/*
|
* 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)
|
*
|
* Copyright (c) 2020 Andrey Semashev
|
*/
|
/*!
|
* \file atomic/detail/memory_order_utils.hpp
|
*
|
* This header contains utilities related to memory order constants.
|
*/
|
|
#ifndef BOOST_ATOMIC_DETAIL_MEMORY_ORDER_UTILS_HPP_INCLUDED_
|
#define BOOST_ATOMIC_DETAIL_MEMORY_ORDER_UTILS_HPP_INCLUDED_
|
|
#include <boost/memory_order.hpp>
|
#include <boost/atomic/detail/config.hpp>
|
#include <boost/atomic/detail/header.hpp>
|
|
#ifdef BOOST_HAS_PRAGMA_ONCE
|
#pragma once
|
#endif
|
|
namespace boost {
|
namespace atomics {
|
namespace detail {
|
|
BOOST_FORCEINLINE BOOST_CONSTEXPR memory_order deduce_failure_order(memory_order order) BOOST_NOEXCEPT
|
{
|
return order == memory_order_acq_rel ? memory_order_acquire : (order == memory_order_release ? memory_order_relaxed : order);
|
}
|
|
BOOST_FORCEINLINE BOOST_CONSTEXPR bool cas_failure_order_must_not_be_stronger_than_success_order(memory_order success_order, memory_order failure_order) BOOST_NOEXCEPT
|
{
|
// 15 == (memory_order_seq_cst | memory_order_consume), see memory_order.hpp
|
// Given the enum values we can test the strength of memory order requirements with this single condition.
|
return (static_cast< unsigned int >(failure_order) & 15u) <= (static_cast< unsigned int >(success_order) & 15u);
|
}
|
|
} // namespace detail
|
} // namespace atomics
|
} // namespace boost
|
|
#include <boost/atomic/detail/footer.hpp>
|
|
#endif // BOOST_ATOMIC_DETAIL_MEMORY_ORDER_UTILS_HPP_INCLUDED_
|
