ceph/src/boost/boost/smart_ptr/detail/atomic_count_gcc_atomic.hpp

   1 #ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_GCC_ATOMIC_HPP_INCLUDED
   2 #define BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_GCC_ATOMIC_HPP_INCLUDED
   3
   4 // boost/detail/atomic_count_gcc_atomic.hpp
   5 //
   6 // atomic_count for g++ 4.7+
   7 //
   8 // Copyright 2007, 2020 Peter Dimov
   9 //
  10 // Distributed under the Boost Software License, Version 1.0.
  11 // https://www.boost.org/LICENSE_1_0.txt
  12
  13 #include <boost/cstdint.hpp>
  14
  15 #if defined(BOOST_SP_REPORT_IMPLEMENTATION)
  16
  17 #include <boost/config/pragma_message.hpp>
  18 BOOST_PRAGMA_MESSAGE("Using __atomic atomic_count")
  19
  20 #endif
  21
  22 namespace boost
  23 {
  24
  25 namespace detail
  26 {
  27
  28 class atomic_count
  29 {
  30 public:
  31
  32     explicit atomic_count( long v ): value_( static_cast< boost::int_least32_t >( v ) )
  33     {
  34     }
  35
  36     long operator++()
  37     {
  38         return __atomic_add_fetch( &value_, +1, __ATOMIC_ACQ_REL );
  39     }
  40
  41     long operator--()
  42     {
  43         return __atomic_add_fetch( &value_, -1, __ATOMIC_ACQ_REL );
  44     }
  45
  46     operator long() const
  47     {
  48         return __atomic_load_n( &value_, __ATOMIC_ACQUIRE );
  49     }
  50
  51 private:
  52
  53     atomic_count(atomic_count const &);
  54     atomic_count & operator=(atomic_count const &);
  55
  56     boost::int_least32_t value_;
  57 };
  58
  59 } // namespace detail
  60
  61 } // namespace boost
  62
  63 #endif // #ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_GCC_ATOMIC_HPP_INCLUDED