1 /* 2 * Distributed under the Boost Software License, Version 1.0. 3 * (See accompanying file LICENSE_1_0.txt or copy at 4 * http://www.boost.org/LICENSE_1_0.txt) 5 * 6 * Copyright (c) 2014 Andrey Semashev 7 */ 8 /*! 9 * \file atomic/detail/atomic_flag.hpp 10 * 11 * This header contains interface definition of \c atomic_flag. 12 */ 13 14 #ifndef BOOST_ATOMIC_DETAIL_ATOMIC_FLAG_HPP_INCLUDED_ 15 #define BOOST_ATOMIC_DETAIL_ATOMIC_FLAG_HPP_INCLUDED_ 16 17 #include <boost/assert.hpp> 18 #include <boost/memory_order.hpp> 19 #include <boost/atomic/detail/config.hpp> 20 #include <boost/atomic/detail/operations_lockfree.hpp> 21 22 #ifdef BOOST_HAS_PRAGMA_ONCE 23 #pragma once 24 #endif 25 26 /* 27 * IMPLEMENTATION NOTE: All interface functions MUST be declared with BOOST_FORCEINLINE, 28 * see comment for convert_memory_order_to_gcc in ops_gcc_atomic.hpp. 29 */ 30 31 namespace boost { 32 namespace atomics { 33 34 #if defined(BOOST_NO_CXX11_CONSTEXPR) || defined(BOOST_NO_CXX11_UNIFIED_INITIALIZATION_SYNTAX) 35 #define BOOST_ATOMIC_NO_ATOMIC_FLAG_INIT 36 #else 37 #define BOOST_ATOMIC_FLAG_INIT {} 38 #endif 39 40 struct atomic_flag 41 { 42 typedef atomics::detail::operations< 1u, false > operations; 43 typedef operations::storage_type storage_type; 44 45 operations::aligned_storage_type m_storage; 46 atomic_flagboost::atomics::atomic_flag47 BOOST_FORCEINLINE BOOST_CONSTEXPR atomic_flag() BOOST_NOEXCEPT : m_storage(0) 48 { 49 } 50 test_and_setboost::atomics::atomic_flag51 BOOST_FORCEINLINE bool test_and_set(memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT 52 { 53 return operations::test_and_set(m_storage.value, order); 54 } 55 clearboost::atomics::atomic_flag56 BOOST_FORCEINLINE void clear(memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT 57 { 58 BOOST_ASSERT(order != memory_order_consume); 59 BOOST_ASSERT(order != memory_order_acquire); 60 BOOST_ASSERT(order != memory_order_acq_rel); 61 operations::clear(m_storage.value, order); 62 } 63 64 BOOST_DELETED_FUNCTION(atomic_flag(atomic_flag const&)) 65 BOOST_DELETED_FUNCTION(atomic_flag& operator= (atomic_flag const&)) 66 }; 67 68 } // namespace atomics 69 } // namespace boost 70 71 #endif // BOOST_ATOMIC_DETAIL_ATOMIC_FLAG_HPP_INCLUDED_ 72