ext-boost/boost/smart_ptr/detail/atomic_count_gcc.hpp
2019-08-24 15:39:04 +02:00

73 lines
1.4 KiB
C++

#ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_GCC_HPP_INCLUDED
#define BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_GCC_HPP_INCLUDED
//
// boost/detail/atomic_count_gcc.hpp
//
// atomic_count for GNU libstdc++ v3
//
// http://gcc.gnu.org/onlinedocs/porting/Thread-safety.html
//
// Copyright (c) 2001, 2002 Peter Dimov and Multi Media Ltd.
// Copyright (c) 2002 Lars Gullik Bjønnes <larsbj@lyx.org>
// Copyright 2003-2005 Peter Dimov
//
// 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)
//
#if __GNUC__ * 100 + __GNUC_MINOR__ >= 402
# include <ext/atomicity.h>
#else
# include <bits/atomicity.h>
#endif
namespace boost
{
namespace detail
{
#if defined(__GLIBCXX__) // g++ 3.4+
using __gnu_cxx::__atomic_add;
using __gnu_cxx::__exchange_and_add;
#endif
class atomic_count
{
public:
explicit atomic_count( long v ) : value_( v ) {}
long operator++()
{
return __exchange_and_add( &value_, +1 ) + 1;
}
long operator--()
{
return __exchange_and_add( &value_, -1 ) - 1;
}
operator long() const
{
return __exchange_and_add( &value_, 0 );
}
private:
atomic_count(atomic_count const &);
atomic_count & operator=(atomic_count const &);
mutable _Atomic_word value_;
};
} // namespace detail
} // namespace boost
#endif // #ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_GCC_HPP_INCLUDED