// // detail/std_fenced_block.hpp // ~~~~~~~~~~~~~~~~~~~~~~~~~~~ // // Copyright (c) 2003-2019 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_STD_FENCED_BLOCK_HPP #define ASIO_DETAIL_STD_FENCED_BLOCK_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_STD_ATOMIC) #include #include "asio/detail/noncopyable.hpp" #include "asio/detail/push_options.hpp" namespace asio { namespace detail { class std_fenced_block : private noncopyable { public: enum half_t { half }; enum full_t { full }; // Constructor for a half fenced block. explicit std_fenced_block(half_t) { } // Constructor for a full fenced block. explicit std_fenced_block(full_t) { std::atomic_thread_fence(std::memory_order_acquire); } // Destructor. ~std_fenced_block() { std::atomic_thread_fence(std::memory_order_release); } }; } // namespace detail } // namespace asio #include "asio/detail/pop_options.hpp" #endif // defined(ASIO_HAS_STD_ATOMIC) #endif // ASIO_DETAIL_STD_FENCED_BLOCK_HPP