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Diffstat (limited to 'src/third_party/boost-1.69.0/boost/atomic/detail/ops_gcc_sync.hpp')
| -rw-r--r-- | src/third_party/boost-1.69.0/boost/atomic/detail/ops_gcc_sync.hpp | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/src/third_party/boost-1.69.0/boost/atomic/detail/ops_gcc_sync.hpp b/src/third_party/boost-1.69.0/boost/atomic/detail/ops_gcc_sync.hpp new file mode 100644 index 00000000000..1597de852a6 --- /dev/null +++ b/src/third_party/boost-1.69.0/boost/atomic/detail/ops_gcc_sync.hpp @@ -0,0 +1,240 @@ +/* + * 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 <cstddef> +#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 full_cas_based = false; + static BOOST_CONSTEXPR_OR_CONST bool is_always_lock_free = true; + + static BOOST_FORCEINLINE void fence_before_store(memory_order order) BOOST_NOEXCEPT + { + if ((static_cast< unsigned int >(order) & static_cast< unsigned int >(memory_order_release)) != 0u) + __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 ((static_cast< unsigned int >(order) & (static_cast< unsigned int >(memory_order_acquire) | static_cast< unsigned int >(memory_order_consume))) != 0u) + __sync_synchronize(); + } +}; + +template< std::size_t Size, bool Signed > +struct gcc_sync_operations : + public gcc_sync_operations_base +{ + typedef typename make_storage_type< Size >::type storage_type; + typedef typename make_storage_type< Size >::aligned aligned_storage_type; + + static BOOST_CONSTEXPR_OR_CONST std::size_t storage_size = Size; + static BOOST_CONSTEXPR_OR_CONST bool is_signed = Signed; + + 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 ((static_cast< unsigned int >(order) & static_cast< unsigned int >(memory_order_release)) != 0u) + __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 ((static_cast< unsigned int >(order) & static_cast< unsigned int >(memory_order_release)) != 0u) + __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(); + } +}; + +#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< 1u, Signed > +#elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2) + public extending_cas_based_operations< gcc_sync_operations< 2u, Signed >, 1u, Signed > +#elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) + public extending_cas_based_operations< gcc_sync_operations< 4u, Signed >, 1u, Signed > +#elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8) + public extending_cas_based_operations< gcc_sync_operations< 8u, Signed >, 1u, Signed > +#else + public extending_cas_based_operations< gcc_sync_operations< 16u, Signed >, 1u, Signed > +#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< 2u, Signed > +#elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) + public extending_cas_based_operations< gcc_sync_operations< 4u, Signed >, 2u, Signed > +#elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8) + public extending_cas_based_operations< gcc_sync_operations< 8u, Signed >, 2u, Signed > +#else + public extending_cas_based_operations< gcc_sync_operations< 16u, Signed >, 2u, Signed > +#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< 4u, Signed > +#elif defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_8) + public extending_cas_based_operations< gcc_sync_operations< 8u, Signed >, 4u, Signed > +#else + public extending_cas_based_operations< gcc_sync_operations< 16u, Signed >, 4u, Signed > +#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< 8u, Signed > +#else + public extending_cas_based_operations< gcc_sync_operations< 16u, Signed >, 8u, Signed > +#endif +{ +}; +#endif + +#if BOOST_ATOMIC_INT128_LOCK_FREE > 0 +template< bool Signed > +struct operations< 16u, Signed > : + public gcc_sync_operations< 16u, Signed > +{ +}; +#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_ |