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			10 KiB
		
	
	
	
		
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			273 lines
		
	
	
		
			10 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) 2011 Helge Bahmann | ||
|  |  * Copyright (c) 2013 Tim Blechmann | ||
|  |  * Copyright (c) 2014 Andrey Semashev | ||
|  |  */ | ||
|  | /*! | ||
|  |  * \file   atomic/detail/ops_gcc_sync.hpp | ||
|  |  * | ||
|  |  * This header contains implementation of the \c operations template. | ||
|  |  */ | ||
|  | 
 | ||
|  | #ifndef BOOST_ATOMIC_DETAIL_OPS_GCC_SYNC_HPP_INCLUDED_ | ||
|  | #define BOOST_ATOMIC_DETAIL_OPS_GCC_SYNC_HPP_INCLUDED_ | ||
|  | 
 | ||
|  | #include <boost/memory_order.hpp> | ||
|  | #include <boost/atomic/detail/config.hpp> | ||
|  | #include <boost/atomic/detail/storage_type.hpp> | ||
|  | #include <boost/atomic/detail/operations_fwd.hpp> | ||
|  | #include <boost/atomic/detail/ops_extending_cas_based.hpp> | ||
|  | #include <boost/atomic/capabilities.hpp> | ||
|  | 
 | ||
|  | #ifdef BOOST_HAS_PRAGMA_ONCE | ||
|  | #pragma once | ||
|  | #endif | ||
|  | 
 | ||
|  | namespace boost { | ||
|  | namespace atomics { | ||
|  | namespace detail { | ||
|  | 
 | ||
|  | struct gcc_sync_operations_base | ||
|  | { | ||
|  |     static BOOST_CONSTEXPR_OR_CONST bool is_always_lock_free = true; | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE void fence_before_store(memory_order order) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         if ((order & memory_order_release) != 0) | ||
|  |             __sync_synchronize(); | ||
|  |     } | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE void fence_after_store(memory_order order) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         if (order == memory_order_seq_cst) | ||
|  |             __sync_synchronize(); | ||
|  |     } | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE void fence_after_load(memory_order order) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         if ((order & (memory_order_acquire | memory_order_consume)) != 0) | ||
|  |             __sync_synchronize(); | ||
|  |     } | ||
|  | }; | ||
|  | 
 | ||
|  | template< typename T > | ||
|  | struct gcc_sync_operations : | ||
|  |     public gcc_sync_operations_base | ||
|  | { | ||
|  |     typedef T storage_type; | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE void store(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         fence_before_store(order); | ||
|  |         storage = v; | ||
|  |         fence_after_store(order); | ||
|  |     } | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE storage_type load(storage_type const volatile& storage, memory_order order) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         storage_type v = storage; | ||
|  |         fence_after_load(order); | ||
|  |         return v; | ||
|  |     } | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         return __sync_fetch_and_add(&storage, v); | ||
|  |     } | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE storage_type fetch_sub(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         return __sync_fetch_and_sub(&storage, v); | ||
|  |     } | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE storage_type exchange(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         // GCC docs mention that not all architectures may support full exchange semantics for this intrinsic. However, GCC's implementation of | ||
|  |         // std::atomic<> uses this intrinsic unconditionally. We do so as well. In case if some architectures actually don't support this, we can always | ||
|  |         // add a check here and fall back to a CAS loop. | ||
|  |         if ((order & memory_order_release) != 0) | ||
|  |             __sync_synchronize(); | ||
|  |         return __sync_lock_test_and_set(&storage, v); | ||
|  |     } | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE bool compare_exchange_strong( | ||
|  |         storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order, memory_order) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         storage_type expected2 = expected; | ||
|  |         storage_type old_val = __sync_val_compare_and_swap(&storage, expected2, desired); | ||
|  | 
 | ||
|  |         if (old_val == expected2) | ||
|  |         { | ||
|  |             return true; | ||
|  |         } | ||
|  |         else | ||
|  |         { | ||
|  |             expected = old_val; | ||
|  |             return false; | ||
|  |         } | ||
|  |     } | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE bool compare_exchange_weak( | ||
|  |         storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order success_order, memory_order failure_order) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         return compare_exchange_strong(storage, expected, desired, success_order, failure_order); | ||
|  |     } | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE storage_type fetch_and(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         return __sync_fetch_and_and(&storage, v); | ||
|  |     } | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE storage_type fetch_or(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         return __sync_fetch_and_or(&storage, v); | ||
|  |     } | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE storage_type fetch_xor(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         return __sync_fetch_and_xor(&storage, v); | ||
|  |     } | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE bool test_and_set(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         if ((order & memory_order_release) != 0) | ||
|  |             __sync_synchronize(); | ||
|  |         return !!__sync_lock_test_and_set(&storage, 1); | ||
|  |     } | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE void clear(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         __sync_lock_release(&storage); | ||
|  |         if (order == memory_order_seq_cst) | ||
|  |             __sync_synchronize(); | ||
|  |     } | ||
|  | 
 | ||
|  |     static BOOST_FORCEINLINE bool is_lock_free(storage_type const volatile&) BOOST_NOEXCEPT | ||
|  |     { | ||
|  |         return true; | ||
|  |     } | ||
|  | }; | ||
|  | 
 | ||
|  | #if BOOST_ATOMIC_INT8_LOCK_FREE > 0 | ||
|  | template< bool Signed > | ||
|  | struct operations< 1u, Signed > : | ||
|  | #if defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_1) | ||
|  |     public gcc_sync_operations< typename make_storage_type< 1u, Signed >::type > | ||
|  | #elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2) | ||
|  |     public extending_cas_based_operations< gcc_sync_operations< typename make_storage_type< 2u, Signed >::type >, 1u, Signed > | ||
|  | #elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) | ||
|  |     public extending_cas_based_operations< gcc_sync_operations< typename make_storage_type< 4u, Signed >::type >, 1u, Signed > | ||
|  | #elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8) | ||
|  |     public extending_cas_based_operations< gcc_sync_operations< typename make_storage_type< 8u, Signed >::type >, 1u, Signed > | ||
|  | #else | ||
|  |     public extending_cas_based_operations< gcc_sync_operations< typename make_storage_type< 16u, Signed >::type >, 1u, Signed > | ||
|  | #endif | ||
|  | { | ||
|  | #if defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_1) | ||
|  |     typedef typename make_storage_type< 1u, Signed >::aligned aligned_storage_type; | ||
|  | #elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2) | ||
|  |     typedef typename make_storage_type< 2u, Signed >::aligned aligned_storage_type; | ||
|  | #elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) | ||
|  |     typedef typename make_storage_type< 4u, Signed >::aligned aligned_storage_type; | ||
|  | #elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8) | ||
|  |     typedef typename make_storage_type< 8u, Signed >::aligned aligned_storage_type; | ||
|  | #else | ||
|  |     typedef typename make_storage_type< 16u, Signed >::aligned aligned_storage_type; | ||
|  | #endif | ||
|  | }; | ||
|  | #endif | ||
|  | 
 | ||
|  | #if BOOST_ATOMIC_INT16_LOCK_FREE > 0 | ||
|  | template< bool Signed > | ||
|  | struct operations< 2u, Signed > : | ||
|  | #if defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2) | ||
|  |     public gcc_sync_operations< typename make_storage_type< 2u, Signed >::type > | ||
|  | #elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) | ||
|  |     public extending_cas_based_operations< gcc_sync_operations< typename make_storage_type< 4u, Signed >::type >, 2u, Signed > | ||
|  | #elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8) | ||
|  |     public extending_cas_based_operations< gcc_sync_operations< typename make_storage_type< 8u, Signed >::type >, 2u, Signed > | ||
|  | #else | ||
|  |     public extending_cas_based_operations< gcc_sync_operations< typename make_storage_type< 16u, Signed >::type >, 2u, Signed > | ||
|  | #endif | ||
|  | { | ||
|  | #if defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2) | ||
|  |     typedef typename make_storage_type< 2u, Signed >::aligned aligned_storage_type; | ||
|  | #elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) | ||
|  |     typedef typename make_storage_type< 4u, Signed >::aligned aligned_storage_type; | ||
|  | #elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8) | ||
|  |     typedef typename make_storage_type< 8u, Signed >::aligned aligned_storage_type; | ||
|  | #else | ||
|  |     typedef typename make_storage_type< 16u, Signed >::aligned aligned_storage_type; | ||
|  | #endif | ||
|  | }; | ||
|  | #endif | ||
|  | 
 | ||
|  | #if BOOST_ATOMIC_INT32_LOCK_FREE > 0 | ||
|  | template< bool Signed > | ||
|  | struct operations< 4u, Signed > : | ||
|  | #if defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) | ||
|  |     public gcc_sync_operations< typename make_storage_type< 4u, Signed >::type > | ||
|  | #elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8) | ||
|  |     public extending_cas_based_operations< gcc_sync_operations< typename make_storage_type< 8u, Signed >::type >, 4u, Signed > | ||
|  | #else | ||
|  |     public extending_cas_based_operations< gcc_sync_operations< typename make_storage_type< 16u, Signed >::type >, 4u, Signed > | ||
|  | #endif | ||
|  | { | ||
|  | #if defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) | ||
|  |     typedef typename make_storage_type< 4u, Signed >::aligned aligned_storage_type; | ||
|  | #elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8) | ||
|  |     typedef typename make_storage_type< 8u, Signed >::aligned aligned_storage_type; | ||
|  | #else | ||
|  |     typedef typename make_storage_type< 16u, Signed >::aligned aligned_storage_type; | ||
|  | #endif | ||
|  | }; | ||
|  | #endif | ||
|  | 
 | ||
|  | #if BOOST_ATOMIC_INT64_LOCK_FREE > 0 | ||
|  | template< bool Signed > | ||
|  | struct operations< 8u, Signed > : | ||
|  | #if defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8) | ||
|  |     public gcc_sync_operations< typename make_storage_type< 8u, Signed >::type > | ||
|  | #else | ||
|  |     public extending_cas_based_operations< gcc_sync_operations< typename make_storage_type< 16u, Signed >::type >, 8u, Signed > | ||
|  | #endif | ||
|  | { | ||
|  | #if defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8) | ||
|  |     typedef typename make_storage_type< 8u, Signed >::aligned aligned_storage_type; | ||
|  | #else | ||
|  |     typedef typename make_storage_type< 16u, Signed >::aligned aligned_storage_type; | ||
|  | #endif | ||
|  | }; | ||
|  | #endif | ||
|  | 
 | ||
|  | #if BOOST_ATOMIC_INT128_LOCK_FREE > 0 | ||
|  | template< bool Signed > | ||
|  | struct operations< 16u, Signed > : | ||
|  |     public gcc_sync_operations< typename make_storage_type< 16u, Signed >::type > | ||
|  | { | ||
|  |     typedef typename make_storage_type< 16u, Signed >::aligned aligned_storage_type; | ||
|  | }; | ||
|  | #endif | ||
|  | 
 | ||
|  | BOOST_FORCEINLINE void thread_fence(memory_order order) BOOST_NOEXCEPT | ||
|  | { | ||
|  |     if (order != memory_order_relaxed) | ||
|  |         __sync_synchronize(); | ||
|  | } | ||
|  | 
 | ||
|  | BOOST_FORCEINLINE void signal_fence(memory_order order) BOOST_NOEXCEPT | ||
|  | { | ||
|  |     if (order != memory_order_relaxed) | ||
|  |         __asm__ __volatile__ ("" ::: "memory"); | ||
|  | } | ||
|  | 
 | ||
|  | } // namespace detail | ||
|  | } // namespace atomics | ||
|  | } // namespace boost | ||
|  | 
 | ||
|  | #endif // BOOST_ATOMIC_DETAIL_OPS_GCC_SYNC_HPP_INCLUDED_ |