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			2.3 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
		
		
			
		
	
	
			69 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
|   | /* | ||
|  |  * 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_extending_cas_based.hpp | ||
|  |  * | ||
|  |  * This header contains a boilerplate of the \c operations template implementation that requires sign/zero extension in arithmetic operations. | ||
|  |  */ | ||
|  | 
 | ||
|  | #ifndef BOOST_ATOMIC_DETAIL_OPS_EXTENDING_CAS_BASED_HPP_INCLUDED_ | ||
|  | #define BOOST_ATOMIC_DETAIL_OPS_EXTENDING_CAS_BASED_HPP_INCLUDED_ | ||
|  | 
 | ||
|  | #include <cstddef> | ||
|  | #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, std::size_t Size, bool Signed > | ||
|  | struct extending_cas_based_operations : | ||
|  |     public Base | ||
|  | { | ||
|  |     typedef typename Base::storage_type storage_type; | ||
|  |     typedef typename make_storage_type< Size, Signed >::type emulated_storage_type; | ||
|  | 
 | ||
|  |     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); | ||
|  |         emulated_storage_type new_val; | ||
|  |         do | ||
|  |         { | ||
|  |             new_val = static_cast< emulated_storage_type >(old_val) + static_cast< emulated_storage_type >(v); | ||
|  |         } | ||
|  |         while (!Base::compare_exchange_weak(storage, old_val, static_cast< storage_type >(new_val), 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); | ||
|  |         emulated_storage_type new_val; | ||
|  |         do | ||
|  |         { | ||
|  |             new_val = static_cast< emulated_storage_type >(old_val) - static_cast< emulated_storage_type >(v); | ||
|  |         } | ||
|  |         while (!Base::compare_exchange_weak(storage, old_val, static_cast< storage_type >(new_val), order, memory_order_relaxed)); | ||
|  |         return old_val; | ||
|  |     } | ||
|  | }; | ||
|  | 
 | ||
|  | } // namespace detail | ||
|  | } // namespace atomics | ||
|  | } // namespace boost | ||
|  | 
 | ||
|  | #endif // BOOST_ATOMIC_DETAIL_OPS_EXTENDING_CAS_BASED_HPP_INCLUDED_ |