriptor_ops::fcntl(fd, F_SETFL, s | O_NONBLOCK, ec);
+  if (s < 0)
+  {
+    asio::error_code ignored_ec;
+    descriptor_ops::close(fd, state, ignored_ec);
+    return ec;
+  }
+
+  // Set up default serial port options.
+  termios ios;
+  errno = 0;
+  s = descriptor_ops::error_wrapper(::tcgetattr(fd, &ios), ec);
+  if (s >= 0)
+  {
+#if defined(_BSD_SOURCE) || defined(_DEFAULT_SOURCE)
+    ::cfmakeraw(&ios);
+#else
+    ios.c_iflag &= ~(IGNBRK | BRKINT | PARMRK
+        | ISTRIP | INLCR | IGNCR | ICRNL | IXON);
+    ios.c_oflag &= ~OPOST;
+    ios.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
+    ios.c_cflag &= ~(CSIZE | PARENB);
+    ios.c_cflag |= CS8;
+#endif
+    ios.c_iflag |= IGNPAR;
+    ios.c_cflag |= CREAD | CLOCAL;
+    errno = 0;
+    s = descriptor_ops::error_wrapper(::tcsetattr(fd, TCSANOW, &ios), ec);
+  }
+  if (s < 0)
+  {
+    asio::error_code ignored_ec;
+    descriptor_ops::close(fd, state, ignored_ec);
+    return ec;
+  }
+
+  // We're done. Take ownership of the serial port descriptor.
+  if (descriptor_service_.assign(impl, fd, ec))
+  {
+    asio::error_code ignored_ec;
+    descriptor_ops::close(fd, state, ignored_ec);
+  }
+
+  return ec;
+}
+
+asio::error_code reactive_serial_port_service::do_set_option(
+    reactive_serial_port_service::implementation_type& impl,
+    reactive_serial_port_service::store_function_type store,
+    const void* option, asio::error_code& ec)
+{
+  termios ios;
+  errno = 0;
+  descriptor_ops::error_wrapper(::tcgetattr(
+        descriptor_service_.native_handle(impl), &ios), ec);
+  if (ec)
+    return ec;
+
+  if (store(option, ios, ec))
+    return ec;
+
+  errno = 0;
+  descriptor_ops::error_wrapper(::tcsetattr(
+        descriptor_service_.native_handle(impl), TCSANOW, &ios), ec);
+  return ec;
+}
+
+asio::error_code reactive_serial_port_service::do_get_option(
+    const reactive_serial_port_service::implementation_type& impl,
+    reactive_serial_port_service::load_function_type load,
+    void* option, asio::error_code& ec) const
+{
+  termios ios;
+  errno = 0;
+  descriptor_ops::error_wrapper(::tcgetattr(
+        descriptor_service_.native_handle(impl), &ios), ec);
+  if (ec)
+    return ec;
+
+  return load(option, ios, ec);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // !defined(ASIO_WINDOWS) && !defined(__CYGWIN__)
+#endif // defined(ASIO_HAS_SERIAL_PORT)
+
+#endif // ASIO_DETAIL_IMPL_REACTIVE_SERIAL_PORT_SERVICE_IPP
diff --git a/lib/asio/detail/impl/reactive_socket_service_base.ipp b/lib/asio/detail/impl/reactive_socket_service_base.ipp
new file mode 100644
index 0000000..129b851
--- /dev/null
+++ b/lib/asio/detail/impl/reactive_socket_service_base.ipp
@@ -0,0 +1,300 @@
+//
+// detail/reactive_socket_service_base.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_REACTIVE_SOCKET_SERVICE_BASE_IPP
+#define ASIO_DETAIL_IMPL_REACTIVE_SOCKET_SERVICE_BASE_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if !defined(ASIO_HAS_IOCP) \
+  && !defined(ASIO_WINDOWS_RUNTIME)
+
+#include "asio/detail/reactive_socket_service_base.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+reactive_socket_service_base::reactive_socket_service_base(
+    asio::io_context& io_context)
+  : io_context_(io_context),
+    reactor_(use_service<reactor>(io_context))
+{
+  reactor_.init_task();
+}
+
+void reactive_socket_service_base::base_shutdown()
+{
+}
+
+void reactive_socket_service_base::construct(
+    reactive_socket_service_base::base_implementation_type& impl)
+{
+  impl.socket_ = invalid_socket;
+  impl.state_ = 0;
+}
+
+void reactive_socket_service_base::base_move_construct(
+    reactive_socket_service_base::base_implementation_type& impl,
+    reactive_socket_service_base::base_implementation_type& other_impl)
+{
+  impl.socket_ = other_impl.socket_;
+  other_impl.socket_ = invalid_socket;
+
+  impl.state_ = other_impl.state_;
+  other_impl.state_ = 0;
+
+  reactor_.move_descriptor(impl.socket_,
+      impl.reactor_data_, other_impl.reactor_data_);
+}
+
+void reactive_socket_service_base::base_move_assign(
+    reactive_socket_service_base::base_implementation_type& impl,
+    reactive_socket_service_base& other_service,
+    reactive_socket_service_base::base_implementation_type& other_impl)
+{
+  destroy(impl);
+
+  impl.socket_ = other_impl.socket_;
+  other_impl.socket_ = invalid_socket;
+
+  impl.state_ = other_impl.state_;
+  other_impl.state_ = 0;
+
+  other_service.reactor_.move_descriptor(impl.socket_,
+      impl.reactor_data_, other_impl.reactor_data_);
+}
+
+void reactive_socket_service_base::destroy(
+    reactive_socket_service_base::base_implementation_type& impl)
+{
+  if (impl.socket_ != invalid_socket)
+  {
+    ASIO_HANDLER_OPERATION((reactor_.context(),
+          "socket", &impl, impl.socket_, "close"));
+
+    reactor_.deregister_descriptor(impl.socket_, impl.reactor_data_,
+        (impl.state_ & socket_ops::possible_dup) == 0);
+
+    asio::error_code ignored_ec;
+    socket_ops::close(impl.socket_, impl.state_, true, ignored_ec);
+
+    reactor_.cleanup_descriptor_data(impl.reactor_data_);
+  }
+}
+
+asio::error_code reactive_socket_service_base::close(
+    reactive_socket_service_base::base_implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ASIO_HANDLER_OPERATION((reactor_.context(),
+          "socket", &impl, impl.socket_, "close"));
+
+    reactor_.deregister_descriptor(impl.socket_, impl.reactor_data_,
+        (impl.state_ & socket_ops::possible_dup) == 0);
+
+    socket_ops::close(impl.socket_, impl.state_, false, ec);
+
+    reactor_.cleanup_descriptor_data(impl.reactor_data_);
+  }
+  else
+  {
+    ec = asio::error_code();
+  }
+
+  // The descriptor is closed by the OS even if close() returns an error.
+  //
+  // (Actually, POSIX says the state of the descriptor is unspecified. On
+  // Linux the descriptor is apparently closed anyway; e.g. see
+  //   http://lkml.org/lkml/2005/9/10/129
+  // We'll just have to assume that other OSes follow the same behaviour. The
+  // known exception is when Windows's closesocket() function fails with
+  // WSAEWOULDBLOCK, but this case is handled inside socket_ops::close().
+  construct(impl);
+
+  return ec;
+}
+
+socket_type reactive_socket_service_base::release(
+    reactive_socket_service_base::base_implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    return invalid_socket;
+  }
+
+  ASIO_HANDLER_OPERATION((reactor_.context(),
+        "socket", &impl, impl.socket_, "release"));
+
+  reactor_.deregister_descriptor(impl.socket_, impl.reactor_data_, false);
+  reactor_.cleanup_descriptor_data(impl.reactor_data_);
+  socket_type sock = impl.socket_;
+  construct(impl);
+  ec = asio::error_code();
+  return sock;
+}
+
+asio::error_code reactive_socket_service_base::cancel(
+    reactive_socket_service_base::base_implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    return ec;
+  }
+
+  ASIO_HANDLER_OPERATION((reactor_.context(),
+        "socket", &impl, impl.socket_, "cancel"));
+
+  reactor_.cancel_ops(impl.socket_, impl.reactor_data_);
+  ec = asio::error_code();
+  return ec;
+}
+
+asio::error_code reactive_socket_service_base::do_open(
+    reactive_socket_service_base::base_implementation_type& impl,
+    int af, int type, int protocol, asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ec = asio::error::already_open;
+    return ec;
+  }
+
+  socket_holder sock(socket_ops::socket(af, type, protocol, ec));
+  if (sock.get() == invalid_socket)
+    return ec;
+
+  if (int err = reactor_.register_descriptor(sock.get(), impl.reactor_data_))
+  {
+    ec = asio::error_code(err,
+        asio::error::get_system_category());
+    return ec;
+  }
+
+  impl.socket_ = sock.release();
+  switch (type)
+  {
+  case SOCK_STREAM: impl.state_ = socket_ops::stream_oriented; break;
+  case SOCK_DGRAM: impl.state_ = socket_ops::datagram_oriented; break;
+  default: impl.state_ = 0; break;
+  }
+  ec = asio::error_code();
+  return ec;
+}
+
+asio::error_code reactive_socket_service_base::do_assign(
+    reactive_socket_service_base::base_implementation_type& impl, int type,
+    const reactive_socket_service_base::native_handle_type& native_socket,
+    asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ec = asio::error::already_open;
+    return ec;
+  }
+
+  if (int err = reactor_.register_descriptor(
+        native_socket, impl.reactor_data_))
+  {
+    ec = asio::error_code(err,
+        asio::error::get_system_category());
+    return ec;
+  }
+
+  impl.socket_ = native_socket;
+  switch (type)
+  {
+  case SOCK_STREAM: impl.state_ = socket_ops::stream_oriented; break;
+  case SOCK_DGRAM: impl.state_ = socket_ops::datagram_oriented; break;
+  default: impl.state_ = 0; break;
+  }
+  impl.state_ |= socket_ops::possible_dup;
+  ec = asio::error_code();
+  return ec;
+}
+
+void reactive_socket_service_base::start_op(
+    reactive_socket_service_base::base_implementation_type& impl,
+    int op_type, reactor_op* op, bool is_continuation,
+    bool is_non_blocking, bool noop)
+{
+  if (!noop)
+  {
+    if ((impl.state_ & socket_ops::non_blocking)
+        || socket_ops::set_internal_non_blocking(
+          impl.socket_, impl.state_, true, op->ec_))
+    {
+      reactor_.start_op(op_type, impl.socket_,
+          impl.reactor_data_, op, is_continuation, is_non_blocking);
+      return;
+    }
+  }
+
+  reactor_.post_immediate_completion(op, is_continuation);
+}
+
+void reactive_socket_service_base::start_accept_op(
+    reactive_socket_service_base::base_implementation_type& impl,
+    reactor_op* op, bool is_continuation, bool peer_is_open)
+{
+  if (!peer_is_open)
+    start_op(impl, reactor::read_op, op, is_continuation, true, false);
+  else
+  {
+    op->ec_ = asio::error::already_open;
+    reactor_.post_immediate_completion(op, is_continuation);
+  }
+}
+
+void reactive_socket_service_base::start_connect_op(
+    reactive_socket_service_base::base_implementation_type& impl,
+    reactor_op* op, bool is_continuation,
+    const socket_addr_type* addr, size_t addrlen)
+{
+  if ((impl.state_ & socket_ops::non_blocking)
+      || socket_ops::set_internal_non_blocking(
+        impl.socket_, impl.state_, true, op->ec_))
+  {
+    if (socket_ops::connect(impl.socket_, addr, addrlen, op->ec_) != 0)
+    {
+      if (op->ec_ == asio::error::in_progress
+          || op->ec_ == asio::error::would_block)
+      {
+        op->ec_ = asio::error_code();
+        reactor_.start_op(reactor::connect_op, impl.socket_,
+            impl.reactor_data_, op, is_continuation, false);
+        return;
+      }
+    }
+  }
+
+  reactor_.post_immediate_completion(op, is_continuation);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // !defined(ASIO_HAS_IOCP)
+       //   && !defined(ASIO_WINDOWS_RUNTIME)
+
+#endif // ASIO_DETAIL_IMPL_REACTIVE_SOCKET_SERVICE_BASE_IPP
diff --git a/lib/asio/detail/impl/resolver_service_base.ipp b/lib/asio/detail/impl/resolver_service_base.ipp
new file mode 100644
index 0000000..540bb66
--- /dev/null
+++ b/lib/asio/detail/impl/resolver_service_base.ipp
@@ -0,0 +1,154 @@
+//
+// detail/impl/resolver_service_base.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_RESOLVER_SERVICE_BASE_IPP
+#define ASIO_DETAIL_IMPL_RESOLVER_SERVICE_BASE_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/resolver_service_base.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class resolver_service_base::work_io_context_runner
+{
+public:
+  work_io_context_runner(asio::io_context& io_context)
+    : io_context_(io_context) {}
+  void operator()() { io_context_.run(); }
+private:
+  asio::io_context& io_context_;
+};
+
+resolver_service_base::resolver_service_base(
+    asio::io_context& io_context)
+  : io_context_impl_(asio::use_service<io_context_impl>(io_context)),
+    work_io_context_(new asio::io_context(-1)),
+    work_io_context_impl_(asio::use_service<
+        io_context_impl>(*work_io_context_)),
+    work_(asio::make_work_guard(*work_io_context_)),
+    work_thread_(0)
+{
+}
+
+resolver_service_base::~resolver_service_base()
+{
+  base_shutdown();
+}
+
+void resolver_service_base::base_shutdown()
+{
+  work_.reset();
+  if (work_io_context_.get())
+  {
+    work_io_context_->stop();
+    if (work_thread_.get())
+    {
+      work_thread_->join();
+      work_thread_.reset();
+    }
+    work_io_context_.reset();
+  }
+}
+
+void resolver_service_base::base_notify_fork(
+    asio::io_context::fork_event fork_ev)
+{
+  if (work_thread_.get())
+  {
+    if (fork_ev == asio::io_context::fork_prepare)
+    {
+      work_io_context_->stop();
+      work_thread_->join();
+    }
+    else
+    {
+      work_io_context_->restart();
+      work_thread_.reset(new asio::detail::thread(
+            work_io_context_runner(*work_io_context_)));
+    }
+  }
+}
+
+void resolver_service_base::construct(
+    resolver_service_base::implementation_type& impl)
+{
+  impl.reset(static_cast<void*>(0), socket_ops::noop_deleter());
+}
+
+void resolver_service_base::destroy(
+    resolver_service_base::implementation_type& impl)
+{
+  ASIO_HANDLER_OPERATION((io_context_impl_.context(),
+        "resolver", &impl, 0, "cancel"));
+
+  impl.reset();
+}
+
+void resolver_service_base::move_construct(implementation_type& impl,
+    implementation_type& other_impl)
+{
+  impl = ASIO_MOVE_CAST(implementation_type)(other_impl);
+}
+
+void resolver_service_base::move_assign(implementation_type& impl,
+    resolver_service_base&, implementation_type& other_impl)
+{
+  destroy(impl);
+  impl = ASIO_MOVE_CAST(implementation_type)(other_impl);
+}
+
+void resolver_service_base::cancel(
+    resolver_service_base::implementation_type& impl)
+{
+  ASIO_HANDLER_OPERATION((io_context_impl_.context(),
+        "resolver", &impl, 0, "cancel"));
+
+  impl.reset(static_cast<void*>(0), socket_ops::noop_deleter());
+}
+
+void resolver_service_base::start_resolve_op(resolve_op* op)
+{
+  if (ASIO_CONCURRENCY_HINT_IS_LOCKING(SCHEDULER,
+        io_context_impl_.concurrency_hint()))
+  {
+    start_work_thread();
+    io_context_impl_.work_started();
+    work_io_context_impl_.post_immediate_completion(op, false);
+  }
+  else
+  {
+    op->ec_ = asio::error::operation_not_supported;
+    io_context_impl_.post_immediate_completion(op, false);
+  }
+}
+
+void resolver_service_base::start_work_thread()
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  if (!work_thread_.get())
+  {
+    work_thread_.reset(new asio::detail::thread(
+          work_io_context_runner(*work_io_context_)));
+  }
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_IMPL_RESOLVER_SERVICE_BASE_IPP
diff --git a/lib/asio/detail/impl/scheduler.ipp b/lib/asio/detail/impl/scheduler.ipp
new file mode 100644
index 0000000..35bc678
--- /dev/null
+++ b/lib/asio/detail/impl/scheduler.ipp
@@ -0,0 +1,571 @@
+//
+// detail/impl/scheduler.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_SCHEDULER_IPP
+#define ASIO_DETAIL_IMPL_SCHEDULER_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#include "asio/detail/concurrency_hint.hpp"
+#include "asio/detail/event.hpp"
+#include "asio/detail/limits.hpp"
+#include "asio/detail/reactor.hpp"
+#include "asio/detail/scheduler.hpp"
+#include "asio/detail/scheduler_thread_info.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+struct scheduler::task_cleanup
+{
+  ~task_cleanup()
+  {
+    if (this_thread_->private_outstanding_work > 0)
+    {
+      asio::detail::increment(
+          scheduler_->outstanding_work_,
+          this_thread_->private_outstanding_work);
+    }
+    this_thread_->private_outstanding_work = 0;
+
+    // Enqueue the completed operations and reinsert the task at the end of
+    // the operation queue.
+    lock_->lock();
+    scheduler_->task_interrupted_ = true;
+    scheduler_->op_queue_.push(this_thread_->private_op_queue);
+    scheduler_->op_queue_.push(&scheduler_->task_operation_);
+  }
+
+  scheduler* scheduler_;
+  mutex::scoped_lock* lock_;
+  thread_info* this_thread_;
+};
+
+struct scheduler::work_cleanup
+{
+  ~work_cleanup()
+  {
+    if (this_thread_->private_outstanding_work > 1)
+    {
+      asio::detail::increment(
+          scheduler_->outstanding_work_,
+          this_thread_->private_outstanding_work - 1);
+    }
+    else if (this_thread_->private_outstanding_work < 1)
+    {
+      scheduler_->work_finished();
+    }
+    this_thread_->private_outstanding_work = 0;
+
+#if defined(ASIO_HAS_THREADS)
+    if (!this_thread_->private_op_queue.empty())
+    {
+      lock_->lock();
+      scheduler_->op_queue_.push(this_thread_->private_op_queue);
+    }
+#endif // defined(ASIO_HAS_THREADS)
+  }
+
+  scheduler* scheduler_;
+  mutex::scoped_lock* lock_;
+  thread_info* this_thread_;
+};
+
+scheduler::scheduler(
+    asio::execution_context& ctx, int concurrency_hint)
+  : asio::detail::execution_context_service_base<scheduler>(ctx),
+    one_thread_(concurrency_hint == 1
+        || !ASIO_CONCURRENCY_HINT_IS_LOCKING(
+          SCHEDULER, concurrency_hint)
+        || !ASIO_CONCURRENCY_HINT_IS_LOCKING(
+          REACTOR_IO, concurrency_hint)),
+    mutex_(ASIO_CONCURRENCY_HINT_IS_LOCKING(
+          SCHEDULER, concurrency_hint)),
+    task_(0),
+    task_interrupted_(true),
+    outstanding_work_(0),
+    stopped_(false),
+    shutdown_(false),
+    concurrency_hint_(concurrency_hint)
+{
+  ASIO_HANDLER_TRACKING_INIT;
+}
+
+void scheduler::shutdown()
+{
+  mutex::scoped_lock lock(mutex_);
+  shutdown_ = true;
+  lock.unlock();
+
+  // Destroy handler objects.
+  while (!op_queue_.empty())
+  {
+    operation* o = op_queue_.front();
+    op_queue_.pop();
+    if (o != &task_operation_)
+      o->destroy();
+  }
+
+  // Reset to initial state.
+  task_ = 0;
+}
+
+void scheduler::init_task()
+{
+  mutex::scoped_lock lock(mutex_);
+  if (!shutdown_ && !task_)
+  {
+    task_ = &use_service<reactor>(this->context());
+    op_queue_.push(&task_operation_);
+    wake_one_thread_and_unlock(lock);
+  }
+}
+
+std::size_t scheduler::run(asio::error_code& ec)
+{
+  ec = asio::error_code();
+  if (outstanding_work_ == 0)
+  {
+    stop();
+    return 0;
+  }
+
+  thread_info this_thread;
+  this_thread.private_outstanding_work = 0;
+  thread_call_stack::context ctx(this, this_thread);
+
+  mutex::scoped_lock lock(mutex_);
+
+  std::size_t n = 0;
+  for (; do_run_one(lock, this_thread, ec); lock.lock())
+    if (n != (std::numeric_limits<std::size_t>::max)())
+      ++n;
+  return n;
+}
+
+std::size_t scheduler::run_one(asio::error_code& ec)
+{
+  ec = asio::error_code();
+  if (outstanding_work_ == 0)
+  {
+    stop();
+    return 0;
+  }
+
+  thread_info this_thread;
+  this_thread.private_outstanding_work = 0;
+  thread_call_stack::context ctx(this, this_thread);
+
+  mutex::scoped_lock lock(mutex_);
+
+  return do_run_one(lock, this_thread, ec);
+}
+
+std::size_t scheduler::wait_one(long usec, asio::error_code& ec)
+{
+  ec = asio::error_code();
+  if (outstanding_work_ == 0)
+  {
+    stop();
+    return 0;
+  }
+
+  thread_info this_thread;
+  this_thread.private_outstanding_work = 0;
+  thread_call_stack::context ctx(this, this_thread);
+
+  mutex::scoped_lock lock(mutex_);
+
+  return do_wait_one(lock, this_thread, usec, ec);
+}
+
+std::size_t scheduler::poll(asio::error_code& ec)
+{
+  ec = asio::error_code();
+  if (outstanding_work_ == 0)
+  {
+    stop();
+    return 0;
+  }
+
+  thread_info this_thread;
+  this_thread.private_outstanding_work = 0;
+  thread_call_stack::context ctx(this, this_thread);
+
+  mutex::scoped_lock lock(mutex_);
+
+#if defined(ASIO_HAS_THREADS)
+  // We want to support nested calls to poll() and poll_one(), so any handlers
+  // that are already on a thread-private queue need to be put on to the main
+  // queue now.
+  if (one_thread_)
+    if (thread_info* outer_info = static_cast<thread_info*>(ctx.next_by_key()))
+      op_queue_.push(outer_info->private_op_queue);
+#endif // defined(ASIO_HAS_THREADS)
+
+  std::size_t n = 0;
+  for (; do_poll_one(lock, this_thread, ec); lock.lock())
+    if (n != (std::numeric_limits<std::size_t>::max)())
+      ++n;
+  return n;
+}
+
+std::size_t scheduler::poll_one(asio::error_code& ec)
+{
+  ec = asio::error_code();
+  if (outstanding_work_ == 0)
+  {
+    stop();
+    return 0;
+  }
+
+  thread_info this_thread;
+  this_thread.private_outstanding_work = 0;
+  thread_call_stack::context ctx(this, this_thread);
+
+  mutex::scoped_lock lock(mutex_);
+
+#if defined(ASIO_HAS_THREADS)
+  // We want to support nested calls to poll() and poll_one(), so any handlers
+  // that are already on a thread-private queue need to be put on to the main
+  // queue now.
+  if (one_thread_)
+    if (thread_info* outer_info = static_cast<thread_info*>(ctx.next_by_key()))
+      op_queue_.push(outer_info->private_op_queue);
+#endif // defined(ASIO_HAS_THREADS)
+
+  return do_poll_one(lock, this_thread, ec);
+}
+
+void scheduler::stop()
+{
+  mutex::scoped_lock lock(mutex_);
+  stop_all_threads(lock);
+}
+
+bool scheduler::stopped() const
+{
+  mutex::scoped_lock lock(mutex_);
+  return stopped_;
+}
+
+void scheduler::restart()
+{
+  mutex::scoped_lock lock(mutex_);
+  stopped_ = false;
+}
+
+void scheduler::compensating_work_started()
+{
+  thread_info_base* this_thread = thread_call_stack::contains(this);
+  ++static_cast<thread_info*>(this_thread)->private_outstanding_work;
+}
+
+void scheduler::post_immediate_completion(
+    scheduler::operation* op, bool is_continuation)
+{
+#if defined(ASIO_HAS_THREADS)
+  if (one_thread_ || is_continuation)
+  {
+    if (thread_info_base* this_thread = thread_call_stack::contains(this))
+    {
+      ++static_cast<thread_info*>(this_thread)->private_outstanding_work;
+      static_cast<thread_info*>(this_thread)->private_op_queue.push(op);
+      return;
+    }
+  }
+#else // defined(ASIO_HAS_THREADS)
+  (void)is_continuation;
+#endif // defined(ASIO_HAS_THREADS)
+
+  work_started();
+  mutex::scoped_lock lock(mutex_);
+  op_queue_.push(op);
+  wake_one_thread_and_unlock(lock);
+}
+
+void scheduler::post_deferred_completion(scheduler::operation* op)
+{
+#if defined(ASIO_HAS_THREADS)
+  if (one_thread_)
+  {
+    if (thread_info_base* this_thread = thread_call_stack::contains(this))
+    {
+      static_cast<thread_info*>(this_thread)->private_op_queue.push(op);
+      return;
+    }
+  }
+#endif // defined(ASIO_HAS_THREADS)
+
+  mutex::scoped_lock lock(mutex_);
+  op_queue_.push(op);
+  wake_one_thread_and_unlock(lock);
+}
+
+void scheduler::post_deferred_completions(
+    op_queue<scheduler::operation>& ops)
+{
+  if (!ops.empty())
+  {
+#if defined(ASIO_HAS_THREADS)
+    if (one_thread_)
+    {
+      if (thread_info_base* this_thread = thread_call_stack::contains(this))
+      {
+        static_cast<thread_info*>(this_thread)->private_op_queue.push(ops);
+        return;
+      }
+    }
+#endif // defined(ASIO_HAS_THREADS)
+
+    mutex::scoped_lock lock(mutex_);
+    op_queue_.push(ops);
+    wake_one_thread_and_unlock(lock);
+  }
+}
+
+void scheduler::do_dispatch(
+    scheduler::operation* op)
+{
+  work_started();
+  mutex::scoped_lock lock(mutex_);
+  op_queue_.push(op);
+  wake_one_thread_and_unlock(lock);
+}
+
+void scheduler::abandon_operations(
+    op_queue<scheduler::operation>& ops)
+{
+  op_queue<scheduler::operation> ops2;
+  ops2.push(ops);
+}
+
+std::size_t scheduler::do_run_one(mutex::scoped_lock& lock,
+    scheduler::thread_info& this_thread,
+    const asio::error_code& ec)
+{
+  while (!stopped_)
+  {
+    if (!op_queue_.empty())
+    {
+      // Prepare to execute first handler from queue.
+      operation* o = op_queue_.front();
+      op_queue_.pop();
+      bool more_handlers = (!op_queue_.empty());
+
+      if (o == &task_operation_)
+      {
+        task_interrupted_ = more_handlers;
+
+        if (more_handlers && !one_thread_)
+          wakeup_event_.unlock_and_signal_one(lock);
+        else
+          lock.unlock();
+
+        task_cleanup on_exit = { this, &lock, &this_thread };
+        (void)on_exit;
+
+        // Run the task. May throw an exception. Only block if the operation
+        // queue is empty and we're not polling, otherwise we want to return
+        // as soon as possible.
+        task_->run(more_handlers ? 0 : -1, this_thread.private_op_queue);
+      }
+      else
+      {
+        std::size_t task_result = o->task_result_;
+
+        if (more_handlers && !one_thread_)
+          wake_one_thread_and_unlock(lock);
+        else
+          lock.unlock();
+
+        // Ensure the count of outstanding work is decremented on block exit.
+        work_cleanup on_exit = { this, &lock, &this_thread };
+        (void)on_exit;
+
+        // Complete the operation. May throw an exception. Deletes the object.
+        o->complete(this, ec, task_result);
+
+        return 1;
+      }
+    }
+    else
+    {
+      wakeup_event_.clear(lock);
+      wakeup_event_.wait(lock);
+    }
+  }
+
+  return 0;
+}
+
+std::size_t scheduler::do_wait_one(mutex::scoped_lock& lock,
+    scheduler::thread_info& this_thread, long usec,
+    const asio::error_code& ec)
+{
+  if (stopped_)
+    return 0;
+
+  operation* o = op_queue_.front();
+  if (o == 0)
+  {
+    wakeup_event_.clear(lock);
+    wakeup_event_.wait_for_usec(lock, usec);
+    usec = 0; // Wait at most once.
+    o = op_queue_.front();
+  }
+
+  if (o == &task_operation_)
+  {
+    op_queue_.pop();
+    bool more_handlers = (!op_queue_.empty());
+
+    task_interrupted_ = more_handlers;
+
+    if (more_handlers && !one_thread_)
+      wakeup_event_.unlock_and_signal_one(lock);
+    else
+      lock.unlock();
+
+    {
+      task_cleanup on_exit = { this, &lock, &this_thread };
+      (void)on_exit;
+
+      // Run the task. May throw an exception. Only block if the operation
+      // queue is empty and we're not polling, otherwise we want to return
+      // as soon as possible.
+      task_->run(more_handlers ? 0 : usec, this_thread.private_op_queue);
+    }
+
+    o = op_queue_.front();
+    if (o == &task_operation_)
+    {
+      if (!one_thread_)
+        wakeup_event_.maybe_unlock_and_signal_one(lock);
+      return 0;
+    }
+  }
+
+  if (o == 0)
+    return 0;
+
+  op_queue_.pop();
+  bool more_handlers = (!op_queue_.empty());
+
+  std::size_t task_result = o->task_result_;
+
+  if (more_handlers && !one_thread_)
+    wake_one_thread_and_unlock(lock);
+  else
+    lock.unlock();
+
+  // Ensure the count of outstanding work is decremented on block exit.
+  work_cleanup on_exit = { this, &lock, &this_thread };
+  (void)on_exit;
+
+  // Complete the operation. May throw an exception. Deletes the object.
+  o->complete(this, ec, task_result);
+
+  return 1;
+}
+
+std::size_t scheduler::do_poll_one(mutex::scoped_lock& lock,
+    scheduler::thread_info& this_thread,
+    const asio::error_code& ec)
+{
+  if (stopped_)
+    return 0;
+
+  operation* o = op_queue_.front();
+  if (o == &task_operation_)
+  {
+    op_queue_.pop();
+    lock.unlock();
+
+    {
+      task_cleanup c = { this, &lock, &this_thread };
+      (void)c;
+
+      // Run the task. May throw an exception. Only block if the operation
+      // queue is empty and we're not polling, otherwise we want to return
+      // as soon as possible.
+      task_->run(0, this_thread.private_op_queue);
+    }
+
+    o = op_queue_.front();
+    if (o == &task_operation_)
+    {
+      wakeup_event_.maybe_unlock_and_signal_one(lock);
+      return 0;
+    }
+  }
+
+  if (o == 0)
+    return 0;
+
+  op_queue_.pop();
+  bool more_handlers = (!op_queue_.empty());
+
+  std::size_t task_result = o->task_result_;
+
+  if (more_handlers && !one_thread_)
+    wake_one_thread_and_unlock(lock);
+  else
+    lock.unlock();
+
+  // Ensure the count of outstanding work is decremented on block exit.
+  work_cleanup on_exit = { this, &lock, &this_thread };
+  (void)on_exit;
+
+  // Complete the operation. May throw an exception. Deletes the object.
+  o->complete(this, ec, task_result);
+
+  return 1;
+}
+
+void scheduler::stop_all_threads(
+    mutex::scoped_lock& lock)
+{
+  stopped_ = true;
+  wakeup_event_.signal_all(lock);
+
+  if (!task_interrupted_ && task_)
+  {
+    task_interrupted_ = true;
+    task_->interrupt();
+  }
+}
+
+void scheduler::wake_one_thread_and_unlock(
+    mutex::scoped_lock& lock)
+{
+  if (!wakeup_event_.maybe_unlock_and_signal_one(lock))
+  {
+    if (!task_interrupted_ && task_)
+    {
+      task_interrupted_ = true;
+      task_->interrupt();
+    }
+    lock.unlock();
+  }
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_IMPL_SCHEDULER_IPP
diff --git a/lib/asio/detail/impl/select_reactor.hpp b/lib/asio/detail/impl/select_reactor.hpp
new file mode 100644
index 0000000..04a04d4
--- /dev/null
+++ b/lib/asio/detail/impl/select_reactor.hpp
@@ -0,0 +1,100 @@
+//
+// detail/impl/select_reactor.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_SELECT_REACTOR_HPP
+#define ASIO_DETAIL_IMPL_SELECT_REACTOR_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_IOCP) \
+  || (!defined(ASIO_HAS_DEV_POLL) \
+      && !defined(ASIO_HAS_EPOLL) \
+      && !defined(ASIO_HAS_KQUEUE) \
+      && !defined(ASIO_WINDOWS_RUNTIME))
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename Time_Traits>
+void select_reactor::add_timer_queue(timer_queue<Time_Traits>& queue)
+{
+  do_add_timer_queue(queue);
+}
+
+// Remove a timer queue from the reactor.
+template <typename Time_Traits>
+void select_reactor::remove_timer_queue(timer_queue<Time_Traits>& queue)
+{
+  do_remove_timer_queue(queue);
+}
+
+template <typename Time_Traits>
+void select_reactor::schedule_timer(timer_queue<Time_Traits>& queue,
+    const typename Time_Traits::time_type& time,
+    typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  if (shutdown_)
+  {
+    scheduler_.post_immediate_completion(op, false);
+    return;
+  }
+
+  bool earliest = queue.enqueue_timer(time, timer, op);
+  scheduler_.work_started();
+  if (earliest)
+    interrupter_.interrupt();
+}
+
+template <typename Time_Traits>
+std::size_t select_reactor::cancel_timer(timer_queue<Time_Traits>& queue,
+    typename timer_queue<Time_Traits>::per_timer_data& timer,
+    std::size_t max_cancelled)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  op_queue<operation> ops;
+  std::size_t n = queue.cancel_timer(timer, ops, max_cancelled);
+  lock.unlock();
+  scheduler_.post_deferred_completions(ops);
+  return n;
+}
+
+template <typename Time_Traits>
+void select_reactor::move_timer(timer_queue<Time_Traits>& queue,
+    typename timer_queue<Time_Traits>::per_timer_data& target,
+    typename timer_queue<Time_Traits>::per_timer_data& source)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  op_queue<operation> ops;
+  queue.cancel_timer(target, ops);
+  queue.move_timer(target, source);
+  lock.unlock();
+  scheduler_.post_deferred_completions(ops);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_IOCP)
+       //   || (!defined(ASIO_HAS_DEV_POLL)
+       //       && !defined(ASIO_HAS_EPOLL)
+       //       && !defined(ASIO_HAS_KQUEUE)
+       //       && !defined(ASIO_WINDOWS_RUNTIME))
+
+#endif // ASIO_DETAIL_IMPL_SELECT_REACTOR_HPP
diff --git a/lib/asio/detail/impl/select_reactor.ipp b/lib/asio/detail/impl/select_reactor.ipp
new file mode 100644
index 0000000..262bc69
--- /dev/null
+++ b/lib/asio/detail/impl/select_reactor.ipp
@@ -0,0 +1,333 @@
+//
+// detail/impl/select_reactor.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_SELECT_REACTOR_IPP
+#define ASIO_DETAIL_IMPL_SELECT_REACTOR_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_IOCP) \
+  || (!defined(ASIO_HAS_DEV_POLL) \
+      && !defined(ASIO_HAS_EPOLL) \
+      && !defined(ASIO_HAS_KQUEUE) \
+      && !defined(ASIO_WINDOWS_RUNTIME))
+
+#include "asio/detail/fd_set_adapter.hpp"
+#include "asio/detail/select_reactor.hpp"
+#include "asio/detail/signal_blocker.hpp"
+#include "asio/detail/socket_ops.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+#if defined(ASIO_HAS_IOCP)
+class select_reactor::thread_function
+{
+public:
+  explicit thread_function(select_reactor* r)
+    : this_(r)
+  {
+  }
+
+  void operator()()
+  {
+    this_->run_thread();
+  }
+
+private:
+  select_reactor* this_;
+};
+#endif // defined(ASIO_HAS_IOCP)
+
+select_reactor::select_reactor(asio::execution_context& ctx)
+  : execution_context_service_base<select_reactor>(ctx),
+    scheduler_(use_service<scheduler_type>(ctx)),
+    mutex_(),
+    interrupter_(),
+#if defined(ASIO_HAS_IOCP)
+    stop_thread_(false),
+    thread_(0),
+#endif // defined(ASIO_HAS_IOCP)
+    shutdown_(false)
+{
+#if defined(ASIO_HAS_IOCP)
+  asio::detail::signal_blocker sb;
+  thread_ = new asio::detail::thread(thread_function(this));
+#endif // defined(ASIO_HAS_IOCP)
+}
+
+select_reactor::~select_reactor()
+{
+  shutdown();
+}
+
+void select_reactor::shutdown()
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  shutdown_ = true;
+#if defined(ASIO_HAS_IOCP)
+  stop_thread_ = true;
+#endif // defined(ASIO_HAS_IOCP)
+  lock.unlock();
+
+#if defined(ASIO_HAS_IOCP)
+  if (thread_)
+  {
+    interrupter_.interrupt();
+    thread_->join();
+    delete thread_;
+    thread_ = 0;
+  }
+#endif // defined(ASIO_HAS_IOCP)
+
+  op_queue<operation> ops;
+
+  for (int i = 0; i < max_ops; ++i)
+    op_queue_[i].get_all_operations(ops);
+
+  timer_queues_.get_all_timers(ops);
+
+  scheduler_.abandon_operations(ops);
+}
+
+void select_reactor::notify_fork(
+    asio::execution_context::fork_event fork_ev)
+{
+  if (fork_ev == asio::execution_context::fork_child)
+    interrupter_.recreate();
+}
+
+void select_reactor::init_task()
+{
+  scheduler_.init_task();
+}
+
+int select_reactor::register_descriptor(socket_type,
+    select_reactor::per_descriptor_data&)
+{
+  return 0;
+}
+
+int select_reactor::register_internal_descriptor(
+    int op_type, socket_type descriptor,
+    select_reactor::per_descriptor_data&, reactor_op* op)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  op_queue_[op_type].enqueue_operation(descriptor, op);
+  interrupter_.interrupt();
+
+  return 0;
+}
+
+void select_reactor::move_descriptor(socket_type,
+    select_reactor::per_descriptor_data&,
+    select_reactor::per_descriptor_data&)
+{
+}
+
+void select_reactor::start_op(int op_type, socket_type descriptor,
+    select_reactor::per_descriptor_data&, reactor_op* op,
+    bool is_continuation, bool)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  if (shutdown_)
+  {
+    post_immediate_completion(op, is_continuation);
+    return;
+  }
+
+  bool first = op_queue_[op_type].enqueue_operation(descriptor, op);
+  scheduler_.work_started();
+  if (first)
+    interrupter_.interrupt();
+}
+
+void select_reactor::cancel_ops(socket_type descriptor,
+    select_reactor::per_descriptor_data&)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  cancel_ops_unlocked(descriptor, asio::error::operation_aborted);
+}
+
+void select_reactor::deregister_descriptor(socket_type descriptor,
+    select_reactor::per_descriptor_data&, bool)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  cancel_ops_unlocked(descriptor, asio::error::operation_aborted);
+}
+
+void select_reactor::deregister_internal_descriptor(
+    socket_type descriptor, select_reactor::per_descriptor_data&)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  op_queue<operation> ops;
+  for (int i = 0; i < max_ops; ++i)
+    op_queue_[i].cancel_operations(descriptor, ops);
+}
+
+void select_reactor::cleanup_descriptor_data(
+    select_reactor::per_descriptor_data&)
+{
+}
+
+void select_reactor::run(long usec, op_queue<operation>& ops)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+#if defined(ASIO_HAS_IOCP)
+  // Check if the thread is supposed to stop.
+  if (stop_thread_)
+    return;
+#endif // defined(ASIO_HAS_IOCP)
+
+  // Set up the descriptor sets.
+  for (int i = 0; i < max_select_ops; ++i)
+    fd_sets_[i].reset();
+  fd_sets_[read_op].set(interrupter_.read_descriptor());
+  socket_type max_fd = 0;
+  bool have_work_to_do = !timer_queues_.all_empty();
+  for (int i = 0; i < max_select_ops; ++i)
+  {
+    have_work_to_do = have_work_to_do || !op_queue_[i].empty();
+    fd_sets_[i].set(op_queue_[i], ops);
+    if (fd_sets_[i].max_descriptor() > max_fd)
+      max_fd = fd_sets_[i].max_descriptor();
+  }
+
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  // Connection operations on Windows use both except and write fd_sets.
+  have_work_to_do = have_work_to_do || !op_queue_[connect_op].empty();
+  fd_sets_[write_op].set(op_queue_[connect_op], ops);
+  if (fd_sets_[write_op].max_descriptor() > max_fd)
+    max_fd = fd_sets_[write_op].max_descriptor();
+  fd_sets_[except_op].set(op_queue_[connect_op], ops);
+  if (fd_sets_[except_op].max_descriptor() > max_fd)
+    max_fd = fd_sets_[except_op].max_descriptor();
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+
+  // We can return immediately if there's no work to do and the reactor is
+  // not supposed to block.
+  if (!usec && !have_work_to_do)
+    return;
+
+  // Determine how long to block while waiting for events.
+  timeval tv_buf = { 0, 0 };
+  timeval* tv = usec ? get_timeout(usec, tv_buf) : &tv_buf;
+
+  lock.unlock();
+
+  // Block on the select call until descriptors become ready.
+  asio::error_code ec;
+  int retval = socket_ops::select(static_cast<int>(max_fd + 1),
+      fd_sets_[read_op], fd_sets_[write_op], fd_sets_[except_op], tv, ec);
+
+  // Reset the interrupter.
+  if (retval > 0 && fd_sets_[read_op].is_set(interrupter_.read_descriptor()))
+  {
+    interrupter_.reset();
+    --retval;
+  }
+
+  lock.lock();
+
+  // Dispatch all ready operations.
+  if (retval > 0)
+  {
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+    // Connection operations on Windows use both except and write fd_sets.
+    fd_sets_[except_op].perform(op_queue_[connect_op], ops);
+    fd_sets_[write_op].perform(op_queue_[connect_op], ops);
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+
+    // Exception operations must be processed first to ensure that any
+    // out-of-band data is read before normal data.
+    for (int i = max_select_ops - 1; i >= 0; --i)
+      fd_sets_[i].perform(op_queue_[i], ops);
+  }
+  timer_queues_.get_ready_timers(ops);
+}
+
+void select_reactor::interrupt()
+{
+  interrupter_.interrupt();
+}
+
+#if defined(ASIO_HAS_IOCP)
+void select_reactor::run_thread()
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  while (!stop_thread_)
+  {
+    lock.unlock();
+    op_queue<operation> ops;
+    run(true, ops);
+    scheduler_.post_deferred_completions(ops);
+    lock.lock();
+  }
+}
+#endif // defined(ASIO_HAS_IOCP)
+
+void select_reactor::do_add_timer_queue(timer_queue_base& queue)
+{
+  mutex::scoped_lock lock(mutex_);
+  timer_queues_.insert(&queue);
+}
+
+void select_reactor::do_remove_timer_queue(timer_queue_base& queue)
+{
+  mutex::scoped_lock lock(mutex_);
+  timer_queues_.erase(&queue);
+}
+
+timeval* select_reactor::get_timeout(long usec, timeval& tv)
+{
+  // By default we will wait no longer than 5 minutes. This will ensure that
+  // any changes to the system clock are detected after no longer than this.
+  const long max_usec = 5 * 60 * 1000 * 1000;
+  usec = timer_queues_.wait_duration_usec(
+      (usec < 0 || max_usec < usec) ? max_usec : usec);
+  tv.tv_sec = usec / 1000000;
+  tv.tv_usec = usec % 1000000;
+  return &tv;
+}
+
+void select_reactor::cancel_ops_unlocked(socket_type descriptor,
+    const asio::error_code& ec)
+{
+  bool need_interrupt = false;
+  op_queue<operation> ops;
+  for (int i = 0; i < max_ops; ++i)
+    need_interrupt = op_queue_[i].cancel_operations(
+        descriptor, ops, ec) || need_interrupt;
+  scheduler_.post_deferred_completions(ops);
+  if (need_interrupt)
+    interrupter_.interrupt();
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_IOCP)
+       //   || (!defined(ASIO_HAS_DEV_POLL)
+       //       && !defined(ASIO_HAS_EPOLL)
+       //       && !defined(ASIO_HAS_KQUEUE))
+       //       && !defined(ASIO_WINDOWS_RUNTIME))
+
+#endif // ASIO_DETAIL_IMPL_SELECT_REACTOR_IPP
diff --git a/lib/asio/detail/impl/service_registry.hpp b/lib/asio/detail/impl/service_registry.hpp
new file mode 100644
index 0000000..d4db589
--- /dev/null
+++ b/lib/asio/detail/impl/service_registry.hpp
@@ -0,0 +1,94 @@
+//
+// detail/impl/service_registry.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_SERVICE_REGISTRY_HPP
+#define ASIO_DETAIL_IMPL_SERVICE_REGISTRY_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename Service>
+Service& service_registry::use_service()
+{
+  execution_context::service::key key;
+  init_key<Service>(key, 0);
+  factory_type factory = &service_registry::create<Service, execution_context>;
+  return *static_cast<Service*>(do_use_service(key, factory, &owner_));
+}
+
+template <typename Service>
+Service& service_registry::use_service(io_context& owner)
+{
+  execution_context::service::key key;
+  init_key<Service>(key, 0);
+  factory_type factory = &service_registry::create<Service, io_context>;
+  return *static_cast<Service*>(do_use_service(key, factory, &owner));
+}
+
+template <typename Service>
+void service_registry::add_service(Service* new_service)
+{
+  execution_context::service::key key;
+  init_key<Service>(key, 0);
+  return do_add_service(key, new_service);
+}
+
+template <typename Service>
+bool service_registry::has_service() const
+{
+  execution_context::service::key key;
+  init_key<Service>(key, 0);
+  return do_has_service(key);
+}
+
+template <typename Service>
+inline void service_registry::init_key(
+    execution_context::service::key& key, ...)
+{
+  init_key_from_id(key, Service::id);
+}
+
+#if !defined(ASIO_NO_TYPEID)
+template <typename Service>
+void service_registry::init_key(execution_context::service::key& key,
+    typename enable_if<
+      is_base_of<typename Service::key_type, Service>::value>::type*)
+{
+  key.type_info_ = &typeid(typeid_wrapper<Service>);
+  key.id_ = 0;
+}
+
+template <typename Service>
+void service_registry::init_key_from_id(execution_context::service::key& key,
+    const service_id<Service>& /*id*/)
+{
+  key.type_info_ = &typeid(typeid_wrapper<Service>);
+  key.id_ = 0;
+}
+#endif // !defined(ASIO_NO_TYPEID)
+
+template <typename Service, typename Owner>
+execution_context::service* service_registry::create(void* owner)
+{
+  return new Service(*static_cast<Owner*>(owner));
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_IMPL_SERVICE_REGISTRY_HPP
diff --git a/lib/asio/detail/impl/service_registry.ipp b/lib/asio/detail/impl/service_registry.ipp
new file mode 100644
index 0000000..a465033
--- /dev/null
+++ b/lib/asio/detail/impl/service_registry.ipp
@@ -0,0 +1,197 @@
+//
+// detail/impl/service_registry.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_SERVICE_REGISTRY_IPP
+#define ASIO_DETAIL_IMPL_SERVICE_REGISTRY_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include <vector>
+#include "asio/detail/service_registry.hpp"
+#include "asio/detail/throw_exception.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+service_registry::service_registry(execution_context& owner)
+  : owner_(owner),
+    first_service_(0)
+{
+}
+
+service_registry::~service_registry()
+{
+}
+
+void service_registry::shutdown_services()
+{
+  execution_context::service* service = first_service_;
+  while (service)
+  {
+    service->shutdown();
+    service = service->next_;
+  }
+}
+
+void service_registry::destroy_services()
+{
+  while (first_service_)
+  {
+    execution_context::service* next_service = first_service_->next_;
+    destroy(first_service_);
+    first_service_ = next_service;
+  }
+}
+
+void service_registry::notify_fork(execution_context::fork_event fork_ev)
+{
+  // Make a copy of all of the services while holding the lock. We don't want
+  // to hold the lock while calling into each service, as it may try to call
+  // back into this class.
+  std::vector<execution_context::service*> services;
+  {
+    asio::detail::mutex::scoped_lock lock(mutex_);
+    execution_context::service* service = first_service_;
+    while (service)
+    {
+      services.push_back(service);
+      service = service->next_;
+    }
+  }
+
+  // If processing the fork_prepare event, we want to go in reverse order of
+  // service registration, which happens to be the existing order of the
+  // services in the vector. For the other events we want to go in the other
+  // direction.
+  std::size_t num_services = services.size();
+  if (fork_ev == execution_context::fork_prepare)
+    for (std::size_t i = 0; i < num_services; ++i)
+      services[i]->notify_fork(fork_ev);
+  else
+    for (std::size_t i = num_services; i > 0; --i)
+      services[i - 1]->notify_fork(fork_ev);
+}
+
+void service_registry::init_key_from_id(execution_context::service::key& key,
+    const execution_context::id& id)
+{
+  key.type_info_ = 0;
+  key.id_ = &id;
+}
+
+bool service_registry::keys_match(
+    const execution_context::service::key& key1,
+    const execution_context::service::key& key2)
+{
+  if (key1.id_ && key2.id_)
+    if (key1.id_ == key2.id_)
+      return true;
+  if (key1.type_info_ && key2.type_info_)
+    if (*key1.type_info_ == *key2.type_info_)
+      return true;
+  return false;
+}
+
+void service_registry::destroy(execution_context::service* service)
+{
+  delete service;
+}
+
+execution_context::service* service_registry::do_use_service(
+    const execution_context::service::key& key,
+    factory_type factory, void* owner)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  // First see if there is an existing service object with the given key.
+  execution_context::service* service = first_service_;
+  while (service)
+  {
+    if (keys_match(service->key_, key))
+      return service;
+    service = service->next_;
+  }
+
+  // Create a new service object. The service registry's mutex is not locked
+  // at this time to allow for nested calls into this function from the new
+  // service's constructor.
+  lock.unlock();
+  auto_service_ptr new_service = { factory(owner) };
+  new_service.ptr_->key_ = key;
+  lock.lock();
+
+  // Check that nobody else created another service object of the same type
+  // while the lock was released.
+  service = first_service_;
+  while (service)
+  {
+    if (keys_match(service->key_, key))
+      return service;
+    service = service->next_;
+  }
+
+  // Service was successfully initialised, pass ownership to registry.
+  new_service.ptr_->next_ = first_service_;
+  first_service_ = new_service.ptr_;
+  new_service.ptr_ = 0;
+  return first_service_;
+}
+
+void service_registry::do_add_service(
+    const execution_context::service::key& key,
+    execution_context::service* new_service)
+{
+  if (&owner_ != &new_service->context())
+    asio::detail::throw_exception(invalid_service_owner());
+
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  // Check if there is an existing service object with the given key.
+  execution_context::service* service = first_service_;
+  while (service)
+  {
+    if (keys_match(service->key_, key))
+      asio::detail::throw_exception(service_already_exists());
+    service = service->next_;
+  }
+
+  // Take ownership of the service object.
+  new_service->key_ = key;
+  new_service->next_ = first_service_;
+  first_service_ = new_service;
+}
+
+bool service_registry::do_has_service(
+    const execution_context::service::key& key) const
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  execution_context::service* service = first_service_;
+  while (service)
+  {
+    if (keys_match(service->key_, key))
+      return true;
+    service = service->next_;
+  }
+
+  return false;
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_IMPL_SERVICE_REGISTRY_IPP
diff --git a/lib/asio/detail/impl/signal_set_service.ipp b/lib/asio/detail/impl/signal_set_service.ipp
new file mode 100644
index 0000000..dd68fc1
--- /dev/null
+++ b/lib/asio/detail/impl/signal_set_service.ipp
@@ -0,0 +1,669 @@
+//
+// detail/impl/signal_set_service.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_SIGNAL_SET_SERVICE_IPP
+#define ASIO_DETAIL_IMPL_SIGNAL_SET_SERVICE_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#include <cstring>
+#include <stdexcept>
+#include "asio/detail/reactor.hpp"
+#include "asio/detail/signal_blocker.hpp"
+#include "asio/detail/signal_set_service.hpp"
+#include "asio/detail/static_mutex.hpp"
+#include "asio/detail/throw_exception.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+struct signal_state
+{
+  // Mutex used for protecting global state.
+  static_mutex mutex_;
+
+  // The read end of the pipe used for signal notifications.
+  int read_descriptor_;
+
+  // The write end of the pipe used for signal notifications.
+  int write_descriptor_;
+
+  // Whether the signal state has been prepared for a fork.
+  bool fork_prepared_;
+
+  // The head of a linked list of all signal_set_service instances.
+  class signal_set_service* service_list_;
+
+  // A count of the number of objects that are registered for each signal.
+  std::size_t registration_count_[max_signal_number];
+};
+
+signal_state* get_signal_state()
+{
+  static signal_state state = {
+    ASIO_STATIC_MUTEX_INIT, -1, -1, false, 0, { 0 } };
+  return &state;
+}
+
+void asio_signal_handler(int signal_number)
+{
+#if defined(ASIO_WINDOWS) \
+  || defined(ASIO_WINDOWS_RUNTIME) \
+  || defined(__CYGWIN__)
+  signal_set_service::deliver_signal(signal_number);
+#else // defined(ASIO_WINDOWS)
+      //   || defined(ASIO_WINDOWS_RUNTIME)
+      //   || defined(__CYGWIN__)
+  int saved_errno = errno;
+  signal_state* state = get_signal_state();
+  signed_size_type result = ::write(state->write_descriptor_,
+      &signal_number, sizeof(signal_number));
+  (void)result;
+  errno = saved_errno;
+#endif // defined(ASIO_WINDOWS)
+       //   || defined(ASIO_WINDOWS_RUNTIME)
+       //   || defined(__CYGWIN__)
+
+#if defined(ASIO_HAS_SIGNAL) && !defined(ASIO_HAS_SIGACTION)
+  ::signal(signal_number, asio_signal_handler);
+#endif // defined(ASIO_HAS_SIGNAL) && !defined(ASIO_HAS_SIGACTION)
+}
+
+#if !defined(ASIO_WINDOWS) \
+  && !defined(ASIO_WINDOWS_RUNTIME) \
+  && !defined(__CYGWIN__)
+class signal_set_service::pipe_read_op : public reactor_op
+{
+public:
+  pipe_read_op()
+    : reactor_op(&pipe_read_op::do_perform, pipe_read_op::do_complete)
+  {
+  }
+
+  static status do_perform(reactor_op*)
+  {
+    signal_state* state = get_signal_state();
+
+    int fd = state->read_descriptor_;
+    int signal_number = 0;
+    while (::read(fd, &signal_number, sizeof(int)) == sizeof(int))
+      if (signal_number >= 0 && signal_number < max_signal_number)
+        signal_set_service::deliver_signal(signal_number);
+
+    return not_done;
+  }
+
+  static void do_complete(void* /*owner*/, operation* base,
+      const asio::error_code& /*ec*/,
+      std::size_t /*bytes_transferred*/)
+  {
+    pipe_read_op* o(static_cast<pipe_read_op*>(base));
+    delete o;
+  }
+};
+#endif // !defined(ASIO_WINDOWS)
+       //   && !defined(ASIO_WINDOWS_RUNTIME)
+       //   && !defined(__CYGWIN__)
+
+signal_set_service::signal_set_service(
+    asio::io_context& io_context)
+  : service_base<signal_set_service>(io_context),
+    io_context_(asio::use_service<io_context_impl>(io_context)),
+#if !defined(ASIO_WINDOWS) \
+  && !defined(ASIO_WINDOWS_RUNTIME) \
+  && !defined(__CYGWIN__)
+    reactor_(asio::use_service<reactor>(io_context)),
+#endif // !defined(ASIO_WINDOWS)
+       //   && !defined(ASIO_WINDOWS_RUNTIME)
+       //   && !defined(__CYGWIN__)
+    next_(0),
+    prev_(0)
+{
+  get_signal_state()->mutex_.init();
+
+#if !defined(ASIO_WINDOWS) \
+  && !defined(ASIO_WINDOWS_RUNTIME) \
+  && !defined(__CYGWIN__)
+  reactor_.init_task();
+#endif // !defined(ASIO_WINDOWS)
+       //   && !defined(ASIO_WINDOWS_RUNTIME)
+       //   && !defined(__CYGWIN__)
+
+  for (int i = 0; i < max_signal_number; ++i)
+    registrations_[i] = 0;
+
+  add_service(this);
+}
+
+signal_set_service::~signal_set_service()
+{
+  remove_service(this);
+}
+
+void signal_set_service::shutdown()
+{
+  remove_service(this);
+
+  op_queue<operation> ops;
+
+  for (int i = 0; i < max_signal_number; ++i)
+  {
+    registration* reg = registrations_[i];
+    while (reg)
+    {
+      ops.push(*reg->queue_);
+      reg = reg->next_in_table_;
+    }
+  }
+
+  io_context_.abandon_operations(ops);
+}
+
+void signal_set_service::notify_fork(
+    asio::io_context::fork_event fork_ev)
+{
+#if !defined(ASIO_WINDOWS) \
+  && !defined(ASIO_WINDOWS_RUNTIME) \
+  && !defined(__CYGWIN__)
+  signal_state* state = get_signal_state();
+  static_mutex::scoped_lock lock(state->mutex_);
+
+  switch (fork_ev)
+  {
+  case asio::io_context::fork_prepare:
+    {
+      int read_descriptor = state->read_descriptor_;
+      state->fork_prepared_ = true;
+      lock.unlock();
+      reactor_.deregister_internal_descriptor(read_descriptor, reactor_data_);
+      reactor_.cleanup_descriptor_data(reactor_data_);
+    }
+    break;
+  case asio::io_context::fork_parent:
+    if (state->fork_prepared_)
+    {
+      int read_descriptor = state->read_descriptor_;
+      state->fork_prepared_ = false;
+      lock.unlock();
+      reactor_.register_internal_descriptor(reactor::read_op,
+          read_descriptor, reactor_data_, new pipe_read_op);
+    }
+    break;
+  case asio::io_context::fork_child:
+    if (state->fork_prepared_)
+    {
+      asio::detail::signal_blocker blocker;
+      close_descriptors();
+      open_descriptors();
+      int read_descriptor = state->read_descriptor_;
+      state->fork_prepared_ = false;
+      lock.unlock();
+      reactor_.register_internal_descriptor(reactor::read_op,
+          read_descriptor, reactor_data_, new pipe_read_op);
+    }
+    break;
+  default:
+    break;
+  }
+#else // !defined(ASIO_WINDOWS)
+      //   && !defined(ASIO_WINDOWS_RUNTIME)
+      //   && !defined(__CYGWIN__)
+  (void)fork_ev;
+#endif // !defined(ASIO_WINDOWS)
+       //   && !defined(ASIO_WINDOWS_RUNTIME)
+       //   && !defined(__CYGWIN__)
+}
+
+void signal_set_service::construct(
+    signal_set_service::implementation_type& impl)
+{
+  impl.signals_ = 0;
+}
+
+void signal_set_service::destroy(
+    signal_set_service::implementation_type& impl)
+{
+  asio::error_code ignored_ec;
+  clear(impl, ignored_ec);
+  cancel(impl, ignored_ec);
+}
+
+asio::error_code signal_set_service::add(
+    signal_set_service::implementation_type& impl,
+    int signal_number, asio::error_code& ec)
+{
+  // Check that the signal number is valid.
+  if (signal_number < 0 || signal_number >= max_signal_number)
+  {
+    ec = asio::error::invalid_argument;
+    return ec;
+  }
+
+  signal_state* state = get_signal_state();
+  static_mutex::scoped_lock lock(state->mutex_);
+
+  // Find the appropriate place to insert the registration.
+  registration** insertion_point = &impl.signals_;
+  registration* next = impl.signals_;
+  while (next && next->signal_number_ < signal_number)
+  {
+    insertion_point = &next->next_in_set_;
+    next = next->next_in_set_;
+  }
+
+  // Only do something if the signal is not already registered.
+  if (next == 0 || next->signal_number_ != signal_number)
+  {
+    registration* new_registration = new registration;
+
+#if defined(ASIO_HAS_SIGNAL) || defined(ASIO_HAS_SIGACTION)
+    // Register for the signal if we're the first.
+    if (state->registration_count_[signal_number] == 0)
+    {
+# if defined(ASIO_HAS_SIGACTION)
+      using namespace std; // For memset.
+      struct sigaction sa;
+      memset(&sa, 0, sizeof(sa));
+      sa.sa_handler = asio_signal_handler;
+      sigfillset(&sa.sa_mask);
+      if (::sigaction(signal_number, &sa, 0) == -1)
+# else // defined(ASIO_HAS_SIGACTION)
+      if (::signal(signal_number, asio_signal_handler) == SIG_ERR)
+# endif // defined(ASIO_HAS_SIGACTION)
+      {
+# if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+        ec = asio::error::invalid_argument;
+# else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+        ec = asio::error_code(errno,
+            asio::error::get_system_category());
+# endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+        delete new_registration;
+        return ec;
+      }
+    }
+#endif // defined(ASIO_HAS_SIGNAL) || defined(ASIO_HAS_SIGACTION)
+
+    // Record the new registration in the set.
+    new_registration->signal_number_ = signal_number;
+    new_registration->queue_ = &impl.queue_;
+    new_registration->next_in_set_ = next;
+    *insertion_point = new_registration;
+
+    // Insert registration into the registration table.
+    new_registration->next_in_table_ = registrations_[signal_number];
+    if (registrations_[signal_number])
+      registrations_[signal_number]->prev_in_table_ = new_registration;
+    registrations_[signal_number] = new_registration;
+
+    ++state->registration_count_[signal_number];
+  }
+
+  ec = asio::error_code();
+  return ec;
+}
+
+asio::error_code signal_set_service::remove(
+    signal_set_service::implementation_type& impl,
+    int signal_number, asio::error_code& ec)
+{
+  // Check that the signal number is valid.
+  if (signal_number < 0 || signal_number >= max_signal_number)
+  {
+    ec = asio::error::invalid_argument;
+    return ec;
+  }
+
+  signal_state* state = get_signal_state();
+  static_mutex::scoped_lock lock(state->mutex_);
+
+  // Find the signal number in the list of registrations.
+  registration** deletion_point = &impl.signals_;
+  registration* reg = impl.signals_;
+  while (reg && reg->signal_number_ < signal_number)
+  {
+    deletion_point = &reg->next_in_set_;
+    reg = reg->next_in_set_;
+  }
+
+  if (reg != 0 && reg->signal_number_ == signal_number)
+  {
+#if defined(ASIO_HAS_SIGNAL) || defined(ASIO_HAS_SIGACTION)
+    // Set signal handler back to the default if we're the last.
+    if (state->registration_count_[signal_number] == 1)
+    {
+# if defined(ASIO_HAS_SIGACTION)
+      using namespace std; // For memset.
+      struct sigaction sa;
+      memset(&sa, 0, sizeof(sa));
+      sa.sa_handler = SIG_DFL;
+      if (::sigaction(signal_number, &sa, 0) == -1)
+# else // defined(ASIO_HAS_SIGACTION)
+      if (::signal(signal_number, SIG_DFL) == SIG_ERR)
+# endif // defined(ASIO_HAS_SIGACTION)
+      {
+# if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+        ec = asio::error::invalid_argument;
+# else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+        ec = asio::error_code(errno,
+            asio::error::get_system_category());
+# endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+        return ec;
+      }
+    }
+#endif // defined(ASIO_HAS_SIGNAL) || defined(ASIO_HAS_SIGACTION)
+
+    // Remove the registration from the set.
+    *deletion_point = reg->next_in_set_;
+
+    // Remove the registration from the registration table.
+    if (registrations_[signal_number] == reg)
+      registrations_[signal_number] = reg->next_in_table_;
+    if (reg->prev_in_table_)
+      reg->prev_in_table_->next_in_table_ = reg->next_in_table_;
+    if (reg->next_in_table_)
+      reg->next_in_table_->prev_in_table_ = reg->prev_in_table_;
+
+    --state->registration_count_[signal_number];
+
+    delete reg;
+  }
+
+  ec = asio::error_code();
+  return ec;
+}
+
+asio::error_code signal_set_service::clear(
+    signal_set_service::implementation_type& impl,
+    asio::error_code& ec)
+{
+  signal_state* state = get_signal_state();
+  static_mutex::scoped_lock lock(state->mutex_);
+
+  while (registration* reg = impl.signals_)
+  {
+#if defined(ASIO_HAS_SIGNAL) || defined(ASIO_HAS_SIGACTION)
+    // Set signal handler back to the default if we're the last.
+    if (state->registration_count_[reg->signal_number_] == 1)
+    {
+# if defined(ASIO_HAS_SIGACTION)
+      using namespace std; // For memset.
+      struct sigaction sa;
+      memset(&sa, 0, sizeof(sa));
+      sa.sa_handler = SIG_DFL;
+      if (::sigaction(reg->signal_number_, &sa, 0) == -1)
+# else // defined(ASIO_HAS_SIGACTION)
+      if (::signal(reg->signal_number_, SIG_DFL) == SIG_ERR)
+# endif // defined(ASIO_HAS_SIGACTION)
+      {
+# if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+        ec = asio::error::invalid_argument;
+# else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+        ec = asio::error_code(errno,
+            asio::error::get_system_category());
+# endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+        return ec;
+      }
+    }
+#endif // defined(ASIO_HAS_SIGNAL) || defined(ASIO_HAS_SIGACTION)
+
+    // Remove the registration from the registration table.
+    if (registrations_[reg->signal_number_] == reg)
+      registrations_[reg->signal_number_] = reg->next_in_table_;
+    if (reg->prev_in_table_)
+      reg->prev_in_table_->next_in_table_ = reg->next_in_table_;
+    if (reg->next_in_table_)
+      reg->next_in_table_->prev_in_table_ = reg->prev_in_table_;
+
+    --state->registration_count_[reg->signal_number_];
+
+    impl.signals_ = reg->next_in_set_;
+    delete reg;
+  }
+
+  ec = asio::error_code();
+  return ec;
+}
+
+asio::error_code signal_set_service::cancel(
+    signal_set_service::implementation_type& impl,
+    asio::error_code& ec)
+{
+  ASIO_HANDLER_OPERATION((io_context_.context(),
+        "signal_set", &impl, 0, "cancel"));
+
+  op_queue<operation> ops;
+  {
+    signal_state* state = get_signal_state();
+    static_mutex::scoped_lock lock(state->mutex_);
+
+    while (signal_op* op = impl.queue_.front())
+    {
+      op->ec_ = asio::error::operation_aborted;
+      impl.queue_.pop();
+      ops.push(op);
+    }
+  }
+
+  io_context_.post_deferred_completions(ops);
+
+  ec = asio::error_code();
+  return ec;
+}
+
+void signal_set_service::deliver_signal(int signal_number)
+{
+  signal_state* state = get_signal_state();
+  static_mutex::scoped_lock lock(state->mutex_);
+
+  signal_set_service* service = state->service_list_;
+  while (service)
+  {
+    op_queue<operation> ops;
+
+    registration* reg = service->registrations_[signal_number];
+    while (reg)
+    {
+      if (reg->queue_->empty())
+      {
+        ++reg->undelivered_;
+      }
+      else
+      {
+        while (signal_op* op = reg->queue_->front())
+        {
+          op->signal_number_ = signal_number;
+          reg->queue_->pop();
+          ops.push(op);
+        }
+      }
+
+      reg = reg->next_in_table_;
+    }
+
+    service->io_context_.post_deferred_completions(ops);
+
+    service = service->next_;
+  }
+}
+
+void signal_set_service::add_service(signal_set_service* service)
+{
+  signal_state* state = get_signal_state();
+  static_mutex::scoped_lock lock(state->mutex_);
+
+#if !defined(ASIO_WINDOWS) && !defined(__CYGWIN__)
+  // If this is the first service to be created, open a new pipe.
+  if (state->service_list_ == 0)
+    open_descriptors();
+#endif // !defined(ASIO_WINDOWS) && !defined(__CYGWIN__)
+
+  // If an io_context object is thread-unsafe then it must be the only
+  // io_context used to create signal_set objects.
+  if (state->service_list_ != 0)
+  {
+    if (!ASIO_CONCURRENCY_HINT_IS_LOCKING(SCHEDULER,
+          service->io_context_.concurrency_hint())
+        || !ASIO_CONCURRENCY_HINT_IS_LOCKING(SCHEDULER,
+          state->service_list_->io_context_.concurrency_hint()))
+    {
+      std::logic_error ex(
+          "Thread-unsafe io_context objects require "
+          "exclusive access to signal handling.");
+      asio::detail::throw_exception(ex);
+    }
+  }
+
+  // Insert service into linked list of all services.
+  service->next_ = state->service_list_;
+  service->prev_ = 0;
+  if (state->service_list_)
+    state->service_list_->prev_ = service;
+  state->service_list_ = service;
+
+#if !defined(ASIO_WINDOWS) \
+  && !defined(ASIO_WINDOWS_RUNTIME) \
+  && !defined(__CYGWIN__)
+  // Register for pipe readiness notifications.
+  int read_descriptor = state->read_descriptor_;
+  lock.unlock();
+  service->reactor_.register_internal_descriptor(reactor::read_op,
+      read_descriptor, service->reactor_data_, new pipe_read_op);
+#endif // !defined(ASIO_WINDOWS)
+       //   && !defined(ASIO_WINDOWS_RUNTIME)
+       //   && !defined(__CYGWIN__)
+}
+
+void signal_set_service::remove_service(signal_set_service* service)
+{
+  signal_state* state = get_signal_state();
+  static_mutex::scoped_lock lock(state->mutex_);
+
+  if (service->next_ || service->prev_ || state->service_list_ == service)
+  {
+#if !defined(ASIO_WINDOWS) \
+  && !defined(ASIO_WINDOWS_RUNTIME) \
+  && !defined(__CYGWIN__)
+    // Disable the pipe readiness notifications.
+    int read_descriptor = state->read_descriptor_;
+    lock.unlock();
+    service->reactor_.deregister_internal_descriptor(
+        read_descriptor, service->reactor_data_);
+    service->reactor_.cleanup_descriptor_data(service->reactor_data_);
+    lock.lock();
+#endif // !defined(ASIO_WINDOWS)
+       //   && !defined(ASIO_WINDOWS_RUNTIME)
+       //   && !defined(__CYGWIN__)
+
+    // Remove service from linked list of all services.
+    if (state->service_list_ == service)
+      state->service_list_ = service->next_;
+    if (service->prev_)
+      service->prev_->next_ = service->next_;
+    if (service->next_)
+      service->next_->prev_= service->prev_;
+    service->next_ = 0;
+    service->prev_ = 0;
+
+#if !defined(ASIO_WINDOWS) && !defined(__CYGWIN__)
+    // If this is the last service to be removed, close the pipe.
+    if (state->service_list_ == 0)
+      close_descriptors();
+#endif // !defined(ASIO_WINDOWS) && !defined(__CYGWIN__)
+  }
+}
+
+void signal_set_service::open_descriptors()
+{
+#if !defined(ASIO_WINDOWS) \
+  && !defined(ASIO_WINDOWS_RUNTIME) \
+  && !defined(__CYGWIN__)
+  signal_state* state = get_signal_state();
+
+  int pipe_fds[2];
+  if (::pipe(pipe_fds) == 0)
+  {
+    state->read_descriptor_ = pipe_fds[0];
+    ::fcntl(state->read_descriptor_, F_SETFL, O_NONBLOCK);
+
+    state->write_descriptor_ = pipe_fds[1];
+    ::fcntl(state->write_descriptor_, F_SETFL, O_NONBLOCK);
+
+#if defined(FD_CLOEXEC)
+    ::fcntl(state->read_descriptor_, F_SETFD, FD_CLOEXEC);
+    ::fcntl(state->write_descriptor_, F_SETFD, FD_CLOEXEC);
+#endif // defined(FD_CLOEXEC)
+  }
+  else
+  {
+    asio::error_code ec(errno,
+        asio::error::get_system_category());
+    asio::detail::throw_error(ec, "signal_set_service pipe");
+  }
+#endif // !defined(ASIO_WINDOWS)
+       //   && !defined(ASIO_WINDOWS_RUNTIME)
+       //   && !defined(__CYGWIN__)
+}
+
+void signal_set_service::close_descriptors()
+{
+#if !defined(ASIO_WINDOWS) \
+  && !defined(ASIO_WINDOWS_RUNTIME) \
+  && !defined(__CYGWIN__)
+  signal_state* state = get_signal_state();
+
+  if (state->read_descriptor_ != -1)
+    ::close(state->read_descriptor_);
+  state->read_descriptor_ = -1;
+
+  if (state->write_descriptor_ != -1)
+    ::close(state->write_descriptor_);
+  state->write_descriptor_ = -1;
+#endif // !defined(ASIO_WINDOWS)
+       //   && !defined(ASIO_WINDOWS_RUNTIME)
+       //   && !defined(__CYGWIN__)
+}
+
+void signal_set_service::start_wait_op(
+    signal_set_service::implementation_type& impl, signal_op* op)
+{
+  io_context_.work_started();
+
+  signal_state* state = get_signal_state();
+  static_mutex::scoped_lock lock(state->mutex_);
+
+  registration* reg = impl.signals_;
+  while (reg)
+  {
+    if (reg->undelivered_ > 0)
+    {
+      --reg->undelivered_;
+      op->signal_number_ = reg->signal_number_;
+      io_context_.post_deferred_completion(op);
+      return;
+    }
+
+    reg = reg->next_in_set_;
+  }
+
+  impl.queue_.push(op);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_IMPL_SIGNAL_SET_SERVICE_IPP
diff --git a/lib/asio/detail/impl/socket_ops.ipp b/lib/asio/detail/impl/socket_ops.ipp
new file mode 100644
index 0000000..5e74733
--- /dev/null
+++ b/lib/asio/detail/impl/socket_ops.ipp
@@ -0,0 +1,3571 @@
+//
+// detail/impl/socket_ops.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_SOCKET_OPS_IPP
+#define ASIO_DETAIL_SOCKET_OPS_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#include <cctype>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <cerrno>
+#include <new>
+#include "asio/detail/assert.hpp"
+#include "asio/detail/socket_ops.hpp"
+#include "asio/error.hpp"
+
+#if defined(ASIO_WINDOWS_RUNTIME)
+# include <codecvt>
+# include <locale>
+# include <string>
+#endif // defined(ASIO_WINDOWS_RUNTIME)
+
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__) \
+  || defined(__MACH__) && defined(__APPLE__)
+# if defined(ASIO_HAS_PTHREADS)
+#  include <pthread.h>
+# endif // defined(ASIO_HAS_PTHREADS)
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+       // || defined(__MACH__) && defined(__APPLE__)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+namespace socket_ops {
+
+#if !defined(ASIO_WINDOWS_RUNTIME)
+
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+struct msghdr { int msg_namelen; };
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+
+#if defined(__hpux)
+// HP-UX doesn't declare these functions extern "C", so they are declared again
+// here to avoid linker errors about undefined symbols.
+extern "C" char* if_indextoname(unsigned int, char*);
+extern "C" unsigned int if_nametoindex(const char*);
+#endif // defined(__hpux)
+
+#endif // !defined(ASIO_WINDOWS_RUNTIME)
+
+inline void clear_last_error()
+{
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  WSASetLastError(0);
+#else
+  errno = 0;
+#endif
+}
+
+#if !defined(ASIO_WINDOWS_RUNTIME)
+
+template <typename ReturnType>
+inline ReturnType error_wrapper(ReturnType return_value,
+    asio::error_code& ec)
+{
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  ec = asio::error_code(WSAGetLastError(),
+      asio::error::get_system_category());
+#else
+  ec = asio::error_code(errno,
+      asio::error::get_system_category());
+#endif
+  return return_value;
+}
+
+template <typename SockLenType>
+inline socket_type call_accept(SockLenType msghdr::*,
+    socket_type s, socket_addr_type* addr, std::size_t* addrlen)
+{
+  SockLenType tmp_addrlen = addrlen ? (SockLenType)*addrlen : 0;
+  socket_type result = ::accept(s, addr, addrlen ? &tmp_addrlen : 0);
+  if (addrlen)
+    *addrlen = (std::size_t)tmp_addrlen;
+  return result;
+}
+
+socket_type accept(socket_type s, socket_addr_type* addr,
+    std::size_t* addrlen, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return invalid_socket;
+  }
+
+  clear_last_error();
+
+  socket_type new_s = error_wrapper(call_accept(
+        &msghdr::msg_namelen, s, addr, addrlen), ec);
+  if (new_s == invalid_socket)
+    return new_s;
+
+#if defined(__MACH__) && defined(__APPLE__) || defined(__FreeBSD__)
+  int optval = 1;
+  int result = error_wrapper(::setsockopt(new_s,
+        SOL_SOCKET, SO_NOSIGPIPE, &optval, sizeof(optval)), ec);
+  if (result != 0)
+  {
+    ::close(new_s);
+    return invalid_socket;
+  }
+#endif
+
+  ec = asio::error_code();
+  return new_s;
+}
+
+socket_type sync_accept(socket_type s, state_type state,
+    socket_addr_type* addr, std::size_t* addrlen, asio::error_code& ec)
+{
+  // Accept a socket.
+  for (;;)
+  {
+    // Try to complete the operation without blocking.
+    socket_type new_socket = socket_ops::accept(s, addr, addrlen, ec);
+
+    // Check if operation succeeded.
+    if (new_socket != invalid_socket)
+      return new_socket;
+
+    // Operation failed.
+    if (ec == asio::error::would_block
+        || ec == asio::error::try_again)
+    {
+      if (state & user_set_non_blocking)
+        return invalid_socket;
+      // Fall through to retry operation.
+    }
+    else if (ec == asio::error::connection_aborted)
+    {
+      if (state & enable_connection_aborted)
+        return invalid_socket;
+      // Fall through to retry operation.
+    }
+#if defined(EPROTO)
+    else if (ec.value() == EPROTO)
+    {
+      if (state & enable_connection_aborted)
+        return invalid_socket;
+      // Fall through to retry operation.
+    }
+#endif // defined(EPROTO)
+    else
+      return invalid_socket;
+
+    // Wait for socket to become ready.
+    if (socket_ops::poll_read(s, 0, -1, ec) < 0)
+      return invalid_socket;
+  }
+}
+
+#if defined(ASIO_HAS_IOCP)
+
+void complete_iocp_accept(socket_type s,
+    void* output_buffer, DWORD address_length,
+    socket_addr_type* addr, std::size_t* addrlen,
+    socket_type new_socket, asio::error_code& ec)
+{
+  // Map non-portable errors to their portable counterparts.
+  if (ec.value() == ERROR_NETNAME_DELETED)
+    ec = asio::error::connection_aborted;
+
+  if (!ec)
+  {
+    // Get the address of the peer.
+    if (addr && addrlen)
+    {
+      LPSOCKADDR local_addr = 0;
+      int local_addr_length = 0;
+      LPSOCKADDR remote_addr = 0;
+      int remote_addr_length = 0;
+      GetAcceptExSockaddrs(output_buffer, 0, address_length,
+          address_length, &local_addr, &local_addr_length,
+          &remote_addr, &remote_addr_length);
+      if (static_cast<std::size_t>(remote_addr_length) > *addrlen)
+      {
+        ec = asio::error::invalid_argument;
+      }
+      else
+      {
+        using namespace std; // For memcpy.
+        memcpy(addr, remote_addr, remote_addr_length);
+        *addrlen = static_cast<std::size_t>(remote_addr_length);
+      }
+    }
+
+    // Need to set the SO_UPDATE_ACCEPT_CONTEXT option so that getsockname
+    // and getpeername will work on the accepted socket.
+    SOCKET update_ctx_param = s;
+    socket_ops::state_type state = 0;
+    socket_ops::setsockopt(new_socket, state,
+          SOL_SOCKET, SO_UPDATE_ACCEPT_CONTEXT,
+          &update_ctx_param, sizeof(SOCKET), ec);
+  }
+}
+
+#else // defined(ASIO_HAS_IOCP)
+
+bool non_blocking_accept(socket_type s,
+    state_type state, socket_addr_type* addr, std::size_t* addrlen,
+    asio::error_code& ec, socket_type& new_socket)
+{
+  for (;;)
+  {
+    // Accept the waiting connection.
+    new_socket = socket_ops::accept(s, addr, addrlen, ec);
+
+    // Check if operation succeeded.
+    if (new_socket != invalid_socket)
+      return true;
+
+    // Retry operation if interrupted by signal.
+    if (ec == asio::error::interrupted)
+      continue;
+
+    // Operation failed.
+    if (ec == asio::error::would_block
+        || ec == asio::error::try_again)
+    {
+      // Fall through to retry operation.
+    }
+    else if (ec == asio::error::connection_aborted)
+    {
+      if (state & enable_connection_aborted)
+        return true;
+      // Fall through to retry operation.
+    }
+#if defined(EPROTO)
+    else if (ec.value() == EPROTO)
+    {
+      if (state & enable_connection_aborted)
+        return true;
+      // Fall through to retry operation.
+    }
+#endif // defined(EPROTO)
+    else
+      return true;
+
+    return false;
+  }
+}
+
+#endif // defined(ASIO_HAS_IOCP)
+
+template <typename SockLenType>
+inline int call_bind(SockLenType msghdr::*,
+    socket_type s, const socket_addr_type* addr, std::size_t addrlen)
+{
+  return ::bind(s, addr, (SockLenType)addrlen);
+}
+
+int bind(socket_type s, const socket_addr_type* addr,
+    std::size_t addrlen, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return socket_error_retval;
+  }
+
+  clear_last_error();
+  int result = error_wrapper(call_bind(
+        &msghdr::msg_namelen, s, addr, addrlen), ec);
+  if (result == 0)
+    ec = asio::error_code();
+  return result;
+}
+
+int close(socket_type s, state_type& state,
+    bool destruction, asio::error_code& ec)
+{
+  int result = 0;
+  if (s != invalid_socket)
+  {
+    // We don't want the destructor to block, so set the socket to linger in
+    // the background. If the user doesn't like this behaviour then they need
+    // to explicitly close the socket.
+    if (destruction && (state & user_set_linger))
+    {
+      ::linger opt;
+      opt.l_onoff = 0;
+      opt.l_linger = 0;
+      asio::error_code ignored_ec;
+      socket_ops::setsockopt(s, state, SOL_SOCKET,
+          SO_LINGER, &opt, sizeof(opt), ignored_ec);
+    }
+
+    clear_last_error();
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+    result = error_wrapper(::closesocket(s), ec);
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+    result = error_wrapper(::close(s), ec);
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+
+    if (result != 0
+        && (ec == asio::error::would_block
+          || ec == asio::error::try_again))
+    {
+      // According to UNIX Network Programming Vol. 1, it is possible for
+      // close() to fail with EWOULDBLOCK under certain circumstances. What
+      // isn't clear is the state of the descriptor after this error. The one
+      // current OS where this behaviour is seen, Windows, says that the socket
+      // remains open. Therefore we'll put the descriptor back into blocking
+      // mode and have another attempt at closing it.
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+      ioctl_arg_type arg = 0;
+      ::ioctlsocket(s, FIONBIO, &arg);
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+# if defined(__SYMBIAN32__)
+      int flags = ::fcntl(s, F_GETFL, 0);
+      if (flags >= 0)
+        ::fcntl(s, F_SETFL, flags & ~O_NONBLOCK);
+# else // defined(__SYMBIAN32__)
+      ioctl_arg_type arg = 0;
+      ::ioctl(s, FIONBIO, &arg);
+# endif // defined(__SYMBIAN32__)
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+      state &= ~non_blocking;
+
+      clear_last_error();
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+      result = error_wrapper(::closesocket(s), ec);
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+      result = error_wrapper(::close(s), ec);
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+    }
+  }
+
+  if (result == 0)
+    ec = asio::error_code();
+  return result;
+}
+
+bool set_user_non_blocking(socket_type s,
+    state_type& state, bool value, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return false;
+  }
+
+  clear_last_error();
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  ioctl_arg_type arg = (value ? 1 : 0);
+  int result = error_wrapper(::ioctlsocket(s, FIONBIO, &arg), ec);
+#elif defined(__SYMBIAN32__)
+  int result = error_wrapper(::fcntl(s, F_GETFL, 0), ec);
+  if (result >= 0)
+  {
+    clear_last_error();
+    int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK));
+    result = error_wrapper(::fcntl(s, F_SETFL, flag), ec);
+  }
+#else
+  ioctl_arg_type arg = (value ? 1 : 0);
+  int result = error_wrapper(::ioctl(s, FIONBIO, &arg), ec);
+#endif
+
+  if (result >= 0)
+  {
+    ec = asio::error_code();
+    if (value)
+      state |= user_set_non_blocking;
+    else
+    {
+      // Clearing the user-set non-blocking mode always overrides any
+      // internally-set non-blocking flag. Any subsequent asynchronous
+      // operations will need to re-enable non-blocking I/O.
+      state &= ~(user_set_non_blocking | internal_non_blocking);
+    }
+    return true;
+  }
+
+  return false;
+}
+
+bool set_internal_non_blocking(socket_type s,
+    state_type& state, bool value, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return false;
+  }
+
+  if (!value && (state & user_set_non_blocking))
+  {
+    // It does not make sense to clear the internal non-blocking flag if the
+    // user still wants non-blocking behaviour. Return an error and let the
+    // caller figure out whether to update the user-set non-blocking flag.
+    ec = asio::error::invalid_argument;
+    return false;
+  }
+
+  clear_last_error();
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  ioctl_arg_type arg = (value ? 1 : 0);
+  int result = error_wrapper(::ioctlsocket(s, FIONBIO, &arg), ec);
+#elif defined(__SYMBIAN32__)
+  int result = error_wrapper(::fcntl(s, F_GETFL, 0), ec);
+  if (result >= 0)
+  {
+    clear_last_error();
+    int flag = (value ? (result | O_NONBLOCK) : (result & ~O_NONBLOCK));
+    result = error_wrapper(::fcntl(s, F_SETFL, flag), ec);
+  }
+#else
+  ioctl_arg_type arg = (value ? 1 : 0);
+  int result = error_wrapper(::ioctl(s, FIONBIO, &arg), ec);
+#endif
+
+  if (result >= 0)
+  {
+    ec = asio::error_code();
+    if (value)
+      state |= internal_non_blocking;
+    else
+      state &= ~internal_non_blocking;
+    return true;
+  }
+
+  return false;
+}
+
+int shutdown(socket_type s, int what, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return socket_error_retval;
+  }
+
+  clear_last_error();
+  int result = error_wrapper(::shutdown(s, what), ec);
+  if (result == 0)
+    ec = asio::error_code();
+  return result;
+}
+
+template <typename SockLenType>
+inline int call_connect(SockLenType msghdr::*,
+    socket_type s, const socket_addr_type* addr, std::size_t addrlen)
+{
+  return ::connect(s, addr, (SockLenType)addrlen);
+}
+
+int connect(socket_type s, const socket_addr_type* addr,
+    std::size_t addrlen, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return socket_error_retval;
+  }
+
+  clear_last_error();
+  int result = error_wrapper(call_connect(
+        &msghdr::msg_namelen, s, addr, addrlen), ec);
+  if (result == 0)
+    ec = asio::error_code();
+#if defined(__linux__)
+  else if (ec == asio::error::try_again)
+    ec = asio::error::no_buffer_space;
+#endif // defined(__linux__)
+  return result;
+}
+
+void sync_connect(socket_type s, const socket_addr_type* addr,
+    std::size_t addrlen, asio::error_code& ec)
+{
+  // Perform the connect operation.
+  socket_ops::connect(s, addr, addrlen, ec);
+  if (ec != asio::error::in_progress
+      && ec != asio::error::would_block)
+  {
+    // The connect operation finished immediately.
+    return;
+  }
+
+  // Wait for socket to become ready.
+  if (socket_ops::poll_connect(s, -1, ec) < 0)
+    return;
+
+  // Get the error code from the connect operation.
+  int connect_error = 0;
+  size_t connect_error_len = sizeof(connect_error);
+  if (socket_ops::getsockopt(s, 0, SOL_SOCKET, SO_ERROR,
+        &connect_error, &connect_error_len, ec) == socket_error_retval)
+    return;
+
+  // Return the result of the connect operation.
+  ec = asio::error_code(connect_error,
+      asio::error::get_system_category());
+}
+
+#if defined(ASIO_HAS_IOCP)
+
+void complete_iocp_connect(socket_type s, asio::error_code& ec)
+{
+  // Map non-portable errors to their portable counterparts.
+  switch (ec.value())
+  {
+  case ERROR_CONNECTION_REFUSED:
+    ec = asio::error::connection_refused;
+    break;
+  case ERROR_NETWORK_UNREACHABLE:
+    ec = asio::error::network_unreachable;
+    break;
+  case ERROR_HOST_UNREACHABLE:
+    ec = asio::error::host_unreachable;
+    break;
+  case ERROR_SEM_TIMEOUT:
+    ec = asio::error::timed_out;
+    break;
+  default:
+    break;
+  }
+
+  if (!ec)
+  {
+    // Need to set the SO_UPDATE_CONNECT_CONTEXT option so that getsockname
+    // and getpeername will work on the connected socket.
+    socket_ops::state_type state = 0;
+    const int so_update_connect_context = 0x7010;
+    socket_ops::setsockopt(s, state, SOL_SOCKET,
+        so_update_connect_context, 0, 0, ec);
+  }
+}
+
+#endif // defined(ASIO_HAS_IOCP)
+
+bool non_blocking_connect(socket_type s, asio::error_code& ec)
+{
+  // Check if the connect operation has finished. This is required since we may
+  // get spurious readiness notifications from the reactor.
+#if defined(ASIO_WINDOWS) \
+  || defined(__CYGWIN__) \
+  || defined(__SYMBIAN32__)
+  fd_set write_fds;
+  FD_ZERO(&write_fds);
+  FD_SET(s, &write_fds);
+  fd_set except_fds;
+  FD_ZERO(&except_fds);
+  FD_SET(s, &except_fds);
+  timeval zero_timeout;
+  zero_timeout.tv_sec = 0;
+  zero_timeout.tv_usec = 0;
+  int ready = ::select(s + 1, 0, &write_fds, &except_fds, &zero_timeout);
+#else // defined(ASIO_WINDOWS)
+      // || defined(__CYGWIN__)
+      // || defined(__SYMBIAN32__)
+  pollfd fds;
+  fds.fd = s;
+  fds.events = POLLOUT;
+  fds.revents = 0;
+  int ready = ::poll(&fds, 1, 0);
+#endif // defined(ASIO_WINDOWS)
+       // || defined(__CYGWIN__)
+       // || defined(__SYMBIAN32__)
+  if (ready == 0)
+  {
+    // The asynchronous connect operation is still in progress.
+    return false;
+  }
+
+  // Get the error code from the connect operation.
+  int connect_error = 0;
+  size_t connect_error_len = sizeof(connect_error);
+  if (socket_ops::getsockopt(s, 0, SOL_SOCKET, SO_ERROR,
+        &connect_error, &connect_error_len, ec) == 0)
+  {
+    if (connect_error)
+    {
+      ec = asio::error_code(connect_error,
+          asio::error::get_system_category());
+    }
+    else
+      ec = asio::error_code();
+  }
+
+  return true;
+}
+
+int socketpair(int af, int type, int protocol,
+    socket_type sv[2], asio::error_code& ec)
+{
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  (void)(af);
+  (void)(type);
+  (void)(protocol);
+  (void)(sv);
+  ec = asio::error::operation_not_supported;
+  return socket_error_retval;
+#else
+  clear_last_error();
+  int result = error_wrapper(::socketpair(af, type, protocol, sv), ec);
+  if (result == 0)
+    ec = asio::error_code();
+  return result;
+#endif
+}
+
+bool sockatmark(socket_type s, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return false;
+  }
+
+#if defined(SIOCATMARK)
+  ioctl_arg_type value = 0;
+# if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  int result = error_wrapper(::ioctlsocket(s, SIOCATMARK, &value), ec);
+# else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  int result = error_wrapper(::ioctl(s, SIOCATMARK, &value), ec);
+# endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  if (result == 0)
+    ec = asio::error_code();
+# if defined(ENOTTY)
+  if (ec.value() == ENOTTY)
+    ec = asio::error::not_socket;
+# endif // defined(ENOTTY)
+#else // defined(SIOCATMARK)
+  int value = error_wrapper(::sockatmark(s), ec);
+  if (value != -1)
+    ec = asio::error_code();
+#endif // defined(SIOCATMARK)
+
+  return ec ? false : value != 0;
+}
+
+size_t available(socket_type s, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return 0;
+  }
+
+  ioctl_arg_type value = 0;
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  int result = error_wrapper(::ioctlsocket(s, FIONREAD, &value), ec);
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  int result = error_wrapper(::ioctl(s, FIONREAD, &value), ec);
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  if (result == 0)
+    ec = asio::error_code();
+#if defined(ENOTTY)
+  if (ec.value() == ENOTTY)
+    ec = asio::error::not_socket;
+#endif // defined(ENOTTY)
+
+  return ec ? static_cast<size_t>(0) : static_cast<size_t>(value);
+}
+
+int listen(socket_type s, int backlog, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return socket_error_retval;
+  }
+
+  clear_last_error();
+  int result = error_wrapper(::listen(s, backlog), ec);
+  if (result == 0)
+    ec = asio::error_code();
+  return result;
+}
+
+inline void init_buf_iov_base(void*& base, void* addr)
+{
+  base = addr;
+}
+
+template <typename T>
+inline void init_buf_iov_base(T& base, void* addr)
+{
+  base = static_cast<T>(addr);
+}
+
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+typedef WSABUF buf;
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+typedef iovec buf;
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+
+void init_buf(buf& b, void* data, size_t size)
+{
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  b.buf = static_cast<char*>(data);
+  b.len = static_cast<u_long>(size);
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  init_buf_iov_base(b.iov_base, data);
+  b.iov_len = size;
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+}
+
+void init_buf(buf& b, const void* data, size_t size)
+{
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  b.buf = static_cast<char*>(const_cast<void*>(data));
+  b.len = static_cast<u_long>(size);
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  init_buf_iov_base(b.iov_base, const_cast<void*>(data));
+  b.iov_len = size;
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+}
+
+inline void init_msghdr_msg_name(void*& name, socket_addr_type* addr)
+{
+  name = addr;
+}
+
+inline void init_msghdr_msg_name(void*& name, const socket_addr_type* addr)
+{
+  name = const_cast<socket_addr_type*>(addr);
+}
+
+template <typename T>
+inline void init_msghdr_msg_name(T& name, socket_addr_type* addr)
+{
+  name = reinterpret_cast<T>(addr);
+}
+
+template <typename T>
+inline void init_msghdr_msg_name(T& name, const socket_addr_type* addr)
+{
+  name = reinterpret_cast<T>(const_cast<socket_addr_type*>(addr));
+}
+
+signed_size_type recv(socket_type s, buf* bufs, size_t count,
+    int flags, asio::error_code& ec)
+{
+  clear_last_error();
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  // Receive some data.
+  DWORD recv_buf_count = static_cast<DWORD>(count);
+  DWORD bytes_transferred = 0;
+  DWORD recv_flags = flags;
+  int result = error_wrapper(::WSARecv(s, bufs,
+        recv_buf_count, &bytes_transferred, &recv_flags, 0, 0), ec);
+  if (ec.value() == ERROR_NETNAME_DELETED)
+    ec = asio::error::connection_reset;
+  else if (ec.value() == ERROR_PORT_UNREACHABLE)
+    ec = asio::error::connection_refused;
+  else if (ec.value() == WSAEMSGSIZE || ec.value() == ERROR_MORE_DATA)
+    ec.assign(0, ec.category());
+  if (result != 0)
+    return socket_error_retval;
+  ec = asio::error_code();
+  return bytes_transferred;
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  msghdr msg = msghdr();
+  msg.msg_iov = bufs;
+  msg.msg_iovlen = static_cast<int>(count);
+  signed_size_type result = error_wrapper(::recvmsg(s, &msg, flags), ec);
+  if (result >= 0)
+    ec = asio::error_code();
+  return result;
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+}
+
+size_t sync_recv(socket_type s, state_type state, buf* bufs,
+    size_t count, int flags, bool all_empty, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return 0;
+  }
+
+  // A request to read 0 bytes on a stream is a no-op.
+  if (all_empty && (state & stream_oriented))
+  {
+    ec = asio::error_code();
+    return 0;
+  }
+
+  // Read some data.
+  for (;;)
+  {
+    // Try to complete the operation without blocking.
+    signed_size_type bytes = socket_ops::recv(s, bufs, count, flags, ec);
+
+    // Check if operation succeeded.
+    if (bytes > 0)
+      return bytes;
+
+    // Check for EOF.
+    if ((state & stream_oriented) && bytes == 0)
+    {
+      ec = asio::error::eof;
+      return 0;
+    }
+
+    // Operation failed.
+    if ((state & user_set_non_blocking)
+        || (ec != asio::error::would_block
+          && ec != asio::error::try_again))
+      return 0;
+
+    // Wait for socket to become ready.
+    if (socket_ops::poll_read(s, 0, -1, ec) < 0)
+      return 0;
+  }
+}
+
+#if defined(ASIO_HAS_IOCP)
+
+void complete_iocp_recv(state_type state,
+    const weak_cancel_token_type& cancel_token, bool all_empty,
+    asio::error_code& ec, size_t bytes_transferred)
+{
+  // Map non-portable errors to their portable counterparts.
+  if (ec.value() == ERROR_NETNAME_DELETED)
+  {
+    if (cancel_token.expired())
+      ec = asio::error::operation_aborted;
+    else
+      ec = asio::error::connection_reset;
+  }
+  else if (ec.value() == ERROR_PORT_UNREACHABLE)
+  {
+    ec = asio::error::connection_refused;
+  }
+  else if (ec.value() == WSAEMSGSIZE || ec.value() == ERROR_MORE_DATA)
+  {
+    ec.assign(0, ec.category());
+  }
+
+  // Check for connection closed.
+  else if (!ec && bytes_transferred == 0
+      && (state & stream_oriented) != 0
+      && !all_empty)
+  {
+    ec = asio::error::eof;
+  }
+}
+
+#else // defined(ASIO_HAS_IOCP)
+
+bool non_blocking_recv(socket_type s,
+    buf* bufs, size_t count, int flags, bool is_stream,
+    asio::error_code& ec, size_t& bytes_transferred)
+{
+  for (;;)
+  {
+    // Read some data.
+    signed_size_type bytes = socket_ops::recv(s, bufs, count, flags, ec);
+
+    // Check for end of stream.
+    if (is_stream && bytes == 0)
+    {
+      ec = asio::error::eof;
+      return true;
+    }
+
+    // Retry operation if interrupted by signal.
+    if (ec == asio::error::interrupted)
+      continue;
+
+    // Check if we need to run the operation again.
+    if (ec == asio::error::would_block
+        || ec == asio::error::try_again)
+      return false;
+
+    // Operation is complete.
+    if (bytes >= 0)
+    {
+      ec = asio::error_code();
+      bytes_transferred = bytes;
+    }
+    else
+      bytes_transferred = 0;
+
+    return true;
+  }
+}
+
+#endif // defined(ASIO_HAS_IOCP)
+
+signed_size_type recvfrom(socket_type s, buf* bufs, size_t count,
+    int flags, socket_addr_type* addr, std::size_t* addrlen,
+    asio::error_code& ec)
+{
+  clear_last_error();
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  // Receive some data.
+  DWORD recv_buf_count = static_cast<DWORD>(count);
+  DWORD bytes_transferred = 0;
+  DWORD recv_flags = flags;
+  int tmp_addrlen = (int)*addrlen;
+  int result = error_wrapper(::WSARecvFrom(s, bufs, recv_buf_count,
+        &bytes_transferred, &recv_flags, addr, &tmp_addrlen, 0, 0), ec);
+  *addrlen = (std::size_t)tmp_addrlen;
+  if (ec.value() == ERROR_NETNAME_DELETED)
+    ec = asio::error::connection_reset;
+  else if (ec.value() == ERROR_PORT_UNREACHABLE)
+    ec = asio::error::connection_refused;
+  else if (ec.value() == WSAEMSGSIZE || ec.value() == ERROR_MORE_DATA)
+    ec.assign(0, ec.category());
+  if (result != 0)
+    return socket_error_retval;
+  ec = asio::error_code();
+  return bytes_transferred;
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  msghdr msg = msghdr();
+  init_msghdr_msg_name(msg.msg_name, addr);
+  msg.msg_namelen = static_cast<int>(*addrlen);
+  msg.msg_iov = bufs;
+  msg.msg_iovlen = static_cast<int>(count);
+  signed_size_type result = error_wrapper(::recvmsg(s, &msg, flags), ec);
+  *addrlen = msg.msg_namelen;
+  if (result >= 0)
+    ec = asio::error_code();
+  return result;
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+}
+
+size_t sync_recvfrom(socket_type s, state_type state, buf* bufs,
+    size_t count, int flags, socket_addr_type* addr,
+    std::size_t* addrlen, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return 0;
+  }
+
+  // Read some data.
+  for (;;)
+  {
+    // Try to complete the operation without blocking.
+    signed_size_type bytes = socket_ops::recvfrom(
+        s, bufs, count, flags, addr, addrlen, ec);
+
+    // Check if operation succeeded.
+    if (bytes >= 0)
+      return bytes;
+
+    // Operation failed.
+    if ((state & user_set_non_blocking)
+        || (ec != asio::error::would_block
+          && ec != asio::error::try_again))
+      return 0;
+
+    // Wait for socket to become ready.
+    if (socket_ops::poll_read(s, 0, -1, ec) < 0)
+      return 0;
+  }
+}
+
+#if defined(ASIO_HAS_IOCP)
+
+void complete_iocp_recvfrom(
+    const weak_cancel_token_type& cancel_token,
+    asio::error_code& ec)
+{
+  // Map non-portable errors to their portable counterparts.
+  if (ec.value() == ERROR_NETNAME_DELETED)
+  {
+    if (cancel_token.expired())
+      ec = asio::error::operation_aborted;
+    else
+      ec = asio::error::connection_reset;
+  }
+  else if (ec.value() == ERROR_PORT_UNREACHABLE)
+  {
+    ec = asio::error::connection_refused;
+  }
+  else if (ec.value() == WSAEMSGSIZE || ec.value() == ERROR_MORE_DATA)
+  {
+    ec.assign(0, ec.category());
+  }
+}
+
+#else // defined(ASIO_HAS_IOCP)
+
+bool non_blocking_recvfrom(socket_type s,
+    buf* bufs, size_t count, int flags,
+    socket_addr_type* addr, std::size_t* addrlen,
+    asio::error_code& ec, size_t& bytes_transferred)
+{
+  for (;;)
+  {
+    // Read some data.
+    signed_size_type bytes = socket_ops::recvfrom(
+        s, bufs, count, flags, addr, addrlen, ec);
+
+    // Retry operation if interrupted by signal.
+    if (ec == asio::error::interrupted)
+      continue;
+
+    // Check if we need to run the operation again.
+    if (ec == asio::error::would_block
+        || ec == asio::error::try_again)
+      return false;
+
+    // Operation is complete.
+    if (bytes >= 0)
+    {
+      ec = asio::error_code();
+      bytes_transferred = bytes;
+    }
+    else
+      bytes_transferred = 0;
+
+    return true;
+  }
+}
+
+#endif // defined(ASIO_HAS_IOCP)
+
+signed_size_type recvmsg(socket_type s, buf* bufs, size_t count,
+    int in_flags, int& out_flags, asio::error_code& ec)
+{
+  clear_last_error();
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  out_flags = 0;
+  return socket_ops::recv(s, bufs, count, in_flags, ec);
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  msghdr msg = msghdr();
+  msg.msg_iov = bufs;
+  msg.msg_iovlen = static_cast<int>(count);
+  signed_size_type result = error_wrapper(::recvmsg(s, &msg, in_flags), ec);
+  if (result >= 0)
+  {
+    ec = asio::error_code();
+    out_flags = msg.msg_flags;
+  }
+  else
+    out_flags = 0;
+  return result;
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+}
+
+size_t sync_recvmsg(socket_type s, state_type state,
+    buf* bufs, size_t count, int in_flags, int& out_flags,
+    asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return 0;
+  }
+
+  // Read some data.
+  for (;;)
+  {
+    // Try to complete the operation without blocking.
+    signed_size_type bytes = socket_ops::recvmsg(
+        s, bufs, count, in_flags, out_flags, ec);
+
+    // Check if operation succeeded.
+    if (bytes >= 0)
+      return bytes;
+
+    // Operation failed.
+    if ((state & user_set_non_blocking)
+        || (ec != asio::error::would_block
+          && ec != asio::error::try_again))
+      return 0;
+
+    // Wait for socket to become ready.
+    if (socket_ops::poll_read(s, 0, -1, ec) < 0)
+      return 0;
+  }
+}
+
+#if defined(ASIO_HAS_IOCP)
+
+void complete_iocp_recvmsg(
+    const weak_cancel_token_type& cancel_token,
+    asio::error_code& ec)
+{
+  // Map non-portable errors to their portable counterparts.
+  if (ec.value() == ERROR_NETNAME_DELETED)
+  {
+    if (cancel_token.expired())
+      ec = asio::error::operation_aborted;
+    else
+      ec = asio::error::connection_reset;
+  }
+  else if (ec.value() == ERROR_PORT_UNREACHABLE)
+  {
+    ec = asio::error::connection_refused;
+  }
+  else if (ec.value() == WSAEMSGSIZE || ec.value() == ERROR_MORE_DATA)
+  {
+    ec.assign(0, ec.category());
+  }
+}
+
+#else // defined(ASIO_HAS_IOCP)
+
+bool non_blocking_recvmsg(socket_type s,
+    buf* bufs, size_t count, int in_flags, int& out_flags,
+    asio::error_code& ec, size_t& bytes_transferred)
+{
+  for (;;)
+  {
+    // Read some data.
+    signed_size_type bytes = socket_ops::recvmsg(
+        s, bufs, count, in_flags, out_flags, ec);
+
+    // Retry operation if interrupted by signal.
+    if (ec == asio::error::interrupted)
+      continue;
+
+    // Check if we need to run the operation again.
+    if (ec == asio::error::would_block
+        || ec == asio::error::try_again)
+      return false;
+
+    // Operation is complete.
+    if (bytes >= 0)
+    {
+      ec = asio::error_code();
+      bytes_transferred = bytes;
+    }
+    else
+      bytes_transferred = 0;
+
+    return true;
+  }
+}
+
+#endif // defined(ASIO_HAS_IOCP)
+
+signed_size_type send(socket_type s, const buf* bufs, size_t count,
+    int flags, asio::error_code& ec)
+{
+  clear_last_error();
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  // Send the data.
+  DWORD send_buf_count = static_cast<DWORD>(count);
+  DWORD bytes_transferred = 0;
+  DWORD send_flags = flags;
+  int result = error_wrapper(::WSASend(s, const_cast<buf*>(bufs),
+        send_buf_count, &bytes_transferred, send_flags, 0, 0), ec);
+  if (ec.value() == ERROR_NETNAME_DELETED)
+    ec = asio::error::connection_reset;
+  else if (ec.value() == ERROR_PORT_UNREACHABLE)
+    ec = asio::error::connection_refused;
+  if (result != 0)
+    return socket_error_retval;
+  ec = asio::error_code();
+  return bytes_transferred;
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  msghdr msg = msghdr();
+  msg.msg_iov = const_cast<buf*>(bufs);
+  msg.msg_iovlen = static_cast<int>(count);
+#if defined(__linux__)
+  flags |= MSG_NOSIGNAL;
+#endif // defined(__linux__)
+  signed_size_type result = error_wrapper(::sendmsg(s, &msg, flags), ec);
+  if (result >= 0)
+    ec = asio::error_code();
+  return result;
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+}
+
+size_t sync_send(socket_type s, state_type state, const buf* bufs,
+    size_t count, int flags, bool all_empty, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return 0;
+  }
+
+  // A request to write 0 bytes to a stream is a no-op.
+  if (all_empty && (state & stream_oriented))
+  {
+    ec = asio::error_code();
+    return 0;
+  }
+
+  // Read some data.
+  for (;;)
+  {
+    // Try to complete the operation without blocking.
+    signed_size_type bytes = socket_ops::send(s, bufs, count, flags, ec);
+
+    // Check if operation succeeded.
+    if (bytes >= 0)
+      return bytes;
+
+    // Operation failed.
+    if ((state & user_set_non_blocking)
+        || (ec != asio::error::would_block
+          && ec != asio::error::try_again))
+      return 0;
+
+    // Wait for socket to become ready.
+    if (socket_ops::poll_write(s, 0, -1, ec) < 0)
+      return 0;
+  }
+}
+
+#if defined(ASIO_HAS_IOCP)
+
+void complete_iocp_send(
+    const weak_cancel_token_type& cancel_token,
+    asio::error_code& ec)
+{
+  // Map non-portable errors to their portable counterparts.
+  if (ec.value() == ERROR_NETNAME_DELETED)
+  {
+    if (cancel_token.expired())
+      ec = asio::error::operation_aborted;
+    else
+      ec = asio::error::connection_reset;
+  }
+  else if (ec.value() == ERROR_PORT_UNREACHABLE)
+  {
+    ec = asio::error::connection_refused;
+  }
+}
+
+#else // defined(ASIO_HAS_IOCP)
+
+bool non_blocking_send(socket_type s,
+    const buf* bufs, size_t count, int flags,
+    asio::error_code& ec, size_t& bytes_transferred)
+{
+  for (;;)
+  {
+    // Write some data.
+    signed_size_type bytes = socket_ops::send(s, bufs, count, flags, ec);
+
+    // Retry operation if interrupted by signal.
+    if (ec == asio::error::interrupted)
+      continue;
+
+    // Check if we need to run the operation again.
+    if (ec == asio::error::would_block
+        || ec == asio::error::try_again)
+      return false;
+
+    // Operation is complete.
+    if (bytes >= 0)
+    {
+      ec = asio::error_code();
+      bytes_transferred = bytes;
+    }
+    else
+      bytes_transferred = 0;
+
+    return true;
+  }
+}
+
+#endif // defined(ASIO_HAS_IOCP)
+
+signed_size_type sendto(socket_type s, const buf* bufs, size_t count,
+    int flags, const socket_addr_type* addr, std::size_t addrlen,
+    asio::error_code& ec)
+{
+  clear_last_error();
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  // Send the data.
+  DWORD send_buf_count = static_cast<DWORD>(count);
+  DWORD bytes_transferred = 0;
+  int result = error_wrapper(::WSASendTo(s, const_cast<buf*>(bufs),
+        send_buf_count, &bytes_transferred, flags, addr,
+        static_cast<int>(addrlen), 0, 0), ec);
+  if (ec.value() == ERROR_NETNAME_DELETED)
+    ec = asio::error::connection_reset;
+  else if (ec.value() == ERROR_PORT_UNREACHABLE)
+    ec = asio::error::connection_refused;
+  if (result != 0)
+    return socket_error_retval;
+  ec = asio::error_code();
+  return bytes_transferred;
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  msghdr msg = msghdr();
+  init_msghdr_msg_name(msg.msg_name, addr);
+  msg.msg_namelen = static_cast<int>(addrlen);
+  msg.msg_iov = const_cast<buf*>(bufs);
+  msg.msg_iovlen = static_cast<int>(count);
+#if defined(__linux__)
+  flags |= MSG_NOSIGNAL;
+#endif // defined(__linux__)
+  signed_size_type result = error_wrapper(::sendmsg(s, &msg, flags), ec);
+  if (result >= 0)
+    ec = asio::error_code();
+  return result;
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+}
+
+size_t sync_sendto(socket_type s, state_type state, const buf* bufs,
+    size_t count, int flags, const socket_addr_type* addr,
+    std::size_t addrlen, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return 0;
+  }
+
+  // Write some data.
+  for (;;)
+  {
+    // Try to complete the operation without blocking.
+    signed_size_type bytes = socket_ops::sendto(
+        s, bufs, count, flags, addr, addrlen, ec);
+
+    // Check if operation succeeded.
+    if (bytes >= 0)
+      return bytes;
+
+    // Operation failed.
+    if ((state & user_set_non_blocking)
+        || (ec != asio::error::would_block
+          && ec != asio::error::try_again))
+      return 0;
+
+    // Wait for socket to become ready.
+    if (socket_ops::poll_write(s, 0, -1, ec) < 0)
+      return 0;
+  }
+}
+
+#if !defined(ASIO_HAS_IOCP)
+
+bool non_blocking_sendto(socket_type s,
+    const buf* bufs, size_t count, int flags,
+    const socket_addr_type* addr, std::size_t addrlen,
+    asio::error_code& ec, size_t& bytes_transferred)
+{
+  for (;;)
+  {
+    // Write some data.
+    signed_size_type bytes = socket_ops::sendto(
+        s, bufs, count, flags, addr, addrlen, ec);
+
+    // Retry operation if interrupted by signal.
+    if (ec == asio::error::interrupted)
+      continue;
+
+    // Check if we need to run the operation again.
+    if (ec == asio::error::would_block
+        || ec == asio::error::try_again)
+      return false;
+
+    // Operation is complete.
+    if (bytes >= 0)
+    {
+      ec = asio::error_code();
+      bytes_transferred = bytes;
+    }
+    else
+      bytes_transferred = 0;
+
+    return true;
+  }
+}
+
+#endif // !defined(ASIO_HAS_IOCP)
+
+socket_type socket(int af, int type, int protocol,
+    asio::error_code& ec)
+{
+  clear_last_error();
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  socket_type s = error_wrapper(::WSASocketW(af, type, protocol, 0, 0,
+        WSA_FLAG_OVERLAPPED), ec);
+  if (s == invalid_socket)
+    return s;
+
+  if (af == ASIO_OS_DEF(AF_INET6))
+  {
+    // Try to enable the POSIX default behaviour of having IPV6_V6ONLY set to
+    // false. This will only succeed on Windows Vista and later versions of
+    // Windows, where a dual-stack IPv4/v6 implementation is available.
+    DWORD optval = 0;
+    ::setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY,
+        reinterpret_cast<const char*>(&optval), sizeof(optval));
+  }
+
+  ec = asio::error_code();
+
+  return s;
+#elif defined(__MACH__) && defined(__APPLE__) || defined(__FreeBSD__)
+  socket_type s = error_wrapper(::socket(af, type, protocol), ec);
+  if (s == invalid_socket)
+    return s;
+
+  int optval = 1;
+  int result = error_wrapper(::setsockopt(s,
+        SOL_SOCKET, SO_NOSIGPIPE, &optval, sizeof(optval)), ec);
+  if (result != 0)
+  {
+    ::close(s);
+    return invalid_socket;
+  }
+
+  return s;
+#else
+  int s = error_wrapper(::socket(af, type, protocol), ec);
+  if (s >= 0)
+    ec = asio::error_code();
+  return s;
+#endif
+}
+
+template <typename SockLenType>
+inline int call_setsockopt(SockLenType msghdr::*,
+    socket_type s, int level, int optname,
+    const void* optval, std::size_t optlen)
+{
+  return ::setsockopt(s, level, optname,
+      (const char*)optval, (SockLenType)optlen);
+}
+
+int setsockopt(socket_type s, state_type& state, int level, int optname,
+    const void* optval, std::size_t optlen, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return socket_error_retval;
+  }
+
+  if (level == custom_socket_option_level && optname == always_fail_option)
+  {
+    ec = asio::error::invalid_argument;
+    return socket_error_retval;
+  }
+
+  if (level == custom_socket_option_level
+      && optname == enable_connection_aborted_option)
+  {
+    if (optlen != sizeof(int))
+    {
+      ec = asio::error::invalid_argument;
+      return socket_error_retval;
+    }
+
+    if (*static_cast<const int*>(optval))
+      state |= enable_connection_aborted;
+    else
+      state &= ~enable_connection_aborted;
+    ec = asio::error_code();
+    return 0;
+  }
+
+  if (level == SOL_SOCKET && optname == SO_LINGER)
+    state |= user_set_linger;
+
+#if defined(__BORLANDC__)
+  // Mysteriously, using the getsockopt and setsockopt functions directly with
+  // Borland C++ results in incorrect values being set and read. The bug can be
+  // worked around by using function addresses resolved with GetProcAddress.
+  if (HMODULE winsock_module = ::GetModuleHandleA("ws2_32"))
+  {
+    typedef int (WSAAPI *sso_t)(SOCKET, int, int, const char*, int);
+    if (sso_t sso = (sso_t)::GetProcAddress(winsock_module, "setsockopt"))
+    {
+      clear_last_error();
+      return error_wrapper(sso(s, level, optname,
+            reinterpret_cast<const char*>(optval),
+            static_cast<int>(optlen)), ec);
+    }
+  }
+  ec = asio::error::fault;
+  return socket_error_retval;
+#else // defined(__BORLANDC__)
+  clear_last_error();
+  int result = error_wrapper(call_setsockopt(&msghdr::msg_namelen,
+        s, level, optname, optval, optlen), ec);
+  if (result == 0)
+  {
+    ec = asio::error_code();
+
+#if defined(__MACH__) && defined(__APPLE__) \
+  || defined(__NetBSD__) || defined(__FreeBSD__) || defined(__OpenBSD__)
+    // To implement portable behaviour for SO_REUSEADDR with UDP sockets we
+    // need to also set SO_REUSEPORT on BSD-based platforms.
+    if ((state & datagram_oriented)
+        && level == SOL_SOCKET && optname == SO_REUSEADDR)
+    {
+      call_setsockopt(&msghdr::msg_namelen, s,
+          SOL_SOCKET, SO_REUSEPORT, optval, optlen);
+    }
+#endif
+  }
+
+  return result;
+#endif // defined(__BORLANDC__)
+}
+
+template <typename SockLenType>
+inline int call_getsockopt(SockLenType msghdr::*,
+    socket_type s, int level, int optname,
+    void* optval, std::size_t* optlen)
+{
+  SockLenType tmp_optlen = (SockLenType)*optlen;
+  int result = ::getsockopt(s, level, optname, (char*)optval, &tmp_optlen);
+  *optlen = (std::size_t)tmp_optlen;
+  return result;
+}
+
+int getsockopt(socket_type s, state_type state, int level, int optname,
+    void* optval, size_t* optlen, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return socket_error_retval;
+  }
+
+  if (level == custom_socket_option_level && optname == always_fail_option)
+  {
+    ec = asio::error::invalid_argument;
+    return socket_error_retval;
+  }
+
+  if (level == custom_socket_option_level
+      && optname == enable_connection_aborted_option)
+  {
+    if (*optlen != sizeof(int))
+    {
+      ec = asio::error::invalid_argument;
+      return socket_error_retval;
+    }
+
+    *static_cast<int*>(optval) = (state & enable_connection_aborted) ? 1 : 0;
+    ec = asio::error_code();
+    return 0;
+  }
+
+#if defined(__BORLANDC__)
+  // Mysteriously, using the getsockopt and setsockopt functions directly with
+  // Borland C++ results in incorrect values being set and read. The bug can be
+  // worked around by using function addresses resolved with GetProcAddress.
+  if (HMODULE winsock_module = ::GetModuleHandleA("ws2_32"))
+  {
+    typedef int (WSAAPI *gso_t)(SOCKET, int, int, char*, int*);
+    if (gso_t gso = (gso_t)::GetProcAddress(winsock_module, "getsockopt"))
+    {
+      clear_last_error();
+      int tmp_optlen = static_cast<int>(*optlen);
+      int result = error_wrapper(gso(s, level, optname,
+            reinterpret_cast<char*>(optval), &tmp_optlen), ec);
+      *optlen = static_cast<size_t>(tmp_optlen);
+      if (result != 0 && level == IPPROTO_IPV6 && optname == IPV6_V6ONLY
+          && ec.value() == WSAENOPROTOOPT && *optlen == sizeof(DWORD))
+      {
+        // Dual-stack IPv4/v6 sockets, and the IPV6_V6ONLY socket option, are
+        // only supported on Windows Vista and later. To simplify program logic
+        // we will fake success of getting this option and specify that the
+        // value is non-zero (i.e. true). This corresponds to the behavior of
+        // IPv6 sockets on Windows platforms pre-Vista.
+        *static_cast<DWORD*>(optval) = 1;
+        ec = asio::error_code();
+      }
+      return result;
+    }
+  }
+  ec = asio::error::fault;
+  return socket_error_retval;
+#elif defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  clear_last_error();
+  int result = error_wrapper(call_getsockopt(&msghdr::msg_namelen,
+        s, level, optname, optval, optlen), ec);
+  if (result != 0 && level == IPPROTO_IPV6 && optname == IPV6_V6ONLY
+      && ec.value() == WSAENOPROTOOPT && *optlen == sizeof(DWORD))
+  {
+    // Dual-stack IPv4/v6 sockets, and the IPV6_V6ONLY socket option, are only
+    // supported on Windows Vista and later. To simplify program logic we will
+    // fake success of getting this option and specify that the value is
+    // non-zero (i.e. true). This corresponds to the behavior of IPv6 sockets
+    // on Windows platforms pre-Vista.
+    *static_cast<DWORD*>(optval) = 1;
+    ec = asio::error_code();
+  }
+  if (result == 0)
+    ec = asio::error_code();
+  return result;
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  clear_last_error();
+  int result = error_wrapper(call_getsockopt(&msghdr::msg_namelen,
+        s, level, optname, optval, optlen), ec);
+#if defined(__linux__)
+  if (result == 0 && level == SOL_SOCKET && *optlen == sizeof(int)
+      && (optname == SO_SNDBUF || optname == SO_RCVBUF))
+  {
+    // On Linux, setting SO_SNDBUF or SO_RCVBUF to N actually causes the kernel
+    // to set the buffer size to N*2. Linux puts additional stuff into the
+    // buffers so that only about half is actually available to the application.
+    // The retrieved value is divided by 2 here to make it appear as though the
+    // correct value has been set.
+    *static_cast<int*>(optval) /= 2;
+  }
+#endif // defined(__linux__)
+  if (result == 0)
+    ec = asio::error_code();
+  return result;
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+}
+
+template <typename SockLenType>
+inline int call_getpeername(SockLenType msghdr::*,
+    socket_type s, socket_addr_type* addr, std::size_t* addrlen)
+{
+  SockLenType tmp_addrlen = (SockLenType)*addrlen;
+  int result = ::getpeername(s, addr, &tmp_addrlen);
+  *addrlen = (std::size_t)tmp_addrlen;
+  return result;
+}
+
+int getpeername(socket_type s, socket_addr_type* addr,
+    std::size_t* addrlen, bool cached, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return socket_error_retval;
+  }
+
+#if defined(ASIO_WINDOWS) && !defined(ASIO_WINDOWS_APP) \
+  || defined(__CYGWIN__)
+  if (cached)
+  {
+    // Check if socket is still connected.
+    DWORD connect_time = 0;
+    size_t connect_time_len = sizeof(connect_time);
+    if (socket_ops::getsockopt(s, 0, SOL_SOCKET, SO_CONNECT_TIME,
+          &connect_time, &connect_time_len, ec) == socket_error_retval)
+    {
+      return socket_error_retval;
+    }
+    if (connect_time == 0xFFFFFFFF)
+    {
+      ec = asio::error::not_connected;
+      return socket_error_retval;
+    }
+
+    // The cached value is still valid.
+    ec = asio::error_code();
+    return 0;
+  }
+#else // defined(ASIO_WINDOWS) && !defined(ASIO_WINDOWS_APP)
+      // || defined(__CYGWIN__)
+  (void)cached;
+#endif // defined(ASIO_WINDOWS) && !defined(ASIO_WINDOWS_APP)
+       // || defined(__CYGWIN__)
+
+  clear_last_error();
+  int result = error_wrapper(call_getpeername(
+        &msghdr::msg_namelen, s, addr, addrlen), ec);
+  if (result == 0)
+    ec = asio::error_code();
+  return result;
+}
+
+template <typename SockLenType>
+inline int call_getsockname(SockLenType msghdr::*,
+    socket_type s, socket_addr_type* addr, std::size_t* addrlen)
+{
+  SockLenType tmp_addrlen = (SockLenType)*addrlen;
+  int result = ::getsockname(s, addr, &tmp_addrlen);
+  *addrlen = (std::size_t)tmp_addrlen;
+  return result;
+}
+
+int getsockname(socket_type s, socket_addr_type* addr,
+    std::size_t* addrlen, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return socket_error_retval;
+  }
+
+  clear_last_error();
+  int result = error_wrapper(call_getsockname(
+        &msghdr::msg_namelen, s, addr, addrlen), ec);
+  if (result == 0)
+    ec = asio::error_code();
+  return result;
+}
+
+int ioctl(socket_type s, state_type& state, int cmd,
+    ioctl_arg_type* arg, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return socket_error_retval;
+  }
+
+  clear_last_error();
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  int result = error_wrapper(::ioctlsocket(s, cmd, arg), ec);
+#elif defined(__MACH__) && defined(__APPLE__) \
+  || defined(__NetBSD__) || defined(__FreeBSD__) || defined(__OpenBSD__)
+  int result = error_wrapper(::ioctl(s,
+        static_cast<unsigned int>(cmd), arg), ec);
+#else
+  int result = error_wrapper(::ioctl(s, cmd, arg), ec);
+#endif
+  if (result >= 0)
+  {
+    ec = asio::error_code();
+
+    // When updating the non-blocking mode we always perform the ioctl syscall,
+    // even if the flags would otherwise indicate that the socket is already in
+    // the correct state. This ensures that the underlying socket is put into
+    // the state that has been requested by the user. If the ioctl syscall was
+    // successful then we need to update the flags to match.
+    if (cmd == static_cast<int>(FIONBIO))
+    {
+      if (*arg)
+      {
+        state |= user_set_non_blocking;
+      }
+      else
+      {
+        // Clearing the non-blocking mode always overrides any internally-set
+        // non-blocking flag. Any subsequent asynchronous operations will need
+        // to re-enable non-blocking I/O.
+        state &= ~(user_set_non_blocking | internal_non_blocking);
+      }
+    }
+  }
+
+  return result;
+}
+
+int select(int nfds, fd_set* readfds, fd_set* writefds,
+    fd_set* exceptfds, timeval* timeout, asio::error_code& ec)
+{
+  clear_last_error();
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  if (!readfds && !writefds && !exceptfds && timeout)
+  {
+    DWORD milliseconds = timeout->tv_sec * 1000 + timeout->tv_usec / 1000;
+    if (milliseconds == 0)
+      milliseconds = 1; // Force context switch.
+    ::Sleep(milliseconds);
+    ec = asio::error_code();
+    return 0;
+  }
+
+  // The select() call allows timeout values measured in microseconds, but the
+  // system clock (as wrapped by boost::posix_time::microsec_clock) typically
+  // has a resolution of 10 milliseconds. This can lead to a spinning select
+  // reactor, meaning increased CPU usage, when waiting for the earliest
+  // scheduled timeout if it's less than 10 milliseconds away. To avoid a tight
+  // spin we'll use a minimum timeout of 1 millisecond.
+  if (timeout && timeout->tv_sec == 0
+      && timeout->tv_usec > 0 && timeout->tv_usec < 1000)
+    timeout->tv_usec = 1000;
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+
+#if defined(__hpux) && defined(__SELECT)
+  timespec ts;
+  ts.tv_sec = timeout ? timeout->tv_sec : 0;
+  ts.tv_nsec = timeout ? timeout->tv_usec * 1000 : 0;
+  return error_wrapper(::pselect(nfds, readfds,
+        writefds, exceptfds, timeout ? &ts : 0, 0), ec);
+#else
+  int result = error_wrapper(::select(nfds, readfds,
+        writefds, exceptfds, timeout), ec);
+  if (result >= 0)
+    ec = asio::error_code();
+  return result;
+#endif
+}
+
+int poll_read(socket_type s, state_type state,
+    int msec, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return socket_error_retval;
+  }
+
+#if defined(ASIO_WINDOWS) \
+  || defined(__CYGWIN__) \
+  || defined(__SYMBIAN32__)
+  fd_set fds;
+  FD_ZERO(&fds);
+  FD_SET(s, &fds);
+  timeval timeout_obj;
+  timeval* timeout;
+  if (state & user_set_non_blocking)
+  {
+    timeout_obj.tv_sec = 0;
+    timeout_obj.tv_usec = 0;
+    timeout = &timeout_obj;
+  }
+  else if (msec >= 0)
+  {
+    timeout_obj.tv_sec = msec / 1000;
+    timeout_obj.tv_usec = (msec % 1000) * 1000;
+    timeout = &timeout_obj;
+  }
+  else
+    timeout = 0;
+  clear_last_error();
+  int result = error_wrapper(::select(s + 1, &fds, 0, 0, timeout), ec);
+#else // defined(ASIO_WINDOWS)
+      // || defined(__CYGWIN__)
+      // || defined(__SYMBIAN32__)
+  pollfd fds;
+  fds.fd = s;
+  fds.events = POLLIN;
+  fds.revents = 0;
+  int timeout = (state & user_set_non_blocking) ? 0 : msec;
+  clear_last_error();
+  int result = error_wrapper(::poll(&fds, 1, timeout), ec);
+#endif // defined(ASIO_WINDOWS)
+       // || defined(__CYGWIN__)
+       // || defined(__SYMBIAN32__)
+  if (result == 0)
+    ec = (state & user_set_non_blocking)
+      ? asio::error::would_block : asio::error_code();
+  else if (result > 0)
+    ec = asio::error_code();
+  return result;
+}
+
+int poll_write(socket_type s, state_type state,
+    int msec, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return socket_error_retval;
+  }
+
+#if defined(ASIO_WINDOWS) \
+  || defined(__CYGWIN__) \
+  || defined(__SYMBIAN32__)
+  fd_set fds;
+  FD_ZERO(&fds);
+  FD_SET(s, &fds);
+  timeval timeout_obj;
+  timeval* timeout;
+  if (state & user_set_non_blocking)
+  {
+    timeout_obj.tv_sec = 0;
+    timeout_obj.tv_usec = 0;
+    timeout = &timeout_obj;
+  }
+  else if (msec >= 0)
+  {
+    timeout_obj.tv_sec = msec / 1000;
+    timeout_obj.tv_usec = (msec % 1000) * 1000;
+    timeout = &timeout_obj;
+  }
+  else
+    timeout = 0;
+  clear_last_error();
+  int result = error_wrapper(::select(s + 1, 0, &fds, 0, timeout), ec);
+#else // defined(ASIO_WINDOWS)
+      // || defined(__CYGWIN__)
+      // || defined(__SYMBIAN32__)
+  pollfd fds;
+  fds.fd = s;
+  fds.events = POLLOUT;
+  fds.revents = 0;
+  int timeout = (state & user_set_non_blocking) ? 0 : msec;
+  clear_last_error();
+  int result = error_wrapper(::poll(&fds, 1, timeout), ec);
+#endif // defined(ASIO_WINDOWS)
+       // || defined(__CYGWIN__)
+       // || defined(__SYMBIAN32__)
+  if (result == 0)
+    ec = (state & user_set_non_blocking)
+      ? asio::error::would_block : asio::error_code();
+  else if (result > 0)
+    ec = asio::error_code();
+  return result;
+}
+
+int poll_error(socket_type s, state_type state,
+    int msec, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return socket_error_retval;
+  }
+
+#if defined(ASIO_WINDOWS) \
+  || defined(__CYGWIN__) \
+  || defined(__SYMBIAN32__)
+  fd_set fds;
+  FD_ZERO(&fds);
+  FD_SET(s, &fds);
+  timeval timeout_obj;
+  timeval* timeout;
+  if (state & user_set_non_blocking)
+  {
+    timeout_obj.tv_sec = 0;
+    timeout_obj.tv_usec = 0;
+    timeout = &timeout_obj;
+  }
+  else if (msec >= 0)
+  {
+    timeout_obj.tv_sec = msec / 1000;
+    timeout_obj.tv_usec = (msec % 1000) * 1000;
+    timeout = &timeout_obj;
+  }
+  else
+    timeout = 0;
+  clear_last_error();
+  int result = error_wrapper(::select(s + 1, 0, 0, &fds, timeout), ec);
+#else // defined(ASIO_WINDOWS)
+      // || defined(__CYGWIN__)
+      // || defined(__SYMBIAN32__)
+  pollfd fds;
+  fds.fd = s;
+  fds.events = POLLPRI | POLLERR | POLLHUP;
+  fds.revents = 0;
+  int timeout = (state & user_set_non_blocking) ? 0 : msec;
+  clear_last_error();
+  int result = error_wrapper(::poll(&fds, 1, timeout), ec);
+#endif // defined(ASIO_WINDOWS)
+       // || defined(__CYGWIN__)
+       // || defined(__SYMBIAN32__)
+  if (result == 0)
+    ec = (state & user_set_non_blocking)
+      ? asio::error::would_block : asio::error_code();
+  else if (result > 0)
+    ec = asio::error_code();
+  return result;
+}
+
+int poll_connect(socket_type s, int msec, asio::error_code& ec)
+{
+  if (s == invalid_socket)
+  {
+    ec = asio::error::bad_descriptor;
+    return socket_error_retval;
+  }
+
+#if defined(ASIO_WINDOWS) \
+  || defined(__CYGWIN__) \
+  || defined(__SYMBIAN32__)
+  fd_set write_fds;
+  FD_ZERO(&write_fds);
+  FD_SET(s, &write_fds);
+  fd_set except_fds;
+  FD_ZERO(&except_fds);
+  FD_SET(s, &except_fds);
+  timeval timeout_obj;
+  timeval* timeout;
+  if (msec >= 0)
+  {
+    timeout_obj.tv_sec = msec / 1000;
+    timeout_obj.tv_usec = (msec % 1000) * 1000;
+    timeout = &timeout_obj;
+  }
+  else
+    timeout = 0;
+  clear_last_error();
+  int result = error_wrapper(::select(
+        s + 1, 0, &write_fds, &except_fds, timeout), ec);
+  if (result >= 0)
+    ec = asio::error_code();
+  return result;
+#else // defined(ASIO_WINDOWS)
+      // || defined(__CYGWIN__)
+      // || defined(__SYMBIAN32__)
+  pollfd fds;
+  fds.fd = s;
+  fds.events = POLLOUT;
+  fds.revents = 0;
+  clear_last_error();
+  int result = error_wrapper(::poll(&fds, 1, msec), ec);
+  if (result >= 0)
+    ec = asio::error_code();
+  return result;
+#endif // defined(ASIO_WINDOWS)
+       // || defined(__CYGWIN__)
+       // || defined(__SYMBIAN32__)
+}
+
+#endif // !defined(ASIO_WINDOWS_RUNTIME)
+
+const char* inet_ntop(int af, const void* src, char* dest, size_t length,
+    unsigned long scope_id, asio::error_code& ec)
+{
+  clear_last_error();
+#if defined(ASIO_WINDOWS_RUNTIME)
+  using namespace std; // For sprintf.
+  const unsigned char* bytes = static_cast<const unsigned char*>(src);
+  if (af == ASIO_OS_DEF(AF_INET))
+  {
+    sprintf_s(dest, length, "%u.%u.%u.%u",
+        bytes[0], bytes[1], bytes[2], bytes[3]);
+    return dest;
+  }
+  else if (af == ASIO_OS_DEF(AF_INET6))
+  {
+    size_t n = 0, b = 0, z = 0;
+    while (n < length && b < 16)
+    {
+      if (bytes[b] == 0 && bytes[b + 1] == 0 && z == 0)
+      {
+        do b += 2; while (b < 16 && bytes[b] == 0 && bytes[b + 1] == 0);
+        n += sprintf_s(dest + n, length - n, ":%s", b < 16 ? "" : ":"), ++z;
+      }
+      else
+      {
+        n += sprintf_s(dest + n, length - n, "%s%x", b ? ":" : "",
+            (static_cast<u_long_type>(bytes[b]) << 8) | bytes[b + 1]);
+        b += 2;
+      }
+    }
+    if (scope_id)
+      n += sprintf_s(dest + n, length - n, "%%%lu", scope_id);
+    return dest;
+  }
+  else
+  {
+    ec = asio::error::address_family_not_supported;
+    return 0;
+  }
+#elif defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  using namespace std; // For memcpy.
+
+  if (af != ASIO_OS_DEF(AF_INET) && af != ASIO_OS_DEF(AF_INET6))
+  {
+    ec = asio::error::address_family_not_supported;
+    return 0;
+  }
+
+  union
+  {
+    socket_addr_type base;
+    sockaddr_storage_type storage;
+    sockaddr_in4_type v4;
+    sockaddr_in6_type v6;
+  } address;
+  DWORD address_length;
+  if (af == ASIO_OS_DEF(AF_INET))
+  {
+    address_length = sizeof(sockaddr_in4_type);
+    address.v4.sin_family = ASIO_OS_DEF(AF_INET);
+    address.v4.sin_port = 0;
+    memcpy(&address.v4.sin_addr, src, sizeof(in4_addr_type));
+  }
+  else // AF_INET6
+  {
+    address_length = sizeof(sockaddr_in6_type);
+    address.v6.sin6_family = ASIO_OS_DEF(AF_INET6);
+    address.v6.sin6_port = 0;
+    address.v6.sin6_flowinfo = 0;
+    address.v6.sin6_scope_id = scope_id;
+    memcpy(&address.v6.sin6_addr, src, sizeof(in6_addr_type));
+  }
+
+  DWORD string_length = static_cast<DWORD>(length);
+#if defined(BOOST_NO_ANSI_APIS) || (defined(_MSC_VER) && (_MSC_VER >= 1800))
+  LPWSTR string_buffer = (LPWSTR)_alloca(length * sizeof(WCHAR));
+  int result = error_wrapper(::WSAAddressToStringW(&address.base,
+        address_length, 0, string_buffer, &string_length), ec);
+  ::WideCharToMultiByte(CP_ACP, 0, string_buffer, -1,
+      dest, static_cast<int>(length), 0, 0);
+#else
+  int result = error_wrapper(::WSAAddressToStringA(
+        &address.base, address_length, 0, dest, &string_length), ec);
+#endif
+
+  // Windows may set error code on success.
+  if (result != socket_error_retval)
+    ec = asio::error_code();
+
+  // Windows may not set an error code on failure.
+  else if (result == socket_error_retval && !ec)
+    ec = asio::error::invalid_argument;
+
+  return result == socket_error_retval ? 0 : dest;
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  const char* result = error_wrapper(::inet_ntop(
+        af, src, dest, static_cast<int>(length)), ec);
+  if (result == 0 && !ec)
+    ec = asio::error::invalid_argument;
+  if (result != 0 && af == ASIO_OS_DEF(AF_INET6) && scope_id != 0)
+  {
+    using namespace std; // For strcat and sprintf.
+    char if_name[IF_NAMESIZE + 1] = "%";
+    const in6_addr_type* ipv6_address = static_cast<const in6_addr_type*>(src);
+    bool is_link_local = ((ipv6_address->s6_addr[0] == 0xfe)
+        && ((ipv6_address->s6_addr[1] & 0xc0) == 0x80));
+    bool is_multicast_link_local = ((ipv6_address->s6_addr[0] == 0xff)
+        && ((ipv6_address->s6_addr[1] & 0x0f) == 0x02));
+    if ((!is_link_local && !is_multicast_link_local)
+        || if_indextoname(static_cast<unsigned>(scope_id), if_name + 1) == 0)
+      sprintf(if_name + 1, "%lu", scope_id);
+    strcat(dest, if_name);
+  }
+  return result;
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+}
+
+int inet_pton(int af, const char* src, void* dest,
+    unsigned long* scope_id, asio::error_code& ec)
+{
+  clear_last_error();
+#if defined(ASIO_WINDOWS_RUNTIME)
+  using namespace std; // For sscanf.
+  unsigned char* bytes = static_cast<unsigned char*>(dest);
+  if (af == ASIO_OS_DEF(AF_INET))
+  {
+    unsigned int b0, b1, b2, b3;
+    if (sscanf_s(src, "%u.%u.%u.%u", &b0, &b1, &b2, &b3) != 4)
+    {
+      ec = asio::error::invalid_argument;
+      return -1;
+    }
+    if (b0 > 255 || b1 > 255 || b2 > 255 || b3 > 255)
+    {
+      ec = asio::error::invalid_argument;
+      return -1;
+    }
+    bytes[0] = static_cast<unsigned char>(b0);
+    bytes[1] = static_cast<unsigned char>(b1);
+    bytes[2] = static_cast<unsigned char>(b2);
+    bytes[3] = static_cast<unsigned char>(b3);
+    ec = asio::error_code();
+    return 1;
+  }
+  else if (af == ASIO_OS_DEF(AF_INET6))
+  {
+    unsigned char* bytes = static_cast<unsigned char*>(dest);
+    std::memset(bytes, 0, 16);
+    unsigned char back_bytes[16] = { 0 };
+    int num_front_bytes = 0, num_back_bytes = 0;
+    const char* p = src;
+
+    enum { fword, fcolon, bword, scope, done } state = fword;
+    unsigned long current_word = 0;
+    while (state != done)
+    {
+      if (current_word > 0xFFFF)
+      {
+        ec = asio::error::invalid_argument;
+        return -1;
+      }
+
+      switch (state)
+      {
+      case fword:
+        if (*p >= '0' && *p <= '9')
+          current_word = current_word * 16 + *p++ - '0';
+        else if (*p >= 'a' && *p <= 'f')
+          current_word = current_word * 16 + *p++ - 'a' + 10;
+        else if (*p >= 'A' && *p <= 'F')
+          current_word = current_word * 16 + *p++ - 'A' + 10;
+        else
+        {
+          if (num_front_bytes == 16)
+          {
+            ec = asio::error::invalid_argument;
+            return -1;
+          }
+
+          bytes[num_front_bytes++] = (current_word >> 8) & 0xFF;
+          bytes[num_front_bytes++] = current_word & 0xFF;
+          current_word = 0;
+
+          if (*p == ':')
+            state = fcolon, ++p;
+          else if (*p == '%')
+            state = scope, ++p;
+          else if (*p == 0)
+            state = done;
+          else
+          {
+            ec = asio::error::invalid_argument;
+            return -1;
+          }
+        }
+        break;
+
+      case fcolon:
+        if (*p == ':')
+          state = bword, ++p;
+        else
+          state = fword;
+        break;
+
+      case bword:
+        if (*p >= '0' && *p <= '9')
+          current_word = current_word * 16 + *p++ - '0';
+        else if (*p >= 'a' && *p <= 'f')
+          current_word = current_word * 16 + *p++ - 'a' + 10;
+        else if (*p >= 'A' && *p <= 'F')
+          current_word = current_word * 16 + *p++ - 'A' + 10;
+        else
+        {
+          if (num_front_bytes + num_back_bytes == 16)
+          {
+            ec = asio::error::invalid_argument;
+            return -1;
+          }
+
+          back_bytes[num_back_bytes++] = (current_word >> 8) & 0xFF;
+          back_bytes[num_back_bytes++] = current_word & 0xFF;
+          current_word = 0;
+
+          if (*p == ':')
+            state = bword, ++p;
+          else if (*p == '%')
+            state = scope, ++p;
+          else if (*p == 0)
+            state = done;
+          else
+          {
+            ec = asio::error::invalid_argument;
+            return -1;
+          }
+        }
+        break;
+
+      case scope:
+        if (*p >= '0' && *p <= '9')
+          current_word = current_word * 10 + *p++ - '0';
+        else if (*p == 0)
+          *scope_id = current_word, state = done;
+        else
+        {
+          ec = asio::error::invalid_argument;
+          return -1;
+        }
+        break;
+
+      default:
+        break;
+      }
+    }
+
+    for (int i = 0; i < num_back_bytes; ++i)
+      bytes[16 - num_back_bytes + i] = back_bytes[i];
+
+    ec = asio::error_code();
+    return 1;
+  }
+  else
+  {
+    ec = asio::error::address_family_not_supported;
+    return -1;
+  }
+#elif defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  using namespace std; // For memcpy and strcmp.
+
+  if (af != ASIO_OS_DEF(AF_INET) && af != ASIO_OS_DEF(AF_INET6))
+  {
+    ec = asio::error::address_family_not_supported;
+    return -1;
+  }
+
+  union
+  {
+    socket_addr_type base;
+    sockaddr_storage_type storage;
+    sockaddr_in4_type v4;
+    sockaddr_in6_type v6;
+  } address;
+  int address_length = sizeof(sockaddr_storage_type);
+#if defined(BOOST_NO_ANSI_APIS) || (defined(_MSC_VER) && (_MSC_VER >= 1800))
+  int num_wide_chars = static_cast<int>(strlen(src)) + 1;
+  LPWSTR wide_buffer = (LPWSTR)_alloca(num_wide_chars * sizeof(WCHAR));
+  ::MultiByteToWideChar(CP_ACP, 0, src, -1, wide_buffer, num_wide_chars);
+  int result = error_wrapper(::WSAStringToAddressW(
+        wide_buffer, af, 0, &address.base, &address_length), ec);
+#else
+  int result = error_wrapper(::WSAStringToAddressA(
+        const_cast<char*>(src), af, 0, &address.base, &address_length), ec);
+#endif
+
+  if (af == ASIO_OS_DEF(AF_INET))
+  {
+    if (result != socket_error_retval)
+    {
+      memcpy(dest, &address.v4.sin_addr, sizeof(in4_addr_type));
+      ec = asio::error_code();
+    }
+    else if (strcmp(src, "255.255.255.255") == 0)
+    {
+      static_cast<in4_addr_type*>(dest)->s_addr = INADDR_NONE;
+      ec = asio::error_code();
+    }
+  }
+  else // AF_INET6
+  {
+    if (result != socket_error_retval)
+    {
+      memcpy(dest, &address.v6.sin6_addr, sizeof(in6_addr_type));
+      if (scope_id)
+        *scope_id = address.v6.sin6_scope_id;
+      ec = asio::error_code();
+    }
+  }
+
+  // Windows may not set an error code on failure.
+  if (result == socket_error_retval && !ec)
+    ec = asio::error::invalid_argument;
+
+  if (result != socket_error_retval)
+    ec = asio::error_code();
+
+  return result == socket_error_retval ? -1 : 1;
+#else // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  using namespace std; // For strchr, memcpy and atoi.
+
+  // On some platforms, inet_pton fails if an address string contains a scope
+  // id. Detect and remove the scope id before passing the string to inet_pton.
+  const bool is_v6 = (af == ASIO_OS_DEF(AF_INET6));
+  const char* if_name = is_v6 ? strchr(src, '%') : 0;
+  char src_buf[max_addr_v6_str_len + 1];
+  const char* src_ptr = src;
+  if (if_name != 0)
+  {
+    if (if_name - src > max_addr_v6_str_len)
+    {
+      ec = asio::error::invalid_argument;
+      return 0;
+    }
+    memcpy(src_buf, src, if_name - src);
+    src_buf[if_name - src] = 0;
+    src_ptr = src_buf;
+  }
+
+  int result = error_wrapper(::inet_pton(af, src_ptr, dest), ec);
+  if (result <= 0 && !ec)
+    ec = asio::error::invalid_argument;
+  if (result > 0 && is_v6 && scope_id)
+  {
+    using namespace std; // For strchr and atoi.
+    *scope_id = 0;
+    if (if_name != 0)
+    {
+      in6_addr_type* ipv6_address = static_cast<in6_addr_type*>(dest);
+      bool is_link_local = ((ipv6_address->s6_addr[0] == 0xfe)
+          && ((ipv6_address->s6_addr[1] & 0xc0) == 0x80));
+      bool is_multicast_link_local = ((ipv6_address->s6_addr[0] == 0xff)
+          && ((ipv6_address->s6_addr[1] & 0x0f) == 0x02));
+      if (is_link_local || is_multicast_link_local)
+        *scope_id = if_nametoindex(if_name + 1);
+      if (*scope_id == 0)
+        *scope_id = atoi(if_name + 1);
+    }
+  }
+  return result;
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+}
+
+int gethostname(char* name, int namelen, asio::error_code& ec)
+{
+  clear_last_error();
+#if defined(ASIO_WINDOWS_RUNTIME)
+  try
+  {
+    using namespace Windows::Foundation::Collections;
+    using namespace Windows::Networking;
+    using namespace Windows::Networking::Connectivity;
+    IVectorView<HostName^>^ hostnames = NetworkInformation::GetHostNames();
+    for (unsigned i = 0; i < hostnames->Size; ++i)
+    {
+      HostName^ hostname = hostnames->GetAt(i);
+      if (hostname->Type == HostNameType::DomainName)
+      {
+        std::wstring_convert<std::codecvt_utf8<wchar_t>> converter;
+        std::string raw_name = converter.to_bytes(hostname->RawName->Data());
+        if (namelen > 0 && raw_name.size() < static_cast<std::size_t>(namelen))
+        {
+          strcpy_s(name, namelen, raw_name.c_str());
+          return 0;
+        }
+      }
+    }
+    return -1;
+  }
+  catch (Platform::Exception^ e)
+  {
+    ec = asio::error_code(e->HResult,
+        asio::system_category());
+    return -1;
+  }
+#else // defined(ASIO_WINDOWS_RUNTIME)
+  int result = error_wrapper(::gethostname(name, namelen), ec);
+# if defined(ASIO_WINDOWS)
+  if (result == 0)
+    ec = asio::error_code();
+# endif // defined(ASIO_WINDOWS)
+  return result;
+#endif // defined(ASIO_WINDOWS_RUNTIME)
+}
+
+#if !defined(ASIO_WINDOWS_RUNTIME)
+
+#if !defined(ASIO_HAS_GETADDRINFO)
+
+// The following functions are only needed for emulation of getaddrinfo and
+// getnameinfo.
+
+inline asio::error_code translate_netdb_error(int error)
+{
+  switch (error)
+  {
+  case 0:
+    return asio::error_code();
+  case HOST_NOT_FOUND:
+    return asio::error::host_not_found;
+  case TRY_AGAIN:
+    return asio::error::host_not_found_try_again;
+  case NO_RECOVERY:
+    return asio::error::no_recovery;
+  case NO_DATA:
+    return asio::error::no_data;
+  default:
+    ASIO_ASSERT(false);
+    return asio::error::invalid_argument;
+  }
+}
+
+inline hostent* gethostbyaddr(const char* addr, int length, int af,
+    hostent* result, char* buffer, int buflength, asio::error_code& ec)
+{
+  clear_last_error();
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  (void)(buffer);
+  (void)(buflength);
+  hostent* retval = error_wrapper(::gethostbyaddr(addr, length, af), ec);
+  if (!retval)
+    return 0;
+  ec = asio::error_code();
+  *result = *retval;
+  return retval;
+#elif defined(__sun) || defined(__QNX__)
+  int error = 0;
+  hostent* retval = error_wrapper(::gethostbyaddr_r(addr, length, af, result,
+        buffer, buflength, &error), ec);
+  if (error)
+    ec = translate_netdb_error(error);
+  return retval;
+#elif defined(__MACH__) && defined(__APPLE__)
+  (void)(buffer);
+  (void)(buflength);
+  int error = 0;
+  hostent* retval = error_wrapper(::getipnodebyaddr(
+        addr, length, af, &error), ec);
+  if (error)
+    ec = translate_netdb_error(error);
+  if (!retval)
+    return 0;
+  *result = *retval;
+  return retval;
+#else
+  hostent* retval = 0;
+  int error = 0;
+  error_wrapper(::gethostbyaddr_r(addr, length, af, result, buffer,
+        buflength, &retval, &error), ec);
+  if (error)
+    ec = translate_netdb_error(error);
+  return retval;
+#endif
+}
+
+inline hostent* gethostbyname(const char* name, int af, struct hostent* result,
+    char* buffer, int buflength, int ai_flags, asio::error_code& ec)
+{
+  clear_last_error();
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+  (void)(buffer);
+  (void)(buflength);
+  (void)(ai_flags);
+  if (af != ASIO_OS_DEF(AF_INET))
+  {
+    ec = asio::error::address_family_not_supported;
+    return 0;
+  }
+  hostent* retval = error_wrapper(::gethostbyname(name), ec);
+  if (!retval)
+    return 0;
+  ec = asio::error_code();
+  *result = *retval;
+  return result;
+#elif defined(__sun) || defined(__QNX__)
+  (void)(ai_flags);
+  if (af != ASIO_OS_DEF(AF_INET))
+  {
+    ec = asio::error::address_family_not_supported;
+    return 0;
+  }
+  int error = 0;
+  hostent* retval = error_wrapper(::gethostbyname_r(name, result, buffer,
+        buflength, &error), ec);
+  if (error)
+    ec = translate_netdb_error(error);
+  return retval;
+#elif defined(__MACH__) && defined(__APPLE__)
+  (void)(buffer);
+  (void)(buflength);
+  int error = 0;
+  hostent* retval = error_wrapper(::getipnodebyname(
+        name, af, ai_flags, &error), ec);
+  if (error)
+    ec = translate_netdb_error(error);
+  if (!retval)
+    return 0;
+  *result = *retval;
+  return retval;
+#else
+  (void)(ai_flags);
+  if (af != ASIO_OS_DEF(AF_INET))
+  {
+    ec = asio::error::address_family_not_supported;
+    return 0;
+  }
+  hostent* retval = 0;
+  int error = 0;
+  error_wrapper(::gethostbyname_r(name, result,
+        buffer, buflength, &retval, &error), ec);
+  if (error)
+    ec = translate_netdb_error(error);
+  return retval;
+#endif
+}
+
+inline void freehostent(hostent* h)
+{
+#if defined(__MACH__) && defined(__APPLE__)
+  if (h)
+    ::freehostent(h);
+#else
+  (void)(h);
+#endif
+}
+
+// Emulation of getaddrinfo based on implementation in:
+// Stevens, W. R., UNIX Network Programming Vol. 1, 2nd Ed., Prentice-Hall 1998.
+
+struct gai_search
+{
+  const char* host;
+  int family;
+};
+
+inline int gai_nsearch(const char* host,
+    const addrinfo_type* hints, gai_search (&search)[2])
+{
+  int search_count = 0;
+  if (host == 0 || host[0] == '\0')
+  {
+    if (hints->ai_flags & AI_PASSIVE)
+    {
+      // No host and AI_PASSIVE implies wildcard bind.
+      switch (hints->ai_family)
+      {
+      case ASIO_OS_DEF(AF_INET):
+        search[search_count].host = "0.0.0.0";
+        search[search_count].family = ASIO_OS_DEF(AF_INET);
+        ++search_count;
+        break;
+      case ASIO_OS_DEF(AF_INET6):
+        search[search_count].host = "0::0";
+        search[search_count].family = ASIO_OS_DEF(AF_INET6);
+        ++search_count;
+        break;
+      case ASIO_OS_DEF(AF_UNSPEC):
+        search[search_count].host = "0::0";
+        search[search_count].family = ASIO_OS_DEF(AF_INET6);
+        ++search_count;
+        search[search_count].host = "0.0.0.0";
+        search[search_count].family = ASIO_OS_DEF(AF_INET);
+        ++search_count;
+        break;
+      default:
+        break;
+      }
+    }
+    else
+    {
+      // No host and not AI_PASSIVE means connect to local host.
+      switch (hints->ai_family)
+      {
+      case ASIO_OS_DEF(AF_INET):
+        search[search_count].host = "localhost";
+        search[search_count].family = ASIO_OS_DEF(AF_INET);
+        ++search_count;
+        break;
+      case ASIO_OS_DEF(AF_INET6):
+        search[search_count].host = "localhost";
+        search[search_count].family = ASIO_OS_DEF(AF_INET6);
+        ++search_count;
+        break;
+      case ASIO_OS_DEF(AF_UNSPEC):
+        search[search_count].host = "localhost";
+        search[search_count].family = ASIO_OS_DEF(AF_INET6);
+        ++search_count;
+        search[search_count].host = "localhost";
+        search[search_count].family = ASIO_OS_DEF(AF_INET);
+        ++search_count;
+        break;
+      default:
+        break;
+      }
+    }
+  }
+  else
+  {
+    // Host is specified.
+    switch (hints->ai_family)
+    {
+    case ASIO_OS_DEF(AF_INET):
+      search[search_count].host = host;
+      search[search_count].family = ASIO_OS_DEF(AF_INET);
+      ++search_count;
+      break;
+    case ASIO_OS_DEF(AF_INET6):
+      search[search_count].host = host;
+      search[search_count].family = ASIO_OS_DEF(AF_INET6);
+      ++search_count;
+      break;
+    case ASIO_OS_DEF(AF_UNSPEC):
+      search[search_count].host = host;
+      search[search_count].family = ASIO_OS_DEF(AF_INET6);
+      ++search_count;
+      search[search_count].host = host;
+      search[search_count].family = ASIO_OS_DEF(AF_INET);
+      ++search_count;
+      break;
+    default:
+      break;
+    }
+  }
+  return search_count;
+}
+
+template <typename T>
+inline T* gai_alloc(std::size_t size = sizeof(T))
+{
+  using namespace std;
+  T* p = static_cast<T*>(::operator new(size, std::nothrow));
+  if (p)
+    memset(p, 0, size);
+  return p;
+}
+
+inline void gai_free(void* p)
+{
+  ::operator delete(p);
+}
+
+inline void gai_strcpy(char* target, const char* source, std::size_t max_size)
+{
+  using namespace std;
+#if defined(ASIO_HAS_SECURE_RTL)
+  strcpy_s(target, max_size, source);
+#else // defined(ASIO_HAS_SECURE_RTL)
+  *target = 0;
+  if (max_size > 0)
+    strncat(target, source, max_size - 1);
+#endif // defined(ASIO_HAS_SECURE_RTL)
+}
+
+enum { gai_clone_flag = 1 << 30 };
+
+inline int gai_aistruct(addrinfo_type*** next, const addrinfo_type* hints,
+    const void* addr, int family)
+{
+  using namespace std;
+
+  addrinfo_type* ai = gai_alloc<addrinfo_type>();
+  if (ai == 0)
+    return EAI_MEMORY;
+
+  ai->ai_next = 0;
+  **next = ai;
+  *next = &ai->ai_next;
+
+  ai->ai_canonname = 0;
+  ai->ai_socktype = hints->ai_socktype;
+  if (ai->ai_socktype == 0)
+    ai->ai_flags |= gai_clone_flag;
+  ai->ai_protocol = hints->ai_protocol;
+  ai->ai_family = family;
+
+  switch (ai->ai_family)
+  {
+  case ASIO_OS_DEF(AF_INET):
+    {
+      sockaddr_in4_type* sinptr = gai_alloc<sockaddr_in4_type>();
+      if (sinptr == 0)
+        return EAI_MEMORY;
+      sinptr->sin_family = ASIO_OS_DEF(AF_INET);
+      memcpy(&sinptr->sin_addr, addr, sizeof(in4_addr_type));
+      ai->ai_addr = reinterpret_cast<sockaddr*>(sinptr);
+      ai->ai_addrlen = sizeof(sockaddr_in4_type);
+      break;
+    }
+  case ASIO_OS_DEF(AF_INET6):
+    {
+      sockaddr_in6_type* sin6ptr = gai_alloc<sockaddr_in6_type>();
+      if (sin6ptr == 0)
+        return EAI_MEMORY;
+      sin6ptr->sin6_family = ASIO_OS_DEF(AF_INET6);
+      memcpy(&sin6ptr->sin6_addr, addr, sizeof(in6_addr_type));
+      ai->ai_addr = reinterpret_cast<sockaddr*>(sin6ptr);
+      ai->ai_addrlen = sizeof(sockaddr_in6_type);
+      break;
+    }
+  default:
+    break;
+  }
+
+  return 0;
+}
+
+inline addrinfo_type* gai_clone(addrinfo_type* ai)
+{
+  using namespace std;
+
+  addrinfo_type* new_ai = gai_alloc<addrinfo_type>();
+  if (new_ai == 0)
+    return new_ai;
+
+  new_ai->ai_next = ai->ai_next;
+  ai->ai_next = new_ai;
+
+  new_ai->ai_flags = 0;
+  new_ai->ai_family = ai->ai_family;
+  new_ai->ai_socktype = ai->ai_socktype;
+  new_ai->ai_protocol = ai->ai_protocol;
+  new_ai->ai_canonname = 0;
+  new_ai->ai_addrlen = ai->ai_addrlen;
+  new_ai->ai_addr = gai_alloc<sockaddr>(ai->ai_addrlen);
+  memcpy(new_ai->ai_addr, ai->ai_addr, ai->ai_addrlen);
+
+  return new_ai;
+}
+
+inline int gai_port(addrinfo_type* aihead, int port, int socktype)
+{
+  int num_found = 0;
+
+  for (addrinfo_type* ai = aihead; ai; ai = ai->ai_next)
+  {
+    if (ai->ai_flags & gai_clone_flag)
+    {
+      if (ai->ai_socktype != 0)
+      {
+        ai = gai_clone(ai);
+        if (ai == 0)
+          return -1;
+        // ai now points to newly cloned entry.
+      }
+    }
+    else if (ai->ai_socktype != socktype)
+    {
+      // Ignore if mismatch on socket type.
+      continue;
+    }
+
+    ai->ai_socktype = socktype;
+
+    switch (ai->ai_family)
+    {
+    case ASIO_OS_DEF(AF_INET):
+      {
+        sockaddr_in4_type* sinptr =
+          reinterpret_cast<sockaddr_in4_type*>(ai->ai_addr);
+        sinptr->sin_port = port;
+        ++num_found;
+        break;
+      }
+    case ASIO_OS_DEF(AF_INET6):
+      {
+        sockaddr_in6_type* sin6ptr =
+          reinterpret_cast<sockaddr_in6_type*>(ai->ai_addr);
+        sin6ptr->sin6_port = port;
+        ++num_found;
+        break;
+      }
+    default:
+      break;
+    }
+  }
+
+  return num_found;
+}
+
+inline int gai_serv(addrinfo_type* aihead,
+    const addrinfo_type* hints, const char* serv)
+{
+  using namespace std;
+
+  int num_found = 0;
+
+  if (
+#if defined(AI_NUMERICSERV)
+      (hints->ai_flags & AI_NUMERICSERV) ||
+#endif
+      isdigit(static_cast<unsigned char>(serv[0])))
+  {
+    int port = htons(atoi(serv));
+    if (hints->ai_socktype)
+    {
+      // Caller specifies socket type.
+      int rc = gai_port(aihead, port, hints->ai_socktype);
+      if (rc < 0)
+        return EAI_MEMORY;
+      num_found += rc;
+    }
+    else
+    {
+      // Caller does not specify socket type.
+      int rc = gai_port(aihead, port, SOCK_STREAM);
+      if (rc < 0)
+        return EAI_MEMORY;
+      num_found += rc;
+      rc = gai_port(aihead, port, SOCK_DGRAM);
+      if (rc < 0)
+        return EAI_MEMORY;
+      num_found += rc;
+    }
+  }
+  else
+  {
+    // Try service name with TCP first, then UDP.
+    if (hints->ai_socktype == 0 || hints->ai_socktype == SOCK_STREAM)
+    {
+      servent* sptr = getservbyname(serv, "tcp");
+      if (sptr != 0)
+      {
+        int rc = gai_port(aihead, sptr->s_port, SOCK_STREAM);
+        if (rc < 0)
+          return EAI_MEMORY;
+        num_found += rc;
+      }
+    }
+    if (hints->ai_socktype == 0 || hints->ai_socktype == SOCK_DGRAM)
+    {
+      servent* sptr = getservbyname(serv, "udp");
+      if (sptr != 0)
+      {
+        int rc = gai_port(aihead, sptr->s_port, SOCK_DGRAM);
+        if (rc < 0)
+          return EAI_MEMORY;
+        num_found += rc;
+      }
+    }
+  }
+
+  if (num_found == 0)
+  {
+    if (hints->ai_socktype == 0)
+    {
+      // All calls to getservbyname() failed.
+      return EAI_NONAME;
+    }
+    else
+    {
+      // Service not supported for socket type.
+      return EAI_SERVICE;
+    }
+  }
+
+  return 0;
+}
+
+inline int gai_echeck(const char* host, const char* service,
+    int flags, int family, int socktype, int protocol)
+{
+  (void)(flags);
+  (void)(protocol);
+
+  // Host or service must be specified.
+  if (host == 0 || host[0] == '\0')
+    if (service == 0 || service[0] == '\0')
+      return EAI_NONAME;
+
+  // Check combination of family and socket type.
+  switch (family)
+  {
+  case ASIO_OS_DEF(AF_UNSPEC):
+    break;
+  case ASIO_OS_DEF(AF_INET):
+  case ASIO_OS_DEF(AF_INET6):
+    if (service != 0 && service[0] != '\0')
+      if (socktype != 0 && socktype != SOCK_STREAM && socktype != SOCK_DGRAM)
+        return EAI_SOCKTYPE;
+    break;
+  default:
+    return EAI_FAMILY;
+  }
+
+  return 0;
+}
+
+inline void freeaddrinfo_emulation(addrinfo_type* aihead)
+{
+  addrinfo_type* ai = aihead;
+  while (ai)
+  {
+    gai_free(ai->ai_addr);
+    gai_free(ai->ai_canonname);
+    addrinfo_type* ainext = ai->ai_next;
+    gai_free(ai);
+    ai = ainext;
+  }
+}
+
+inline int getaddrinfo_emulation(const char* host, const char* service,
+    const addrinfo_type* hintsp, addrinfo_type** result)
+{
+  // Set up linked list of addrinfo structures.
+  addrinfo_type* aihead = 0;
+  addrinfo_type** ainext = &aihead;
+  char* canon = 0;
+
+  // Supply default hints if not specified by caller.
+  addrinfo_type hints = addrinfo_type();
+  hints.ai_family = ASIO_OS_DEF(AF_UNSPEC);
+  if (hintsp)
+    hints = *hintsp;
+
+  // If the resolution is not specifically for AF_INET6, remove the AI_V4MAPPED
+  // and AI_ALL flags.
+#if defined(AI_V4MAPPED)
+  if (hints.ai_family != ASIO_OS_DEF(AF_INET6))
+    hints.ai_flags &= ~AI_V4MAPPED;
+#endif
+#if defined(AI_ALL)
+  if (hints.ai_family != ASIO_OS_DEF(AF_INET6))
+    hints.ai_flags &= ~AI_ALL;
+#endif
+
+  // Basic error checking.
+  int rc = gai_echeck(host, service, hints.ai_flags, hints.ai_family,
+      hints.ai_socktype, hints.ai_protocol);
+  if (rc != 0)
+  {
+    freeaddrinfo_emulation(aihead);
+    return rc;
+  }
+
+  gai_search search[2];
+  int search_count = gai_nsearch(host, &hints, search);
+  for (gai_search* sptr = search; sptr < search + search_count; ++sptr)
+  {
+    // Check for IPv4 dotted decimal string.
+    in4_addr_type inaddr;
+    asio::error_code ec;
+    if (socket_ops::inet_pton(ASIO_OS_DEF(AF_INET),
+          sptr->host, &inaddr, 0, ec) == 1)
+    {
+      if (hints.ai_family != ASIO_OS_DEF(AF_UNSPEC)
+          && hints.ai_family != ASIO_OS_DEF(AF_INET))
+      {
+        freeaddrinfo_emulation(aihead);
+        gai_free(canon);
+        return EAI_FAMILY;
+      }
+      if (sptr->family == ASIO_OS_DEF(AF_INET))
+      {
+        rc = gai_aistruct(&ainext, &hints, &inaddr, ASIO_OS_DEF(AF_INET));
+        if (rc != 0)
+        {
+          freeaddrinfo_emulation(aihead);
+          gai_free(canon);
+          return rc;
+        }
+      }
+      continue;
+    }
+
+    // Check for IPv6 hex string.
+    in6_addr_type in6addr;
+    if (socket_ops::inet_pton(ASIO_OS_DEF(AF_INET6),
+          sptr->host, &in6addr, 0, ec) == 1)
+    {
+      if (hints.ai_family != ASIO_OS_DEF(AF_UNSPEC)
+          && hints.ai_family != ASIO_OS_DEF(AF_INET6))
+      {
+        freeaddrinfo_emulation(aihead);
+        gai_free(canon);
+        return EAI_FAMILY;
+      }
+      if (sptr->family == ASIO_OS_DEF(AF_INET6))
+      {
+        rc = gai_aistruct(&ainext, &hints, &in6addr,
+            ASIO_OS_DEF(AF_INET6));
+        if (rc != 0)
+        {
+          freeaddrinfo_emulation(aihead);
+          gai_free(canon);
+          return rc;
+        }
+      }
+      continue;
+    }
+
+    // Look up hostname.
+    hostent hent;
+    char hbuf[8192] = "";
+    hostent* hptr = socket_ops::gethostbyname(sptr->host,
+        sptr->family, &hent, hbuf, sizeof(hbuf), hints.ai_flags, ec);
+    if (hptr == 0)
+    {
+      if (search_count == 2)
+      {
+        // Failure is OK if there are multiple searches.
+        continue;
+      }
+      freeaddrinfo_emulation(aihead);
+      gai_free(canon);
+      if (ec == asio::error::host_not_found)
+        return EAI_NONAME;
+      if (ec == asio::error::host_not_found_try_again)
+        return EAI_AGAIN;
+      if (ec == asio::error::no_recovery)
+        return EAI_FAIL;
+      if (ec == asio::error::no_data)
+        return EAI_NONAME;
+      return EAI_NONAME;
+    }
+
+    // Check for address family mismatch if one was specified.
+    if (hints.ai_family != ASIO_OS_DEF(AF_UNSPEC)
+        && hints.ai_family != hptr->h_addrtype)
+    {
+      freeaddrinfo_emulation(aihead);
+      gai_free(canon);
+      socket_ops::freehostent(hptr);
+      return EAI_FAMILY;
+    }
+
+    // Save canonical name first time.
+    if (host != 0 && host[0] != '\0' && hptr->h_name && hptr->h_name[0]
+        && (hints.ai_flags & AI_CANONNAME) && canon == 0)
+    {
+      std::size_t canon_len = strlen(hptr->h_name) + 1;
+      canon = gai_alloc<char>(canon_len);
+      if (canon == 0)
+      {
+        freeaddrinfo_emulation(aihead);
+        socket_ops::freehostent(hptr);
+        return EAI_MEMORY;
+      }
+      gai_strcpy(canon, hptr->h_name, canon_len);
+    }
+
+    // Create an addrinfo structure for each returned address.
+    for (char** ap = hptr->h_addr_list; *ap; ++ap)
+    {
+      rc = gai_aistruct(&ainext, &hints, *ap, hptr->h_addrtype);
+      if (rc != 0)
+      {
+        freeaddrinfo_emulation(aihead);
+        gai_free(canon);
+        socket_ops::freehostent(hptr);
+        return EAI_FAMILY;
+      }
+    }
+
+    socket_ops::freehostent(hptr);
+  }
+
+  // Check if we found anything.
+  if (aihead == 0)
+  {
+    gai_free(canon);
+    return EAI_NONAME;
+  }
+
+  // Return canonical name in first entry.
+  if (host != 0 && host[0] != '\0' && (hints.ai_flags & AI_CANONNAME))
+  {
+    if (canon)
+    {
+      aihead->ai_canonname = canon;
+      canon = 0;
+    }
+    else
+    {
+      std::size_t canonname_len = strlen(search[0].host) + 1;
+      aihead->ai_canonname = gai_alloc<char>(canonname_len);
+      if (aihead->ai_canonname == 0)
+      {
+        freeaddrinfo_emulation(aihead);
+        return EAI_MEMORY;
+      }
+      gai_strcpy(aihead->ai_canonname, search[0].host, canonname_len);
+    }
+  }
+  gai_free(canon);
+
+  // Process the service name.
+  if (service != 0 && service[0] != '\0')
+  {
+    rc = gai_serv(aihead, &hints, service);
+    if (rc != 0)
+    {
+      freeaddrinfo_emulation(aihead);
+      return rc;
+    }
+  }
+
+  // Return result to caller.
+  *result = aihead;
+  return 0;
+}
+
+inline asio::error_code getnameinfo_emulation(
+    const socket_addr_type* sa, std::size_t salen, char* host,
+    std::size_t hostlen, char* serv, std::size_t servlen, int flags,
+    asio::error_code& ec)
+{
+  using namespace std;
+
+  const char* addr;
+  size_t addr_len;
+  unsigned short port;
+  switch (sa->sa_family)
+  {
+  case ASIO_OS_DEF(AF_INET):
+    if (salen != sizeof(sockaddr_in4_type))
+    {
+      return ec = asio::error::invalid_argument;
+    }
+    addr = reinterpret_cast<const char*>(
+        &reinterpret_cast<const sockaddr_in4_type*>(sa)->sin_addr);
+    addr_len = sizeof(in4_addr_type);
+    port = reinterpret_cast<const sockaddr_in4_type*>(sa)->sin_port;
+    break;
+  case ASIO_OS_DEF(AF_INET6):
+    if (salen != sizeof(sockaddr_in6_type))
+    {
+      return ec = asio::error::invalid_argument;
+    }
+    addr = reinterpret_cast<const char*>(
+        &reinterpret_cast<const sockaddr_in6_type*>(sa)->sin6_addr);
+    addr_len = sizeof(in6_addr_type);
+    port = reinterpret_cast<const sockaddr_in6_type*>(sa)->sin6_port;
+    break;
+  default:
+    return ec = asio::error::address_family_not_supported;
+  }
+
+  if (host && hostlen > 0)
+  {
+    if (flags & NI_NUMERICHOST)
+    {
+      if (socket_ops::inet_ntop(sa->sa_family, addr, host, hostlen, 0, ec) == 0)
+      {
+        return ec;
+      }
+    }
+    else
+    {
+      hostent hent;
+      char hbuf[8192] = "";
+      hostent* hptr = socket_ops::gethostbyaddr(addr,
+          static_cast<int>(addr_len), sa->sa_family,
+          &hent, hbuf, sizeof(hbuf), ec);
+      if (hptr && hptr->h_name && hptr->h_name[0] != '\0')
+      {
+        if (flags & NI_NOFQDN)
+        {
+          char* dot = strchr(hptr->h_name, '.');
+          if (dot)
+          {
+            *dot = 0;
+          }
+        }
+        gai_strcpy(host, hptr->h_name, hostlen);
+        socket_ops::freehostent(hptr);
+      }
+      else
+      {
+        socket_ops::freehostent(hptr);
+        if (flags & NI_NAMEREQD)
+        {
+          return ec = asio::error::host_not_found;
+        }
+        if (socket_ops::inet_ntop(sa->sa_family,
+              addr, host, hostlen, 0, ec) == 0)
+        {
+          return ec;
+        }
+      }
+    }
+  }
+
+  if (serv && servlen > 0)
+  {
+    if (flags & NI_NUMERICSERV)
+    {
+      if (servlen < 6)
+      {
+        return ec = asio::error::no_buffer_space;
+      }
+#if defined(ASIO_HAS_SECURE_RTL)
+      sprintf_s(serv, servlen, "%u", ntohs(port));
+#else // defined(ASIO_HAS_SECURE_RTL)
+      sprintf(serv, "%u", ntohs(port));
+#endif // defined(ASIO_HAS_SECURE_RTL)
+    }
+    else
+    {
+#if defined(ASIO_HAS_PTHREADS)
+      static ::pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+      ::pthread_mutex_lock(&mutex);
+#endif // defined(ASIO_HAS_PTHREADS)
+      servent* sptr = ::getservbyport(port, (flags & NI_DGRAM) ? "udp" : 0);
+      if (sptr && sptr->s_name && sptr->s_name[0] != '\0')
+      {
+        gai_strcpy(serv, sptr->s_name, servlen);
+      }
+      else
+      {
+        if (servlen < 6)
+        {
+          return ec = asio::error::no_buffer_space;
+        }
+#if defined(ASIO_HAS_SECURE_RTL)
+        sprintf_s(serv, servlen, "%u", ntohs(port));
+#else // defined(ASIO_HAS_SECURE_RTL)
+        sprintf(serv, "%u", ntohs(port));
+#endif // defined(ASIO_HAS_SECURE_RTL)
+      }
+#if defined(ASIO_HAS_PTHREADS)
+      ::pthread_mutex_unlock(&mutex);
+#endif // defined(ASIO_HAS_PTHREADS)
+    }
+  }
+
+  ec = asio::error_code();
+  return ec;
+}
+
+#endif // !defined(ASIO_HAS_GETADDRINFO)
+
+inline asio::error_code translate_addrinfo_error(int error)
+{
+  switch (error)
+  {
+  case 0:
+    return asio::error_code();
+  case EAI_AGAIN:
+    return asio::error::host_not_found_try_again;
+  case EAI_BADFLAGS:
+    return asio::error::invalid_argument;
+  case EAI_FAIL:
+    return asio::error::no_recovery;
+  case EAI_FAMILY:
+    return asio::error::address_family_not_supported;
+  case EAI_MEMORY:
+    return asio::error::no_memory;
+  case EAI_NONAME:
+#if defined(EAI_ADDRFAMILY)
+  case EAI_ADDRFAMILY:
+#endif
+#if defined(EAI_NODATA) && (EAI_NODATA != EAI_NONAME)
+  case EAI_NODATA:
+#endif
+    return asio::error::host_not_found;
+  case EAI_SERVICE:
+    return asio::error::service_not_found;
+  case EAI_SOCKTYPE:
+    return asio::error::socket_type_not_supported;
+  default: // Possibly the non-portable EAI_SYSTEM.
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+    return asio::error_code(
+        WSAGetLastError(), asio::error::get_system_category());
+#else
+    return asio::error_code(
+        errno, asio::error::get_system_category());
+#endif
+  }
+}
+
+asio::error_code getaddrinfo(const char* host,
+    const char* service, const addrinfo_type& hints,
+    addrinfo_type** result, asio::error_code& ec)
+{
+  host = (host && *host) ? host : 0;
+  service = (service && *service) ? service : 0;
+  clear_last_error();
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+# if defined(ASIO_HAS_GETADDRINFO)
+  // Building for Windows XP, Windows Server 2003, or later.
+  int error = ::getaddrinfo(host, service, &hints, result);
+  return ec = translate_addrinfo_error(error);
+# else
+  // Building for Windows 2000 or earlier.
+  typedef int (WSAAPI *gai_t)(const char*,
+      const char*, const addrinfo_type*, addrinfo_type**);
+  if (HMODULE winsock_module = ::GetModuleHandleA("ws2_32"))
+  {
+    if (gai_t gai = (gai_t)::GetProcAddress(winsock_module, "getaddrinfo"))
+    {
+      int error = gai(host, service, &hints, result);
+      return ec = translate_addrinfo_error(error);
+    }
+  }
+  int error = getaddrinfo_emulation(host, service, &hints, result);
+  return ec = translate_addrinfo_error(error);
+# endif
+#elif !defined(ASIO_HAS_GETADDRINFO)
+  int error = getaddrinfo_emulation(host, service, &hints, result);
+  return ec = translate_addrinfo_error(error);
+#else
+  int error = ::getaddrinfo(host, service, &hints, result);
+#if defined(__MACH__) && defined(__APPLE__)
+  using namespace std; // For isdigit and atoi.
+  if (error == 0 && service && isdigit(static_cast<unsigned char>(service[0])))
+  {
+    u_short_type port = host_to_network_short(atoi(service));
+    for (addrinfo_type* ai = *result; ai; ai = ai->ai_next)
+    {
+      switch (ai->ai_family)
+      {
+      case ASIO_OS_DEF(AF_INET):
+        {
+          sockaddr_in4_type* sinptr =
+            reinterpret_cast<sockaddr_in4_type*>(ai->ai_addr);
+          if (sinptr->sin_port == 0)
+            sinptr->sin_port = port;
+          break;
+        }
+      case ASIO_OS_DEF(AF_INET6):
+        {
+          sockaddr_in6_type* sin6ptr =
+            reinterpret_cast<sockaddr_in6_type*>(ai->ai_addr);
+          if (sin6ptr->sin6_port == 0)
+            sin6ptr->sin6_port = port;
+          break;
+        }
+      default:
+        break;
+      }
+    }
+  }
+#endif
+  return ec = translate_addrinfo_error(error);
+#endif
+}
+
+asio::error_code background_getaddrinfo(
+    const weak_cancel_token_type& cancel_token, const char* host,
+    const char* service, const addrinfo_type& hints,
+    addrinfo_type** result, asio::error_code& ec)
+{
+  if (cancel_token.expired())
+    ec = asio::error::operation_aborted;
+  else
+    socket_ops::getaddrinfo(host, service, hints, result, ec);
+  return ec;
+}
+
+void freeaddrinfo(addrinfo_type* ai)
+{
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+# if defined(ASIO_HAS_GETADDRINFO)
+  // Building for Windows XP, Windows Server 2003, or later.
+  ::freeaddrinfo(ai);
+# else
+  // Building for Windows 2000 or earlier.
+  typedef int (WSAAPI *fai_t)(addrinfo_type*);
+  if (HMODULE winsock_module = ::GetModuleHandleA("ws2_32"))
+  {
+    if (fai_t fai = (fai_t)::GetProcAddress(winsock_module, "freeaddrinfo"))
+    {
+      fai(ai);
+      return;
+    }
+  }
+  freeaddrinfo_emulation(ai);
+# endif
+#elif !defined(ASIO_HAS_GETADDRINFO)
+  freeaddrinfo_emulation(ai);
+#else
+  ::freeaddrinfo(ai);
+#endif
+}
+
+asio::error_code getnameinfo(const socket_addr_type* addr,
+    std::size_t addrlen, char* host, std::size_t hostlen,
+    char* serv, std::size_t servlen, int flags, asio::error_code& ec)
+{
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+# if defined(ASIO_HAS_GETADDRINFO)
+  // Building for Windows XP, Windows Server 2003, or later.
+  clear_last_error();
+  int error = ::getnameinfo(addr, static_cast<socklen_t>(addrlen),
+      host, static_cast<DWORD>(hostlen),
+      serv, static_cast<DWORD>(servlen), flags);
+  return ec = translate_addrinfo_error(error);
+# else
+  // Building for Windows 2000 or earlier.
+  typedef int (WSAAPI *gni_t)(const socket_addr_type*,
+      int, char*, DWORD, char*, DWORD, int);
+  if (HMODULE winsock_module = ::GetModuleHandleA("ws2_32"))
+  {
+    if (gni_t gni = (gni_t)::GetProcAddress(winsock_module, "getnameinfo"))
+    {
+      clear_last_error();
+      int error = gni(addr, static_cast<int>(addrlen),
+          host, static_cast<DWORD>(hostlen),
+          serv, static_cast<DWORD>(servlen), flags);
+      return ec = translate_addrinfo_error(error);
+    }
+  }
+  clear_last_error();
+  return getnameinfo_emulation(addr, addrlen,
+      host, hostlen, serv, servlen, flags, ec);
+# endif
+#elif !defined(ASIO_HAS_GETADDRINFO)
+  using namespace std; // For memcpy.
+  sockaddr_storage_type tmp_addr;
+  memcpy(&tmp_addr, addr, addrlen);
+  addr = reinterpret_cast<socket_addr_type*>(&tmp_addr);
+  clear_last_error();
+  return getnameinfo_emulation(addr, addrlen,
+      host, hostlen, serv, servlen, flags, ec);
+#else
+  clear_last_error();
+  int error = ::getnameinfo(addr, addrlen, host, hostlen, serv, servlen, flags);
+  return ec = translate_addrinfo_error(error);
+#endif
+}
+
+asio::error_code sync_getnameinfo(
+    const socket_addr_type* addr, std::size_t addrlen,
+    char* host, std::size_t hostlen, char* serv,
+    std::size_t servlen, int sock_type, asio::error_code& ec)
+{
+  // First try resolving with the service name. If that fails try resolving
+  // but allow the service to be returned as a number.
+  int flags = (sock_type == SOCK_DGRAM) ? NI_DGRAM : 0;
+  socket_ops::getnameinfo(addr, addrlen, host,
+      hostlen, serv, servlen, flags, ec);
+  if (ec)
+  {
+    socket_ops::getnameinfo(addr, addrlen, host, hostlen,
+        serv, servlen, flags | NI_NUMERICSERV, ec);
+  }
+
+  return ec;
+}
+
+asio::error_code background_getnameinfo(
+    const weak_cancel_token_type& cancel_token,
+    const socket_addr_type* addr, std::size_t addrlen,
+    char* host, std::size_t hostlen, char* serv,
+    std::size_t servlen, int sock_type, asio::error_code& ec)
+{
+  if (cancel_token.expired())
+  {
+    ec = asio::error::operation_aborted;
+  }
+  else
+  {
+    // First try resolving with the service name. If that fails try resolving
+    // but allow the service to be returned as a number.
+    int flags = (sock_type == SOCK_DGRAM) ? NI_DGRAM : 0;
+    socket_ops::getnameinfo(addr, addrlen, host,
+        hostlen, serv, servlen, flags, ec);
+    if (ec)
+    {
+      socket_ops::getnameinfo(addr, addrlen, host, hostlen,
+          serv, servlen, flags | NI_NUMERICSERV, ec);
+    }
+  }
+
+  return ec;
+}
+
+#endif // !defined(ASIO_WINDOWS_RUNTIME)
+
+u_long_type network_to_host_long(u_long_type value)
+{
+#if defined(ASIO_WINDOWS_RUNTIME)
+  unsigned char* value_p = reinterpret_cast<unsigned char*>(&value);
+  u_long_type result = (static_cast<u_long_type>(value_p[0]) << 24)
+    | (static_cast<u_long_type>(value_p[1]) << 16)
+    | (static_cast<u_long_type>(value_p[2]) << 8)
+    | static_cast<u_long_type>(value_p[3]);
+  return result;
+#else // defined(ASIO_WINDOWS_RUNTIME)
+  return ntohl(value);
+#endif // defined(ASIO_WINDOWS_RUNTIME)
+}
+
+u_long_type host_to_network_long(u_long_type value)
+{
+#if defined(ASIO_WINDOWS_RUNTIME)
+  u_long_type result;
+  unsigned char* result_p = reinterpret_cast<unsigned char*>(&result);
+  result_p[0] = static_cast<unsigned char>((value >> 24) & 0xFF);
+  result_p[1] = static_cast<unsigned char>((value >> 16) & 0xFF);
+  result_p[2] = static_cast<unsigned char>((value >> 8) & 0xFF);
+  result_p[3] = static_cast<unsigned char>(value & 0xFF);
+  return result;
+#else // defined(ASIO_WINDOWS_RUNTIME)
+  return htonl(value);
+#endif // defined(ASIO_WINDOWS_RUNTIME)
+}
+
+u_short_type network_to_host_short(u_short_type value)
+{
+#if defined(ASIO_WINDOWS_RUNTIME)
+  unsigned char* value_p = reinterpret_cast<unsigned char*>(&value);
+  u_short_type result = (static_cast<u_short_type>(value_p[0]) << 8)
+    | static_cast<u_short_type>(value_p[1]);
+  return result;
+#else // defined(ASIO_WINDOWS_RUNTIME)
+  return ntohs(value);
+#endif // defined(ASIO_WINDOWS_RUNTIME)
+}
+
+u_short_type host_to_network_short(u_short_type value)
+{
+#if defined(ASIO_WINDOWS_RUNTIME)
+  u_short_type result;
+  unsigned char* result_p = reinterpret_cast<unsigned char*>(&result);
+  result_p[0] = static_cast<unsigned char>((value >> 8) & 0xFF);
+  result_p[1] = static_cast<unsigned char>(value & 0xFF);
+  return result;
+#else // defined(ASIO_WINDOWS_RUNTIME)
+  return htons(value);
+#endif // defined(ASIO_WINDOWS_RUNTIME)
+}
+
+} // namespace socket_ops
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_SOCKET_OPS_IPP
diff --git a/lib/asio/detail/impl/socket_select_interrupter.ipp b/lib/asio/detail/impl/socket_select_interrupter.ipp
new file mode 100644
index 0000000..052f2a7
--- /dev/null
+++ b/lib/asio/detail/impl/socket_select_interrupter.ipp
@@ -0,0 +1,176 @@
+//
+// detail/impl/socket_select_interrupter.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_SOCKET_SELECT_INTERRUPTER_IPP
+#define ASIO_DETAIL_IMPL_SOCKET_SELECT_INTERRUPTER_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if !defined(ASIO_WINDOWS_RUNTIME)
+
+#if defined(ASIO_WINDOWS) \
+  || defined(__CYGWIN__) \
+  || defined(__SYMBIAN32__)
+
+#include <cstdlib>
+#include "asio/detail/socket_holder.hpp"
+#include "asio/detail/socket_ops.hpp"
+#include "asio/detail/socket_select_interrupter.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+socket_select_interrupter::socket_select_interrupter()
+{
+  open_descriptors();
+}
+
+void socket_select_interrupter::open_descriptors()
+{
+  asio::error_code ec;
+  socket_holder acceptor(socket_ops::socket(
+        AF_INET, SOCK_STREAM, IPPROTO_TCP, ec));
+  if (acceptor.get() == invalid_socket)
+    asio::detail::throw_error(ec, "socket_select_interrupter");
+
+  int opt = 1;
+  socket_ops::state_type acceptor_state = 0;
+  socket_ops::setsockopt(acceptor.get(), acceptor_state,
+      SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt), ec);
+
+  using namespace std; // For memset.
+  sockaddr_in4_type addr;
+  std::size_t addr_len = sizeof(addr);
+  memset(&addr, 0, sizeof(addr));
+  addr.sin_family = AF_INET;
+  addr.sin_addr.s_addr = socket_ops::host_to_network_long(INADDR_LOOPBACK);
+  addr.sin_port = 0;
+  if (socket_ops::bind(acceptor.get(), (const socket_addr_type*)&addr,
+        addr_len, ec) == socket_error_retval)
+    asio::detail::throw_error(ec, "socket_select_interrupter");
+
+  if (socket_ops::getsockname(acceptor.get(), (socket_addr_type*)&addr,
+        &addr_len, ec) == socket_error_retval)
+    asio::detail::throw_error(ec, "socket_select_interrupter");
+
+  // Some broken firewalls on Windows will intermittently cause getsockname to
+  // return 0.0.0.0 when the socket is actually bound to 127.0.0.1. We
+  // explicitly specify the target address here to work around this problem.
+  if (addr.sin_addr.s_addr == socket_ops::host_to_network_long(INADDR_ANY))
+    addr.sin_addr.s_addr = socket_ops::host_to_network_long(INADDR_LOOPBACK);
+
+  if (socket_ops::listen(acceptor.get(),
+        SOMAXCONN, ec) == socket_error_retval)
+    asio::detail::throw_error(ec, "socket_select_interrupter");
+
+  socket_holder client(socket_ops::socket(
+        AF_INET, SOCK_STREAM, IPPROTO_TCP, ec));
+  if (client.get() == invalid_socket)
+    asio::detail::throw_error(ec, "socket_select_interrupter");
+
+  if (socket_ops::connect(client.get(), (const socket_addr_type*)&addr,
+        addr_len, ec) == socket_error_retval)
+    asio::detail::throw_error(ec, "socket_select_interrupter");
+
+  socket_holder server(socket_ops::accept(acceptor.get(), 0, 0, ec));
+  if (server.get() == invalid_socket)
+    asio::detail::throw_error(ec, "socket_select_interrupter");
+  
+  ioctl_arg_type non_blocking = 1;
+  socket_ops::state_type client_state = 0;
+  if (socket_ops::ioctl(client.get(), client_state,
+        FIONBIO, &non_blocking, ec))
+    asio::detail::throw_error(ec, "socket_select_interrupter");
+
+  opt = 1;
+  socket_ops::setsockopt(client.get(), client_state,
+      IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt), ec);
+
+  non_blocking = 1;
+  socket_ops::state_type server_state = 0;
+  if (socket_ops::ioctl(server.get(), server_state,
+        FIONBIO, &non_blocking, ec))
+    asio::detail::throw_error(ec, "socket_select_interrupter");
+
+  opt = 1;
+  socket_ops::setsockopt(server.get(), server_state,
+      IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt), ec);
+
+  read_descriptor_ = server.release();
+  write_descriptor_ = client.release();
+}
+
+socket_select_interrupter::~socket_select_interrupter()
+{
+  close_descriptors();
+}
+
+void socket_select_interrupter::close_descriptors()
+{
+  asio::error_code ec;
+  socket_ops::state_type state = socket_ops::internal_non_blocking;
+  if (read_descriptor_ != invalid_socket)
+    socket_ops::close(read_descriptor_, state, true, ec);
+  if (write_descriptor_ != invalid_socket)
+    socket_ops::close(write_descriptor_, state, true, ec);
+}
+
+void socket_select_interrupter::recreate()
+{
+  close_descriptors();
+
+  write_descriptor_ = invalid_socket;
+  read_descriptor_ = invalid_socket;
+
+  open_descriptors();
+}
+
+void socket_select_interrupter::interrupt()
+{
+  char byte = 0;
+  socket_ops::buf b;
+  socket_ops::init_buf(b, &byte, 1);
+  asio::error_code ec;
+  socket_ops::send(write_descriptor_, &b, 1, 0, ec);
+}
+
+bool socket_select_interrupter::reset()
+{
+  char data[1024];
+  socket_ops::buf b;
+  socket_ops::init_buf(b, data, sizeof(data));
+  asio::error_code ec;
+  int bytes_read = socket_ops::recv(read_descriptor_, &b, 1, 0, ec);
+  bool was_interrupted = (bytes_read > 0);
+  while (bytes_read == sizeof(data))
+    bytes_read = socket_ops::recv(read_descriptor_, &b, 1, 0, ec);
+  return was_interrupted;
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_WINDOWS)
+       // || defined(__CYGWIN__)
+       // || defined(__SYMBIAN32__)
+
+#endif // !defined(ASIO_WINDOWS_RUNTIME)
+
+#endif // ASIO_DETAIL_IMPL_SOCKET_SELECT_INTERRUPTER_IPP
diff --git a/lib/asio/detail/impl/strand_executor_service.hpp b/lib/asio/detail/impl/strand_executor_service.hpp
new file mode 100644
index 0000000..0e18ca0
--- /dev/null
+++ b/lib/asio/detail/impl/strand_executor_service.hpp
@@ -0,0 +1,179 @@
+//
+// detail/impl/strand_executor_service.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_STRAND_EXECUTOR_SERVICE_HPP
+#define ASIO_DETAIL_IMPL_STRAND_EXECUTOR_SERVICE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/call_stack.hpp"
+#include "asio/detail/fenced_block.hpp"
+#include "asio/detail/handler_invoke_helpers.hpp"
+#include "asio/detail/recycling_allocator.hpp"
+#include "asio/executor_work_guard.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename Executor>
+class strand_executor_service::invoker
+{
+public:
+  invoker(const implementation_type& impl, Executor& ex)
+    : impl_(impl),
+      work_(ex)
+  {
+  }
+
+  invoker(const invoker& other)
+    : impl_(other.impl_),
+      work_(other.work_)
+  {
+  }
+
+#if defined(ASIO_HAS_MOVE)
+  invoker(invoker&& other)
+    : impl_(ASIO_MOVE_CAST(implementation_type)(other.impl_)),
+      work_(ASIO_MOVE_CAST(executor_work_guard<Executor>)(other.work_))
+  {
+  }
+#endif // defined(ASIO_HAS_MOVE)
+
+  struct on_invoker_exit
+  {
+    invoker* this_;
+
+    ~on_invoker_exit()
+    {
+      this_->impl_->mutex_->lock();
+      this_->impl_->ready_queue_.push(this_->impl_->waiting_queue_);
+      bool more_handlers = this_->impl_->locked_ =
+        !this_->impl_->ready_queue_.empty();
+      this_->impl_->mutex_->unlock();
+
+      if (more_handlers)
+      {
+        Executor ex(this_->work_.get_executor());
+        recycling_allocator<void> allocator;
+        ex.post(ASIO_MOVE_CAST(invoker)(*this_), allocator);
+      }
+    }
+  };
+
+  void operator()()
+  {
+    // Indicate that this strand is executing on the current thread.
+    call_stack<strand_impl>::context ctx(impl_.get());
+
+    // Ensure the next handler, if any, is scheduled on block exit.
+    on_invoker_exit on_exit = { this };
+    (void)on_exit;
+
+    // Run all ready handlers. No lock is required since the ready queue is
+    // accessed only within the strand.
+    asio::error_code ec;
+    while (scheduler_operation* o = impl_->ready_queue_.front())
+    {
+      impl_->ready_queue_.pop();
+      o->complete(impl_.get(), ec, 0);
+    }
+  }
+
+private:
+  implementation_type impl_;
+  executor_work_guard<Executor> work_;
+};
+
+template <typename Executor, typename Function, typename Allocator>
+void strand_executor_service::dispatch(const implementation_type& impl,
+    Executor& ex, ASIO_MOVE_ARG(Function) function, const Allocator& a)
+{
+  typedef typename decay<Function>::type function_type;
+
+  // If we are already in the strand then the function can run immediately.
+  if (call_stack<strand_impl>::contains(impl.get()))
+  {
+    // Make a local, non-const copy of the function.
+    function_type tmp(ASIO_MOVE_CAST(Function)(function));
+
+    fenced_block b(fenced_block::full);
+    asio_handler_invoke_helpers::invoke(tmp, tmp);
+    return;
+  }
+
+  // Allocate and construct an operation to wrap the function.
+  typedef executor_op<function_type, Allocator> op;
+  typename op::ptr p = { detail::addressof(a), op::ptr::allocate(a), 0 };
+  p.p = new (p.v) op(ASIO_MOVE_CAST(Function)(function), a);
+
+  ASIO_HANDLER_CREATION((impl->service_->context(), *p.p,
+        "strand_executor", impl.get(), 0, "dispatch"));
+
+  // Add the function to the strand and schedule the strand if required.
+  bool first = enqueue(impl, p.p);
+  p.v = p.p = 0;
+  if (first)
+    ex.dispatch(invoker<Executor>(impl, ex), a);
+}
+
+// Request invocation of the given function and return immediately.
+template <typename Executor, typename Function, typename Allocator>
+void strand_executor_service::post(const implementation_type& impl,
+    Executor& ex, ASIO_MOVE_ARG(Function) function, const Allocator& a)
+{
+  typedef typename decay<Function>::type function_type;
+
+  // Allocate and construct an operation to wrap the function.
+  typedef executor_op<function_type, Allocator> op;
+  typename op::ptr p = { detail::addressof(a), op::ptr::allocate(a), 0 };
+  p.p = new (p.v) op(ASIO_MOVE_CAST(Function)(function), a);
+
+  ASIO_HANDLER_CREATION((impl->service_->context(), *p.p,
+        "strand_executor", impl.get(), 0, "post"));
+
+  // Add the function to the strand and schedule the strand if required.
+  bool first = enqueue(impl, p.p);
+  p.v = p.p = 0;
+  if (first)
+    ex.post(invoker<Executor>(impl, ex), a);
+}
+
+// Request invocation of the given function and return immediately.
+template <typename Executor, typename Function, typename Allocator>
+void strand_executor_service::defer(const implementation_type& impl,
+    Executor& ex, ASIO_MOVE_ARG(Function) function, const Allocator& a)
+{
+  typedef typename decay<Function>::type function_type;
+
+  // Allocate and construct an operation to wrap the function.
+  typedef executor_op<function_type, Allocator> op;
+  typename op::ptr p = { detail::addressof(a), op::ptr::allocate(a), 0 };
+  p.p = new (p.v) op(ASIO_MOVE_CAST(Function)(function), a);
+
+  ASIO_HANDLER_CREATION((impl->service_->context(), *p.p,
+        "strand_executor", impl.get(), 0, "defer"));
+
+  // Add the function to the strand and schedule the strand if required.
+  bool first = enqueue(impl, p.p);
+  p.v = p.p = 0;
+  if (first)
+    ex.defer(invoker<Executor>(impl, ex), a);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_IMPL_STRAND_EXECUTOR_SERVICE_HPP
diff --git a/lib/asio/detail/impl/strand_executor_service.ipp b/lib/asio/detail/impl/strand_executor_service.ipp
new file mode 100644
index 0000000..365652e
--- /dev/null
+++ b/lib/asio/detail/impl/strand_executor_service.ipp
@@ -0,0 +1,134 @@
+//
+// detail/impl/strand_executor_service.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_STRAND_EXECUTOR_SERVICE_IPP
+#define ASIO_DETAIL_IMPL_STRAND_EXECUTOR_SERVICE_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/strand_executor_service.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+strand_executor_service::strand_executor_service(execution_context& ctx)
+  : execution_context_service_base<strand_executor_service>(ctx),
+    mutex_(),
+    salt_(0),
+    impl_list_(0)
+{
+}
+
+void strand_executor_service::shutdown()
+{
+  op_queue<scheduler_operation> ops;
+
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  strand_impl* impl = impl_list_;
+  while (impl)
+  {
+    impl->mutex_->lock();
+    impl->shutdown_ = true;
+    ops.push(impl->waiting_queue_);
+    ops.push(impl->ready_queue_);
+    impl->mutex_->unlock();
+    impl = impl->next_;
+  }
+}
+
+strand_executor_service::implementation_type
+strand_executor_service::create_implementation()
+{
+  implementation_type new_impl(new strand_impl);
+  new_impl->locked_ = false;
+  new_impl->shutdown_ = false;
+
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  // Select a mutex from the pool of shared mutexes.
+  std::size_t salt = salt_++;
+  std::size_t mutex_index = reinterpret_cast<std::size_t>(new_impl.get());
+  mutex_index += (reinterpret_cast<std::size_t>(new_impl.get()) >> 3);
+  mutex_index ^= salt + 0x9e3779b9 + (mutex_index << 6) + (mutex_index >> 2);
+  mutex_index = mutex_index % num_mutexes;
+  if (!mutexes_[mutex_index].get())
+    mutexes_[mutex_index].reset(new mutex);
+  new_impl->mutex_ = mutexes_[mutex_index].get();
+
+  // Insert implementation into linked list of all implementations.
+  new_impl->next_ = impl_list_;
+  new_impl->prev_ = 0;
+  if (impl_list_)
+    impl_list_->prev_ = new_impl.get();
+  impl_list_ = new_impl.get();
+  new_impl->service_ = this;
+
+  return new_impl;
+}
+
+strand_executor_service::strand_impl::~strand_impl()
+{
+  asio::detail::mutex::scoped_lock lock(service_->mutex_);
+
+  // Remove implementation from linked list of all implementations.
+  if (service_->impl_list_ == this)
+    service_->impl_list_ = next_;
+  if (prev_)
+    prev_->next_ = next_;
+  if (next_)
+    next_->prev_= prev_;
+}
+
+bool strand_executor_service::enqueue(const implementation_type& impl,
+    scheduler_operation* op)
+{
+  impl->mutex_->lock();
+  if (impl->shutdown_)
+  {
+    impl->mutex_->unlock();
+    op->destroy();
+    return false;
+  }
+  else if (impl->locked_)
+  {
+    // Some other function already holds the strand lock. Enqueue for later.
+    impl->waiting_queue_.push(op);
+    impl->mutex_->unlock();
+    return false;
+  }
+  else
+  {
+    // The function is acquiring the strand lock and so is responsible for
+    // scheduling the strand.
+    impl->locked_ = true;
+    impl->mutex_->unlock();
+    impl->ready_queue_.push(op);
+    return true;
+  }
+}
+
+bool strand_executor_service::running_in_this_thread(
+    const implementation_type& impl)
+{
+  return !!call_stack<strand_impl>::contains(impl.get());
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_IMPL_STRAND_EXECUTOR_SERVICE_IPP
diff --git a/lib/asio/detail/impl/strand_service.hpp b/lib/asio/detail/impl/strand_service.hpp
new file mode 100644
index 0000000..da5b716
--- /dev/null
+++ b/lib/asio/detail/impl/strand_service.hpp
@@ -0,0 +1,118 @@
+//
+// detail/impl/strand_service.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_STRAND_SERVICE_HPP
+#define ASIO_DETAIL_IMPL_STRAND_SERVICE_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/call_stack.hpp"
+#include "asio/detail/completion_handler.hpp"
+#include "asio/detail/fenced_block.hpp"
+#include "asio/detail/handler_alloc_helpers.hpp"
+#include "asio/detail/handler_invoke_helpers.hpp"
+#include "asio/detail/memory.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+inline strand_service::strand_impl::strand_impl()
+  : operation(&strand_service::do_complete),
+    locked_(false)
+{
+}
+
+struct strand_service::on_dispatch_exit
+{
+  io_context_impl* io_context_;
+  strand_impl* impl_;
+
+  ~on_dispatch_exit()
+  {
+    impl_->mutex_.lock();
+    impl_->ready_queue_.push(impl_->waiting_queue_);
+    bool more_handlers = impl_->locked_ = !impl_->ready_queue_.empty();
+    impl_->mutex_.unlock();
+
+    if (more_handlers)
+      io_context_->post_immediate_completion(impl_, false);
+  }
+};
+
+template <typename Handler>
+void strand_service::dispatch(strand_service::implementation_type& impl,
+    Handler& handler)
+{
+  // If we are already in the strand then the handler can run immediately.
+  if (call_stack<strand_impl>::contains(impl))
+  {
+    fenced_block b(fenced_block::full);
+    asio_handler_invoke_helpers::invoke(handler, handler);
+    return;
+  }
+
+  // Allocate and construct an operation to wrap the handler.
+  typedef completion_handler<Handler> op;
+  typename op::ptr p = { asio::detail::addressof(handler),
+    op::ptr::allocate(handler), 0 };
+  p.p = new (p.v) op(handler);
+
+  ASIO_HANDLER_CREATION((this->context(),
+        *p.p, "strand", impl, 0, "dispatch"));
+
+  bool dispatch_immediately = do_dispatch(impl, p.p);
+  operation* o = p.p;
+  p.v = p.p = 0;
+
+  if (dispatch_immediately)
+  {
+    // Indicate that this strand is executing on the current thread.
+    call_stack<strand_impl>::context ctx(impl);
+
+    // Ensure the next handler, if any, is scheduled on block exit.
+    on_dispatch_exit on_exit = { &io_context_, impl };
+    (void)on_exit;
+
+    completion_handler<Handler>::do_complete(
+        &io_context_, o, asio::error_code(), 0);
+  }
+}
+
+// Request the io_context to invoke the given handler and return immediately.
+template <typename Handler>
+void strand_service::post(strand_service::implementation_type& impl,
+    Handler& handler)
+{
+  bool is_continuation =
+    asio_handler_cont_helpers::is_continuation(handler);
+
+  // Allocate and construct an operation to wrap the handler.
+  typedef completion_handler<Handler> op;
+  typename op::ptr p = { asio::detail::addressof(handler),
+    op::ptr::allocate(handler), 0 };
+  p.p = new (p.v) op(handler);
+
+  ASIO_HANDLER_CREATION((this->context(),
+        *p.p, "strand", impl, 0, "post"));
+
+  do_post(impl, p.p, is_continuation);
+  p.v = p.p = 0;
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_IMPL_STRAND_SERVICE_HPP
diff --git a/lib/asio/detail/impl/strand_service.ipp b/lib/asio/detail/impl/strand_service.ipp
new file mode 100644
index 0000000..cbaf25b
--- /dev/null
+++ b/lib/asio/detail/impl/strand_service.ipp
@@ -0,0 +1,177 @@
+//
+// detail/impl/strand_service.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_STRAND_SERVICE_IPP
+#define ASIO_DETAIL_IMPL_STRAND_SERVICE_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/call_stack.hpp"
+#include "asio/detail/strand_service.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+struct strand_service::on_do_complete_exit
+{
+  io_context_impl* owner_;
+  strand_impl* impl_;
+
+  ~on_do_complete_exit()
+  {
+    impl_->mutex_.lock();
+    impl_->ready_queue_.push(impl_->waiting_queue_);
+    bool more_handlers = impl_->locked_ = !impl_->ready_queue_.empty();
+    impl_->mutex_.unlock();
+
+    if (more_handlers)
+      owner_->post_immediate_completion(impl_, true);
+  }
+};
+
+strand_service::strand_service(asio::io_context& io_context)
+  : asio::detail::service_base<strand_service>(io_context),
+    io_context_(asio::use_service<io_context_impl>(io_context)),
+    mutex_(),
+    salt_(0)
+{
+}
+
+void strand_service::shutdown()
+{
+  op_queue<operation> ops;
+
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  for (std::size_t i = 0; i < num_implementations; ++i)
+  {
+    if (strand_impl* impl = implementations_[i].get())
+    {
+      ops.push(impl->waiting_queue_);
+      ops.push(impl->ready_queue_);
+    }
+  }
+}
+
+void strand_service::construct(strand_service::implementation_type& impl)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  std::size_t salt = salt_++;
+#if defined(ASIO_ENABLE_SEQUENTIAL_STRAND_ALLOCATION)
+  std::size_t index = salt;
+#else // defined(ASIO_ENABLE_SEQUENTIAL_STRAND_ALLOCATION)
+  std::size_t index = reinterpret_cast<std::size_t>(&impl);
+  index += (reinterpret_cast<std::size_t>(&impl) >> 3);
+  index ^= salt + 0x9e3779b9 + (index << 6) + (index >> 2);
+#endif // defined(ASIO_ENABLE_SEQUENTIAL_STRAND_ALLOCATION)
+  index = index % num_implementations;
+
+  if (!implementations_[index].get())
+    implementations_[index].reset(new strand_impl);
+  impl = implementations_[index].get();
+}
+
+bool strand_service::running_in_this_thread(
+    const implementation_type& impl) const
+{
+  return call_stack<strand_impl>::contains(impl) != 0;
+}
+
+bool strand_service::do_dispatch(implementation_type& impl, operation* op)
+{
+  // If we are running inside the io_context, and no other handler already
+  // holds the strand lock, then the handler can run immediately.
+  bool can_dispatch = io_context_.can_dispatch();
+  impl->mutex_.lock();
+  if (can_dispatch && !impl->locked_)
+  {
+    // Immediate invocation is allowed.
+    impl->locked_ = true;
+    impl->mutex_.unlock();
+    return true;
+  }
+
+  if (impl->locked_)
+  {
+    // Some other handler already holds the strand lock. Enqueue for later.
+    impl->waiting_queue_.push(op);
+    impl->mutex_.unlock();
+  }
+  else
+  {
+    // The handler is acquiring the strand lock and so is responsible for
+    // scheduling the strand.
+    impl->locked_ = true;
+    impl->mutex_.unlock();
+    impl->ready_queue_.push(op);
+    io_context_.post_immediate_completion(impl, false);
+  }
+
+  return false;
+}
+
+void strand_service::do_post(implementation_type& impl,
+    operation* op, bool is_continuation)
+{
+  impl->mutex_.lock();
+  if (impl->locked_)
+  {
+    // Some other handler already holds the strand lock. Enqueue for later.
+    impl->waiting_queue_.push(op);
+    impl->mutex_.unlock();
+  }
+  else
+  {
+    // The handler is acquiring the strand lock and so is responsible for
+    // scheduling the strand.
+    impl->locked_ = true;
+    impl->mutex_.unlock();
+    impl->ready_queue_.push(op);
+    io_context_.post_immediate_completion(impl, is_continuation);
+  }
+}
+
+void strand_service::do_complete(void* owner, operation* base,
+    const asio::error_code& ec, std::size_t /*bytes_transferred*/)
+{
+  if (owner)
+  {
+    strand_impl* impl = static_cast<strand_impl*>(base);
+
+    // Indicate that this strand is executing on the current thread.
+    call_stack<strand_impl>::context ctx(impl);
+
+    // Ensure the next handler, if any, is scheduled on block exit.
+    on_do_complete_exit on_exit;
+    on_exit.owner_ = static_cast<io_context_impl*>(owner);
+    on_exit.impl_ = impl;
+
+    // Run all ready handlers. No lock is required since the ready queue is
+    // accessed only within the strand.
+    while (operation* o = impl->ready_queue_.front())
+    {
+      impl->ready_queue_.pop();
+      o->complete(owner, ec, 0);
+    }
+  }
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_IMPL_STRAND_SERVICE_IPP
diff --git a/lib/asio/detail/impl/throw_error.ipp b/lib/asio/detail/impl/throw_error.ipp
new file mode 100644
index 0000000..a540cd2
--- /dev/null
+++ b/lib/asio/detail/impl/throw_error.ipp
@@ -0,0 +1,60 @@
+//
+// detail/impl/throw_error.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_THROW_ERROR_IPP
+#define ASIO_DETAIL_IMPL_THROW_ERROR_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/detail/throw_exception.hpp"
+#include "asio/system_error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+void do_throw_error(const asio::error_code& err)
+{
+  asio::system_error e(err);
+  asio::detail::throw_exception(e);
+}
+
+void do_throw_error(const asio::error_code& err, const char* location)
+{
+  // boostify: non-boost code starts here
+#if defined(ASIO_MSVC) && defined(ASIO_HAS_STD_SYSTEM_ERROR)
+  // Microsoft's implementation of std::system_error is non-conformant in that
+  // it ignores the error code's message when a "what" string is supplied. We'll
+  // work around this by explicitly formatting the "what" string.
+  std::string what_msg = location;
+  what_msg += ": ";
+  what_msg += err.message();
+  asio::system_error e(err, what_msg);
+  asio::detail::throw_exception(e);
+#else // defined(ASIO_MSVC) && defined(ASIO_HAS_STD_SYSTEM_ERROR)
+  // boostify: non-boost code ends here
+  asio::system_error e(err, location);
+  asio::detail::throw_exception(e);
+  // boostify: non-boost code starts here
+#endif // defined(ASIO_MSVC) && defined(ASIO_HAS_STD_SYSTEM_ERROR)
+  // boostify: non-boost code ends here
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_IMPL_THROW_ERROR_IPP
diff --git a/lib/asio/detail/impl/timer_queue_ptime.ipp b/lib/asio/detail/impl/timer_queue_ptime.ipp
new file mode 100644
index 0000000..742837f
--- /dev/null
+++ b/lib/asio/detail/impl/timer_queue_ptime.ipp
@@ -0,0 +1,91 @@
+//
+// detail/impl/timer_queue_ptime.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_TIMER_QUEUE_PTIME_IPP
+#define ASIO_DETAIL_IMPL_TIMER_QUEUE_PTIME_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_BOOST_DATE_TIME)
+
+#include "asio/detail/timer_queue_ptime.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+timer_queue<time_traits<boost::posix_time::ptime> >::timer_queue()
+{
+}
+
+timer_queue<time_traits<boost::posix_time::ptime> >::~timer_queue()
+{
+}
+
+bool timer_queue<time_traits<boost::posix_time::ptime> >::enqueue_timer(
+    const time_type& time, per_timer_data& timer, wait_op* op)
+{
+  return impl_.enqueue_timer(time, timer, op);
+}
+
+bool timer_queue<time_traits<boost::posix_time::ptime> >::empty() const
+{
+  return impl_.empty();
+}
+
+long timer_queue<time_traits<boost::posix_time::ptime> >::wait_duration_msec(
+    long max_duration) const
+{
+  return impl_.wait_duration_msec(max_duration);
+}
+
+long timer_queue<time_traits<boost::posix_time::ptime> >::wait_duration_usec(
+    long max_duration) const
+{
+  return impl_.wait_duration_usec(max_duration);
+}
+
+void timer_queue<time_traits<boost::posix_time::ptime> >::get_ready_timers(
+    op_queue<operation>& ops)
+{
+  impl_.get_ready_timers(ops);
+}
+
+void timer_queue<time_traits<boost::posix_time::ptime> >::get_all_timers(
+    op_queue<operation>& ops)
+{
+  impl_.get_all_timers(ops);
+}
+
+std::size_t timer_queue<time_traits<boost::posix_time::ptime> >::cancel_timer(
+    per_timer_data& timer, op_queue<operation>& ops, std::size_t max_cancelled)
+{
+  return impl_.cancel_timer(timer, ops, max_cancelled);
+}
+
+void timer_queue<time_traits<boost::posix_time::ptime> >::move_timer(
+    per_timer_data& target, per_timer_data& source)
+{
+  impl_.move_timer(target, source);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_BOOST_DATE_TIME)
+
+#endif // ASIO_DETAIL_IMPL_TIMER_QUEUE_PTIME_IPP
diff --git a/lib/asio/detail/impl/timer_queue_set.ipp b/lib/asio/detail/impl/timer_queue_set.ipp
new file mode 100644
index 0000000..b516548
--- /dev/null
+++ b/lib/asio/detail/impl/timer_queue_set.ipp
@@ -0,0 +1,101 @@
+//
+// detail/impl/timer_queue_set.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_TIMER_QUEUE_SET_IPP
+#define ASIO_DETAIL_IMPL_TIMER_QUEUE_SET_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/timer_queue_set.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+timer_queue_set::timer_queue_set()
+  : first_(0)
+{
+}
+
+void timer_queue_set::insert(timer_queue_base* q)
+{
+  q->next_ = first_;
+  first_ = q;
+}
+
+void timer_queue_set::erase(timer_queue_base* q)
+{
+  if (first_)
+  {
+    if (q == first_)
+    {
+      first_ = q->next_;
+      q->next_ = 0;
+      return;
+    }
+
+    for (timer_queue_base* p = first_; p->next_; p = p->next_)
+    {
+      if (p->next_ == q)
+      {
+        p->next_ = q->next_;
+        q->next_ = 0;
+        return;
+      }
+    }
+  }
+}
+
+bool timer_queue_set::all_empty() const
+{
+  for (timer_queue_base* p = first_; p; p = p->next_)
+    if (!p->empty())
+      return false;
+  return true;
+}
+
+long timer_queue_set::wait_duration_msec(long max_duration) const
+{
+  long min_duration = max_duration;
+  for (timer_queue_base* p = first_; p; p = p->next_)
+    min_duration = p->wait_duration_msec(min_duration);
+  return min_duration;
+}
+
+long timer_queue_set::wait_duration_usec(long max_duration) const
+{
+  long min_duration = max_duration;
+  for (timer_queue_base* p = first_; p; p = p->next_)
+    min_duration = p->wait_duration_usec(min_duration);
+  return min_duration;
+}
+
+void timer_queue_set::get_ready_timers(op_queue<operation>& ops)
+{
+  for (timer_queue_base* p = first_; p; p = p->next_)
+    p->get_ready_timers(ops);
+}
+
+void timer_queue_set::get_all_timers(op_queue<operation>& ops)
+{
+  for (timer_queue_base* p = first_; p; p = p->next_)
+    p->get_all_timers(ops);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_IMPL_TIMER_QUEUE_SET_IPP
diff --git a/lib/asio/detail/impl/win_event.ipp b/lib/asio/detail/impl/win_event.ipp
new file mode 100644
index 0000000..6f74649
--- /dev/null
+++ b/lib/asio/detail/impl/win_event.ipp
@@ -0,0 +1,76 @@
+//
+// detail/win_event.ipp
+// ~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_WIN_EVENT_IPP
+#define ASIO_DETAIL_IMPL_WIN_EVENT_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_WINDOWS)
+
+#include "asio/detail/throw_error.hpp"
+#include "asio/detail/win_event.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+win_event::win_event()
+  : state_(0)
+{
+#if defined(ASIO_WINDOWS_APP)
+  events_[0] = ::CreateEventExW(0, 0,
+      CREATE_EVENT_MANUAL_RESET, EVENT_ALL_ACCESS);
+#else // defined(ASIO_WINDOWS_APP)
+  events_[0] = ::CreateEventW(0, true, false, 0);
+#endif // defined(ASIO_WINDOWS_APP)
+  if (!events_[0])
+  {
+    DWORD last_error = ::GetLastError();
+    asio::error_code ec(last_error,
+        asio::error::get_system_category());
+    asio::detail::throw_error(ec, "event");
+  }
+
+#if defined(ASIO_WINDOWS_APP)
+  events_[1] = ::CreateEventExW(0, 0, 0, EVENT_ALL_ACCESS);
+#else // defined(ASIO_WINDOWS_APP)
+  events_[1] = ::CreateEventW(0, false, false, 0);
+#endif // defined(ASIO_WINDOWS_APP)
+  if (!events_[1])
+  {
+    DWORD last_error = ::GetLastError();
+    ::CloseHandle(events_[0]);
+    asio::error_code ec(last_error,
+        asio::error::get_system_category());
+    asio::detail::throw_error(ec, "event");
+  }
+}
+
+win_event::~win_event()
+{
+  ::CloseHandle(events_[0]);
+  ::CloseHandle(events_[1]);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_WINDOWS)
+
+#endif // ASIO_DETAIL_IMPL_WIN_EVENT_IPP
diff --git a/lib/asio/detail/impl/win_iocp_handle_service.ipp b/lib/asio/detail/impl/win_iocp_handle_service.ipp
new file mode 100644
index 0000000..9cba2b0
--- /dev/null
+++ b/lib/asio/detail/impl/win_iocp_handle_service.ipp
@@ -0,0 +1,525 @@
+//
+// detail/impl/win_iocp_handle_service.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2008 Rep Invariant Systems, Inc. (info@repinvariant.com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_WIN_IOCP_HANDLE_SERVICE_IPP
+#define ASIO_DETAIL_IMPL_WIN_IOCP_HANDLE_SERVICE_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_IOCP)
+
+#include "asio/detail/win_iocp_handle_service.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class win_iocp_handle_service::overlapped_wrapper
+  : public OVERLAPPED
+{
+public:
+  explicit overlapped_wrapper(asio::error_code& ec)
+  {
+    Internal = 0;
+    InternalHigh = 0;
+    Offset = 0;
+    OffsetHigh = 0;
+
+    // Create a non-signalled manual-reset event, for GetOverlappedResult.
+    hEvent = ::CreateEventW(0, TRUE, FALSE, 0);
+    if (hEvent)
+    {
+      // As documented in GetQueuedCompletionStatus, setting the low order
+      // bit of this event prevents our synchronous writes from being treated
+      // as completion port events.
+      DWORD_PTR tmp = reinterpret_cast<DWORD_PTR>(hEvent);
+      hEvent = reinterpret_cast<HANDLE>(tmp | 1);
+    }
+    else
+    {
+      DWORD last_error = ::GetLastError();
+      ec = asio::error_code(last_error,
+          asio::error::get_system_category());
+    }
+  }
+
+  ~overlapped_wrapper()
+  {
+    if (hEvent)
+    {
+      ::CloseHandle(hEvent);
+    }
+  }
+};
+
+win_iocp_handle_service::win_iocp_handle_service(
+    asio::io_context& io_context)
+  : service_base<win_iocp_handle_service>(io_context),
+    iocp_service_(asio::use_service<win_iocp_io_context>(io_context)),
+    mutex_(),
+    impl_list_(0)
+{
+}
+
+void win_iocp_handle_service::shutdown()
+{
+  // Close all implementations, causing all operations to complete.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  implementation_type* impl = impl_list_;
+  while (impl)
+  {
+    close_for_destruction(*impl);
+    impl = impl->next_;
+  }
+}
+
+void win_iocp_handle_service::construct(
+    win_iocp_handle_service::implementation_type& impl)
+{
+  impl.handle_ = INVALID_HANDLE_VALUE;
+  impl.safe_cancellation_thread_id_ = 0;
+
+  // Insert implementation into linked list of all implementations.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  impl.next_ = impl_list_;
+  impl.prev_ = 0;
+  if (impl_list_)
+    impl_list_->prev_ = &impl;
+  impl_list_ = &impl;
+}
+
+void win_iocp_handle_service::move_construct(
+    win_iocp_handle_service::implementation_type& impl,
+    win_iocp_handle_service::implementation_type& other_impl)
+{
+  impl.handle_ = other_impl.handle_;
+  other_impl.handle_ = INVALID_HANDLE_VALUE;
+
+  impl.safe_cancellation_thread_id_ = other_impl.safe_cancellation_thread_id_;
+  other_impl.safe_cancellation_thread_id_ = 0;
+
+  // Insert implementation into linked list of all implementations.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  impl.next_ = impl_list_;
+  impl.prev_ = 0;
+  if (impl_list_)
+    impl_list_->prev_ = &impl;
+  impl_list_ = &impl;
+}
+
+void win_iocp_handle_service::move_assign(
+    win_iocp_handle_service::implementation_type& impl,
+    win_iocp_handle_service& other_service,
+    win_iocp_handle_service::implementation_type& other_impl)
+{
+  close_for_destruction(impl);
+
+  if (this != &other_service)
+  {
+    // Remove implementation from linked list of all implementations.
+    asio::detail::mutex::scoped_lock lock(mutex_);
+    if (impl_list_ == &impl)
+      impl_list_ = impl.next_;
+    if (impl.prev_)
+      impl.prev_->next_ = impl.next_;
+    if (impl.next_)
+      impl.next_->prev_= impl.prev_;
+    impl.next_ = 0;
+    impl.prev_ = 0;
+  }
+
+  impl.handle_ = other_impl.handle_;
+  other_impl.handle_ = INVALID_HANDLE_VALUE;
+
+  impl.safe_cancellation_thread_id_ = other_impl.safe_cancellation_thread_id_;
+  other_impl.safe_cancellation_thread_id_ = 0;
+
+  if (this != &other_service)
+  {
+    // Insert implementation into linked list of all implementations.
+    asio::detail::mutex::scoped_lock lock(other_service.mutex_);
+    impl.next_ = other_service.impl_list_;
+    impl.prev_ = 0;
+    if (other_service.impl_list_)
+      other_service.impl_list_->prev_ = &impl;
+    other_service.impl_list_ = &impl;
+  }
+}
+
+void win_iocp_handle_service::destroy(
+    win_iocp_handle_service::implementation_type& impl)
+{
+  close_for_destruction(impl);
+  
+  // Remove implementation from linked list of all implementations.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  if (impl_list_ == &impl)
+    impl_list_ = impl.next_;
+  if (impl.prev_)
+    impl.prev_->next_ = impl.next_;
+  if (impl.next_)
+    impl.next_->prev_= impl.prev_;
+  impl.next_ = 0;
+  impl.prev_ = 0;
+}
+
+asio::error_code win_iocp_handle_service::assign(
+    win_iocp_handle_service::implementation_type& impl,
+    const native_handle_type& handle, asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ec = asio::error::already_open;
+    return ec;
+  }
+
+  if (iocp_service_.register_handle(handle, ec))
+    return ec;
+
+  impl.handle_ = handle;
+  ec = asio::error_code();
+  return ec;
+}
+
+asio::error_code win_iocp_handle_service::close(
+    win_iocp_handle_service::implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ASIO_HANDLER_OPERATION((iocp_service_.context(), "handle",
+          &impl, reinterpret_cast<uintmax_t>(impl.handle_), "close"));
+
+    if (!::CloseHandle(impl.handle_))
+    {
+      DWORD last_error = ::GetLastError();
+      ec = asio::error_code(last_error,
+          asio::error::get_system_category());
+    }
+    else
+    {
+      ec = asio::error_code();
+    }
+
+    impl.handle_ = INVALID_HANDLE_VALUE;
+    impl.safe_cancellation_thread_id_ = 0;
+  }
+  else
+  {
+    ec = asio::error_code();
+  }
+
+  return ec;
+}
+
+asio::error_code win_iocp_handle_service::cancel(
+    win_iocp_handle_service::implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    return ec;
+  }
+
+  ASIO_HANDLER_OPERATION((iocp_service_.context(), "handle",
+        &impl, reinterpret_cast<uintmax_t>(impl.handle_), "cancel"));
+
+  if (FARPROC cancel_io_ex_ptr = ::GetProcAddress(
+        ::GetModuleHandleA("KERNEL32"), "CancelIoEx"))
+  {
+    // The version of Windows supports cancellation from any thread.
+    typedef BOOL (WINAPI* cancel_io_ex_t)(HANDLE, LPOVERLAPPED);
+    cancel_io_ex_t cancel_io_ex = (cancel_io_ex_t)cancel_io_ex_ptr;
+    if (!cancel_io_ex(impl.handle_, 0))
+    {
+      DWORD last_error = ::GetLastError();
+      if (last_error == ERROR_NOT_FOUND)
+      {
+        // ERROR_NOT_FOUND means that there were no operations to be
+        // cancelled. We swallow this error to match the behaviour on other
+        // platforms.
+        ec = asio::error_code();
+      }
+      else
+      {
+        ec = asio::error_code(last_error,
+            asio::error::get_system_category());
+      }
+    }
+    else
+    {
+      ec = asio::error_code();
+    }
+  }
+  else if (impl.safe_cancellation_thread_id_ == 0)
+  {
+    // No operations have been started, so there's nothing to cancel.
+    ec = asio::error_code();
+  }
+  else if (impl.safe_cancellation_thread_id_ == ::GetCurrentThreadId())
+  {
+    // Asynchronous operations have been started from the current thread only,
+    // so it is safe to try to cancel them using CancelIo.
+    if (!::CancelIo(impl.handle_))
+    {
+      DWORD last_error = ::GetLastError();
+      ec = asio::error_code(last_error,
+          asio::error::get_system_category());
+    }
+    else
+    {
+      ec = asio::error_code();
+    }
+  }
+  else
+  {
+    // Asynchronous operations have been started from more than one thread,
+    // so cancellation is not safe.
+    ec = asio::error::operation_not_supported;
+  }
+
+  return ec;
+}
+
+size_t win_iocp_handle_service::do_write(
+    win_iocp_handle_service::implementation_type& impl, uint64_t offset,
+    const asio::const_buffer& buffer, asio::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    return 0;
+  }
+
+  // A request to write 0 bytes on a handle is a no-op.
+  if (buffer.size() == 0)
+  {
+    ec = asio::error_code();
+    return 0;
+  }
+
+  overlapped_wrapper overlapped(ec);
+  if (ec)
+  {
+    return 0;
+  }
+
+  // Write the data. 
+  overlapped.Offset = offset & 0xFFFFFFFF;
+  overlapped.OffsetHigh = (offset >> 32) & 0xFFFFFFFF;
+  BOOL ok = ::WriteFile(impl.handle_, buffer.data(),
+      static_cast<DWORD>(buffer.size()), 0, &overlapped);
+  if (!ok) 
+  {
+    DWORD last_error = ::GetLastError();
+    if (last_error != ERROR_IO_PENDING)
+    {
+      ec = asio::error_code(last_error,
+          asio::error::get_system_category());
+      return 0;
+    }
+  }
+
+  // Wait for the operation to complete.
+  DWORD bytes_transferred = 0;
+  ok = ::GetOverlappedResult(impl.handle_,
+      &overlapped, &bytes_transferred, TRUE);
+  if (!ok)
+  {
+    DWORD last_error = ::GetLastError();
+    ec = asio::error_code(last_error,
+        asio::error::get_system_category());
+    return 0;
+  }
+
+  ec = asio::error_code();
+  return bytes_transferred;
+}
+
+void win_iocp_handle_service::start_write_op(
+    win_iocp_handle_service::implementation_type& impl, uint64_t offset,
+    const asio::const_buffer& buffer, operation* op)
+{
+  update_cancellation_thread_id(impl);
+  iocp_service_.work_started();
+
+  if (!is_open(impl))
+  {
+    iocp_service_.on_completion(op, asio::error::bad_descriptor);
+  }
+  else if (buffer.size() == 0)
+  {
+    // A request to write 0 bytes on a handle is a no-op.
+    iocp_service_.on_completion(op);
+  }
+  else
+  {
+    DWORD bytes_transferred = 0;
+    op->Offset = offset & 0xFFFFFFFF;
+    op->OffsetHigh = (offset >> 32) & 0xFFFFFFFF;
+    BOOL ok = ::WriteFile(impl.handle_, buffer.data(),
+        static_cast<DWORD>(buffer.size()),
+        &bytes_transferred, op);
+    DWORD last_error = ::GetLastError();
+    if (!ok && last_error != ERROR_IO_PENDING
+        && last_error != ERROR_MORE_DATA)
+    {
+      iocp_service_.on_completion(op, last_error, bytes_transferred);
+    }
+    else
+    {
+      iocp_service_.on_pending(op);
+    }
+  }
+}
+
+size_t win_iocp_handle_service::do_read(
+    win_iocp_handle_service::implementation_type& impl, uint64_t offset,
+    const asio::mutable_buffer& buffer, asio::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    return 0;
+  }
+  
+  // A request to read 0 bytes on a stream handle is a no-op.
+  if (buffer.size() == 0)
+  {
+    ec = asio::error_code();
+    return 0;
+  }
+
+  overlapped_wrapper overlapped(ec);
+  if (ec)
+  {
+    return 0;
+  }
+
+  // Read some data.
+  overlapped.Offset = offset & 0xFFFFFFFF;
+  overlapped.OffsetHigh = (offset >> 32) & 0xFFFFFFFF;
+  BOOL ok = ::ReadFile(impl.handle_, buffer.data(),
+      static_cast<DWORD>(buffer.size()), 0, &overlapped);
+  if (!ok) 
+  {
+    DWORD last_error = ::GetLastError();
+    if (last_error != ERROR_IO_PENDING && last_error != ERROR_MORE_DATA)
+    {
+      if (last_error == ERROR_HANDLE_EOF)
+      {
+        ec = asio::error::eof;
+      }
+      else
+      {
+        ec = asio::error_code(last_error,
+            asio::error::get_system_category());
+      }
+      return 0;
+    }
+  }
+
+  // Wait for the operation to complete.
+  DWORD bytes_transferred = 0;
+  ok = ::GetOverlappedResult(impl.handle_,
+      &overlapped, &bytes_transferred, TRUE);
+  if (!ok)
+  {
+    DWORD last_error = ::GetLastError();
+    if (last_error == ERROR_HANDLE_EOF)
+    {
+      ec = asio::error::eof;
+    }
+    else
+    {
+      ec = asio::error_code(last_error,
+          asio::error::get_system_category());
+    }
+    return (last_error == ERROR_MORE_DATA) ? bytes_transferred : 0;
+  }
+
+  ec = asio::error_code();
+  return bytes_transferred;
+}
+
+void win_iocp_handle_service::start_read_op(
+    win_iocp_handle_service::implementation_type& impl, uint64_t offset,
+    const asio::mutable_buffer& buffer, operation* op)
+{
+  update_cancellation_thread_id(impl);
+  iocp_service_.work_started();
+
+  if (!is_open(impl))
+  {
+    iocp_service_.on_completion(op, asio::error::bad_descriptor);
+  }
+  else if (buffer.size() == 0)
+  {
+    // A request to read 0 bytes on a handle is a no-op.
+    iocp_service_.on_completion(op);
+  }
+  else
+  {
+    DWORD bytes_transferred = 0;
+    op->Offset = offset & 0xFFFFFFFF;
+    op->OffsetHigh = (offset >> 32) & 0xFFFFFFFF;
+    BOOL ok = ::ReadFile(impl.handle_, buffer.data(),
+        static_cast<DWORD>(buffer.size()),
+        &bytes_transferred, op);
+    DWORD last_error = ::GetLastError();
+    if (!ok && last_error != ERROR_IO_PENDING
+        && last_error != ERROR_MORE_DATA)
+    {
+      iocp_service_.on_completion(op, last_error, bytes_transferred);
+    }
+    else
+    {
+      iocp_service_.on_pending(op);
+    }
+  }
+}
+
+void win_iocp_handle_service::update_cancellation_thread_id(
+    win_iocp_handle_service::implementation_type& impl)
+{
+  if (impl.safe_cancellation_thread_id_ == 0)
+    impl.safe_cancellation_thread_id_ = ::GetCurrentThreadId();
+  else if (impl.safe_cancellation_thread_id_ != ::GetCurrentThreadId())
+    impl.safe_cancellation_thread_id_ = ~DWORD(0);
+}
+
+void win_iocp_handle_service::close_for_destruction(implementation_type& impl)
+{
+  if (is_open(impl))
+  {
+    ASIO_HANDLER_OPERATION((iocp_service_.context(), "handle",
+          &impl, reinterpret_cast<uintmax_t>(impl.handle_), "close"));
+
+    ::CloseHandle(impl.handle_);
+    impl.handle_ = INVALID_HANDLE_VALUE;
+    impl.safe_cancellation_thread_id_ = 0;
+  }
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_IOCP)
+
+#endif // ASIO_DETAIL_IMPL_WIN_IOCP_HANDLE_SERVICE_IPP
diff --git a/lib/asio/detail/impl/win_iocp_io_context.hpp b/lib/asio/detail/impl/win_iocp_io_context.hpp
new file mode 100644
index 0000000..44887d7
--- /dev/null
+++ b/lib/asio/detail/impl/win_iocp_io_context.hpp
@@ -0,0 +1,103 @@
+//
+// detail/impl/win_iocp_io_context.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_WIN_IOCP_IO_CONTEXT_HPP
+#define ASIO_DETAIL_IMPL_WIN_IOCP_IO_CONTEXT_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_IOCP)
+
+#include "asio/detail/completion_handler.hpp"
+#include "asio/detail/fenced_block.hpp"
+#include "asio/detail/handler_alloc_helpers.hpp"
+#include "asio/detail/handler_invoke_helpers.hpp"
+#include "asio/detail/memory.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename Time_Traits>
+void win_iocp_io_context::add_timer_queue(
+    timer_queue<Time_Traits>& queue)
+{
+  do_add_timer_queue(queue);
+}
+
+template <typename Time_Traits>
+void win_iocp_io_context::remove_timer_queue(
+    timer_queue<Time_Traits>& queue)
+{
+  do_remove_timer_queue(queue);
+}
+
+template <typename Time_Traits>
+void win_iocp_io_context::schedule_timer(timer_queue<Time_Traits>& queue,
+    const typename Time_Traits::time_type& time,
+    typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op)
+{
+  // If the service has been shut down we silently discard the timer.
+  if (::InterlockedExchangeAdd(&shutdown_, 0) != 0)
+  {
+    post_immediate_completion(op, false);
+    return;
+  }
+
+  mutex::scoped_lock lock(dispatch_mutex_);
+
+  bool earliest = queue.enqueue_timer(time, timer, op);
+  work_started();
+  if (earliest)
+    update_timeout();
+}
+
+template <typename Time_Traits>
+std::size_t win_iocp_io_context::cancel_timer(timer_queue<Time_Traits>& queue,
+    typename timer_queue<Time_Traits>::per_timer_data& timer,
+    std::size_t max_cancelled)
+{
+  // If the service has been shut down we silently ignore the cancellation.
+  if (::InterlockedExchangeAdd(&shutdown_, 0) != 0)
+    return 0;
+
+  mutex::scoped_lock lock(dispatch_mutex_);
+  op_queue<win_iocp_operation> ops;
+  std::size_t n = queue.cancel_timer(timer, ops, max_cancelled);
+  post_deferred_completions(ops);
+  return n;
+}
+
+template <typename Time_Traits>
+void win_iocp_io_context::move_timer(timer_queue<Time_Traits>& queue,
+    typename timer_queue<Time_Traits>::per_timer_data& to,
+    typename timer_queue<Time_Traits>::per_timer_data& from)
+{
+  asio::detail::mutex::scoped_lock lock(dispatch_mutex_);
+  op_queue<operation> ops;
+  queue.cancel_timer(to, ops);
+  queue.move_timer(to, from);
+  lock.unlock();
+  post_deferred_completions(ops);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_IOCP)
+
+#endif // ASIO_DETAIL_IMPL_WIN_IOCP_IO_CONTEXT_HPP
diff --git a/lib/asio/detail/impl/win_iocp_io_context.ipp b/lib/asio/detail/impl/win_iocp_io_context.ipp
new file mode 100644
index 0000000..c371b86
--- /dev/null
+++ b/lib/asio/detail/impl/win_iocp_io_context.ipp
@@ -0,0 +1,554 @@
+//
+// detail/impl/win_iocp_io_context.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_WIN_IOCP_IO_CONTEXT_IPP
+#define ASIO_DETAIL_IMPL_WIN_IOCP_IO_CONTEXT_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_IOCP)
+
+#include "asio/error.hpp"
+#include "asio/detail/cstdint.hpp"
+#include "asio/detail/handler_alloc_helpers.hpp"
+#include "asio/detail/handler_invoke_helpers.hpp"
+#include "asio/detail/limits.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/detail/win_iocp_io_context.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+struct win_iocp_io_context::work_finished_on_block_exit
+{
+  ~work_finished_on_block_exit()
+  {
+    io_context_->work_finished();
+  }
+
+  win_iocp_io_context* io_context_;
+};
+
+struct win_iocp_io_context::timer_thread_function
+{
+  void operator()()
+  {
+    while (::InterlockedExchangeAdd(&io_context_->shutdown_, 0) == 0)
+    {
+      if (::WaitForSingleObject(io_context_->waitable_timer_.handle,
+            INFINITE) == WAIT_OBJECT_0)
+      {
+        ::InterlockedExchange(&io_context_->dispatch_required_, 1);
+        ::PostQueuedCompletionStatus(io_context_->iocp_.handle,
+            0, wake_for_dispatch, 0);
+      }
+    }
+  }
+
+  win_iocp_io_context* io_context_;
+};
+
+win_iocp_io_context::win_iocp_io_context(
+    asio::execution_context& ctx, int concurrency_hint)
+  : execution_context_service_base<win_iocp_io_context>(ctx),
+    iocp_(),
+    outstanding_work_(0),
+    stopped_(0),
+    stop_event_posted_(0),
+    shutdown_(0),
+    gqcs_timeout_(get_gqcs_timeout()),
+    dispatch_required_(0),
+    concurrency_hint_(concurrency_hint)
+{
+  ASIO_HANDLER_TRACKING_INIT;
+
+  iocp_.handle = ::CreateIoCompletionPort(INVALID_HANDLE_VALUE, 0, 0,
+      static_cast<DWORD>(concurrency_hint >= 0 ? concurrency_hint : DWORD(~0)));
+  if (!iocp_.handle)
+  {
+    DWORD last_error = ::GetLastError();
+    asio::error_code ec(last_error,
+        asio::error::get_system_category());
+    asio::detail::throw_error(ec, "iocp");
+  }
+}
+
+void win_iocp_io_context::shutdown()
+{
+  ::InterlockedExchange(&shutdown_, 1);
+
+  if (timer_thread_.get())
+  {
+    LARGE_INTEGER timeout;
+    timeout.QuadPart = 1;
+    ::SetWaitableTimer(waitable_timer_.handle, &timeout, 1, 0, 0, FALSE);
+  }
+
+  while (::InterlockedExchangeAdd(&outstanding_work_, 0) > 0)
+  {
+    op_queue<win_iocp_operation> ops;
+    timer_queues_.get_all_timers(ops);
+    ops.push(completed_ops_);
+    if (!ops.empty())
+    {
+      while (win_iocp_operation* op = ops.front())
+      {
+        ops.pop();
+        ::InterlockedDecrement(&outstanding_work_);
+        op->destroy();
+      }
+    }
+    else
+    {
+      DWORD bytes_transferred = 0;
+      dword_ptr_t completion_key = 0;
+      LPOVERLAPPED overlapped = 0;
+      ::GetQueuedCompletionStatus(iocp_.handle, &bytes_transferred,
+          &completion_key, &overlapped, gqcs_timeout_);
+      if (overlapped)
+      {
+        ::InterlockedDecrement(&outstanding_work_);
+        static_cast<win_iocp_operation*>(overlapped)->destroy();
+      }
+    }
+  }
+
+  if (timer_thread_.get())
+    timer_thread_->join();
+}
+
+asio::error_code win_iocp_io_context::register_handle(
+    HANDLE handle, asio::error_code& ec)
+{
+  if (::CreateIoCompletionPort(handle, iocp_.handle, 0, 0) == 0)
+  {
+    DWORD last_error = ::GetLastError();
+    ec = asio::error_code(last_error,
+        asio::error::get_system_category());
+  }
+  else
+  {
+    ec = asio::error_code();
+  }
+  return ec;
+}
+
+size_t win_iocp_io_context::run(asio::error_code& ec)
+{
+  if (::InterlockedExchangeAdd(&outstanding_work_, 0) == 0)
+  {
+    stop();
+    ec = asio::error_code();
+    return 0;
+  }
+
+  win_iocp_thread_info this_thread;
+  thread_call_stack::context ctx(this, this_thread);
+
+  size_t n = 0;
+  while (do_one(INFINITE, ec))
+    if (n != (std::numeric_limits<size_t>::max)())
+      ++n;
+  return n;
+}
+
+size_t win_iocp_io_context::run_one(asio::error_code& ec)
+{
+  if (::InterlockedExchangeAdd(&outstanding_work_, 0) == 0)
+  {
+    stop();
+    ec = asio::error_code();
+    return 0;
+  }
+
+  win_iocp_thread_info this_thread;
+  thread_call_stack::context ctx(this, this_thread);
+
+  return do_one(INFINITE, ec);
+}
+
+size_t win_iocp_io_context::wait_one(long usec, asio::error_code& ec)
+{
+  if (::InterlockedExchangeAdd(&outstanding_work_, 0) == 0)
+  {
+    stop();
+    ec = asio::error_code();
+    return 0;
+  }
+
+  win_iocp_thread_info this_thread;
+  thread_call_stack::context ctx(this, this_thread);
+
+  return do_one(usec < 0 ? INFINITE : ((usec - 1) / 1000 + 1), ec);
+}
+
+size_t win_iocp_io_context::poll(asio::error_code& ec)
+{
+  if (::InterlockedExchangeAdd(&outstanding_work_, 0) == 0)
+  {
+    stop();
+    ec = asio::error_code();
+    return 0;
+  }
+
+  win_iocp_thread_info this_thread;
+  thread_call_stack::context ctx(this, this_thread);
+
+  size_t n = 0;
+  while (do_one(0, ec))
+    if (n != (std::numeric_limits<size_t>::max)())
+      ++n;
+  return n;
+}
+
+size_t win_iocp_io_context::poll_one(asio::error_code& ec)
+{
+  if (::InterlockedExchangeAdd(&outstanding_work_, 0) == 0)
+  {
+    stop();
+    ec = asio::error_code();
+    return 0;
+  }
+
+  win_iocp_thread_info this_thread;
+  thread_call_stack::context ctx(this, this_thread);
+
+  return do_one(0, ec);
+}
+
+void win_iocp_io_context::stop()
+{
+  if (::InterlockedExchange(&stopped_, 1) == 0)
+  {
+    if (::InterlockedExchange(&stop_event_posted_, 1) == 0)
+    {
+      if (!::PostQueuedCompletionStatus(iocp_.handle, 0, 0, 0))
+      {
+        DWORD last_error = ::GetLastError();
+        asio::error_code ec(last_error,
+            asio::error::get_system_category());
+        asio::detail::throw_error(ec, "pqcs");
+      }
+    }
+  }
+}
+
+void win_iocp_io_context::post_deferred_completion(win_iocp_operation* op)
+{
+  // Flag the operation as ready.
+  op->ready_ = 1;
+
+  // Enqueue the operation on the I/O completion port.
+  if (!::PostQueuedCompletionStatus(iocp_.handle, 0, 0, op))
+  {
+    // Out of resources. Put on completed queue instead.
+    mutex::scoped_lock lock(dispatch_mutex_);
+    completed_ops_.push(op);
+    ::InterlockedExchange(&dispatch_required_, 1);
+  }
+}
+
+void win_iocp_io_context::post_deferred_completions(
+    op_queue<win_iocp_operation>& ops)
+{
+  while (win_iocp_operation* op = ops.front())
+  {
+    ops.pop();
+
+    // Flag the operation as ready.
+    op->ready_ = 1;
+
+    // Enqueue the operation on the I/O completion port.
+    if (!::PostQueuedCompletionStatus(iocp_.handle, 0, 0, op))
+    {
+      // Out of resources. Put on completed queue instead.
+      mutex::scoped_lock lock(dispatch_mutex_);
+      completed_ops_.push(op);
+      completed_ops_.push(ops);
+      ::InterlockedExchange(&dispatch_required_, 1);
+    }
+  }
+}
+
+void win_iocp_io_context::abandon_operations(
+    op_queue<win_iocp_operation>& ops)
+{
+  while (win_iocp_operation* op = ops.front())
+  {
+    ops.pop();
+    ::InterlockedDecrement(&outstanding_work_);
+    op->destroy();
+  }
+}
+
+void win_iocp_io_context::on_pending(win_iocp_operation* op)
+{
+  if (::InterlockedCompareExchange(&op->ready_, 1, 0) == 1)
+  {
+    // Enqueue the operation on the I/O completion port.
+    if (!::PostQueuedCompletionStatus(iocp_.handle,
+          0, overlapped_contains_result, op))
+    {
+      // Out of resources. Put on completed queue instead.
+      mutex::scoped_lock lock(dispatch_mutex_);
+      completed_ops_.push(op);
+      ::InterlockedExchange(&dispatch_required_, 1);
+    }
+  }
+}
+
+void win_iocp_io_context::on_completion(win_iocp_operation* op,
+    DWORD last_error, DWORD bytes_transferred)
+{
+  // Flag that the operation is ready for invocation.
+  op->ready_ = 1;
+
+  // Store results in the OVERLAPPED structure.
+  op->Internal = reinterpret_cast<ulong_ptr_t>(
+      &asio::error::get_system_category());
+  op->Offset = last_error;
+  op->OffsetHigh = bytes_transferred;
+
+  // Enqueue the operation on the I/O completion port.
+  if (!::PostQueuedCompletionStatus(iocp_.handle,
+        0, overlapped_contains_result, op))
+  {
+    // Out of resources. Put on completed queue instead.
+    mutex::scoped_lock lock(dispatch_mutex_);
+    completed_ops_.push(op);
+    ::InterlockedExchange(&dispatch_required_, 1);
+  }
+}
+
+void win_iocp_io_context::on_completion(win_iocp_operation* op,
+    const asio::error_code& ec, DWORD bytes_transferred)
+{
+  // Flag that the operation is ready for invocation.
+  op->ready_ = 1;
+
+  // Store results in the OVERLAPPED structure.
+  op->Internal = reinterpret_cast<ulong_ptr_t>(&ec.category());
+  op->Offset = ec.value();
+  op->OffsetHigh = bytes_transferred;
+
+  // Enqueue the operation on the I/O completion port.
+  if (!::PostQueuedCompletionStatus(iocp_.handle,
+        0, overlapped_contains_result, op))
+  {
+    // Out of resources. Put on completed queue instead.
+    mutex::scoped_lock lock(dispatch_mutex_);
+    completed_ops_.push(op);
+    ::InterlockedExchange(&dispatch_required_, 1);
+  }
+}
+
+size_t win_iocp_io_context::do_one(DWORD msec, asio::error_code& ec)
+{
+  for (;;)
+  {
+    // Try to acquire responsibility for dispatching timers and completed ops.
+    if (::InterlockedCompareExchange(&dispatch_required_, 0, 1) == 1)
+    {
+      mutex::scoped_lock lock(dispatch_mutex_);
+
+      // Dispatch pending timers and operations.
+      op_queue<win_iocp_operation> ops;
+      ops.push(completed_ops_);
+      timer_queues_.get_ready_timers(ops);
+      post_deferred_completions(ops);
+      update_timeout();
+    }
+
+    // Get the next operation from the queue.
+    DWORD bytes_transferred = 0;
+    dword_ptr_t completion_key = 0;
+    LPOVERLAPPED overlapped = 0;
+    ::SetLastError(0);
+    BOOL ok = ::GetQueuedCompletionStatus(iocp_.handle,
+        &bytes_transferred, &completion_key, &overlapped,
+        msec < gqcs_timeout_ ? msec : gqcs_timeout_);
+    DWORD last_error = ::GetLastError();
+
+    if (overlapped)
+    {
+      win_iocp_operation* op = static_cast<win_iocp_operation*>(overlapped);
+      asio::error_code result_ec(last_error,
+          asio::error::get_system_category());
+
+      // We may have been passed the last_error and bytes_transferred in the
+      // OVERLAPPED structure itself.
+      if (completion_key == overlapped_contains_result)
+      {
+        result_ec = asio::error_code(static_cast<int>(op->Offset),
+            *reinterpret_cast<asio::error_category*>(op->Internal));
+        bytes_transferred = op->OffsetHigh;
+      }
+
+      // Otherwise ensure any result has been saved into the OVERLAPPED
+      // structure.
+      else
+      {
+        op->Internal = reinterpret_cast<ulong_ptr_t>(&result_ec.category());
+        op->Offset = result_ec.value();
+        op->OffsetHigh = bytes_transferred;
+      }
+
+      // Dispatch the operation only if ready. The operation may not be ready
+      // if the initiating function (e.g. a call to WSARecv) has not yet
+      // returned. This is because the initiating function still wants access
+      // to the operation's OVERLAPPED structure.
+      if (::InterlockedCompareExchange(&op->ready_, 1, 0) == 1)
+      {
+        // Ensure the count of outstanding work is decremented on block exit.
+        work_finished_on_block_exit on_exit = { this };
+        (void)on_exit;
+
+        op->complete(this, result_ec, bytes_transferred);
+        ec = asio::error_code();
+        return 1;
+      }
+    }
+    else if (!ok)
+    {
+      if (last_error != WAIT_TIMEOUT)
+      {
+        ec = asio::error_code(last_error,
+            asio::error::get_system_category());
+        return 0;
+      }
+
+      // If we're waiting indefinitely we need to keep going until we get a
+      // real handler.
+      if (msec == INFINITE)
+        continue;
+
+      ec = asio::error_code();
+      return 0;
+    }
+    else if (completion_key == wake_for_dispatch)
+    {
+      // We have been woken up to try to acquire responsibility for dispatching
+      // timers and completed operations.
+    }
+    else
+    {
+      // Indicate that there is no longer an in-flight stop event.
+      ::InterlockedExchange(&stop_event_posted_, 0);
+
+      // The stopped_ flag is always checked to ensure that any leftover
+      // stop events from a previous run invocation are ignored.
+      if (::InterlockedExchangeAdd(&stopped_, 0) != 0)
+      {
+        // Wake up next thread that is blocked on GetQueuedCompletionStatus.
+        if (::InterlockedExchange(&stop_event_posted_, 1) == 0)
+        {
+          if (!::PostQueuedCompletionStatus(iocp_.handle, 0, 0, 0))
+          {
+            last_error = ::GetLastError();
+            ec = asio::error_code(last_error,
+                asio::error::get_system_category());
+            return 0;
+          }
+        }
+
+        ec = asio::error_code();
+        return 0;
+      }
+    }
+  }
+}
+
+DWORD win_iocp_io_context::get_gqcs_timeout()
+{
+  OSVERSIONINFOEX osvi;
+  ZeroMemory(&osvi, sizeof(osvi));
+  osvi.dwOSVersionInfoSize = sizeof(osvi);
+  osvi.dwMajorVersion = 6ul;
+
+  const uint64_t condition_mask = ::VerSetConditionMask(
+      0, VER_MAJORVERSION, VER_GREATER_EQUAL);
+
+  if (!!::VerifyVersionInfo(&osvi, VER_MAJORVERSION, condition_mask))
+    return INFINITE;
+
+  return default_gqcs_timeout;
+}
+
+void win_iocp_io_context::do_add_timer_queue(timer_queue_base& queue)
+{
+  mutex::scoped_lock lock(dispatch_mutex_);
+
+  timer_queues_.insert(&queue);
+
+  if (!waitable_timer_.handle)
+  {
+    waitable_timer_.handle = ::CreateWaitableTimer(0, FALSE, 0);
+    if (waitable_timer_.handle == 0)
+    {
+      DWORD last_error = ::GetLastError();
+      asio::error_code ec(last_error,
+          asio::error::get_system_category());
+      asio::detail::throw_error(ec, "timer");
+    }
+
+    LARGE_INTEGER timeout;
+    timeout.QuadPart = -max_timeout_usec;
+    timeout.QuadPart *= 10;
+    ::SetWaitableTimer(waitable_timer_.handle,
+        &timeout, max_timeout_msec, 0, 0, FALSE);
+  }
+
+  if (!timer_thread_.get())
+  {
+    timer_thread_function thread_function = { this };
+    timer_thread_.reset(new thread(thread_function, 65536));
+  }
+}
+
+void win_iocp_io_context::do_remove_timer_queue(timer_queue_base& queue)
+{
+  mutex::scoped_lock lock(dispatch_mutex_);
+
+  timer_queues_.erase(&queue);
+}
+
+void win_iocp_io_context::update_timeout()
+{
+  if (timer_thread_.get())
+  {
+    // There's no point updating the waitable timer if the new timeout period
+    // exceeds the maximum timeout. In that case, we might as well wait for the
+    // existing period of the timer to expire.
+    long timeout_usec = timer_queues_.wait_duration_usec(max_timeout_usec);
+    if (timeout_usec < max_timeout_usec)
+    {
+      LARGE_INTEGER timeout;
+      timeout.QuadPart = -timeout_usec;
+      timeout.QuadPart *= 10;
+      ::SetWaitableTimer(waitable_timer_.handle,
+          &timeout, max_timeout_msec, 0, 0, FALSE);
+    }
+  }
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_IOCP)
+
+#endif // ASIO_DETAIL_IMPL_WIN_IOCP_IO_CONTEXT_IPP
diff --git a/lib/asio/detail/impl/win_iocp_serial_port_service.ipp b/lib/asio/detail/impl/win_iocp_serial_port_service.ipp
new file mode 100644
index 0000000..4a9b8cd
--- /dev/null
+++ b/lib/asio/detail/impl/win_iocp_serial_port_service.ipp
@@ -0,0 +1,181 @@
+//
+// detail/impl/win_iocp_serial_port_service.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2008 Rep Invariant Systems, Inc. (info@repinvariant.com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_WIN_IOCP_SERIAL_PORT_SERVICE_IPP
+#define ASIO_DETAIL_IMPL_WIN_IOCP_SERIAL_PORT_SERVICE_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_IOCP) && defined(ASIO_HAS_SERIAL_PORT)
+
+#include <cstring>
+#include "asio/detail/win_iocp_serial_port_service.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+win_iocp_serial_port_service::win_iocp_serial_port_service(
+    asio::io_context& io_context)
+  : service_base<win_iocp_serial_port_service>(io_context),
+    handle_service_(io_context)
+{
+}
+
+void win_iocp_serial_port_service::shutdown()
+{
+}
+
+asio::error_code win_iocp_serial_port_service::open(
+    win_iocp_serial_port_service::implementation_type& impl,
+    const std::string& device, asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ec = asio::error::already_open;
+    return ec;
+  }
+
+  // For convenience, add a leading \\.\ sequence if not already present.
+  std::string name = (device[0] == '\\') ? device : "\\\\.\\" + device;
+
+  // Open a handle to the serial port.
+  ::HANDLE handle = ::CreateFileA(name.c_str(),
+      GENERIC_READ | GENERIC_WRITE, 0, 0,
+      OPEN_EXISTING, FILE_FLAG_OVERLAPPED, 0);
+  if (handle == INVALID_HANDLE_VALUE)
+  {
+    DWORD last_error = ::GetLastError();
+    ec = asio::error_code(last_error,
+        asio::error::get_system_category());
+    return ec;
+  }
+
+  // Determine the initial serial port parameters.
+  using namespace std; // For memset.
+  ::DCB dcb;
+  memset(&dcb, 0, sizeof(DCB));
+  dcb.DCBlength = sizeof(DCB);
+  if (!::GetCommState(handle, &dcb))
+  {
+    DWORD last_error = ::GetLastError();
+    ::CloseHandle(handle);
+    ec = asio::error_code(last_error,
+        asio::error::get_system_category());
+    return ec;
+  }
+
+  // Set some default serial port parameters. This implementation does not
+  // support changing these, so they might as well be in a known state.
+  dcb.fBinary = TRUE; // Win32 only supports binary mode.
+  dcb.fDsrSensitivity = FALSE;
+  dcb.fNull = FALSE; // Do not ignore NULL characters.
+  dcb.fAbortOnError = FALSE; // Ignore serial framing errors.
+  if (!::SetCommState(handle, &dcb))
+  {
+    DWORD last_error = ::GetLastError();
+    ::CloseHandle(handle);
+    ec = asio::error_code(last_error,
+        asio::error::get_system_category());
+    return ec;
+  }
+
+  // Set up timeouts so that the serial port will behave similarly to a
+  // network socket. Reads wait for at least one byte, then return with
+  // whatever they have. Writes return once everything is out the door.
+  ::COMMTIMEOUTS timeouts;
+  timeouts.ReadIntervalTimeout = 1;
+  timeouts.ReadTotalTimeoutMultiplier = 0;
+  timeouts.ReadTotalTimeoutConstant = 0;
+  timeouts.WriteTotalTimeoutMultiplier = 0;
+  timeouts.WriteTotalTimeoutConstant = 0;
+  if (!::SetCommTimeouts(handle, &timeouts))
+  {
+    DWORD last_error = ::GetLastError();
+    ::CloseHandle(handle);
+    ec = asio::error_code(last_error,
+        asio::error::get_system_category());
+    return ec;
+  }
+
+  // We're done. Take ownership of the serial port handle.
+  if (handle_service_.assign(impl, handle, ec))
+    ::CloseHandle(handle);
+  return ec;
+}
+
+asio::error_code win_iocp_serial_port_service::do_set_option(
+    win_iocp_serial_port_service::implementation_type& impl,
+    win_iocp_serial_port_service::store_function_type store,
+    const void* option, asio::error_code& ec)
+{
+  using namespace std; // For memcpy.
+
+  ::DCB dcb;
+  memset(&dcb, 0, sizeof(DCB));
+  dcb.DCBlength = sizeof(DCB);
+  if (!::GetCommState(handle_service_.native_handle(impl), &dcb))
+  {
+    DWORD last_error = ::GetLastError();
+    ec = asio::error_code(last_error,
+        asio::error::get_system_category());
+    return ec;
+  }
+
+  if (store(option, dcb, ec))
+    return ec;
+
+  if (!::SetCommState(handle_service_.native_handle(impl), &dcb))
+  {
+    DWORD last_error = ::GetLastError();
+    ec = asio::error_code(last_error,
+        asio::error::get_system_category());
+    return ec;
+  }
+
+  ec = asio::error_code();
+  return ec;
+}
+
+asio::error_code win_iocp_serial_port_service::do_get_option(
+    const win_iocp_serial_port_service::implementation_type& impl,
+    win_iocp_serial_port_service::load_function_type load,
+    void* option, asio::error_code& ec) const
+{
+  using namespace std; // For memset.
+
+  ::DCB dcb;
+  memset(&dcb, 0, sizeof(DCB));
+  dcb.DCBlength = sizeof(DCB);
+  if (!::GetCommState(handle_service_.native_handle(impl), &dcb))
+  {
+    DWORD last_error = ::GetLastError();
+    ec = asio::error_code(last_error,
+        asio::error::get_system_category());
+    return ec;
+  }
+
+  return load(option, dcb, ec);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_IOCP) && defined(ASIO_HAS_SERIAL_PORT)
+
+#endif // ASIO_DETAIL_IMPL_WIN_IOCP_SERIAL_PORT_SERVICE_IPP
diff --git a/lib/asio/detail/impl/win_iocp_socket_service_base.ipp b/lib/asio/detail/impl/win_iocp_socket_service_base.ipp
new file mode 100644
index 0000000..6c478cd
--- /dev/null
+++ b/lib/asio/detail/impl/win_iocp_socket_service_base.ipp
@@ -0,0 +1,799 @@
+//
+// detail/impl/win_iocp_socket_service_base.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_WIN_IOCP_SOCKET_SERVICE_BASE_IPP
+#define ASIO_DETAIL_IMPL_WIN_IOCP_SOCKET_SERVICE_BASE_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_IOCP)
+
+#include "asio/detail/win_iocp_socket_service_base.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+win_iocp_socket_service_base::win_iocp_socket_service_base(
+    asio::io_context& io_context)
+  : io_context_(io_context),
+    iocp_service_(use_service<win_iocp_io_context>(io_context)),
+    reactor_(0),
+    connect_ex_(0),
+    nt_set_info_(0),
+    mutex_(),
+    impl_list_(0)
+{
+}
+
+void win_iocp_socket_service_base::base_shutdown()
+{
+  // Close all implementations, causing all operations to complete.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  base_implementation_type* impl = impl_list_;
+  while (impl)
+  {
+    close_for_destruction(*impl);
+    impl = impl->next_;
+  }
+}
+
+void win_iocp_socket_service_base::construct(
+    win_iocp_socket_service_base::base_implementation_type& impl)
+{
+  impl.socket_ = invalid_socket;
+  impl.state_ = 0;
+  impl.cancel_token_.reset();
+#if defined(ASIO_ENABLE_CANCELIO)
+  impl.safe_cancellation_thread_id_ = 0;
+#endif // defined(ASIO_ENABLE_CANCELIO)
+
+  // Insert implementation into linked list of all implementations.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  impl.next_ = impl_list_;
+  impl.prev_ = 0;
+  if (impl_list_)
+    impl_list_->prev_ = &impl;
+  impl_list_ = &impl;
+}
+
+void win_iocp_socket_service_base::base_move_construct(
+    win_iocp_socket_service_base::base_implementation_type& impl,
+    win_iocp_socket_service_base::base_implementation_type& other_impl)
+{
+  impl.socket_ = other_impl.socket_;
+  other_impl.socket_ = invalid_socket;
+
+  impl.state_ = other_impl.state_;
+  other_impl.state_ = 0;
+
+  impl.cancel_token_ = other_impl.cancel_token_;
+  other_impl.cancel_token_.reset();
+
+#if defined(ASIO_ENABLE_CANCELIO)
+  impl.safe_cancellation_thread_id_ = other_impl.safe_cancellation_thread_id_;
+  other_impl.safe_cancellation_thread_id_ = 0;
+#endif // defined(ASIO_ENABLE_CANCELIO)
+
+  // Insert implementation into linked list of all implementations.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  impl.next_ = impl_list_;
+  impl.prev_ = 0;
+  if (impl_list_)
+    impl_list_->prev_ = &impl;
+  impl_list_ = &impl;
+}
+
+void win_iocp_socket_service_base::base_move_assign(
+    win_iocp_socket_service_base::base_implementation_type& impl,
+    win_iocp_socket_service_base& other_service,
+    win_iocp_socket_service_base::base_implementation_type& other_impl)
+{
+  close_for_destruction(impl);
+
+  if (this != &other_service)
+  {
+    // Remove implementation from linked list of all implementations.
+    asio::detail::mutex::scoped_lock lock(mutex_);
+    if (impl_list_ == &impl)
+      impl_list_ = impl.next_;
+    if (impl.prev_)
+      impl.prev_->next_ = impl.next_;
+    if (impl.next_)
+      impl.next_->prev_= impl.prev_;
+    impl.next_ = 0;
+    impl.prev_ = 0;
+  }
+
+  impl.socket_ = other_impl.socket_;
+  other_impl.socket_ = invalid_socket;
+
+  impl.state_ = other_impl.state_;
+  other_impl.state_ = 0;
+
+  impl.cancel_token_ = other_impl.cancel_token_;
+  other_impl.cancel_token_.reset();
+
+#if defined(ASIO_ENABLE_CANCELIO)
+  impl.safe_cancellation_thread_id_ = other_impl.safe_cancellation_thread_id_;
+  other_impl.safe_cancellation_thread_id_ = 0;
+#endif // defined(ASIO_ENABLE_CANCELIO)
+
+  if (this != &other_service)
+  {
+    // Insert implementation into linked list of all implementations.
+    asio::detail::mutex::scoped_lock lock(other_service.mutex_);
+    impl.next_ = other_service.impl_list_;
+    impl.prev_ = 0;
+    if (other_service.impl_list_)
+      other_service.impl_list_->prev_ = &impl;
+    other_service.impl_list_ = &impl;
+  }
+}
+
+void win_iocp_socket_service_base::destroy(
+    win_iocp_socket_service_base::base_implementation_type& impl)
+{
+  close_for_destruction(impl);
+
+  // Remove implementation from linked list of all implementations.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  if (impl_list_ == &impl)
+    impl_list_ = impl.next_;
+  if (impl.prev_)
+    impl.prev_->next_ = impl.next_;
+  if (impl.next_)
+    impl.next_->prev_= impl.prev_;
+  impl.next_ = 0;
+  impl.prev_ = 0;
+}
+
+asio::error_code win_iocp_socket_service_base::close(
+    win_iocp_socket_service_base::base_implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ASIO_HANDLER_OPERATION((iocp_service_.context(),
+          "socket", &impl, impl.socket_, "close"));
+
+    // Check if the reactor was created, in which case we need to close the
+    // socket on the reactor as well to cancel any operations that might be
+    // running there.
+    select_reactor* r = static_cast<select_reactor*>(
+          interlocked_compare_exchange_pointer(
+            reinterpret_cast<void**>(&reactor_), 0, 0));
+    if (r)
+      r->deregister_descriptor(impl.socket_, impl.reactor_data_, true);
+
+    socket_ops::close(impl.socket_, impl.state_, false, ec);
+
+    if (r)
+      r->cleanup_descriptor_data(impl.reactor_data_);
+  }
+  else
+  {
+    ec = asio::error_code();
+  }
+
+  impl.socket_ = invalid_socket;
+  impl.state_ = 0;
+  impl.cancel_token_.reset();
+#if defined(ASIO_ENABLE_CANCELIO)
+  impl.safe_cancellation_thread_id_ = 0;
+#endif // defined(ASIO_ENABLE_CANCELIO)
+
+  return ec;
+}
+
+socket_type win_iocp_socket_service_base::release(
+    win_iocp_socket_service_base::base_implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (!is_open(impl))
+    return invalid_socket;
+
+  cancel(impl, ec);
+  if (ec)
+    return invalid_socket;
+
+  nt_set_info_fn fn = get_nt_set_info();
+  if (fn == 0)
+  {
+    ec = asio::error::operation_not_supported;
+    return invalid_socket;
+  }
+
+  HANDLE sock_as_handle = reinterpret_cast<HANDLE>(impl.socket_);
+  ULONG_PTR iosb[2] = { 0, 0 };
+  void* info[2] = { 0, 0 };
+  if (fn(sock_as_handle, iosb, &info, sizeof(info),
+        61 /* FileReplaceCompletionInformation */))
+  {
+    ec = asio::error::operation_not_supported;
+    return invalid_socket;
+  }
+
+  socket_type tmp = impl.socket_;
+  impl.socket_ = invalid_socket;
+  return tmp;
+}
+
+asio::error_code win_iocp_socket_service_base::cancel(
+    win_iocp_socket_service_base::base_implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    return ec;
+  }
+
+  ASIO_HANDLER_OPERATION((iocp_service_.context(),
+        "socket", &impl, impl.socket_, "cancel"));
+
+  if (FARPROC cancel_io_ex_ptr = ::GetProcAddress(
+        ::GetModuleHandleA("KERNEL32"), "CancelIoEx"))
+  {
+    // The version of Windows supports cancellation from any thread.
+    typedef BOOL (WINAPI* cancel_io_ex_t)(HANDLE, LPOVERLAPPED);
+    cancel_io_ex_t cancel_io_ex = (cancel_io_ex_t)cancel_io_ex_ptr;
+    socket_type sock = impl.socket_;
+    HANDLE sock_as_handle = reinterpret_cast<HANDLE>(sock);
+    if (!cancel_io_ex(sock_as_handle, 0))
+    {
+      DWORD last_error = ::GetLastError();
+      if (last_error == ERROR_NOT_FOUND)
+      {
+        // ERROR_NOT_FOUND means that there were no operations to be
+        // cancelled. We swallow this error to match the behaviour on other
+        // platforms.
+        ec = asio::error_code();
+      }
+      else
+      {
+        ec = asio::error_code(last_error,
+            asio::error::get_system_category());
+      }
+    }
+    else
+    {
+      ec = asio::error_code();
+    }
+  }
+#if defined(ASIO_ENABLE_CANCELIO)
+  else if (impl.safe_cancellation_thread_id_ == 0)
+  {
+    // No operations have been started, so there's nothing to cancel.
+    ec = asio::error_code();
+  }
+  else if (impl.safe_cancellation_thread_id_ == ::GetCurrentThreadId())
+  {
+    // Asynchronous operations have been started from the current thread only,
+    // so it is safe to try to cancel them using CancelIo.
+    socket_type sock = impl.socket_;
+    HANDLE sock_as_handle = reinterpret_cast<HANDLE>(sock);
+    if (!::CancelIo(sock_as_handle))
+    {
+      DWORD last_error = ::GetLastError();
+      ec = asio::error_code(last_error,
+          asio::error::get_system_category());
+    }
+    else
+    {
+      ec = asio::error_code();
+    }
+  }
+  else
+  {
+    // Asynchronous operations have been started from more than one thread,
+    // so cancellation is not safe.
+    ec = asio::error::operation_not_supported;
+  }
+#else // defined(ASIO_ENABLE_CANCELIO)
+  else
+  {
+    // Cancellation is not supported as CancelIo may not be used.
+    ec = asio::error::operation_not_supported;
+  }
+#endif // defined(ASIO_ENABLE_CANCELIO)
+
+  // Cancel any operations started via the reactor.
+  if (!ec)
+  {
+    select_reactor* r = static_cast<select_reactor*>(
+          interlocked_compare_exchange_pointer(
+            reinterpret_cast<void**>(&reactor_), 0, 0));
+    if (r)
+      r->cancel_ops(impl.socket_, impl.reactor_data_);
+  }
+
+  return ec;
+}
+
+asio::error_code win_iocp_socket_service_base::do_open(
+    win_iocp_socket_service_base::base_implementation_type& impl,
+    int family, int type, int protocol, asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ec = asio::error::already_open;
+    return ec;
+  }
+
+  socket_holder sock(socket_ops::socket(family, type, protocol, ec));
+  if (sock.get() == invalid_socket)
+    return ec;
+
+  HANDLE sock_as_handle = reinterpret_cast<HANDLE>(sock.get());
+  if (iocp_service_.register_handle(sock_as_handle, ec))
+    return ec;
+
+  impl.socket_ = sock.release();
+  switch (type)
+  {
+  case SOCK_STREAM: impl.state_ = socket_ops::stream_oriented; break;
+  case SOCK_DGRAM: impl.state_ = socket_ops::datagram_oriented; break;
+  default: impl.state_ = 0; break;
+  }
+  impl.cancel_token_.reset(static_cast<void*>(0), socket_ops::noop_deleter());
+  ec = asio::error_code();
+  return ec;
+}
+
+asio::error_code win_iocp_socket_service_base::do_assign(
+    win_iocp_socket_service_base::base_implementation_type& impl,
+    int type, socket_type native_socket, asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ec = asio::error::already_open;
+    return ec;
+  }
+
+  HANDLE sock_as_handle = reinterpret_cast<HANDLE>(native_socket);
+  if (iocp_service_.register_handle(sock_as_handle, ec))
+    return ec;
+
+  impl.socket_ = native_socket;
+  switch (type)
+  {
+  case SOCK_STREAM: impl.state_ = socket_ops::stream_oriented; break;
+  case SOCK_DGRAM: impl.state_ = socket_ops::datagram_oriented; break;
+  default: impl.state_ = 0; break;
+  }
+  impl.cancel_token_.reset(static_cast<void*>(0), socket_ops::noop_deleter());
+  ec = asio::error_code();
+  return ec;
+}
+
+void win_iocp_socket_service_base::start_send_op(
+    win_iocp_socket_service_base::base_implementation_type& impl,
+    WSABUF* buffers, std::size_t buffer_count,
+    socket_base::message_flags flags, bool noop, operation* op)
+{
+  update_cancellation_thread_id(impl);
+  iocp_service_.work_started();
+
+  if (noop)
+    iocp_service_.on_completion(op);
+  else if (!is_open(impl))
+    iocp_service_.on_completion(op, asio::error::bad_descriptor);
+  else
+  {
+    DWORD bytes_transferred = 0;
+    int result = ::WSASend(impl.socket_, buffers,
+        static_cast<DWORD>(buffer_count), &bytes_transferred, flags, op, 0);
+    DWORD last_error = ::WSAGetLastError();
+    if (last_error == ERROR_PORT_UNREACHABLE)
+      last_error = WSAECONNREFUSED;
+    if (result != 0 && last_error != WSA_IO_PENDING)
+      iocp_service_.on_completion(op, last_error, bytes_transferred);
+    else
+      iocp_service_.on_pending(op);
+  }
+}
+
+void win_iocp_socket_service_base::start_send_to_op(
+    win_iocp_socket_service_base::base_implementation_type& impl,
+    WSABUF* buffers, std::size_t buffer_count,
+    const socket_addr_type* addr, int addrlen,
+    socket_base::message_flags flags, operation* op)
+{
+  update_cancellation_thread_id(impl);
+  iocp_service_.work_started();
+
+  if (!is_open(impl))
+    iocp_service_.on_completion(op, asio::error::bad_descriptor);
+  else
+  {
+    DWORD bytes_transferred = 0;
+    int result = ::WSASendTo(impl.socket_, buffers,
+        static_cast<DWORD>(buffer_count),
+        &bytes_transferred, flags, addr, addrlen, op, 0);
+    DWORD last_error = ::WSAGetLastError();
+    if (last_error == ERROR_PORT_UNREACHABLE)
+      last_error = WSAECONNREFUSED;
+    if (result != 0 && last_error != WSA_IO_PENDING)
+      iocp_service_.on_completion(op, last_error, bytes_transferred);
+    else
+      iocp_service_.on_pending(op);
+  }
+}
+
+void win_iocp_socket_service_base::start_receive_op(
+    win_iocp_socket_service_base::base_implementation_type& impl,
+    WSABUF* buffers, std::size_t buffer_count,
+    socket_base::message_flags flags, bool noop, operation* op)
+{
+  update_cancellation_thread_id(impl);
+  iocp_service_.work_started();
+
+  if (noop)
+    iocp_service_.on_completion(op);
+  else if (!is_open(impl))
+    iocp_service_.on_completion(op, asio::error::bad_descriptor);
+  else
+  {
+    DWORD bytes_transferred = 0;
+    DWORD recv_flags = flags;
+    int result = ::WSARecv(impl.socket_, buffers,
+        static_cast<DWORD>(buffer_count),
+        &bytes_transferred, &recv_flags, op, 0);
+    DWORD last_error = ::WSAGetLastError();
+    if (last_error == ERROR_NETNAME_DELETED)
+      last_error = WSAECONNRESET;
+    else if (last_error == ERROR_PORT_UNREACHABLE)
+      last_error = WSAECONNREFUSED;
+    if (result != 0 && last_error != WSA_IO_PENDING)
+      iocp_service_.on_completion(op, last_error, bytes_transferred);
+    else
+      iocp_service_.on_pending(op);
+  }
+}
+
+void win_iocp_socket_service_base::start_null_buffers_receive_op(
+    win_iocp_socket_service_base::base_implementation_type& impl,
+    socket_base::message_flags flags, reactor_op* op)
+{
+  if ((impl.state_ & socket_ops::stream_oriented) != 0)
+  {
+    // For stream sockets on Windows, we may issue a 0-byte overlapped
+    // WSARecv to wait until there is data available on the socket.
+    ::WSABUF buf = { 0, 0 };
+    start_receive_op(impl, &buf, 1, flags, false, op);
+  }
+  else
+  {
+    start_reactor_op(impl,
+        (flags & socket_base::message_out_of_band)
+          ? select_reactor::except_op : select_reactor::read_op,
+        op);
+  }
+}
+
+void win_iocp_socket_service_base::start_receive_from_op(
+    win_iocp_socket_service_base::base_implementation_type& impl,
+    WSABUF* buffers, std::size_t buffer_count, socket_addr_type* addr,
+    socket_base::message_flags flags, int* addrlen, operation* op)
+{
+  update_cancellation_thread_id(impl);
+  iocp_service_.work_started();
+
+  if (!is_open(impl))
+    iocp_service_.on_completion(op, asio::error::bad_descriptor);
+  else
+  {
+    DWORD bytes_transferred = 0;
+    DWORD recv_flags = flags;
+    int result = ::WSARecvFrom(impl.socket_, buffers,
+        static_cast<DWORD>(buffer_count),
+        &bytes_transferred, &recv_flags, addr, addrlen, op, 0);
+    DWORD last_error = ::WSAGetLastError();
+    if (last_error == ERROR_PORT_UNREACHABLE)
+      last_error = WSAECONNREFUSED;
+    if (result != 0 && last_error != WSA_IO_PENDING)
+      iocp_service_.on_completion(op, last_error, bytes_transferred);
+    else
+      iocp_service_.on_pending(op);
+  }
+}
+
+void win_iocp_socket_service_base::start_accept_op(
+    win_iocp_socket_service_base::base_implementation_type& impl,
+    bool peer_is_open, socket_holder& new_socket, int family, int type,
+    int protocol, void* output_buffer, DWORD address_length, operation* op)
+{
+  update_cancellation_thread_id(impl);
+  iocp_service_.work_started();
+
+  if (!is_open(impl))
+    iocp_service_.on_completion(op, asio::error::bad_descriptor);
+  else if (peer_is_open)
+    iocp_service_.on_completion(op, asio::error::already_open);
+  else
+  {
+    asio::error_code ec;
+    new_socket.reset(socket_ops::socket(family, type, protocol, ec));
+    if (new_socket.get() == invalid_socket)
+      iocp_service_.on_completion(op, ec);
+    else
+    {
+      DWORD bytes_read = 0;
+      BOOL result = ::AcceptEx(impl.socket_, new_socket.get(), output_buffer,
+          0, address_length, address_length, &bytes_read, op);
+      DWORD last_error = ::WSAGetLastError();
+      if (!result && last_error != WSA_IO_PENDING)
+        iocp_service_.on_completion(op, last_error);
+      else
+        iocp_service_.on_pending(op);
+    }
+  }
+}
+
+void win_iocp_socket_service_base::restart_accept_op(
+    socket_type s, socket_holder& new_socket, int family, int type,
+    int protocol, void* output_buffer, DWORD address_length, operation* op)
+{
+  new_socket.reset();
+  iocp_service_.work_started();
+
+  asio::error_code ec;
+  new_socket.reset(socket_ops::socket(family, type, protocol, ec));
+  if (new_socket.get() == invalid_socket)
+    iocp_service_.on_completion(op, ec);
+  else
+  {
+    DWORD bytes_read = 0;
+    BOOL result = ::AcceptEx(s, new_socket.get(), output_buffer,
+        0, address_length, address_length, &bytes_read, op);
+    DWORD last_error = ::WSAGetLastError();
+    if (!result && last_error != WSA_IO_PENDING)
+      iocp_service_.on_completion(op, last_error);
+    else
+      iocp_service_.on_pending(op);
+  }
+}
+
+void win_iocp_socket_service_base::start_reactor_op(
+    win_iocp_socket_service_base::base_implementation_type& impl,
+    int op_type, reactor_op* op)
+{
+  select_reactor& r = get_reactor();
+  update_cancellation_thread_id(impl);
+
+  if (is_open(impl))
+  {
+    r.start_op(op_type, impl.socket_, impl.reactor_data_, op, false, false);
+    return;
+  }
+  else
+    op->ec_ = asio::error::bad_descriptor;
+
+  iocp_service_.post_immediate_completion(op, false);
+}
+
+void win_iocp_socket_service_base::start_connect_op(
+    win_iocp_socket_service_base::base_implementation_type& impl,
+    int family, int type, const socket_addr_type* addr,
+    std::size_t addrlen, win_iocp_socket_connect_op_base* op)
+{
+  // If ConnectEx is available, use that.
+  if (family == ASIO_OS_DEF(AF_INET)
+      || family == ASIO_OS_DEF(AF_INET6))
+  {
+    if (connect_ex_fn connect_ex = get_connect_ex(impl, type))
+    {
+      union address_union
+      {
+        socket_addr_type base;
+        sockaddr_in4_type v4;
+        sockaddr_in6_type v6;
+      } a;
+
+      using namespace std; // For memset.
+      memset(&a, 0, sizeof(a));
+      a.base.sa_family = family;
+
+      socket_ops::bind(impl.socket_, &a.base,
+          family == ASIO_OS_DEF(AF_INET)
+          ? sizeof(a.v4) : sizeof(a.v6), op->ec_);
+      if (op->ec_ && op->ec_ != asio::error::invalid_argument)
+      {
+        iocp_service_.post_immediate_completion(op, false);
+        return;
+      }
+
+      op->connect_ex_ = true;
+      update_cancellation_thread_id(impl);
+      iocp_service_.work_started();
+
+      BOOL result = connect_ex(impl.socket_,
+          addr, static_cast<int>(addrlen), 0, 0, 0, op);
+      DWORD last_error = ::WSAGetLastError();
+      if (!result && last_error != WSA_IO_PENDING)
+        iocp_service_.on_completion(op, last_error);
+      else
+        iocp_service_.on_pending(op);
+      return;
+    }
+  }
+
+  // Otherwise, fall back to a reactor-based implementation.
+  select_reactor& r = get_reactor();
+  update_cancellation_thread_id(impl);
+
+  if ((impl.state_ & socket_ops::non_blocking) != 0
+      || socket_ops::set_internal_non_blocking(
+        impl.socket_, impl.state_, true, op->ec_))
+  {
+    if (socket_ops::connect(impl.socket_, addr, addrlen, op->ec_) != 0)
+    {
+      if (op->ec_ == asio::error::in_progress
+          || op->ec_ == asio::error::would_block)
+      {
+        op->ec_ = asio::error_code();
+        r.start_op(select_reactor::connect_op, impl.socket_,
+            impl.reactor_data_, op, false, false);
+        return;
+      }
+    }
+  }
+
+  r.post_immediate_completion(op, false);
+}
+
+void win_iocp_socket_service_base::close_for_destruction(
+    win_iocp_socket_service_base::base_implementation_type& impl)
+{
+  if (is_open(impl))
+  {
+    ASIO_HANDLER_OPERATION((iocp_service_.context(),
+          "socket", &impl, impl.socket_, "close"));
+
+    // Check if the reactor was created, in which case we need to close the
+    // socket on the reactor as well to cancel any operations that might be
+    // running there.
+    select_reactor* r = static_cast<select_reactor*>(
+          interlocked_compare_exchange_pointer(
+            reinterpret_cast<void**>(&reactor_), 0, 0));
+    if (r)
+      r->deregister_descriptor(impl.socket_, impl.reactor_data_, true);
+
+    asio::error_code ignored_ec;
+    socket_ops::close(impl.socket_, impl.state_, true, ignored_ec);
+
+    if (r)
+      r->cleanup_descriptor_data(impl.reactor_data_);
+  }
+
+  impl.socket_ = invalid_socket;
+  impl.state_ = 0;
+  impl.cancel_token_.reset();
+#if defined(ASIO_ENABLE_CANCELIO)
+  impl.safe_cancellation_thread_id_ = 0;
+#endif // defined(ASIO_ENABLE_CANCELIO)
+}
+
+void win_iocp_socket_service_base::update_cancellation_thread_id(
+    win_iocp_socket_service_base::base_implementation_type& impl)
+{
+#if defined(ASIO_ENABLE_CANCELIO)
+  if (impl.safe_cancellation_thread_id_ == 0)
+    impl.safe_cancellation_thread_id_ = ::GetCurrentThreadId();
+  else if (impl.safe_cancellation_thread_id_ != ::GetCurrentThreadId())
+    impl.safe_cancellation_thread_id_ = ~DWORD(0);
+#else // defined(ASIO_ENABLE_CANCELIO)
+  (void)impl;
+#endif // defined(ASIO_ENABLE_CANCELIO)
+}
+
+select_reactor& win_iocp_socket_service_base::get_reactor()
+{
+  select_reactor* r = static_cast<select_reactor*>(
+        interlocked_compare_exchange_pointer(
+          reinterpret_cast<void**>(&reactor_), 0, 0));
+  if (!r)
+  {
+    r = &(use_service<select_reactor>(io_context_));
+    interlocked_exchange_pointer(reinterpret_cast<void**>(&reactor_), r);
+  }
+  return *r;
+}
+
+win_iocp_socket_service_base::connect_ex_fn
+win_iocp_socket_service_base::get_connect_ex(
+    win_iocp_socket_service_base::base_implementation_type& impl, int type)
+{
+#if defined(ASIO_DISABLE_CONNECTEX)
+  (void)impl;
+  (void)type;
+  return 0;
+#else // defined(ASIO_DISABLE_CONNECTEX)
+  if (type != ASIO_OS_DEF(SOCK_STREAM)
+      && type != ASIO_OS_DEF(SOCK_SEQPACKET))
+    return 0;
+
+  void* ptr = interlocked_compare_exchange_pointer(&connect_ex_, 0, 0);
+  if (!ptr)
+  {
+    GUID guid = { 0x25a207b9, 0xddf3, 0x4660,
+      { 0x8e, 0xe9, 0x76, 0xe5, 0x8c, 0x74, 0x06, 0x3e } };
+
+    DWORD bytes = 0;
+    if (::WSAIoctl(impl.socket_, SIO_GET_EXTENSION_FUNCTION_POINTER,
+          &guid, sizeof(guid), &ptr, sizeof(ptr), &bytes, 0, 0) != 0)
+    {
+      // Set connect_ex_ to a special value to indicate that ConnectEx is
+      // unavailable. That way we won't bother trying to look it up again.
+      ptr = this;
+    }
+
+    interlocked_exchange_pointer(&connect_ex_, ptr);
+  }
+
+  return reinterpret_cast<connect_ex_fn>(ptr == this ? 0 : ptr);
+#endif // defined(ASIO_DISABLE_CONNECTEX)
+}
+
+win_iocp_socket_service_base::nt_set_info_fn
+win_iocp_socket_service_base::get_nt_set_info()
+{
+  void* ptr = interlocked_compare_exchange_pointer(&nt_set_info_, 0, 0);
+  if (!ptr)
+  {
+    if (HMODULE h = ::GetModuleHandleA("NTDLL.DLL"))
+      ptr = reinterpret_cast<void*>(GetProcAddress(h, "NtSetInformationFile"));
+
+    // On failure, set nt_set_info_ to a special value to indicate that the
+    // NtSetInformationFile function is unavailable. That way we won't bother
+    // trying to look it up again.
+    interlocked_exchange_pointer(&nt_set_info_, ptr ? ptr : this);
+  }
+
+  return reinterpret_cast<nt_set_info_fn>(ptr == this ? 0 : ptr);
+}
+
+void* win_iocp_socket_service_base::interlocked_compare_exchange_pointer(
+    void** dest, void* exch, void* cmp)
+{
+#if defined(_M_IX86)
+  return reinterpret_cast<void*>(InterlockedCompareExchange(
+        reinterpret_cast<PLONG>(dest), reinterpret_cast<LONG>(exch),
+        reinterpret_cast<LONG>(cmp)));
+#else
+  return InterlockedCompareExchangePointer(dest, exch, cmp);
+#endif
+}
+
+void* win_iocp_socket_service_base::interlocked_exchange_pointer(
+    void** dest, void* val)
+{
+#if defined(_M_IX86)
+  return reinterpret_cast<void*>(InterlockedExchange(
+        reinterpret_cast<PLONG>(dest), reinterpret_cast<LONG>(val)));
+#else
+  return InterlockedExchangePointer(dest, val);
+#endif
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_IOCP)
+
+#endif // ASIO_DETAIL_IMPL_WIN_IOCP_SOCKET_SERVICE_BASE_IPP
diff --git a/lib/asio/detail/impl/win_mutex.ipp b/lib/asio/detail/impl/win_mutex.ipp
new file mode 100644
index 0000000..dc58a12
--- /dev/null
+++ b/lib/asio/detail/impl/win_mutex.ipp
@@ -0,0 +1,84 @@
+//
+// detail/impl/win_mutex.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_WIN_MUTEX_IPP
+#define ASIO_DETAIL_IMPL_WIN_MUTEX_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_WINDOWS)
+
+#include "asio/detail/throw_error.hpp"
+#include "asio/detail/win_mutex.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+win_mutex::win_mutex()
+{
+  int error = do_init();
+  asio::error_code ec(error,
+      asio::error::get_system_category());
+  asio::detail::throw_error(ec, "mutex");
+}
+
+int win_mutex::do_init()
+{
+#if defined(__MINGW32__)
+  // Not sure if MinGW supports structured exception handling, so for now
+  // we'll just call the Windows API and hope.
+# if defined(UNDER_CE)
+  ::InitializeCriticalSection(&crit_section_);
+# elif defined(ASIO_WINDOWS_APP)
+  if (!::InitializeCriticalSectionEx(&crit_section_, 0, 0))
+    return ::GetLastError();
+# else
+  if (!::InitializeCriticalSectionAndSpinCount(&crit_section_, 0x80000000))
+    return ::GetLastError();
+# endif
+  return 0;
+#else
+  __try
+  {
+# if defined(UNDER_CE)
+    ::InitializeCriticalSection(&crit_section_);
+# elif defined(ASIO_WINDOWS_APP)
+    if (!::InitializeCriticalSectionEx(&crit_section_, 0, 0))
+      return ::GetLastError();
+# else
+    if (!::InitializeCriticalSectionAndSpinCount(&crit_section_, 0x80000000))
+      return ::GetLastError();
+# endif
+  }
+  __except(GetExceptionCode() == STATUS_NO_MEMORY
+      ? EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH)
+  {
+    return ERROR_OUTOFMEMORY;
+  }
+
+  return 0;
+#endif
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_WINDOWS)
+
+#endif // ASIO_DETAIL_IMPL_WIN_MUTEX_IPP
diff --git a/lib/asio/detail/impl/win_object_handle_service.ipp b/lib/asio/detail/impl/win_object_handle_service.ipp
new file mode 100644
index 0000000..c5e59d1
--- /dev/null
+++ b/lib/asio/detail/impl/win_object_handle_service.ipp
@@ -0,0 +1,449 @@
+//
+// detail/impl/win_object_handle_service.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2011 Boris Schaeling (boris@highscore.de)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_WIN_OBJECT_HANDLE_SERVICE_IPP
+#define ASIO_DETAIL_IMPL_WIN_OBJECT_HANDLE_SERVICE_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_WINDOWS_OBJECT_HANDLE)
+
+#include "asio/detail/win_object_handle_service.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+win_object_handle_service::win_object_handle_service(
+    asio::io_context& io_context)
+  : service_base<win_object_handle_service>(io_context),
+    io_context_(asio::use_service<io_context_impl>(io_context)),
+    mutex_(),
+    impl_list_(0),
+    shutdown_(false)
+{
+}
+
+void win_object_handle_service::shutdown()
+{
+  mutex::scoped_lock lock(mutex_);
+
+  // Setting this flag to true prevents new objects from being registered, and
+  // new asynchronous wait operations from being started. We only need to worry
+  // about cleaning up the operations that are currently in progress.
+  shutdown_ = true;
+
+  op_queue<operation> ops;
+  for (implementation_type* impl = impl_list_; impl; impl = impl->next_)
+    ops.push(impl->op_queue_);
+
+  lock.unlock();
+
+  io_context_.abandon_operations(ops);
+}
+
+void win_object_handle_service::construct(
+    win_object_handle_service::implementation_type& impl)
+{
+  impl.handle_ = INVALID_HANDLE_VALUE;
+  impl.wait_handle_ = INVALID_HANDLE_VALUE;
+  impl.owner_ = this;
+
+  // Insert implementation into linked list of all implementations.
+  mutex::scoped_lock lock(mutex_);
+  if (!shutdown_)
+  {
+    impl.next_ = impl_list_;
+    impl.prev_ = 0;
+    if (impl_list_)
+      impl_list_->prev_ = &impl;
+    impl_list_ = &impl;
+  }
+}
+
+void win_object_handle_service::move_construct(
+    win_object_handle_service::implementation_type& impl,
+    win_object_handle_service::implementation_type& other_impl)
+{
+  mutex::scoped_lock lock(mutex_);
+
+  // Insert implementation into linked list of all implementations.
+  if (!shutdown_)
+  {
+    impl.next_ = impl_list_;
+    impl.prev_ = 0;
+    if (impl_list_)
+      impl_list_->prev_ = &impl;
+    impl_list_ = &impl;
+  }
+
+  impl.handle_ = other_impl.handle_;
+  other_impl.handle_ = INVALID_HANDLE_VALUE;
+  impl.wait_handle_ = other_impl.wait_handle_;
+  other_impl.wait_handle_ = INVALID_HANDLE_VALUE;
+  impl.op_queue_.push(other_impl.op_queue_);
+  impl.owner_ = this;
+
+  // We must not hold the lock while calling UnregisterWaitEx. This is because
+  // the registered callback function might be invoked while we are waiting for
+  // UnregisterWaitEx to complete.
+  lock.unlock();
+
+  if (impl.wait_handle_ != INVALID_HANDLE_VALUE)
+    ::UnregisterWaitEx(impl.wait_handle_, INVALID_HANDLE_VALUE);
+
+  if (!impl.op_queue_.empty())
+    register_wait_callback(impl, lock);
+}
+
+void win_object_handle_service::move_assign(
+    win_object_handle_service::implementation_type& impl,
+    win_object_handle_service& other_service,
+    win_object_handle_service::implementation_type& other_impl)
+{
+  asio::error_code ignored_ec;
+  close(impl, ignored_ec);
+
+  mutex::scoped_lock lock(mutex_);
+
+  if (this != &other_service)
+  {
+    // Remove implementation from linked list of all implementations.
+    if (impl_list_ == &impl)
+      impl_list_ = impl.next_;
+    if (impl.prev_)
+      impl.prev_->next_ = impl.next_;
+    if (impl.next_)
+      impl.next_->prev_= impl.prev_;
+    impl.next_ = 0;
+    impl.prev_ = 0;
+  }
+
+  impl.handle_ = other_impl.handle_;
+  other_impl.handle_ = INVALID_HANDLE_VALUE;
+  impl.wait_handle_ = other_impl.wait_handle_;
+  other_impl.wait_handle_ = INVALID_HANDLE_VALUE;
+  impl.op_queue_.push(other_impl.op_queue_);
+  impl.owner_ = this;
+
+  if (this != &other_service)
+  {
+    // Insert implementation into linked list of all implementations.
+    impl.next_ = other_service.impl_list_;
+    impl.prev_ = 0;
+    if (other_service.impl_list_)
+      other_service.impl_list_->prev_ = &impl;
+    other_service.impl_list_ = &impl;
+  }
+
+  // We must not hold the lock while calling UnregisterWaitEx. This is because
+  // the registered callback function might be invoked while we are waiting for
+  // UnregisterWaitEx to complete.
+  lock.unlock();
+
+  if (impl.wait_handle_ != INVALID_HANDLE_VALUE)
+    ::UnregisterWaitEx(impl.wait_handle_, INVALID_HANDLE_VALUE);
+
+  if (!impl.op_queue_.empty())
+    register_wait_callback(impl, lock);
+}
+
+void win_object_handle_service::destroy(
+    win_object_handle_service::implementation_type& impl)
+{
+  mutex::scoped_lock lock(mutex_);
+
+  // Remove implementation from linked list of all implementations.
+  if (impl_list_ == &impl)
+    impl_list_ = impl.next_;
+  if (impl.prev_)
+    impl.prev_->next_ = impl.next_;
+  if (impl.next_)
+    impl.next_->prev_= impl.prev_;
+  impl.next_ = 0;
+  impl.prev_ = 0;
+
+  if (is_open(impl))
+  {
+    ASIO_HANDLER_OPERATION((io_context_.context(), "object_handle",
+          &impl, reinterpret_cast<uintmax_t>(impl.wait_handle_), "close"));
+
+    HANDLE wait_handle = impl.wait_handle_;
+    impl.wait_handle_ = INVALID_HANDLE_VALUE;
+
+    op_queue<operation> ops;
+    while (wait_op* op = impl.op_queue_.front())
+    {
+      op->ec_ = asio::error::operation_aborted;
+      impl.op_queue_.pop();
+      ops.push(op);
+    }
+
+    // We must not hold the lock while calling UnregisterWaitEx. This is
+    // because the registered callback function might be invoked while we are
+    // waiting for UnregisterWaitEx to complete.
+    lock.unlock();
+
+    if (wait_handle != INVALID_HANDLE_VALUE)
+      ::UnregisterWaitEx(wait_handle, INVALID_HANDLE_VALUE);
+
+    ::CloseHandle(impl.handle_);
+    impl.handle_ = INVALID_HANDLE_VALUE;
+
+    io_context_.post_deferred_completions(ops);
+  }
+}
+
+asio::error_code win_object_handle_service::assign(
+    win_object_handle_service::implementation_type& impl,
+    const native_handle_type& handle, asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ec = asio::error::already_open;
+    return ec;
+  }
+
+  impl.handle_ = handle;
+  ec = asio::error_code();
+  return ec;
+}
+
+asio::error_code win_object_handle_service::close(
+    win_object_handle_service::implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ASIO_HANDLER_OPERATION((io_context_.context(), "object_handle",
+          &impl, reinterpret_cast<uintmax_t>(impl.wait_handle_), "close"));
+
+    mutex::scoped_lock lock(mutex_);
+
+    HANDLE wait_handle = impl.wait_handle_;
+    impl.wait_handle_ = INVALID_HANDLE_VALUE;
+
+    op_queue<operation> completed_ops;
+    while (wait_op* op = impl.op_queue_.front())
+    {
+      impl.op_queue_.pop();
+      op->ec_ = asio::error::operation_aborted;
+      completed_ops.push(op);
+    }
+
+    // We must not hold the lock while calling UnregisterWaitEx. This is
+    // because the registered callback function might be invoked while we are
+    // waiting for UnregisterWaitEx to complete.
+    lock.unlock();
+
+    if (wait_handle != INVALID_HANDLE_VALUE)
+      ::UnregisterWaitEx(wait_handle, INVALID_HANDLE_VALUE);
+
+    if (::CloseHandle(impl.handle_))
+    {
+      impl.handle_ = INVALID_HANDLE_VALUE;
+      ec = asio::error_code();
+    }
+    else
+    {
+      DWORD last_error = ::GetLastError();
+      ec = asio::error_code(last_error,
+          asio::error::get_system_category());
+    }
+
+    io_context_.post_deferred_completions(completed_ops);
+  }
+  else
+  {
+    ec = asio::error_code();
+  }
+
+  return ec;
+}
+
+asio::error_code win_object_handle_service::cancel(
+    win_object_handle_service::implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ASIO_HANDLER_OPERATION((io_context_.context(), "object_handle",
+          &impl, reinterpret_cast<uintmax_t>(impl.wait_handle_), "cancel"));
+
+    mutex::scoped_lock lock(mutex_);
+
+    HANDLE wait_handle = impl.wait_handle_;
+    impl.wait_handle_ = INVALID_HANDLE_VALUE;
+
+    op_queue<operation> completed_ops;
+    while (wait_op* op = impl.op_queue_.front())
+    {
+      op->ec_ = asio::error::operation_aborted;
+      impl.op_queue_.pop();
+      completed_ops.push(op);
+    }
+
+    // We must not hold the lock while calling UnregisterWaitEx. This is
+    // because the registered callback function might be invoked while we are
+    // waiting for UnregisterWaitEx to complete.
+    lock.unlock();
+
+    if (wait_handle != INVALID_HANDLE_VALUE)
+      ::UnregisterWaitEx(wait_handle, INVALID_HANDLE_VALUE);
+
+    ec = asio::error_code();
+
+    io_context_.post_deferred_completions(completed_ops);
+  }
+  else
+  {
+    ec = asio::error::bad_descriptor;
+  }
+
+  return ec;
+}
+
+void win_object_handle_service::wait(
+    win_object_handle_service::implementation_type& impl,
+    asio::error_code& ec)
+{
+  switch (::WaitForSingleObject(impl.handle_, INFINITE))
+  {
+  case WAIT_FAILED:
+    {
+      DWORD last_error = ::GetLastError();
+      ec = asio::error_code(last_error,
+          asio::error::get_system_category());
+      break;
+    }
+  case WAIT_OBJECT_0:
+  case WAIT_ABANDONED:
+  default:
+    ec = asio::error_code();
+    break;
+  }
+}
+
+void win_object_handle_service::start_wait_op(
+    win_object_handle_service::implementation_type& impl, wait_op* op)
+{
+  io_context_.work_started();
+
+  if (is_open(impl))
+  {
+    mutex::scoped_lock lock(mutex_);
+
+    if (!shutdown_)
+    {
+      impl.op_queue_.push(op);
+
+      // Only the first operation to be queued gets to register a wait callback.
+      // Subsequent operations have to wait for the first to finish.
+      if (impl.op_queue_.front() == op)
+        register_wait_callback(impl, lock);
+    }
+    else
+    {
+      lock.unlock();
+      io_context_.post_deferred_completion(op);
+    }
+  }
+  else
+  {
+    op->ec_ = asio::error::bad_descriptor;
+    io_context_.post_deferred_completion(op);
+  }
+}
+
+void win_object_handle_service::register_wait_callback(
+    win_object_handle_service::implementation_type& impl,
+    mutex::scoped_lock& lock)
+{
+  lock.lock();
+
+  if (!RegisterWaitForSingleObject(&impl.wait_handle_,
+        impl.handle_, &win_object_handle_service::wait_callback,
+        &impl, INFINITE, WT_EXECUTEONLYONCE))
+  {
+    DWORD last_error = ::GetLastError();
+    asio::error_code ec(last_error,
+        asio::error::get_system_category());
+
+    op_queue<operation> completed_ops;
+    while (wait_op* op = impl.op_queue_.front())
+    {
+      op->ec_ = ec;
+      impl.op_queue_.pop();
+      completed_ops.push(op);
+    }
+
+    lock.unlock();
+    io_context_.post_deferred_completions(completed_ops);
+  }
+}
+
+void win_object_handle_service::wait_callback(PVOID param, BOOLEAN)
+{
+  implementation_type* impl = static_cast<implementation_type*>(param);
+  mutex::scoped_lock lock(impl->owner_->mutex_);
+
+  if (impl->wait_handle_ != INVALID_HANDLE_VALUE)
+  {
+    ::UnregisterWaitEx(impl->wait_handle_, NULL);
+    impl->wait_handle_ = INVALID_HANDLE_VALUE;
+  }
+
+  if (wait_op* op = impl->op_queue_.front())
+  {
+    op_queue<operation> completed_ops;
+
+    op->ec_ = asio::error_code();
+    impl->op_queue_.pop();
+    completed_ops.push(op);
+
+    if (!impl->op_queue_.empty())
+    {
+      if (!RegisterWaitForSingleObject(&impl->wait_handle_,
+            impl->handle_, &win_object_handle_service::wait_callback,
+            param, INFINITE, WT_EXECUTEONLYONCE))
+      {
+        DWORD last_error = ::GetLastError();
+        asio::error_code ec(last_error,
+            asio::error::get_system_category());
+
+        while ((op = impl->op_queue_.front()) != 0)
+        {
+          op->ec_ = ec;
+          impl->op_queue_.pop();
+          completed_ops.push(op);
+        }
+      }
+    }
+
+    io_context_impl& ioc = impl->owner_->io_context_;
+    lock.unlock();
+    ioc.post_deferred_completions(completed_ops);
+  }
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_WINDOWS_OBJECT_HANDLE)
+
+#endif // ASIO_DETAIL_IMPL_WIN_OBJECT_HANDLE_SERVICE_IPP
diff --git a/lib/asio/detail/impl/win_static_mutex.ipp b/lib/asio/detail/impl/win_static_mutex.ipp
new file mode 100644
index 0000000..42089bd
--- /dev/null
+++ b/lib/asio/detail/impl/win_static_mutex.ipp
@@ -0,0 +1,136 @@
+//
+// detail/impl/win_static_mutex.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_WIN_STATIC_MUTEX_IPP
+#define ASIO_DETAIL_IMPL_WIN_STATIC_MUTEX_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_WINDOWS)
+
+#include <cstdio>
+#include "asio/detail/throw_error.hpp"
+#include "asio/detail/win_static_mutex.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+void win_static_mutex::init()
+{
+  int error = do_init();
+  asio::error_code ec(error,
+      asio::error::get_system_category());
+  asio::detail::throw_error(ec, "static_mutex");
+}
+
+int win_static_mutex::do_init()
+{
+  using namespace std; // For sprintf.
+  wchar_t mutex_name[128];
+#if defined(ASIO_HAS_SECURE_RTL)
+  swprintf_s(
+#else // defined(ASIO_HAS_SECURE_RTL)
+  _snwprintf(
+#endif // defined(ASIO_HAS_SECURE_RTL)
+      mutex_name, 128, L"asio-58CCDC44-6264-4842-90C2-F3C545CB8AA7-%u-%p",
+      static_cast<unsigned int>(::GetCurrentProcessId()), this);
+
+#if defined(ASIO_WINDOWS_APP)
+  HANDLE mutex = ::CreateMutexExW(0, mutex_name, CREATE_MUTEX_INITIAL_OWNER, 0);
+#else // defined(ASIO_WINDOWS_APP)
+  HANDLE mutex = ::CreateMutexW(0, TRUE, mutex_name);
+#endif // defined(ASIO_WINDOWS_APP)
+  DWORD last_error = ::GetLastError();
+  if (mutex == 0)
+    return ::GetLastError();
+
+  if (last_error == ERROR_ALREADY_EXISTS)
+  {
+#if defined(ASIO_WINDOWS_APP)
+    ::WaitForSingleObjectEx(mutex, INFINITE, false);
+#else // defined(ASIO_WINDOWS_APP)
+    ::WaitForSingleObject(mutex, INFINITE);
+#endif // defined(ASIO_WINDOWS_APP)
+  }
+
+  if (initialised_)
+  {
+    ::ReleaseMutex(mutex);
+    ::CloseHandle(mutex);
+    return 0;
+  }
+
+#if defined(__MINGW32__)
+  // Not sure if MinGW supports structured exception handling, so for now
+  // we'll just call the Windows API and hope.
+# if defined(UNDER_CE)
+  ::InitializeCriticalSection(&crit_section_);
+# else
+  if (!::InitializeCriticalSectionAndSpinCount(&crit_section_, 0x80000000))
+  {
+    last_error = ::GetLastError();
+    ::ReleaseMutex(mutex);
+    ::CloseHandle(mutex);
+    return last_error;
+  }
+# endif
+#else
+  __try
+  {
+# if defined(UNDER_CE)
+    ::InitializeCriticalSection(&crit_section_);
+# elif defined(ASIO_WINDOWS_APP)
+    if (!::InitializeCriticalSectionEx(&crit_section_, 0, 0))
+    {
+      last_error = ::GetLastError();
+      ::ReleaseMutex(mutex);
+      ::CloseHandle(mutex);
+      return last_error;
+    }
+# else
+    if (!::InitializeCriticalSectionAndSpinCount(&crit_section_, 0x80000000))
+    {
+      last_error = ::GetLastError();
+      ::ReleaseMutex(mutex);
+      ::CloseHandle(mutex);
+      return last_error;
+    }
+# endif
+  }
+  __except(GetExceptionCode() == STATUS_NO_MEMORY
+      ? EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH)
+  {
+    ::ReleaseMutex(mutex);
+    ::CloseHandle(mutex);
+    return ERROR_OUTOFMEMORY;
+  }
+#endif
+
+  initialised_ = true;
+  ::ReleaseMutex(mutex);
+  ::CloseHandle(mutex);
+  return 0;
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_WINDOWS)
+
+#endif // ASIO_DETAIL_IMPL_WIN_STATIC_MUTEX_IPP
diff --git a/lib/asio/detail/impl/win_thread.ipp b/lib/asio/detail/impl/win_thread.ipp
new file mode 100644
index 0000000..ed6dbaf
--- /dev/null
+++ b/lib/asio/detail/impl/win_thread.ipp
@@ -0,0 +1,150 @@
+//
+// detail/impl/win_thread.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_WIN_THREAD_IPP
+#define ASIO_DETAIL_IMPL_WIN_THREAD_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_WINDOWS) \
+  && !defined(ASIO_WINDOWS_APP) \
+  && !defined(UNDER_CE)
+
+#include <process.h>
+#include "asio/detail/throw_error.hpp"
+#include "asio/detail/win_thread.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+win_thread::~win_thread()
+{
+  ::CloseHandle(thread_);
+
+  // The exit_event_ handle is deliberately allowed to leak here since it
+  // is an error for the owner of an internal thread not to join() it.
+}
+
+void win_thread::join()
+{
+  HANDLE handles[2] = { exit_event_, thread_ };
+  ::WaitForMultipleObjects(2, handles, FALSE, INFINITE);
+  ::CloseHandle(exit_event_);
+  if (terminate_threads())
+  {
+    ::TerminateThread(thread_, 0);
+  }
+  else
+  {
+    ::QueueUserAPC(apc_function, thread_, 0);
+    ::WaitForSingleObject(thread_, INFINITE);
+  }
+}
+
+std::size_t win_thread::hardware_concurrency()
+{
+  SYSTEM_INFO system_info;
+  ::GetSystemInfo(&system_info);
+  return system_info.dwNumberOfProcessors;
+}
+
+void win_thread::start_thread(func_base* arg, unsigned int stack_size)
+{
+  ::HANDLE entry_event = 0;
+  arg->entry_event_ = entry_event = ::CreateEventW(0, true, false, 0);
+  if (!entry_event)
+  {
+    DWORD last_error = ::GetLastError();
+    delete arg;
+    asio::error_code ec(last_error,
+        asio::error::get_system_category());
+    asio::detail::throw_error(ec, "thread.entry_event");
+  }
+
+  arg->exit_event_ = exit_event_ = ::CreateEventW(0, true, false, 0);
+  if (!exit_event_)
+  {
+    DWORD last_error = ::GetLastError();
+    delete arg;
+    asio::error_code ec(last_error,
+        asio::error::get_system_category());
+    asio::detail::throw_error(ec, "thread.exit_event");
+  }
+
+  unsigned int thread_id = 0;
+  thread_ = reinterpret_cast<HANDLE>(::_beginthreadex(0,
+        stack_size, win_thread_function, arg, 0, &thread_id));
+  if (!thread_)
+  {
+    DWORD last_error = ::GetLastError();
+    delete arg;
+    if (entry_event)
+      ::CloseHandle(entry_event);
+    if (exit_event_)
+      ::CloseHandle(exit_event_);
+    asio::error_code ec(last_error,
+        asio::error::get_system_category());
+    asio::detail::throw_error(ec, "thread");
+  }
+
+  if (entry_event)
+  {
+    ::WaitForSingleObject(entry_event, INFINITE);
+    ::CloseHandle(entry_event);
+  }
+}
+
+unsigned int __stdcall win_thread_function(void* arg)
+{
+  win_thread::auto_func_base_ptr func = {
+      static_cast<win_thread::func_base*>(arg) };
+
+  ::SetEvent(func.ptr->entry_event_);
+
+  func.ptr->run();
+
+  // Signal that the thread has finished its work, but rather than returning go
+  // to sleep to put the thread into a well known state. If the thread is being
+  // joined during global object destruction then it may be killed using
+  // TerminateThread (to avoid a deadlock in DllMain). Otherwise, the SleepEx
+  // call will be interrupted using QueueUserAPC and the thread will shut down
+  // cleanly.
+  HANDLE exit_event = func.ptr->exit_event_;
+  delete func.ptr;
+  func.ptr = 0;
+  ::SetEvent(exit_event);
+  ::SleepEx(INFINITE, TRUE);
+
+  return 0;
+}
+
+#if defined(WINVER) && (WINVER < 0x0500)
+void __stdcall apc_function(ULONG) {}
+#else
+void __stdcall apc_function(ULONG_PTR) {}
+#endif
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_WINDOWS)
+       // && !defined(ASIO_WINDOWS_APP)
+       // && !defined(UNDER_CE)
+
+#endif // ASIO_DETAIL_IMPL_WIN_THREAD_IPP
diff --git a/lib/asio/detail/impl/win_tss_ptr.ipp b/lib/asio/detail/impl/win_tss_ptr.ipp
new file mode 100644
index 0000000..61df0ce
--- /dev/null
+++ b/lib/asio/detail/impl/win_tss_ptr.ipp
@@ -0,0 +1,57 @@
+//
+// detail/impl/win_tss_ptr.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_WIN_TSS_PTR_IPP
+#define ASIO_DETAIL_IMPL_WIN_TSS_PTR_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_WINDOWS)
+
+#include "asio/detail/throw_error.hpp"
+#include "asio/detail/win_tss_ptr.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+DWORD win_tss_ptr_create()
+{
+#if defined(UNDER_CE)
+  const DWORD out_of_indexes = 0xFFFFFFFF;
+#else
+  const DWORD out_of_indexes = TLS_OUT_OF_INDEXES;
+#endif
+
+  DWORD tss_key = ::TlsAlloc();
+  if (tss_key == out_of_indexes)
+  {
+    DWORD last_error = ::GetLastError();
+    asio::error_code ec(last_error,
+        asio::error::get_system_category());
+    asio::detail::throw_error(ec, "tss");
+  }
+  return tss_key;
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_WINDOWS)
+
+#endif // ASIO_DETAIL_IMPL_WIN_TSS_PTR_IPP
diff --git a/lib/asio/detail/impl/winrt_ssocket_service_base.ipp b/lib/asio/detail/impl/winrt_ssocket_service_base.ipp
new file mode 100644
index 0000000..288ca8b
--- /dev/null
+++ b/lib/asio/detail/impl/winrt_ssocket_service_base.ipp
@@ -0,0 +1,629 @@
+//
+// detail/impl/winrt_ssocket_service_base.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_WINRT_SSOCKET_SERVICE_BASE_IPP
+#define ASIO_DETAIL_IMPL_WINRT_SSOCKET_SERVICE_BASE_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_WINDOWS_RUNTIME)
+
+#include <cstring>
+#include "asio/detail/winrt_ssocket_service_base.hpp"
+#include "asio/detail/winrt_async_op.hpp"
+#include "asio/detail/winrt_utils.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+winrt_ssocket_service_base::winrt_ssocket_service_base(
+    asio::io_context& io_context)
+  : io_context_(use_service<io_context_impl>(io_context)),
+    async_manager_(use_service<winrt_async_manager>(io_context)),
+    mutex_(),
+    impl_list_(0)
+{
+}
+
+void winrt_ssocket_service_base::base_shutdown()
+{
+  // Close all implementations, causing all operations to complete.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  base_implementation_type* impl = impl_list_;
+  while (impl)
+  {
+    asio::error_code ignored_ec;
+    close(*impl, ignored_ec);
+    impl = impl->next_;
+  }
+}
+
+void winrt_ssocket_service_base::construct(
+    winrt_ssocket_service_base::base_implementation_type& impl)
+{
+  // Insert implementation into linked list of all implementations.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  impl.next_ = impl_list_;
+  impl.prev_ = 0;
+  if (impl_list_)
+    impl_list_->prev_ = &impl;
+  impl_list_ = &impl;
+}
+
+void winrt_ssocket_service_base::base_move_construct(
+    winrt_ssocket_service_base::base_implementation_type& impl,
+    winrt_ssocket_service_base::base_implementation_type& other_impl)
+{
+  impl.socket_ = other_impl.socket_;
+  other_impl.socket_ = nullptr;
+
+  // Insert implementation into linked list of all implementations.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  impl.next_ = impl_list_;
+  impl.prev_ = 0;
+  if (impl_list_)
+    impl_list_->prev_ = &impl;
+  impl_list_ = &impl;
+}
+
+void winrt_ssocket_service_base::base_move_assign(
+    winrt_ssocket_service_base::base_implementation_type& impl,
+    winrt_ssocket_service_base& other_service,
+    winrt_ssocket_service_base::base_implementation_type& other_impl)
+{
+  asio::error_code ignored_ec;
+  close(impl, ignored_ec);
+
+  if (this != &other_service)
+  {
+    // Remove implementation from linked list of all implementations.
+    asio::detail::mutex::scoped_lock lock(mutex_);
+    if (impl_list_ == &impl)
+      impl_list_ = impl.next_;
+    if (impl.prev_)
+      impl.prev_->next_ = impl.next_;
+    if (impl.next_)
+      impl.next_->prev_= impl.prev_;
+    impl.next_ = 0;
+    impl.prev_ = 0;
+  }
+
+  impl.socket_ = other_impl.socket_;
+  other_impl.socket_ = nullptr;
+
+  if (this != &other_service)
+  {
+    // Insert implementation into linked list of all implementations.
+    asio::detail::mutex::scoped_lock lock(other_service.mutex_);
+    impl.next_ = other_service.impl_list_;
+    impl.prev_ = 0;
+    if (other_service.impl_list_)
+      other_service.impl_list_->prev_ = &impl;
+    other_service.impl_list_ = &impl;
+  }
+}
+
+void winrt_ssocket_service_base::destroy(
+    winrt_ssocket_service_base::base_implementation_type& impl)
+{
+  asio::error_code ignored_ec;
+  close(impl, ignored_ec);
+
+  // Remove implementation from linked list of all implementations.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  if (impl_list_ == &impl)
+    impl_list_ = impl.next_;
+  if (impl.prev_)
+    impl.prev_->next_ = impl.next_;
+  if (impl.next_)
+    impl.next_->prev_= impl.prev_;
+  impl.next_ = 0;
+  impl.prev_ = 0;
+}
+
+asio::error_code winrt_ssocket_service_base::close(
+    winrt_ssocket_service_base::base_implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (impl.socket_)
+  {
+    delete impl.socket_;
+    impl.socket_ = nullptr;
+  }
+
+  ec = asio::error_code();
+  return ec;
+}
+
+winrt_ssocket_service_base::native_handle_type
+winrt_ssocket_service_base::release(
+    winrt_ssocket_service_base::base_implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (!is_open(impl))
+    return nullptr;
+
+  cancel(impl, ec);
+  if (ec)
+    return nullptr;
+
+  native_handle_type tmp = impl.socket_;
+  impl.socket_ = nullptr;
+  return tmp;
+}
+
+std::size_t winrt_ssocket_service_base::do_get_endpoint(
+    const base_implementation_type& impl, bool local,
+    void* addr, std::size_t addr_len, asio::error_code& ec) const
+{
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    return addr_len;
+  }
+
+  try
+  {
+    std::string addr_string = winrt_utils::string(local
+        ? impl.socket_->Information->LocalAddress->CanonicalName
+        : impl.socket_->Information->RemoteAddress->CanonicalName);
+    unsigned short port = winrt_utils::integer(local
+        ? impl.socket_->Information->LocalPort
+        : impl.socket_->Information->RemotePort);
+    unsigned long scope = 0;
+
+    switch (reinterpret_cast<const socket_addr_type*>(addr)->sa_family)
+    {
+    case ASIO_OS_DEF(AF_INET):
+      if (addr_len < sizeof(sockaddr_in4_type))
+      {
+        ec = asio::error::invalid_argument;
+        return addr_len;
+      }
+      else
+      {
+        socket_ops::inet_pton(ASIO_OS_DEF(AF_INET), addr_string.c_str(),
+            &reinterpret_cast<sockaddr_in4_type*>(addr)->sin_addr, &scope, ec);
+        reinterpret_cast<sockaddr_in4_type*>(addr)->sin_port
+          = socket_ops::host_to_network_short(port);
+        ec = asio::error_code();
+        return sizeof(sockaddr_in4_type);
+      }
+    case ASIO_OS_DEF(AF_INET6):
+      if (addr_len < sizeof(sockaddr_in6_type))
+      {
+        ec = asio::error::invalid_argument;
+        return addr_len;
+      }
+      else
+      {
+        socket_ops::inet_pton(ASIO_OS_DEF(AF_INET6), addr_string.c_str(),
+            &reinterpret_cast<sockaddr_in6_type*>(addr)->sin6_addr, &scope, ec);
+        reinterpret_cast<sockaddr_in6_type*>(addr)->sin6_port
+          = socket_ops::host_to_network_short(port);
+        ec = asio::error_code();
+        return sizeof(sockaddr_in6_type);
+      }
+    default:
+      ec = asio::error::address_family_not_supported;
+      return addr_len;
+    }
+  }
+  catch (Platform::Exception^ e)
+  {
+    ec = asio::error_code(e->HResult,
+        asio::system_category());
+    return addr_len;
+  }
+}
+
+asio::error_code winrt_ssocket_service_base::do_set_option(
+    winrt_ssocket_service_base::base_implementation_type& impl,
+    int level, int optname, const void* optval,
+    std::size_t optlen, asio::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    return ec;
+  }
+
+  try
+  {
+    if (level == ASIO_OS_DEF(SOL_SOCKET)
+        && optname == ASIO_OS_DEF(SO_KEEPALIVE))
+    {
+      if (optlen == sizeof(int))
+      {
+        int value = 0;
+        std::memcpy(&value, optval, optlen);
+        impl.socket_->Control->KeepAlive = !!value;
+        ec = asio::error_code();
+      }
+      else
+      {
+        ec = asio::error::invalid_argument;
+      }
+    }
+    else if (level == ASIO_OS_DEF(IPPROTO_TCP)
+        && optname == ASIO_OS_DEF(TCP_NODELAY))
+    {
+      if (optlen == sizeof(int))
+      {
+        int value = 0;
+        std::memcpy(&value, optval, optlen);
+        impl.socket_->Control->NoDelay = !!value;
+        ec = asio::error_code();
+      }
+      else
+      {
+        ec = asio::error::invalid_argument;
+      }
+    }
+    else
+    {
+      ec = asio::error::invalid_argument;
+    }
+  }
+  catch (Platform::Exception^ e)
+  {
+    ec = asio::error_code(e->HResult,
+        asio::system_category());
+  }
+
+  return ec;
+}
+
+void winrt_ssocket_service_base::do_get_option(
+    const winrt_ssocket_service_base::base_implementation_type& impl,
+    int level, int optname, void* optval,
+    std::size_t* optlen, asio::error_code& ec) const
+{
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    return;
+  }
+
+  try
+  {
+    if (level == ASIO_OS_DEF(SOL_SOCKET)
+        && optname == ASIO_OS_DEF(SO_KEEPALIVE))
+    {
+      if (*optlen >= sizeof(int))
+      {
+        int value = impl.socket_->Control->KeepAlive ? 1 : 0;
+        std::memcpy(optval, &value, sizeof(int));
+        *optlen = sizeof(int);
+        ec = asio::error_code();
+      }
+      else
+      {
+        ec = asio::error::invalid_argument;
+      }
+    }
+    else if (level == ASIO_OS_DEF(IPPROTO_TCP)
+        && optname == ASIO_OS_DEF(TCP_NODELAY))
+    {
+      if (*optlen >= sizeof(int))
+      {
+        int value = impl.socket_->Control->NoDelay ? 1 : 0;
+        std::memcpy(optval, &value, sizeof(int));
+        *optlen = sizeof(int);
+        ec = asio::error_code();
+      }
+      else
+      {
+        ec = asio::error::invalid_argument;
+      }
+    }
+    else
+    {
+      ec = asio::error::invalid_argument;
+    }
+  }
+  catch (Platform::Exception^ e)
+  {
+    ec = asio::error_code(e->HResult,
+        asio::system_category());
+  }
+}
+
+asio::error_code winrt_ssocket_service_base::do_connect(
+    winrt_ssocket_service_base::base_implementation_type& impl,
+    const void* addr, asio::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    return ec;
+  }
+
+  char addr_string[max_addr_v6_str_len];
+  unsigned short port;
+  switch (reinterpret_cast<const socket_addr_type*>(addr)->sa_family)
+  {
+  case ASIO_OS_DEF(AF_INET):
+    socket_ops::inet_ntop(ASIO_OS_DEF(AF_INET),
+        &reinterpret_cast<const sockaddr_in4_type*>(addr)->sin_addr,
+        addr_string, sizeof(addr_string), 0, ec);
+    port = socket_ops::network_to_host_short(
+        reinterpret_cast<const sockaddr_in4_type*>(addr)->sin_port);
+    break;
+  case ASIO_OS_DEF(AF_INET6):
+    socket_ops::inet_ntop(ASIO_OS_DEF(AF_INET6),
+        &reinterpret_cast<const sockaddr_in6_type*>(addr)->sin6_addr,
+        addr_string, sizeof(addr_string), 0, ec);
+    port = socket_ops::network_to_host_short(
+        reinterpret_cast<const sockaddr_in6_type*>(addr)->sin6_port);
+    break;
+  default:
+    ec = asio::error::address_family_not_supported;
+    return ec;
+  }
+
+  if (!ec) try
+  {
+    async_manager_.sync(impl.socket_->ConnectAsync(
+          ref new Windows::Networking::HostName(
+            winrt_utils::string(addr_string)),
+          winrt_utils::string(port)), ec);
+  }
+  catch (Platform::Exception^ e)
+  {
+    ec = asio::error_code(e->HResult,
+        asio::system_category());
+  }
+
+  return ec;
+}
+
+void winrt_ssocket_service_base::start_connect_op(
+    winrt_ssocket_service_base::base_implementation_type& impl,
+    const void* addr, winrt_async_op<void>* op, bool is_continuation)
+{
+  if (!is_open(impl))
+  {
+    op->ec_ = asio::error::bad_descriptor;
+    io_context_.post_immediate_completion(op, is_continuation);
+    return;
+  }
+
+  char addr_string[max_addr_v6_str_len];
+  unsigned short port = 0;
+  switch (reinterpret_cast<const socket_addr_type*>(addr)->sa_family)
+  {
+  case ASIO_OS_DEF(AF_INET):
+    socket_ops::inet_ntop(ASIO_OS_DEF(AF_INET),
+        &reinterpret_cast<const sockaddr_in4_type*>(addr)->sin_addr,
+        addr_string, sizeof(addr_string), 0, op->ec_);
+    port = socket_ops::network_to_host_short(
+        reinterpret_cast<const sockaddr_in4_type*>(addr)->sin_port);
+    break;
+  case ASIO_OS_DEF(AF_INET6):
+    socket_ops::inet_ntop(ASIO_OS_DEF(AF_INET6),
+        &reinterpret_cast<const sockaddr_in6_type*>(addr)->sin6_addr,
+        addr_string, sizeof(addr_string), 0, op->ec_);
+    port = socket_ops::network_to_host_short(
+        reinterpret_cast<const sockaddr_in6_type*>(addr)->sin6_port);
+    break;
+  default:
+    op->ec_ = asio::error::address_family_not_supported;
+    break;
+  }
+
+  if (op->ec_)
+  {
+    io_context_.post_immediate_completion(op, is_continuation);
+    return;
+  }
+
+  try
+  {
+    async_manager_.async(impl.socket_->ConnectAsync(
+          ref new Windows::Networking::HostName(
+            winrt_utils::string(addr_string)),
+          winrt_utils::string(port)), op);
+  }
+  catch (Platform::Exception^ e)
+  {
+    op->ec_ = asio::error_code(
+        e->HResult, asio::system_category());
+    io_context_.post_immediate_completion(op, is_continuation);
+  }
+}
+
+std::size_t winrt_ssocket_service_base::do_send(
+    winrt_ssocket_service_base::base_implementation_type& impl,
+    const asio::const_buffer& data,
+    socket_base::message_flags flags, asio::error_code& ec)
+{
+  if (flags)
+  {
+    ec = asio::error::operation_not_supported;
+    return 0;
+  }
+
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    return 0;
+  }
+
+  try
+  {
+    buffer_sequence_adapter<asio::const_buffer,
+      asio::const_buffer> bufs(asio::buffer(data));
+
+    if (bufs.all_empty())
+    {
+      ec = asio::error_code();
+      return 0;
+    }
+
+    return async_manager_.sync(
+        impl.socket_->OutputStream->WriteAsync(bufs.buffers()[0]), ec);
+  }
+  catch (Platform::Exception^ e)
+  {
+    ec = asio::error_code(e->HResult,
+        asio::system_category());
+    return 0;
+  }
+}
+
+void winrt_ssocket_service_base::start_send_op(
+      winrt_ssocket_service_base::base_implementation_type& impl,
+      const asio::const_buffer& data, socket_base::message_flags flags,
+      winrt_async_op<unsigned int>* op, bool is_continuation)
+{
+  if (flags)
+  {
+    op->ec_ = asio::error::operation_not_supported;
+    io_context_.post_immediate_completion(op, is_continuation);
+    return;
+  }
+
+  if (!is_open(impl))
+  {
+    op->ec_ = asio::error::bad_descriptor;
+    io_context_.post_immediate_completion(op, is_continuation);
+    return;
+  }
+
+  try
+  {
+    buffer_sequence_adapter<asio::const_buffer,
+        asio::const_buffer> bufs(asio::buffer(data));
+
+    if (bufs.all_empty())
+    {
+      io_context_.post_immediate_completion(op, is_continuation);
+      return;
+    }
+
+    async_manager_.async(
+        impl.socket_->OutputStream->WriteAsync(bufs.buffers()[0]), op);
+  }
+  catch (Platform::Exception^ e)
+  {
+    op->ec_ = asio::error_code(e->HResult,
+        asio::system_category());
+    io_context_.post_immediate_completion(op, is_continuation);
+  }
+}
+
+std::size_t winrt_ssocket_service_base::do_receive(
+    winrt_ssocket_service_base::base_implementation_type& impl,
+    const asio::mutable_buffer& data,
+    socket_base::message_flags flags, asio::error_code& ec)
+{
+  if (flags)
+  {
+    ec = asio::error::operation_not_supported;
+    return 0;
+  }
+
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    return 0;
+  }
+
+  try
+  {
+    buffer_sequence_adapter<asio::mutable_buffer,
+        asio::mutable_buffer> bufs(asio::buffer(data));
+
+    if (bufs.all_empty())
+    {
+      ec = asio::error_code();
+      return 0;
+    }
+
+    async_manager_.sync(
+        impl.socket_->InputStream->ReadAsync(
+          bufs.buffers()[0], bufs.buffers()[0]->Capacity,
+          Windows::Storage::Streams::InputStreamOptions::Partial), ec);
+
+    std::size_t bytes_transferred = bufs.buffers()[0]->Length;
+    if (bytes_transferred == 0 && !ec)
+    {
+      ec = asio::error::eof;
+    }
+
+    return bytes_transferred;
+  }
+  catch (Platform::Exception^ e)
+  {
+    ec = asio::error_code(e->HResult,
+        asio::system_category());
+    return 0;
+  }
+}
+
+void winrt_ssocket_service_base::start_receive_op(
+      winrt_ssocket_service_base::base_implementation_type& impl,
+      const asio::mutable_buffer& data, socket_base::message_flags flags,
+      winrt_async_op<Windows::Storage::Streams::IBuffer^>* op,
+      bool is_continuation)
+{
+  if (flags)
+  {
+    op->ec_ = asio::error::operation_not_supported;
+    io_context_.post_immediate_completion(op, is_continuation);
+    return;
+  }
+
+  if (!is_open(impl))
+  {
+    op->ec_ = asio::error::bad_descriptor;
+    io_context_.post_immediate_completion(op, is_continuation);
+    return;
+  }
+
+  try
+  {
+    buffer_sequence_adapter<asio::mutable_buffer,
+        asio::mutable_buffer> bufs(asio::buffer(data));
+
+    if (bufs.all_empty())
+    {
+      io_context_.post_immediate_completion(op, is_continuation);
+      return;
+    }
+
+    async_manager_.async(
+        impl.socket_->InputStream->ReadAsync(
+          bufs.buffers()[0], bufs.buffers()[0]->Capacity,
+          Windows::Storage::Streams::InputStreamOptions::Partial), op);
+  }
+  catch (Platform::Exception^ e)
+  {
+    op->ec_ = asio::error_code(e->HResult,
+        asio::system_category());
+    io_context_.post_immediate_completion(op, is_continuation);
+  }
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_WINDOWS_RUNTIME)
+
+#endif // ASIO_DETAIL_IMPL_WINRT_SSOCKET_SERVICE_BASE_IPP
diff --git a/lib/asio/detail/impl/winrt_timer_scheduler.hpp b/lib/asio/detail/impl/winrt_timer_scheduler.hpp
new file mode 100644
index 0000000..856378f
--- /dev/null
+++ b/lib/asio/detail/impl/winrt_timer_scheduler.hpp
@@ -0,0 +1,92 @@
+//
+// detail/impl/winrt_timer_scheduler.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_WINRT_TIMER_SCHEDULER_HPP
+#define ASIO_DETAIL_IMPL_WINRT_TIMER_SCHEDULER_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_WINDOWS_RUNTIME)
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename Time_Traits>
+void winrt_timer_scheduler::add_timer_queue(timer_queue<Time_Traits>& queue)
+{
+  do_add_timer_queue(queue);
+}
+
+// Remove a timer queue from the reactor.
+template <typename Time_Traits>
+void winrt_timer_scheduler::remove_timer_queue(timer_queue<Time_Traits>& queue)
+{
+  do_remove_timer_queue(queue);
+}
+
+template <typename Time_Traits>
+void winrt_timer_scheduler::schedule_timer(timer_queue<Time_Traits>& queue,
+    const typename Time_Traits::time_type& time,
+    typename timer_queue<Time_Traits>::per_timer_data& timer, wait_op* op)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+
+  if (shutdown_)
+  {
+    io_context_.post_immediate_completion(op, false);
+    return;
+  }
+
+  bool earliest = queue.enqueue_timer(time, timer, op);
+  io_context_.work_started();
+  if (earliest)
+    event_.signal(lock);
+}
+
+template <typename Time_Traits>
+std::size_t winrt_timer_scheduler::cancel_timer(timer_queue<Time_Traits>& queue,
+    typename timer_queue<Time_Traits>::per_timer_data& timer,
+    std::size_t max_cancelled)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  op_queue<operation> ops;
+  std::size_t n = queue.cancel_timer(timer, ops, max_cancelled);
+  lock.unlock();
+  io_context_.post_deferred_completions(ops);
+  return n;
+}
+
+template <typename Time_Traits>
+void winrt_timer_scheduler::move_timer(timer_queue<Time_Traits>& queue,
+    typename timer_queue<Time_Traits>::per_timer_data& to,
+    typename timer_queue<Time_Traits>::per_timer_data& from)
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  op_queue<operation> ops;
+  queue.cancel_timer(to, ops);
+  queue.move_timer(to, from);
+  lock.unlock();
+  scheduler_.post_deferred_completions(ops);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_WINDOWS_RUNTIME)
+
+#endif // ASIO_DETAIL_IMPL_WINRT_TIMER_SCHEDULER_HPP
diff --git a/lib/asio/detail/impl/winrt_timer_scheduler.ipp b/lib/asio/detail/impl/winrt_timer_scheduler.ipp
new file mode 100644
index 0000000..ef21399
--- /dev/null
+++ b/lib/asio/detail/impl/winrt_timer_scheduler.ipp
@@ -0,0 +1,122 @@
+//
+// detail/impl/winrt_timer_scheduler.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_WINRT_TIMER_SCHEDULER_IPP
+#define ASIO_DETAIL_IMPL_WINRT_TIMER_SCHEDULER_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_WINDOWS_RUNTIME)
+
+#include "asio/detail/bind_handler.hpp"
+#include "asio/detail/winrt_timer_scheduler.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+winrt_timer_scheduler::winrt_timer_scheduler(
+    asio::io_context& io_context)
+  : asio::detail::service_base<winrt_timer_scheduler>(io_context),
+    io_context_(use_service<io_context_impl>(io_context)),
+    mutex_(),
+    event_(),
+    timer_queues_(),
+    thread_(0),
+    stop_thread_(false),
+    shutdown_(false)
+{
+  thread_ = new asio::detail::thread(
+      bind_handler(&winrt_timer_scheduler::call_run_thread, this));
+}
+
+winrt_timer_scheduler::~winrt_timer_scheduler()
+{
+  shutdown();
+}
+
+void winrt_timer_scheduler::shutdown()
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  shutdown_ = true;
+  stop_thread_ = true;
+  event_.signal(lock);
+  lock.unlock();
+
+  if (thread_)
+  {
+    thread_->join();
+    delete thread_;
+    thread_ = 0;
+  }
+
+  op_queue<operation> ops;
+  timer_queues_.get_all_timers(ops);
+  io_context_.abandon_operations(ops);
+}
+
+void winrt_timer_scheduler::notify_fork(asio::io_context::fork_event)
+{
+}
+
+void winrt_timer_scheduler::init_task()
+{
+}
+
+void winrt_timer_scheduler::run_thread()
+{
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  while (!stop_thread_)
+  {
+    const long max_wait_duration = 5 * 60 * 1000000;
+    long wait_duration = timer_queues_.wait_duration_usec(max_wait_duration);
+    event_.wait_for_usec(lock, wait_duration);
+    event_.clear(lock);
+    op_queue<operation> ops;
+    timer_queues_.get_ready_timers(ops);
+    if (!ops.empty())
+    {
+      lock.unlock();
+      io_context_.post_deferred_completions(ops);
+      lock.lock();
+    }
+  }
+}
+
+void winrt_timer_scheduler::call_run_thread(winrt_timer_scheduler* scheduler)
+{
+  scheduler->run_thread();
+}
+
+void winrt_timer_scheduler::do_add_timer_queue(timer_queue_base& queue)
+{
+  mutex::scoped_lock lock(mutex_);
+  timer_queues_.insert(&queue);
+}
+
+void winrt_timer_scheduler::do_remove_timer_queue(timer_queue_base& queue)
+{
+  mutex::scoped_lock lock(mutex_);
+  timer_queues_.erase(&queue);
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_WINDOWS_RUNTIME)
+
+#endif // ASIO_DETAIL_IMPL_WINRT_TIMER_SCHEDULER_IPP
diff --git a/lib/asio/detail/impl/winsock_init.ipp b/lib/asio/detail/impl/winsock_init.ipp
new file mode 100644
index 0000000..da4b0c0
--- /dev/null
+++ b/lib/asio/detail/impl/winsock_init.ipp
@@ -0,0 +1,82 @@
+//
+// detail/impl/winsock_init.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef ASIO_DETAIL_IMPL_WINSOCK_INIT_IPP
+#define ASIO_DETAIL_IMPL_WINSOCK_INIT_IPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+
+#include "asio/detail/socket_types.hpp"
+#include "asio/detail/winsock_init.hpp"
+#include "asio/detail/throw_error.hpp"
+#include "asio/error.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+void winsock_init_base::startup(data& d,
+    unsigned char major, unsigned char minor)
+{
+  if (::InterlockedIncrement(&d.init_count_) == 1)
+  {
+    WSADATA wsa_data;
+    long result = ::WSAStartup(MAKEWORD(major, minor), &wsa_data);
+    ::InterlockedExchange(&d.result_, result);
+  }
+}
+
+void winsock_init_base::manual_startup(data& d)
+{
+  if (::InterlockedIncrement(&d.init_count_) == 1)
+  {
+    ::InterlockedExchange(&d.result_, 0);
+  }
+}
+
+void winsock_init_base::cleanup(data& d)
+{
+  if (::InterlockedDecrement(&d.init_count_) == 0)
+  {
+    ::WSACleanup();
+  }
+}
+
+void winsock_init_base::manual_cleanup(data& d)
+{
+  ::InterlockedDecrement(&d.init_count_);
+}
+
+void winsock_init_base::throw_on_error(data& d)
+{
+  long result = ::InterlockedExchangeAdd(&d.result_, 0);
+  if (result != 0)
+  {
+    asio::error_code ec(result,
+        asio::error::get_system_category());
+    asio::detail::throw_error(ec, "winsock");
+  }
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_WINDOWS) || defined(__CYGWIN__)
+
+#endif // ASIO_DETAIL_IMPL_WINSOCK_INIT_IPP