asio/detail/std_fenced_block.hpp

0001 //
0002 // detail/std_fenced_block.hpp
0003 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~
0004 //
0005 // Copyright (c) 2003-2023 Christopher M. Kohlhoff (chris at kohlhoff dot com)
0006 //
0007 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0008 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0009 //
0010
0011 #ifndef BOOST_ASIO_DETAIL_STD_FENCED_BLOCK_HPP
0012 #define BOOST_ASIO_DETAIL_STD_FENCED_BLOCK_HPP
0013
0014 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
0015 # pragma once
0016 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
0017
0018 #include <boost/asio/detail/config.hpp>
0019 #include <atomic>
0020 #include <boost/asio/detail/noncopyable.hpp>
0021
0022 #include <boost/asio/detail/push_options.hpp>
0023
0024 namespace boost {
0025 namespace asio {
0026 namespace detail {
0027
0028 class std_fenced_block
0029   : private noncopyable
0030 {
0031 public:
0032   enum half_t { half };
0033   enum full_t { full };
0034
0035   // Constructor for a half fenced block.
0036   explicit std_fenced_block(half_t)
0037   {
0038   }
0039
0040   // Constructor for a full fenced block.
0041   explicit std_fenced_block(full_t)
0042   {
0043     std::atomic_thread_fence(std::memory_order_acquire);
0044   }
0045
0046   // Destructor.
0047   ~std_fenced_block()
0048   {
0049     std::atomic_thread_fence(std::memory_order_release);
0050   }
0051 };
0052
0053 } // namespace detail
0054 } // namespace asio
0055 } // namespace boost
0056
0057 #include <boost/asio/detail/pop_options.hpp>
0058
0059 #endif // BOOST_ASIO_DETAIL_STD_FENCED_BLOCK_HPP