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 <boost/memory_order.hpp>
18 #include <boost/atomic/detail/config.hpp>
19 #include <boost/atomic/detail/storage_type.hpp>
20 #include <boost/atomic/detail/operations_fwd.hpp>
21 #include <boost/atomic/detail/lockpool.hpp>
22 #include <boost/atomic/capabilities.hpp>
23 
24 #ifdef BOOST_HAS_PRAGMA_ONCE
25 #pragma once
26 #endif
27 
28 namespace boost {
29 namespace atomics {
30 namespace detail {
31 
32 template< typename T >
33 struct emulated_operations
34 {
35     typedef T storage_type;
36 
storeboost::atomics::detail::emulated_operations37     static BOOST_FORCEINLINE void store(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
38     {
39         lockpool::scoped_lock lock(&storage);
40         const_cast< storage_type& >(storage) = v;
41     }
42 
loadboost::atomics::detail::emulated_operations43     static BOOST_FORCEINLINE storage_type load(storage_type const volatile& storage, memory_order) BOOST_NOEXCEPT
44     {
45         lockpool::scoped_lock lock(&storage);
46         return const_cast< storage_type const& >(storage);
47     }
48 
fetch_addboost::atomics::detail::emulated_operations49     static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
50     {
51         storage_type& s = const_cast< storage_type& >(storage);
52         lockpool::scoped_lock lock(&storage);
53         storage_type old_val = s;
54         s += v;
55         return old_val;
56     }
57 
fetch_subboost::atomics::detail::emulated_operations58     static BOOST_FORCEINLINE storage_type fetch_sub(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
59     {
60         storage_type& s = const_cast< storage_type& >(storage);
61         lockpool::scoped_lock lock(&storage);
62         storage_type old_val = s;
63         s -= v;
64         return old_val;
65     }
66 
exchangeboost::atomics::detail::emulated_operations67     static BOOST_FORCEINLINE storage_type exchange(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
68     {
69         storage_type& s = const_cast< storage_type& >(storage);
70         lockpool::scoped_lock lock(&storage);
71         storage_type old_val = s;
72         s = v;
73         return old_val;
74     }
75 
compare_exchange_strongboost::atomics::detail::emulated_operations76     static BOOST_FORCEINLINE bool compare_exchange_strong(
77         storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order, memory_order) BOOST_NOEXCEPT
78     {
79         storage_type& s = const_cast< storage_type& >(storage);
80         lockpool::scoped_lock lock(&storage);
81         storage_type old_val = s;
82         const bool res = old_val == expected;
83         if (res)
84             s = desired;
85         expected = old_val;
86 
87         return res;
88     }
89 
compare_exchange_weakboost::atomics::detail::emulated_operations90     static BOOST_FORCEINLINE bool compare_exchange_weak(
91         storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order success_order, memory_order failure_order) BOOST_NOEXCEPT
92     {
93         return compare_exchange_strong(storage, expected, desired, success_order, failure_order);
94     }
95 
fetch_andboost::atomics::detail::emulated_operations96     static BOOST_FORCEINLINE storage_type fetch_and(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
97     {
98         storage_type& s = const_cast< storage_type& >(storage);
99         lockpool::scoped_lock lock(&storage);
100         storage_type old_val = s;
101         s &= v;
102         return old_val;
103     }
104 
fetch_orboost::atomics::detail::emulated_operations105     static BOOST_FORCEINLINE storage_type fetch_or(storage_type volatile& storage, storage_type v, memory_order) BOOST_NOEXCEPT
106     {
107         storage_type& s = const_cast< storage_type& >(storage);
108         lockpool::scoped_lock lock(&storage);
109         storage_type old_val = s;
110         s |= v;
111         return old_val;
112     }
113 
fetch_xorboost::atomics::detail::emulated_operations114     static BOOST_FORCEINLINE storage_type fetch_xor(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 
test_and_setboost::atomics::detail::emulated_operations123     static BOOST_FORCEINLINE bool test_and_set(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
124     {
125         return !!exchange(storage, (storage_type)1, order);
126     }
127 
clearboost::atomics::detail::emulated_operations128     static BOOST_FORCEINLINE void clear(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
129     {
130         store(storage, (storage_type)0, order);
131     }
132 
is_lock_freeboost::atomics::detail::emulated_operations133     static BOOST_FORCEINLINE bool is_lock_free(storage_type const volatile&) BOOST_NOEXCEPT
134     {
135         return false;
136     }
137 };
138 
139 template< unsigned int Size, bool Signed >
140 struct operations :
141     public emulated_operations< typename make_storage_type< Size, Signed >::type >
142 {
143 };
144 
145 } // namespace detail
146 } // namespace atomics
147 } // namespace boost
148 
149 #endif // BOOST_ATOMIC_DETAIL_OPS_EMULATED_HPP_INCLUDED_
150