#ifndef BOOST_THREAD_PTHREAD_ONCE_HPP
#define BOOST_THREAD_PTHREAD_ONCE_HPP

//  once.hpp
//
//  (C) Copyright 2007-8 Anthony Williams
//  (C) Copyright 2011-2012 Vicente J. Botet Escriba
//
//  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 <boost/thread/detail/config.hpp>

#include <boost/cstdint.hpp>
#include <boost/detail/no_exceptions_support.hpp>

#include <boost/config/abi_prefix.hpp>

namespace boost
{

struct once_flag
{
#if defined(__GNUC__)
    __attribute__((may_alias))
#endif
    uintmax_t storage;
};

#define BOOST_ONCE_INIT {0}

namespace thread_detail
{
BOOST_THREAD_DECL bool enter_once_region(once_flag& flag) BOOST_NOEXCEPT;
BOOST_THREAD_DECL void commit_once_region(once_flag& flag) BOOST_NOEXCEPT;
BOOST_THREAD_DECL void rollback_once_region(once_flag& flag) BOOST_NOEXCEPT;
}

template<typename Function>
inline void call_once(once_flag& flag, Function f)
{
    if (thread_detail::enter_once_region(flag))
    {
        BOOST_TRY
        {
            f();
        }
        BOOST_CATCH (...)
        {
            thread_detail::rollback_once_region(flag);
            BOOST_RETHROW
        }
        BOOST_CATCH_END
        thread_detail::commit_once_region(flag);
    }
}

}

#include <boost/config/abi_suffix.hpp>

#endif