| // |
| // detail/gcc_x86_fenced_block.hpp |
| // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| // |
| // Copyright (c) 2003-2010 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 BOOST_ASIO_DETAIL_GCC_X86_FENCED_BLOCK_HPP |
| #define BOOST_ASIO_DETAIL_GCC_X86_FENCED_BLOCK_HPP |
| |
| #if defined(_MSC_VER) && (_MSC_VER >= 1200) |
| # pragma once |
| #endif // defined(_MSC_VER) && (_MSC_VER >= 1200) |
| |
| #include <boost/asio/detail/config.hpp> |
| |
| #if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) |
| |
| #include <boost/asio/detail/push_options.hpp> |
| |
| namespace boost { |
| namespace asio { |
| namespace detail { |
| |
| class gcc_x86_fenced_block |
| : private noncopyable |
| { |
| public: |
| // Constructor. |
| gcc_x86_fenced_block() |
| { |
| barrier(); |
| } |
| |
| // Destructor. |
| ~gcc_x86_fenced_block() |
| { |
| barrier(); |
| } |
| |
| private: |
| static int barrier() |
| { |
| int r = 0; |
| __asm__ __volatile__ ("xchgl %%eax, %0" : "=m" (r) : : "memory", "cc"); |
| return r; |
| } |
| }; |
| |
| } // namespace detail |
| } // namespace asio |
| } // namespace boost |
| |
| #include <boost/asio/detail/pop_options.hpp> |
| |
| #endif // defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) |
| |
| #endif // BOOST_ASIO_DETAIL_GCC_X86_FENCED_BLOCK_HPP |