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Diffstat (limited to 'lib/asio/detail/thread_info_base.hpp')
-rw-r--r-- | lib/asio/detail/thread_info_base.hpp | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/lib/asio/detail/thread_info_base.hpp b/lib/asio/detail/thread_info_base.hpp new file mode 100644 index 0000000..1b22207 --- /dev/null +++ b/lib/asio/detail/thread_info_base.hpp @@ -0,0 +1,121 @@ +// +// detail/thread_info_base.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_THREAD_INFO_BASE_HPP +#define ASIO_DETAIL_THREAD_INFO_BASE_HPP + +#if defined(_MSC_VER) && (_MSC_VER >= 1200) +# pragma once +#endif // defined(_MSC_VER) && (_MSC_VER >= 1200) + +#include <climits> +#include <cstddef> +#include "asio/detail/noncopyable.hpp" + +#include "asio/detail/push_options.hpp" + +namespace asio { +namespace detail { + +class thread_info_base + : private noncopyable +{ +public: + struct default_tag + { + enum { mem_index = 0 }; + }; + + struct awaitee_tag + { + enum { mem_index = 1 }; + }; + + thread_info_base() + { + for (int i = 0; i < max_mem_index; ++i) + reusable_memory_[i] = 0; + } + + ~thread_info_base() + { + for (int i = 0; i < max_mem_index; ++i) + if (reusable_memory_[i]) + ::operator delete(reusable_memory_[i]); + } + + static void* allocate(thread_info_base* this_thread, std::size_t size) + { + return allocate(default_tag(), this_thread, size); + } + + static void deallocate(thread_info_base* this_thread, + void* pointer, std::size_t size) + { + deallocate(default_tag(), this_thread, pointer, size); + } + + template <typename Purpose> + static void* allocate(Purpose, thread_info_base* this_thread, + std::size_t size) + { + std::size_t chunks = (size + chunk_size - 1) / chunk_size; + + if (this_thread && this_thread->reusable_memory_[Purpose::mem_index]) + { + void* const pointer = this_thread->reusable_memory_[Purpose::mem_index]; + this_thread->reusable_memory_[Purpose::mem_index] = 0; + + unsigned char* const mem = static_cast<unsigned char*>(pointer); + if (static_cast<std::size_t>(mem[0]) >= chunks) + { + mem[size] = mem[0]; + return pointer; + } + + ::operator delete(pointer); + } + + void* const pointer = ::operator new(chunks * chunk_size + 1); + unsigned char* const mem = static_cast<unsigned char*>(pointer); + mem[size] = (chunks <= UCHAR_MAX) ? static_cast<unsigned char>(chunks) : 0; + return pointer; + } + + template <typename Purpose> + static void deallocate(Purpose, thread_info_base* this_thread, + void* pointer, std::size_t size) + { + if (size <= chunk_size * UCHAR_MAX) + { + if (this_thread && this_thread->reusable_memory_[Purpose::mem_index] == 0) + { + unsigned char* const mem = static_cast<unsigned char*>(pointer); + mem[0] = mem[size]; + this_thread->reusable_memory_[Purpose::mem_index] = pointer; + return; + } + } + + ::operator delete(pointer); + } + +private: + enum { chunk_size = 4 }; + enum { max_mem_index = 2 }; + void* reusable_memory_[max_mem_index]; +}; + +} // namespace detail +} // namespace asio + +#include "asio/detail/pop_options.hpp" + +#endif // ASIO_DETAIL_THREAD_INFO_BASE_HPP |