ceph/src/boost/libs/atomic/include/boost/atomic/detail/atomic_flag.hpp

   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
  47     BOOST_FORCEINLINE BOOST_CONSTEXPR atomic_flag() BOOST_NOEXCEPT : m_storage(0)
  48     {
  49     }
  50
  51     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
  56     BOOST_FORCEINLINE void clear(memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
  57     {
  58         BOOST_ASSERT(order != memory_order_acquire);
  59         BOOST_ASSERT(order != memory_order_acq_rel);
  60         operations::clear(m_storage.value, order);
  61     }
  62
  63     BOOST_DELETED_FUNCTION(atomic_flag(atomic_flag const&))
  64     BOOST_DELETED_FUNCTION(atomic_flag& operator= (atomic_flag const&))
  65 };
  66
  67 } // namespace atomics
  68 } // namespace boost
  69
  70 #endif // BOOST_ATOMIC_DETAIL_ATOMIC_FLAG_HPP_INCLUDED_