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- /*
- * 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) 2014 Andrey Semashev
- */
- /*!
- * \file atomic/detail/ops_cas_based.hpp
- *
- * This header contains CAS-based implementation of the \c operations template.
- */
- #ifndef BOOST_ATOMIC_DETAIL_OPS_CAS_BASED_HPP_INCLUDED_
- #define BOOST_ATOMIC_DETAIL_OPS_CAS_BASED_HPP_INCLUDED_
- #include <boost/memory_order.hpp>
- #include <boost/atomic/detail/config.hpp>
- #include <boost/atomic/detail/storage_type.hpp>
- #ifdef BOOST_HAS_PRAGMA_ONCE
- #pragma once
- #endif
- namespace boost {
- namespace atomics {
- namespace detail {
- template< typename Base >
- struct cas_based_exchange :
- public Base
- {
- typedef typename Base::storage_type storage_type;
- static BOOST_FORCEINLINE storage_type exchange(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
- {
- storage_type old_val;
- atomics::detail::non_atomic_load(storage, old_val);
- while (!Base::compare_exchange_weak(storage, old_val, v, order, memory_order_relaxed)) {}
- return old_val;
- }
- };
- template< typename Base >
- struct cas_based_operations :
- public Base
- {
- typedef typename Base::storage_type storage_type;
- static BOOST_CONSTEXPR_OR_CONST bool full_cas_based = true;
- static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
- {
- storage_type old_val;
- atomics::detail::non_atomic_load(storage, old_val);
- while (!Base::compare_exchange_weak(storage, old_val, old_val + v, order, memory_order_relaxed)) {}
- return old_val;
- }
- static BOOST_FORCEINLINE storage_type fetch_sub(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
- {
- storage_type old_val;
- atomics::detail::non_atomic_load(storage, old_val);
- while (!Base::compare_exchange_weak(storage, old_val, old_val - v, order, memory_order_relaxed)) {}
- return old_val;
- }
- static BOOST_FORCEINLINE storage_type fetch_and(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
- {
- storage_type old_val;
- atomics::detail::non_atomic_load(storage, old_val);
- while (!Base::compare_exchange_weak(storage, old_val, old_val & v, order, memory_order_relaxed)) {}
- return old_val;
- }
- static BOOST_FORCEINLINE storage_type fetch_or(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
- {
- storage_type old_val;
- atomics::detail::non_atomic_load(storage, old_val);
- while (!Base::compare_exchange_weak(storage, old_val, old_val | v, order, memory_order_relaxed)) {}
- return old_val;
- }
- static BOOST_FORCEINLINE storage_type fetch_xor(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
- {
- storage_type old_val;
- atomics::detail::non_atomic_load(storage, old_val);
- while (!Base::compare_exchange_weak(storage, old_val, old_val ^ v, order, memory_order_relaxed)) {}
- return old_val;
- }
- static BOOST_FORCEINLINE bool test_and_set(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
- {
- return !!Base::exchange(storage, (storage_type)1, order);
- }
- static BOOST_FORCEINLINE void clear(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
- {
- Base::store(storage, (storage_type)0, order);
- }
- };
- } // namespace detail
- } // namespace atomics
- } // namespace boost
- #endif // BOOST_ATOMIC_DETAIL_OPS_CAS_BASED_HPP_INCLUDED_
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