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Diffstat (limited to 'lib/asio/io_context_strand.hpp')
| -rw-r--r-- | lib/asio/io_context_strand.hpp | 384 |
1 files changed, 0 insertions, 384 deletions
diff --git a/lib/asio/io_context_strand.hpp b/lib/asio/io_context_strand.hpp deleted file mode 100644 index 3c596f1..0000000 --- a/lib/asio/io_context_strand.hpp +++ /dev/null @@ -1,384 +0,0 @@ -// -// io_context_strand.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_IO_CONTEXT_STRAND_HPP -#define ASIO_IO_CONTEXT_STRAND_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_NO_EXTENSIONS) - -#include "asio/async_result.hpp" -#include "asio/detail/handler_type_requirements.hpp" -#include "asio/detail/strand_service.hpp" -#include "asio/detail/wrapped_handler.hpp" -#include "asio/io_context.hpp" - -#include "asio/detail/push_options.hpp" - -namespace asio { - -/// Provides serialised handler execution. -/** - * The io_context::strand class provides the ability to post and dispatch - * handlers with the guarantee that none of those handlers will execute - * concurrently. - * - * @par Order of handler invocation - * Given: - * - * @li a strand object @c s - * - * @li an object @c a meeting completion handler requirements - * - * @li an object @c a1 which is an arbitrary copy of @c a made by the - * implementation - * - * @li an object @c b meeting completion handler requirements - * - * @li an object @c b1 which is an arbitrary copy of @c b made by the - * implementation - * - * if any of the following conditions are true: - * - * @li @c s.post(a) happens-before @c s.post(b) - * - * @li @c s.post(a) happens-before @c s.dispatch(b), where the latter is - * performed outside the strand - * - * @li @c s.dispatch(a) happens-before @c s.post(b), where the former is - * performed outside the strand - * - * @li @c s.dispatch(a) happens-before @c s.dispatch(b), where both are - * performed outside the strand - * - * then @c asio_handler_invoke(a1, &a1) happens-before - * @c asio_handler_invoke(b1, &b1). - * - * Note that in the following case: - * @code async_op_1(..., s.wrap(a)); - * async_op_2(..., s.wrap(b)); @endcode - * the completion of the first async operation will perform @c s.dispatch(a), - * and the second will perform @c s.dispatch(b), but the order in which those - * are performed is unspecified. That is, you cannot state whether one - * happens-before the other. Therefore none of the above conditions are met and - * no ordering guarantee is made. - * - * @note The implementation makes no guarantee that handlers posted or - * dispatched through different @c strand objects will be invoked concurrently. - * - * @par Thread Safety - * @e Distinct @e objects: Safe.@n - * @e Shared @e objects: Safe. - * - * @par Concepts: - * Dispatcher. - */ -class io_context::strand -{ -public: - /// Constructor. - /** - * Constructs the strand. - * - * @param io_context The io_context object that the strand will use to - * dispatch handlers that are ready to be run. - */ - explicit strand(asio::io_context& io_context) - : service_(asio::use_service< - asio::detail::strand_service>(io_context)) - { - service_.construct(impl_); - } - - /// Destructor. - /** - * Destroys a strand. - * - * Handlers posted through the strand that have not yet been invoked will - * still be dispatched in a way that meets the guarantee of non-concurrency. - */ - ~strand() - { - } - -#if !defined(ASIO_NO_DEPRECATED) - /// (Deprecated: Use context().) Get the io_context associated with the - /// strand. - /** - * This function may be used to obtain the io_context object that the strand - * uses to dispatch handlers for asynchronous operations. - * - * @return A reference to the io_context object that the strand will use to - * dispatch handlers. Ownership is not transferred to the caller. - */ - asio::io_context& get_io_context() - { - return service_.get_io_context(); - } - - /// (Deprecated: Use context().) Get the io_context associated with the - /// strand. - /** - * This function may be used to obtain the io_context object that the strand - * uses to dispatch handlers for asynchronous operations. - * - * @return A reference to the io_context object that the strand will use to - * dispatch handlers. Ownership is not transferred to the caller. - */ - asio::io_context& get_io_service() - { - return service_.get_io_context(); - } -#endif // !defined(ASIO_NO_DEPRECATED) - - /// Obtain the underlying execution context. - asio::io_context& context() const ASIO_NOEXCEPT - { - return service_.get_io_context(); - } - - /// Inform the strand that it has some outstanding work to do. - /** - * The strand delegates this call to its underlying io_context. - */ - void on_work_started() const ASIO_NOEXCEPT - { - context().get_executor().on_work_started(); - } - - /// Inform the strand that some work is no longer outstanding. - /** - * The strand delegates this call to its underlying io_context. - */ - void on_work_finished() const ASIO_NOEXCEPT - { - context().get_executor().on_work_finished(); - } - - /// Request the strand to invoke the given function object. - /** - * This function is used to ask the strand to execute the given function - * object on its underlying io_context. The function object will be executed - * inside this function if the strand is not otherwise busy and if the - * underlying io_context's executor's @c dispatch() function is also able to - * execute the function before returning. - * - * @param f The function object to be called. The executor will make - * a copy of the handler object as required. The function signature of the - * function object must be: @code void function(); @endcode - * - * @param a An allocator that may be used by the executor to allocate the - * internal storage needed for function invocation. - */ - template <typename Function, typename Allocator> - void dispatch(ASIO_MOVE_ARG(Function) f, const Allocator& a) const - { - typename decay<Function>::type tmp(ASIO_MOVE_CAST(Function)(f)); - service_.dispatch(impl_, tmp); - (void)a; - } - -#if !defined(ASIO_NO_DEPRECATED) - /// (Deprecated: Use asio::dispatch().) Request the strand to invoke - /// the given handler. - /** - * This function is used to ask the strand to execute the given handler. - * - * The strand object guarantees that handlers posted or dispatched through - * the strand will not be executed concurrently. The handler may be executed - * inside this function if the guarantee can be met. If this function is - * called from within a handler that was posted or dispatched through the same - * strand, then the new handler will be executed immediately. - * - * The strand's guarantee is in addition to the guarantee provided by the - * underlying io_context. The io_context guarantees that the handler will only - * be called in a thread in which the io_context's run member function is - * currently being invoked. - * - * @param handler The handler to be called. The strand will make a copy of the - * handler object as required. The function signature of the handler must be: - * @code void handler(); @endcode - */ - template <typename LegacyCompletionHandler> - ASIO_INITFN_RESULT_TYPE(LegacyCompletionHandler, void ()) - dispatch(ASIO_MOVE_ARG(LegacyCompletionHandler) handler) - { - // If you get an error on the following line it means that your handler does - // not meet the documented type requirements for a LegacyCompletionHandler. - ASIO_LEGACY_COMPLETION_HANDLER_CHECK( - LegacyCompletionHandler, handler) type_check; - - async_completion<LegacyCompletionHandler, void ()> init(handler); - - service_.dispatch(impl_, init.completion_handler); - - return init.result.get(); - } -#endif // !defined(ASIO_NO_DEPRECATED) - - /// Request the strand to invoke the given function object. - /** - * This function is used to ask the executor to execute the given function - * object. The function object will never be executed inside this function. - * Instead, it will be scheduled to run by the underlying io_context. - * - * @param f The function object to be called. The executor will make - * a copy of the handler object as required. The function signature of the - * function object must be: @code void function(); @endcode - * - * @param a An allocator that may be used by the executor to allocate the - * internal storage needed for function invocation. - */ - template <typename Function, typename Allocator> - void post(ASIO_MOVE_ARG(Function) f, const Allocator& a) const - { - typename decay<Function>::type tmp(ASIO_MOVE_CAST(Function)(f)); - service_.post(impl_, tmp); - (void)a; - } - -#if !defined(ASIO_NO_DEPRECATED) - /// (Deprecated: Use asio::post().) Request the strand to invoke the - /// given handler and return immediately. - /** - * This function is used to ask the strand to execute the given handler, but - * without allowing the strand to call the handler from inside this function. - * - * The strand object guarantees that handlers posted or dispatched through - * the strand will not be executed concurrently. The strand's guarantee is in - * addition to the guarantee provided by the underlying io_context. The - * io_context guarantees that the handler will only be called in a thread in - * which the io_context's run member function is currently being invoked. - * - * @param handler The handler to be called. The strand will make a copy of the - * handler object as required. The function signature of the handler must be: - * @code void handler(); @endcode - */ - template <typename LegacyCompletionHandler> - ASIO_INITFN_RESULT_TYPE(LegacyCompletionHandler, void ()) - post(ASIO_MOVE_ARG(LegacyCompletionHandler) handler) - { - // If you get an error on the following line it means that your handler does - // not meet the documented type requirements for a LegacyCompletionHandler. - ASIO_LEGACY_COMPLETION_HANDLER_CHECK( - LegacyCompletionHandler, handler) type_check; - - async_completion<LegacyCompletionHandler, void ()> init(handler); - - service_.post(impl_, init.completion_handler); - - return init.result.get(); - } -#endif // !defined(ASIO_NO_DEPRECATED) - - /// Request the strand to invoke the given function object. - /** - * This function is used to ask the executor to execute the given function - * object. The function object will never be executed inside this function. - * Instead, it will be scheduled to run by the underlying io_context. - * - * @param f The function object to be called. The executor will make - * a copy of the handler object as required. The function signature of the - * function object must be: @code void function(); @endcode - * - * @param a An allocator that may be used by the executor to allocate the - * internal storage needed for function invocation. - */ - template <typename Function, typename Allocator> - void defer(ASIO_MOVE_ARG(Function) f, const Allocator& a) const - { - typename decay<Function>::type tmp(ASIO_MOVE_CAST(Function)(f)); - service_.post(impl_, tmp); - (void)a; - } - -#if !defined(ASIO_NO_DEPRECATED) - /// (Deprecated: Use asio::bind_executor().) Create a new handler that - /// automatically dispatches the wrapped handler on the strand. - /** - * This function is used to create a new handler function object that, when - * invoked, will automatically pass the wrapped handler to the strand's - * dispatch function. - * - * @param handler The handler to be wrapped. The strand will make a copy of - * the handler object as required. The function signature of the handler must - * be: @code void handler(A1 a1, ... An an); @endcode - * - * @return A function object that, when invoked, passes the wrapped handler to - * the strand's dispatch function. Given a function object with the signature: - * @code R f(A1 a1, ... An an); @endcode - * If this function object is passed to the wrap function like so: - * @code strand.wrap(f); @endcode - * then the return value is a function object with the signature - * @code void g(A1 a1, ... An an); @endcode - * that, when invoked, executes code equivalent to: - * @code strand.dispatch(boost::bind(f, a1, ... an)); @endcode - */ - template <typename Handler> -#if defined(GENERATING_DOCUMENTATION) - unspecified -#else - detail::wrapped_handler<strand, Handler, detail::is_continuation_if_running> -#endif - wrap(Handler handler) - { - return detail::wrapped_handler<io_context::strand, Handler, - detail::is_continuation_if_running>(*this, handler); - } -#endif // !defined(ASIO_NO_DEPRECATED) - - /// Determine whether the strand is running in the current thread. - /** - * @return @c true if the current thread is executing a handler that was - * submitted to the strand using post(), dispatch() or wrap(). Otherwise - * returns @c false. - */ - bool running_in_this_thread() const ASIO_NOEXCEPT - { - return service_.running_in_this_thread(impl_); - } - - /// Compare two strands for equality. - /** - * Two strands are equal if they refer to the same ordered, non-concurrent - * state. - */ - friend bool operator==(const strand& a, const strand& b) ASIO_NOEXCEPT - { - return a.impl_ == b.impl_; - } - - /// Compare two strands for inequality. - /** - * Two strands are equal if they refer to the same ordered, non-concurrent - * state. - */ - friend bool operator!=(const strand& a, const strand& b) ASIO_NOEXCEPT - { - return a.impl_ != b.impl_; - } - -private: - asio::detail::strand_service& service_; - mutable asio::detail::strand_service::implementation_type impl_; -}; - -} // namespace asio - -#include "asio/detail/pop_options.hpp" - -#endif // !defined(ASIO_NO_EXTENSIONS) - -#endif // ASIO_IO_CONTEXT_STRAND_HPP |