| /* |
| * 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, 2020 Andrey Semashev |
| */ |
| /*! |
| * \file atomic/detail/core_operations_emulated.hpp |
| * |
| * This header contains lock pool-based implementation of the core atomic operations. |
| */ |
| |
| #ifndef BOOST_ATOMIC_DETAIL_CORE_OPERATIONS_EMULATED_HPP_INCLUDED_ |
| #define BOOST_ATOMIC_DETAIL_CORE_OPERATIONS_EMULATED_HPP_INCLUDED_ |
| |
| #include <cstddef> |
| #include <boost/static_assert.hpp> |
| #include <boost/memory_order.hpp> |
| #include <boost/atomic/detail/config.hpp> |
| #include <boost/atomic/detail/storage_traits.hpp> |
| #include <boost/atomic/detail/core_operations_emulated_fwd.hpp> |
| #include <boost/atomic/detail/lock_pool.hpp> |
| #include <boost/atomic/detail/header.hpp> |
| |
| #ifdef BOOST_HAS_PRAGMA_ONCE |
| #pragma once |
| #endif |
| |
| namespace boost { |
| namespace atomics { |
| namespace detail { |
| |
| template< std::size_t Size, std::size_t Alignment, bool = Alignment >= storage_traits< Size >::native_alignment > |
| struct core_operations_emulated_base |
| { |
| typedef typename storage_traits< Size >::type storage_type; |
| }; |
| |
| template< std::size_t Size, std::size_t Alignment > |
| struct core_operations_emulated_base< Size, Alignment, false > |
| { |
| typedef buffer_storage< Size, Alignment > storage_type; |
| }; |
| |
| //! Emulated implementation of core atomic operations |
| template< std::size_t Size, std::size_t Alignment, bool Signed, bool Interprocess > |
| struct core_operations_emulated : |
| public core_operations_emulated_base< Size, Alignment > |
| { |
| typedef core_operations_emulated_base< Size, Alignment > base_type; |
| |
| // Define storage_type to have alignment not greater than Alignment. This will allow operations to work with value_types |
| // that possibly have weaker alignment requirements than storage_traits< Size >::type would. This is important for atomic_ref<>. |
| // atomic<> will allow higher alignment requirement than its value_type. |
| // Note that storage_type should be an integral type, if possible, so that arithmetic and bitwise operations are possible. |
| typedef typename base_type::storage_type storage_type; |
| |
| static BOOST_CONSTEXPR_OR_CONST std::size_t storage_size = Size; |
| static BOOST_CONSTEXPR_OR_CONST std::size_t storage_alignment = Alignment >= storage_traits< Size >::alignment ? storage_traits< Size >::alignment : Alignment; |
| |
| static BOOST_CONSTEXPR_OR_CONST bool is_signed = Signed; |
| static BOOST_CONSTEXPR_OR_CONST bool is_interprocess = Interprocess; |
| static BOOST_CONSTEXPR_OR_CONST bool full_cas_based = false; |
| |
| static BOOST_CONSTEXPR_OR_CONST bool is_always_lock_free = false; |
| |
| typedef lock_pool::scoped_lock< storage_alignment > scoped_lock; |
| |
| static void store(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT |
| { |
| BOOST_STATIC_ASSERT_MSG(!is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object"); |
| scoped_lock lock(&storage); |
| const_cast< storage_type& >(storage) = v; |
| } |
| |
| static storage_type load(storage_type const volatile& storage, memory_order) BOOST_NOEXCEPT |
| { |
| BOOST_STATIC_ASSERT_MSG(!is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object"); |
| scoped_lock lock(&storage); |
| return const_cast< storage_type const& >(storage); |
| } |
| |
| static storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT |
| { |
| BOOST_STATIC_ASSERT_MSG(!is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object"); |
| storage_type& s = const_cast< storage_type& >(storage); |
| scoped_lock lock(&storage); |
| storage_type old_val = s; |
| s += v; |
| return old_val; |
| } |
| |
| static storage_type fetch_sub(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT |
| { |
| BOOST_STATIC_ASSERT_MSG(!is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object"); |
| storage_type& s = const_cast< storage_type& >(storage); |
| scoped_lock lock(&storage); |
| storage_type old_val = s; |
| s -= v; |
| return old_val; |
| } |
| |
| static storage_type exchange(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT |
| { |
| BOOST_STATIC_ASSERT_MSG(!is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object"); |
| storage_type& s = const_cast< storage_type& >(storage); |
| scoped_lock lock(&storage); |
| storage_type old_val = s; |
| s = v; |
| return old_val; |
| } |
| |
| static bool compare_exchange_strong( |
| storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order, memory_order) BOOST_NOEXCEPT |
| { |
| BOOST_STATIC_ASSERT_MSG(!is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object"); |
| storage_type& s = const_cast< storage_type& >(storage); |
| scoped_lock lock(&storage); |
| storage_type old_val = s; |
| const bool res = old_val == expected; |
| if (res) |
| s = desired; |
| expected = old_val; |
| |
| return res; |
| } |
| |
| static bool compare_exchange_weak( |
| storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order, memory_order) BOOST_NOEXCEPT |
| { |
| // Note: This function is the exact copy of compare_exchange_strong. The reason we're not just forwarding the call |
| // is that MSVC-12 ICEs in this case. |
| BOOST_STATIC_ASSERT_MSG(!is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object"); |
| storage_type& s = const_cast< storage_type& >(storage); |
| scoped_lock lock(&storage); |
| storage_type old_val = s; |
| const bool res = old_val == expected; |
| if (res) |
| s = desired; |
| expected = old_val; |
| |
| return res; |
| } |
| |
| static storage_type fetch_and(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT |
| { |
| BOOST_STATIC_ASSERT_MSG(!is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object"); |
| storage_type& s = const_cast< storage_type& >(storage); |
| scoped_lock lock(&storage); |
| storage_type old_val = s; |
| s &= v; |
| return old_val; |
| } |
| |
| static storage_type fetch_or(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT |
| { |
| BOOST_STATIC_ASSERT_MSG(!is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object"); |
| storage_type& s = const_cast< storage_type& >(storage); |
| scoped_lock lock(&storage); |
| storage_type old_val = s; |
| s |= v; |
| return old_val; |
| } |
| |
| static storage_type fetch_xor(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT |
| { |
| BOOST_STATIC_ASSERT_MSG(!is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object"); |
| storage_type& s = const_cast< storage_type& >(storage); |
| scoped_lock lock(&storage); |
| storage_type old_val = s; |
| s ^= v; |
| return old_val; |
| } |
| |
| static BOOST_FORCEINLINE bool test_and_set(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT |
| { |
| BOOST_STATIC_ASSERT_MSG(!is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object"); |
| return !!exchange(storage, (storage_type)1, order); |
| } |
| |
| static BOOST_FORCEINLINE void clear(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT |
| { |
| BOOST_STATIC_ASSERT_MSG(!is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object"); |
| store(storage, (storage_type)0, order); |
| } |
| }; |
| |
| } // namespace detail |
| } // namespace atomics |
| } // namespace boost |
| |
| #include <boost/atomic/detail/footer.hpp> |
| |
| #endif // BOOST_ATOMIC_DETAIL_CORE_OPERATIONS_EMULATED_HPP_INCLUDED_ |