ceph/src/boost/libs/asio/include/boost/asio/detail/gcc_x86_fenced_block.hpp

   1 //
   2 // detail/gcc_x86_fenced_block.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2016 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_GCC_X86_FENCED_BLOCK_HPP
  12 #define BOOST_ASIO_DETAIL_GCC_X86_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(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
  21
  22 #include <boost/asio/detail/push_options.hpp>
  23
  24 namespace boost {
  25 namespace asio {
  26 namespace detail {
  27
  28 class gcc_x86_fenced_block
  29   : private noncopyable
  30 {
  31 public:
  32   enum half_t { half };
  33   enum full_t { full };
  34
  35   // Constructor for a half fenced block.
  36   explicit gcc_x86_fenced_block(half_t)
  37   {
  38   }
  39
  40   // Constructor for a full fenced block.
  41   explicit gcc_x86_fenced_block(full_t)
  42   {
  43     lbarrier();
  44   }
  45
  46   // Destructor.
  47   ~gcc_x86_fenced_block()
  48   {
  49     sbarrier();
  50   }
  51
  52 private:
  53   static int barrier()
  54   {
  55     int r = 0, m = 1;
  56     __asm__ __volatile__ (
  57         "xchgl %0, %1" :
  58         "=r"(r), "=m"(m) :
  59         "0"(1), "m"(m) :
  60         "memory", "cc");
  61     return r;
  62   }
  63
  64   static void lbarrier()
  65   {
  66 #if defined(__SSE2__)
  67 # if (__GNUC__ >= 4) && !defined(__INTEL_COMPILER) && !defined(__ICL)
  68     __builtin_ia32_lfence();
  69 # else // (__GNUC__ >= 4) && !defined(__INTEL_COMPILER) && !defined(__ICL)
  70     __asm__ __volatile__ ("lfence" ::: "memory");
  71 # endif // (__GNUC__ >= 4) && !defined(__INTEL_COMPILER) && !defined(__ICL)
  72 #else // defined(__SSE2__)
  73     barrier();
  74 #endif // defined(__SSE2__)
  75   }
  76
  77   static void sbarrier()
  78   {
  79 #if defined(__SSE2__)
  80 # if (__GNUC__ >= 4) && !defined(__INTEL_COMPILER) && !defined(__ICL)
  81     __builtin_ia32_sfence();
  82 # else // (__GNUC__ >= 4) && !defined(__INTEL_COMPILER) && !defined(__ICL)
  83     __asm__ __volatile__ ("sfence" ::: "memory");
  84 # endif // (__GNUC__ >= 4) && !defined(__INTEL_COMPILER) && !defined(__ICL)
  85 #else // defined(__SSE2__)
  86     barrier();
  87 #endif // defined(__SSE2__)
  88   }
  89 };
  90
  91 } // namespace detail
  92 } // namespace asio
  93 } // namespace boost
  94
  95 #include <boost/asio/detail/pop_options.hpp>
  96
  97 #endif // defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
  98
  99 #endif // BOOST_ASIO_DETAIL_GCC_X86_FENCED_BLOCK_HPP