1 // 2 // detail/win_fenced_block.hpp 3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~ 4 // 5 // Copyright (c) 2003-2021 Christopher M. Kohlhoff (chris at kohlhoff dot com) 6 // 7 // Distributed under the Boost Software License, Version 1.0. (See accompanying 8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 9 // 10 11 #ifndef BOOST_ASIO_DETAIL_WIN_FENCED_BLOCK_HPP 12 #define BOOST_ASIO_DETAIL_WIN_FENCED_BLOCK_HPP 13 14 #if defined(_MSC_VER) && (_MSC_VER >= 1200) 15 # pragma once 16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) 17 18 #include <boost/asio/detail/config.hpp> 19 20 #if defined(BOOST_ASIO_WINDOWS) && !defined(UNDER_CE) 21 22 #include <boost/asio/detail/socket_types.hpp> 23 #include <boost/asio/detail/noncopyable.hpp> 24 25 #include <boost/asio/detail/push_options.hpp> 26 27 namespace boost { 28 namespace asio { 29 namespace detail { 30 31 class win_fenced_block 32 : private noncopyable 33 { 34 public: 35 enum half_t { half }; 36 enum full_t { full }; 37 38 // Constructor for a half fenced block. win_fenced_block(half_t)39 explicit win_fenced_block(half_t) 40 { 41 } 42 43 // Constructor for a full fenced block. win_fenced_block(full_t)44 explicit win_fenced_block(full_t) 45 { 46 #if defined(__BORLANDC__) 47 LONG barrier = 0; 48 ::InterlockedExchange(&barrier, 1); 49 #elif defined(BOOST_ASIO_MSVC) \ 50 && ((BOOST_ASIO_MSVC < 1400) || !defined(MemoryBarrier)) 51 # if defined(_M_IX86) 52 # pragma warning(push) 53 # pragma warning(disable:4793) 54 LONG barrier; 55 __asm { xchg barrier, eax } 56 # pragma warning(pop) 57 # endif // defined(_M_IX86) 58 #else 59 MemoryBarrier(); 60 #endif 61 } 62 63 // Destructor. ~win_fenced_block()64 ~win_fenced_block() 65 { 66 #if defined(__BORLANDC__) 67 LONG barrier = 0; 68 ::InterlockedExchange(&barrier, 1); 69 #elif defined(BOOST_ASIO_MSVC) \ 70 && ((BOOST_ASIO_MSVC < 1400) || !defined(MemoryBarrier)) 71 # if defined(_M_IX86) 72 # pragma warning(push) 73 # pragma warning(disable:4793) 74 LONG barrier; 75 __asm { xchg barrier, eax } 76 # pragma warning(pop) 77 # endif // defined(_M_IX86) 78 #else 79 MemoryBarrier(); 80 #endif 81 } 82 }; 83 84 } // namespace detail 85 } // namespace asio 86 } // namespace boost 87 88 #include <boost/asio/detail/pop_options.hpp> 89 90 #endif // defined(BOOST_ASIO_WINDOWS) && !defined(UNDER_CE) 91 92 #endif // BOOST_ASIO_DETAIL_WIN_FENCED_BLOCK_HPP 93