ceph/src/boost/boost/atomic/detail/core_ops_cas_based.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/core_ops_cas_based.hpp
  10  *
  11  * This header contains CAS-based implementation of core atomic operations.
  12  */
  13
  14 #ifndef BOOST_ATOMIC_DETAIL_CORE_OPS_CAS_BASED_HPP_INCLUDED_
  15 #define BOOST_ATOMIC_DETAIL_CORE_OPS_CAS_BASED_HPP_INCLUDED_
  16
  17 #include <boost/memory_order.hpp>
  18 #include <boost/atomic/detail/config.hpp>
  19 #include <boost/atomic/detail/header.hpp>
  20
  21 #ifdef BOOST_HAS_PRAGMA_ONCE
  22 #pragma once
  23 #endif
  24
  25 namespace boost {
  26 namespace atomics {
  27 namespace detail {
  28
  29 template< typename Base >
  30 struct core_operations_cas_based :
  31     public Base
  32 {
  33     typedef typename Base::storage_type storage_type;
  34
  35     static BOOST_CONSTEXPR_OR_CONST bool full_cas_based = true;
  36
  37     static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
  38     {
  39         storage_type old_val;
  40         atomics::detail::non_atomic_load(storage, old_val);
  41         while (!Base::compare_exchange_weak(storage, old_val, old_val + v, order, memory_order_relaxed)) {}
  42         return old_val;
  43     }
  44
  45     static BOOST_FORCEINLINE storage_type fetch_sub(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
  46     {
  47         storage_type old_val;
  48         atomics::detail::non_atomic_load(storage, old_val);
  49         while (!Base::compare_exchange_weak(storage, old_val, old_val - v, order, memory_order_relaxed)) {}
  50         return old_val;
  51     }
  52
  53     static BOOST_FORCEINLINE storage_type fetch_and(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
  54     {
  55         storage_type old_val;
  56         atomics::detail::non_atomic_load(storage, old_val);
  57         while (!Base::compare_exchange_weak(storage, old_val, old_val & v, order, memory_order_relaxed)) {}
  58         return old_val;
  59     }
  60
  61     static BOOST_FORCEINLINE storage_type fetch_or(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
  62     {
  63         storage_type old_val;
  64         atomics::detail::non_atomic_load(storage, old_val);
  65         while (!Base::compare_exchange_weak(storage, old_val, old_val | v, order, memory_order_relaxed)) {}
  66         return old_val;
  67     }
  68
  69     static BOOST_FORCEINLINE storage_type fetch_xor(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
  70     {
  71         storage_type old_val;
  72         atomics::detail::non_atomic_load(storage, old_val);
  73         while (!Base::compare_exchange_weak(storage, old_val, old_val ^ v, order, memory_order_relaxed)) {}
  74         return old_val;
  75     }
  76
  77     static BOOST_FORCEINLINE bool test_and_set(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
  78     {
  79         return !!Base::exchange(storage, (storage_type)1, order);
  80     }
  81
  82     static BOOST_FORCEINLINE void clear(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
  83     {
  84         Base::store(storage, (storage_type)0, order);
  85     }
  86 };
  87
  88 } // namespace detail
  89 } // namespace atomics
  90 } // namespace boost
  91
  92 #include <boost/atomic/detail/footer.hpp>
  93
  94 #endif // BOOST_ATOMIC_DETAIL_CORE_OPS_CAS_BASED_HPP_INCLUDED_