AngelscriptDebuggerServer/extern/asio-1.18.2/include/asio/detail/atomic_count.hpp

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2021-09-28 16:13:22 +00:00
//
// detail/atomic_count.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2021 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// 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)
//
#ifndef ASIO_DETAIL_ATOMIC_COUNT_HPP
#define ASIO_DETAIL_ATOMIC_COUNT_HPP
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
#include "asio/detail/config.hpp"
#if !defined(ASIO_HAS_THREADS)
// Nothing to include.
#elif defined(ASIO_HAS_STD_ATOMIC)
# include <atomic>
#else // defined(ASIO_HAS_STD_ATOMIC)
# include <boost/detail/atomic_count.hpp>
#endif // defined(ASIO_HAS_STD_ATOMIC)
namespace asio {
namespace detail {
#if !defined(ASIO_HAS_THREADS)
typedef long atomic_count;
inline void increment(atomic_count& a, long b) { a += b; }
inline void ref_count_up(atomic_count& a) { ++a; }
inline bool ref_count_down(atomic_count& a) { return --a == 0; }
#elif defined(ASIO_HAS_STD_ATOMIC)
typedef std::atomic<long> atomic_count;
inline void increment(atomic_count& a, long b) { a += b; }
inline void ref_count_up(atomic_count& a)
{
a.fetch_add(1, std::memory_order_relaxed);
}
inline bool ref_count_down(atomic_count& a)
{
if (a.fetch_sub(1, std::memory_order_release) == 1)
{
std::atomic_thread_fence(std::memory_order_acquire);
return true;
}
return false;
}
#else // defined(ASIO_HAS_STD_ATOMIC)
typedef boost::detail::atomic_count atomic_count;
inline void increment(atomic_count& a, long b) { while (b > 0) ++a, --b; }
inline void ref_count_up(atomic_count& a) { ++a; }
inline bool ref_count_down(atomic_count& a) { return --a == 0; }
#endif // defined(ASIO_HAS_STD_ATOMIC)
} // namespace detail
} // namespace asio
#endif // ASIO_DETAIL_ATOMIC_COUNT_HPP