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1fba0606 JW |
1 | // std::unique_lock implementation -*- C++ -*- |
2 | ||
7adcbafe | 3 | // Copyright (C) 2008-2022 Free Software Foundation, Inc. |
1fba0606 JW |
4 | // |
5 | // This file is part of the GNU ISO C++ Library. This library is free | |
6 | // software; you can redistribute it and/or modify it under the | |
7 | // terms of the GNU General Public License as published by the | |
8 | // Free Software Foundation; either version 3, or (at your option) | |
9 | // any later version. | |
10 | ||
11 | // This library is distributed in the hope that it will be useful, | |
12 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | // GNU General Public License for more details. | |
15 | ||
16 | // Under Section 7 of GPL version 3, you are granted additional | |
17 | // permissions described in the GCC Runtime Library Exception, version | |
18 | // 3.1, as published by the Free Software Foundation. | |
19 | ||
20 | // You should have received a copy of the GNU General Public License and | |
21 | // a copy of the GCC Runtime Library Exception along with this program; | |
22 | // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
23 | // <http://www.gnu.org/licenses/>. | |
24 | ||
25 | /** @file bits/unique_lock.h | |
26 | * This is an internal header file, included by other library headers. | |
27 | * Do not attempt to use it directly. @headername{mutex} | |
28 | */ | |
29 | ||
30 | #ifndef _GLIBCXX_UNIQUE_LOCK_H | |
31 | #define _GLIBCXX_UNIQUE_LOCK_H 1 | |
32 | ||
33 | #pragma GCC system_header | |
34 | ||
35 | #if __cplusplus < 201103L | |
36 | # include <bits/c++0x_warning.h> | |
37 | #else | |
38 | ||
7f78718b | 39 | #include <bits/chrono.h> |
1fba0606 | 40 | #include <bits/move.h> // for std::swap |
47cca028 | 41 | #include <bits/std_mutex.h> // for std::defer_lock_t |
1fba0606 JW |
42 | |
43 | namespace std _GLIBCXX_VISIBILITY(default) | |
44 | { | |
45 | _GLIBCXX_BEGIN_NAMESPACE_VERSION | |
46 | ||
1fba0606 JW |
47 | /** @brief A movable scoped lock type. |
48 | * | |
49 | * A unique_lock controls mutex ownership within a scope. Ownership of the | |
50 | * mutex can be delayed until after construction and can be transferred | |
51 | * to another unique_lock by move construction or move assignment. If a | |
52 | * mutex lock is owned when the destructor runs ownership will be released. | |
725708ab JW |
53 | * |
54 | * @ingroup mutexes | |
1fba0606 JW |
55 | */ |
56 | template<typename _Mutex> | |
57 | class unique_lock | |
58 | { | |
59 | public: | |
60 | typedef _Mutex mutex_type; | |
61 | ||
62 | unique_lock() noexcept | |
63 | : _M_device(0), _M_owns(false) | |
64 | { } | |
65 | ||
66 | explicit unique_lock(mutex_type& __m) | |
67 | : _M_device(std::__addressof(__m)), _M_owns(false) | |
68 | { | |
69 | lock(); | |
70 | _M_owns = true; | |
71 | } | |
72 | ||
73 | unique_lock(mutex_type& __m, defer_lock_t) noexcept | |
74 | : _M_device(std::__addressof(__m)), _M_owns(false) | |
75 | { } | |
76 | ||
77 | unique_lock(mutex_type& __m, try_to_lock_t) | |
78 | : _M_device(std::__addressof(__m)), _M_owns(_M_device->try_lock()) | |
79 | { } | |
80 | ||
81 | unique_lock(mutex_type& __m, adopt_lock_t) noexcept | |
82 | : _M_device(std::__addressof(__m)), _M_owns(true) | |
83 | { | |
84 | // XXX calling thread owns mutex | |
85 | } | |
86 | ||
1fba0606 JW |
87 | template<typename _Clock, typename _Duration> |
88 | unique_lock(mutex_type& __m, | |
89 | const chrono::time_point<_Clock, _Duration>& __atime) | |
90 | : _M_device(std::__addressof(__m)), | |
91 | _M_owns(_M_device->try_lock_until(__atime)) | |
92 | { } | |
93 | ||
94 | template<typename _Rep, typename _Period> | |
95 | unique_lock(mutex_type& __m, | |
96 | const chrono::duration<_Rep, _Period>& __rtime) | |
97 | : _M_device(std::__addressof(__m)), | |
98 | _M_owns(_M_device->try_lock_for(__rtime)) | |
99 | { } | |
1fba0606 JW |
100 | |
101 | ~unique_lock() | |
102 | { | |
103 | if (_M_owns) | |
104 | unlock(); | |
105 | } | |
106 | ||
107 | unique_lock(const unique_lock&) = delete; | |
108 | unique_lock& operator=(const unique_lock&) = delete; | |
109 | ||
110 | unique_lock(unique_lock&& __u) noexcept | |
111 | : _M_device(__u._M_device), _M_owns(__u._M_owns) | |
112 | { | |
113 | __u._M_device = 0; | |
114 | __u._M_owns = false; | |
115 | } | |
116 | ||
117 | unique_lock& operator=(unique_lock&& __u) noexcept | |
118 | { | |
119 | if(_M_owns) | |
120 | unlock(); | |
121 | ||
122 | unique_lock(std::move(__u)).swap(*this); | |
123 | ||
124 | __u._M_device = 0; | |
125 | __u._M_owns = false; | |
126 | ||
127 | return *this; | |
128 | } | |
129 | ||
130 | void | |
131 | lock() | |
132 | { | |
133 | if (!_M_device) | |
134 | __throw_system_error(int(errc::operation_not_permitted)); | |
135 | else if (_M_owns) | |
136 | __throw_system_error(int(errc::resource_deadlock_would_occur)); | |
137 | else | |
138 | { | |
139 | _M_device->lock(); | |
140 | _M_owns = true; | |
141 | } | |
142 | } | |
143 | ||
144 | bool | |
145 | try_lock() | |
146 | { | |
147 | if (!_M_device) | |
148 | __throw_system_error(int(errc::operation_not_permitted)); | |
149 | else if (_M_owns) | |
150 | __throw_system_error(int(errc::resource_deadlock_would_occur)); | |
151 | else | |
152 | { | |
153 | _M_owns = _M_device->try_lock(); | |
154 | return _M_owns; | |
155 | } | |
156 | } | |
157 | ||
1fba0606 JW |
158 | template<typename _Clock, typename _Duration> |
159 | bool | |
160 | try_lock_until(const chrono::time_point<_Clock, _Duration>& __atime) | |
161 | { | |
162 | if (!_M_device) | |
163 | __throw_system_error(int(errc::operation_not_permitted)); | |
164 | else if (_M_owns) | |
165 | __throw_system_error(int(errc::resource_deadlock_would_occur)); | |
166 | else | |
167 | { | |
168 | _M_owns = _M_device->try_lock_until(__atime); | |
169 | return _M_owns; | |
170 | } | |
171 | } | |
172 | ||
173 | template<typename _Rep, typename _Period> | |
174 | bool | |
175 | try_lock_for(const chrono::duration<_Rep, _Period>& __rtime) | |
176 | { | |
177 | if (!_M_device) | |
178 | __throw_system_error(int(errc::operation_not_permitted)); | |
179 | else if (_M_owns) | |
180 | __throw_system_error(int(errc::resource_deadlock_would_occur)); | |
181 | else | |
182 | { | |
183 | _M_owns = _M_device->try_lock_for(__rtime); | |
184 | return _M_owns; | |
185 | } | |
186 | } | |
1fba0606 JW |
187 | |
188 | void | |
189 | unlock() | |
190 | { | |
191 | if (!_M_owns) | |
192 | __throw_system_error(int(errc::operation_not_permitted)); | |
193 | else if (_M_device) | |
194 | { | |
195 | _M_device->unlock(); | |
196 | _M_owns = false; | |
197 | } | |
198 | } | |
199 | ||
200 | void | |
201 | swap(unique_lock& __u) noexcept | |
202 | { | |
203 | std::swap(_M_device, __u._M_device); | |
204 | std::swap(_M_owns, __u._M_owns); | |
205 | } | |
206 | ||
207 | mutex_type* | |
208 | release() noexcept | |
209 | { | |
210 | mutex_type* __ret = _M_device; | |
211 | _M_device = 0; | |
212 | _M_owns = false; | |
213 | return __ret; | |
214 | } | |
215 | ||
216 | bool | |
217 | owns_lock() const noexcept | |
218 | { return _M_owns; } | |
219 | ||
220 | explicit operator bool() const noexcept | |
221 | { return owns_lock(); } | |
222 | ||
223 | mutex_type* | |
224 | mutex() const noexcept | |
225 | { return _M_device; } | |
226 | ||
227 | private: | |
228 | mutex_type* _M_device; | |
229 | bool _M_owns; | |
230 | }; | |
231 | ||
232 | /// Swap overload for unique_lock objects. | |
725708ab | 233 | /// @relates unique_lock |
1fba0606 JW |
234 | template<typename _Mutex> |
235 | inline void | |
236 | swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y) noexcept | |
237 | { __x.swap(__y); } | |
238 | ||
1fba0606 JW |
239 | _GLIBCXX_END_NAMESPACE_VERSION |
240 | } // namespace | |
241 | ||
242 | #endif // C++11 | |
243 | #endif // _GLIBCXX_UNIQUE_LOCK_H |