#ifndef BOOST_DETAIL_ATOMIC_COUNT_GCC_HPP_INCLUDED

#define BOOST_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)

//



#include <bits/atomicity.h>



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) {}



    void operator++()

    {

        __atomic_add(&value_, 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_DETAIL_ATOMIC_COUNT_GCC_HPP_INCLUDED

