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realtimeroboticsgroup.org / RealtimeRoboticsGroup / test / 7e1710214f27faafa533409d132bba0cfcb2fc3c / . / include / boost / atomic / detail / ops_emulated.hpp
blob: f30fbdab9f7adca0341600fd4ffc2ee3f4a86d6b [file] [log] [blame]
Brian Silverman7e171022018-08-05 00:17:49 -0700[diff] [blame^]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/ops_emulated.hpp
10 *
11 * This header contains lockpool-based implementation of the \c operations template.
12 */
13
14#ifndef BOOST_ATOMIC_DETAIL_OPS_EMULATED_HPP_INCLUDED_
15#define BOOST_ATOMIC_DETAIL_OPS_EMULATED_HPP_INCLUDED_
16
17#include <cstddef>
18#include <boost/memory_order.hpp>
19#include <boost/atomic/detail/config.hpp>
20#include <boost/atomic/detail/storage_type.hpp>
21#include <boost/atomic/detail/operations_fwd.hpp>
22#include <boost/atomic/detail/lockpool.hpp>
23#include <boost/atomic/capabilities.hpp>
24
25#ifdef BOOST_HAS_PRAGMA_ONCE
26#pragma once
27#endif
28
29namespace boost {
30namespace atomics {
31namespace detail {
32
33template< std::size_t Size, bool Signed >
34struct emulated_operations
35{
36 typedef typename make_storage_type< Size >::type storage_type;
37 typedef typename make_storage_type< Size >::aligned aligned_storage_type;
38
39 static BOOST_CONSTEXPR_OR_CONST std::size_t storage_size = Size;
40 static BOOST_CONSTEXPR_OR_CONST bool is_signed = Signed;
41 static BOOST_CONSTEXPR_OR_CONST bool full_cas_based = false;
42
43 static BOOST_CONSTEXPR_OR_CONST bool is_always_lock_free = false;
44
45 static BOOST_FORCEINLINE void store(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
46 {
47 lockpool::scoped_lock lock(&storage);
48 const_cast< storage_type& >(storage) = v;
49 }
50
51 static BOOST_FORCEINLINE storage_type load(storage_type const volatile& storage, memory_order) BOOST_NOEXCEPT
52 {
53 lockpool::scoped_lock lock(&storage);
54 return const_cast< storage_type const& >(storage);
55 }
56
57 static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
58 {
59 storage_type& s = const_cast< storage_type& >(storage);
60 lockpool::scoped_lock lock(&storage);
61 storage_type old_val = s;
62 s += v;
63 return old_val;
64 }
65
66 static BOOST_FORCEINLINE storage_type fetch_sub(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
67 {
68 storage_type& s = const_cast< storage_type& >(storage);
69 lockpool::scoped_lock lock(&storage);
70 storage_type old_val = s;
71 s -= v;
72 return old_val;
73 }
74
75 static BOOST_FORCEINLINE storage_type exchange(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
76 {
77 storage_type& s = const_cast< storage_type& >(storage);
78 lockpool::scoped_lock lock(&storage);
79 storage_type old_val = s;
80 s = v;
81 return old_val;
82 }
83
84 static BOOST_FORCEINLINE bool compare_exchange_strong(
85 storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order, memory_order) BOOST_NOEXCEPT
86 {
87 storage_type& s = const_cast< storage_type& >(storage);
88 lockpool::scoped_lock lock(&storage);
89 storage_type old_val = s;
90 const bool res = old_val == expected;
91 if (res)
92 s = desired;
93 expected = old_val;
94
95 return res;
96 }
97
98 static BOOST_FORCEINLINE bool compare_exchange_weak(
99 storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order, memory_order) BOOST_NOEXCEPT
100 {
101 // Note: This function is the exact copy of compare_exchange_strong. The reason we're not just forwarding the call
102 // is that MSVC-12 ICEs in this case.
103 storage_type& s = const_cast< storage_type& >(storage);
104 lockpool::scoped_lock lock(&storage);
105 storage_type old_val = s;
106 const bool res = old_val == expected;
107 if (res)
108 s = desired;
109 expected = old_val;
110
111 return res;
112 }
113
114 static BOOST_FORCEINLINE storage_type fetch_and(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
115 {
116 storage_type& s = const_cast< storage_type& >(storage);
117 lockpool::scoped_lock lock(&storage);
118 storage_type old_val = s;
119 s &= v;
120 return old_val;
121 }
122
123 static BOOST_FORCEINLINE storage_type fetch_or(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
124 {
125 storage_type& s = const_cast< storage_type& >(storage);
126 lockpool::scoped_lock lock(&storage);
127 storage_type old_val = s;
128 s |= v;
129 return old_val;
130 }
131
132 static BOOST_FORCEINLINE storage_type fetch_xor(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
133 {
134 storage_type& s = const_cast< storage_type& >(storage);
135 lockpool::scoped_lock lock(&storage);
136 storage_type old_val = s;
137 s ^= v;
138 return old_val;
139 }
140
141 static BOOST_FORCEINLINE bool test_and_set(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
142 {
143 return !!exchange(storage, (storage_type)1, order);
144 }
145
146 static BOOST_FORCEINLINE void clear(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
147 {
148 store(storage, (storage_type)0, order);
149 }
150};
151
152template< std::size_t Size, bool Signed >
153struct operations :
154 public emulated_operations< Size, Signed >
155{
156};
157
158} // namespace detail
159} // namespace atomics
160} // namespace boost
161
162#endif // BOOST_ATOMIC_DETAIL_OPS_EMULATED_HPP_INCLUDED_