--- /dev/null
+/*
+ * 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_
projects / ceph.git / blobdiff