master
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_MUTEX
11#define _LIBCPP_MUTEX
12
13/*
14 mutex synopsis
15
16namespace std
17{
18
19class mutex
20{
21public:
22 constexpr mutex() noexcept;
23 ~mutex();
24
25 mutex(const mutex&) = delete;
26 mutex& operator=(const mutex&) = delete;
27
28 void lock();
29 bool try_lock();
30 void unlock();
31
32 typedef pthread_mutex_t* native_handle_type;
33 native_handle_type native_handle();
34};
35
36class recursive_mutex
37{
38public:
39 recursive_mutex();
40 ~recursive_mutex();
41
42 recursive_mutex(const recursive_mutex&) = delete;
43 recursive_mutex& operator=(const recursive_mutex&) = delete;
44
45 void lock();
46 bool try_lock() noexcept;
47 void unlock();
48
49 typedef pthread_mutex_t* native_handle_type;
50 native_handle_type native_handle();
51};
52
53class timed_mutex
54{
55public:
56 timed_mutex();
57 ~timed_mutex();
58
59 timed_mutex(const timed_mutex&) = delete;
60 timed_mutex& operator=(const timed_mutex&) = delete;
61
62 void lock();
63 bool try_lock();
64 template <class Rep, class Period>
65 bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
66 template <class Clock, class Duration>
67 bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
68 void unlock();
69};
70
71class recursive_timed_mutex
72{
73public:
74 recursive_timed_mutex();
75 ~recursive_timed_mutex();
76
77 recursive_timed_mutex(const recursive_timed_mutex&) = delete;
78 recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete;
79
80 void lock();
81 bool try_lock() noexcept;
82 template <class Rep, class Period>
83 bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
84 template <class Clock, class Duration>
85 bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
86 void unlock();
87};
88
89struct defer_lock_t { explicit defer_lock_t() = default; };
90struct try_to_lock_t { explicit try_to_lock_t() = default; };
91struct adopt_lock_t { explicit adopt_lock_t() = default; };
92
93inline constexpr defer_lock_t defer_lock{};
94inline constexpr try_to_lock_t try_to_lock{};
95inline constexpr adopt_lock_t adopt_lock{};
96
97template <class Mutex>
98class lock_guard
99{
100public:
101 typedef Mutex mutex_type;
102
103 explicit lock_guard(mutex_type& m);
104 lock_guard(mutex_type& m, adopt_lock_t);
105 ~lock_guard();
106
107 lock_guard(lock_guard const&) = delete;
108 lock_guard& operator=(lock_guard const&) = delete;
109};
110
111template <class... MutexTypes>
112class scoped_lock // C++17
113{
114public:
115 using mutex_type = Mutex; // Only if sizeof...(MutexTypes) == 1
116
117 explicit scoped_lock(MutexTypes&... m);
118 scoped_lock(adopt_lock_t, MutexTypes&... m);
119 ~scoped_lock();
120 scoped_lock(scoped_lock const&) = delete;
121 scoped_lock& operator=(scoped_lock const&) = delete;
122private:
123 tuple<MutexTypes&...> pm; // exposition only
124};
125
126template <class Mutex>
127class unique_lock
128{
129public:
130 typedef Mutex mutex_type;
131 unique_lock() noexcept;
132 explicit unique_lock(mutex_type& m);
133 unique_lock(mutex_type& m, defer_lock_t) noexcept;
134 unique_lock(mutex_type& m, try_to_lock_t);
135 unique_lock(mutex_type& m, adopt_lock_t);
136 template <class Clock, class Duration>
137 unique_lock(mutex_type& m, const chrono::time_point<Clock, Duration>& abs_time);
138 template <class Rep, class Period>
139 unique_lock(mutex_type& m, const chrono::duration<Rep, Period>& rel_time);
140 ~unique_lock();
141
142 unique_lock(unique_lock const&) = delete;
143 unique_lock& operator=(unique_lock const&) = delete;
144
145 unique_lock(unique_lock&& u) noexcept;
146 unique_lock& operator=(unique_lock&& u) noexcept;
147
148 void lock();
149 bool try_lock();
150
151 template <class Rep, class Period>
152 bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
153 template <class Clock, class Duration>
154 bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
155
156 void unlock();
157
158 void swap(unique_lock& u) noexcept;
159 mutex_type* release() noexcept;
160
161 bool owns_lock() const noexcept;
162 explicit operator bool () const noexcept;
163 mutex_type* mutex() const noexcept;
164};
165
166template <class Mutex>
167 void swap(unique_lock<Mutex>& x, unique_lock<Mutex>& y) noexcept;
168
169template <class L1, class L2, class... L3>
170 int try_lock(L1&, L2&, L3&...);
171template <class L1, class L2, class... L3>
172 void lock(L1&, L2&, L3&...);
173
174struct once_flag
175{
176 constexpr once_flag() noexcept;
177
178 once_flag(const once_flag&) = delete;
179 once_flag& operator=(const once_flag&) = delete;
180};
181
182template<class Callable, class ...Args>
183 void call_once(once_flag& flag, Callable&& func, Args&&... args);
184
185} // std
186
187*/
188
189#if __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
190# include <__cxx03/mutex>
191#else
192# include <__chrono/steady_clock.h>
193# include <__chrono/time_point.h>
194# include <__condition_variable/condition_variable.h>
195# include <__config>
196# include <__mutex/lock_guard.h>
197# include <__mutex/mutex.h>
198# include <__mutex/once_flag.h>
199# include <__mutex/tag_types.h>
200# include <__mutex/unique_lock.h>
201# include <__thread/id.h>
202# include <__thread/support.h>
203# include <__utility/forward.h>
204# include <limits>
205# ifndef _LIBCPP_CXX03_LANG
206# include <tuple>
207# endif
208# include <version>
209
210# if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
211# pragma GCC system_header
212# endif
213
214_LIBCPP_PUSH_MACROS
215# include <__undef_macros>
216
217_LIBCPP_BEGIN_NAMESPACE_STD
218
219# if _LIBCPP_HAS_THREADS
220
221class _LIBCPP_EXPORTED_FROM_ABI recursive_mutex {
222 __libcpp_recursive_mutex_t __m_;
223
224public:
225 recursive_mutex();
226 ~recursive_mutex();
227
228 recursive_mutex(const recursive_mutex&) = delete;
229 recursive_mutex& operator=(const recursive_mutex&) = delete;
230
231 void lock();
232 bool try_lock() _NOEXCEPT;
233 void unlock() _NOEXCEPT;
234
235 typedef __libcpp_recursive_mutex_t* native_handle_type;
236
237 _LIBCPP_HIDE_FROM_ABI native_handle_type native_handle() { return &__m_; }
238};
239
240class _LIBCPP_EXPORTED_FROM_ABI timed_mutex {
241 mutex __m_;
242 condition_variable __cv_;
243 bool __locked_;
244
245public:
246 timed_mutex();
247 ~timed_mutex();
248
249 timed_mutex(const timed_mutex&) = delete;
250 timed_mutex& operator=(const timed_mutex&) = delete;
251
252public:
253 void lock();
254 bool try_lock() _NOEXCEPT;
255 template <class _Rep, class _Period>
256 _LIBCPP_HIDE_FROM_ABI bool try_lock_for(const chrono::duration<_Rep, _Period>& __d) {
257 return try_lock_until(chrono::steady_clock::now() + __d);
258 }
259
260 template <class _Clock, class _Duration>
261 _LIBCPP_HIDE_FROM_ABI bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t) {
262 using namespace chrono;
263 unique_lock<mutex> __lk(__m_);
264 bool __no_timeout = _Clock::now() < __t;
265 while (__no_timeout && __locked_)
266 __no_timeout = __cv_.wait_until(__lk, __t) == cv_status::no_timeout;
267 if (!__locked_) {
268 __locked_ = true;
269 return true;
270 }
271 return false;
272 }
273
274 void unlock() _NOEXCEPT;
275};
276
277class _LIBCPP_EXPORTED_FROM_ABI recursive_timed_mutex {
278 mutex __m_;
279 condition_variable __cv_;
280 size_t __count_;
281 __thread_id __id_;
282
283public:
284 recursive_timed_mutex();
285 ~recursive_timed_mutex();
286
287 recursive_timed_mutex(const recursive_timed_mutex&) = delete;
288 recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete;
289
290 void lock();
291 bool try_lock() _NOEXCEPT;
292 template <class _Rep, class _Period>
293 _LIBCPP_HIDE_FROM_ABI bool try_lock_for(const chrono::duration<_Rep, _Period>& __d) {
294 return try_lock_until(chrono::steady_clock::now() + __d);
295 }
296
297 template <class _Clock, class _Duration>
298 _LIBCPP_HIDE_FROM_ABI bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t) {
299 using namespace chrono;
300 __thread_id __id = this_thread::get_id();
301 unique_lock<mutex> __lk(__m_);
302 if (__id == __id_) {
303 if (__count_ == numeric_limits<size_t>::max())
304 return false;
305 ++__count_;
306 return true;
307 }
308 bool __no_timeout = _Clock::now() < __t;
309 while (__no_timeout && __count_ != 0)
310 __no_timeout = __cv_.wait_until(__lk, __t) == cv_status::no_timeout;
311 if (__count_ == 0) {
312 __count_ = 1;
313 __id_ = __id;
314 return true;
315 }
316 return false;
317 }
318
319 void unlock() _NOEXCEPT;
320};
321
322template <class _L0, class _L1>
323_LIBCPP_HIDE_FROM_ABI int try_lock(_L0& __l0, _L1& __l1) {
324 unique_lock<_L0> __u0(__l0, try_to_lock_t());
325 if (__u0.owns_lock()) {
326 if (__l1.try_lock()) {
327 __u0.release();
328 return -1;
329 } else
330 return 1;
331 }
332 return 0;
333}
334
335# ifndef _LIBCPP_CXX03_LANG
336
337template <class _L0, class _L1, class _L2, class... _L3>
338_LIBCPP_HIDE_FROM_ABI int try_lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3) {
339 int __r = 0;
340 unique_lock<_L0> __u0(__l0, try_to_lock);
341 if (__u0.owns_lock()) {
342 __r = std::try_lock(__l1, __l2, __l3...);
343 if (__r == -1)
344 __u0.release();
345 else
346 ++__r;
347 }
348 return __r;
349}
350
351# endif // _LIBCPP_CXX03_LANG
352
353template <class _L0, class _L1>
354_LIBCPP_HIDE_FROM_ABI void lock(_L0& __l0, _L1& __l1) {
355 while (true) {
356 {
357 unique_lock<_L0> __u0(__l0);
358 if (__l1.try_lock()) {
359 __u0.release();
360 break;
361 }
362 }
363 __libcpp_thread_yield();
364 {
365 unique_lock<_L1> __u1(__l1);
366 if (__l0.try_lock()) {
367 __u1.release();
368 break;
369 }
370 }
371 __libcpp_thread_yield();
372 }
373}
374
375# ifndef _LIBCPP_CXX03_LANG
376
377template <class _L0, class _L1, class _L2, class... _L3>
378void __lock_first(int __i, _L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3) {
379 while (true) {
380 switch (__i) {
381 case 0: {
382 unique_lock<_L0> __u0(__l0);
383 __i = std::try_lock(__l1, __l2, __l3...);
384 if (__i == -1) {
385 __u0.release();
386 return;
387 }
388 }
389 ++__i;
390 __libcpp_thread_yield();
391 break;
392 case 1: {
393 unique_lock<_L1> __u1(__l1);
394 __i = std::try_lock(__l2, __l3..., __l0);
395 if (__i == -1) {
396 __u1.release();
397 return;
398 }
399 }
400 if (__i == sizeof...(_L3) + 1)
401 __i = 0;
402 else
403 __i += 2;
404 __libcpp_thread_yield();
405 break;
406 default:
407 std::__lock_first(__i - 2, __l2, __l3..., __l0, __l1);
408 return;
409 }
410 }
411}
412
413template <class _L0, class _L1, class _L2, class... _L3>
414inline _LIBCPP_HIDE_FROM_ABI void lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3) {
415 std::__lock_first(0, __l0, __l1, __l2, __l3...);
416}
417
418# endif // _LIBCPP_CXX03_LANG
419
420# if _LIBCPP_STD_VER >= 17
421template <class... _Mutexes>
422class scoped_lock;
423
424template <>
425class scoped_lock<> {
426public:
427 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI explicit scoped_lock() {}
428 ~scoped_lock() = default;
429
430 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI explicit scoped_lock(adopt_lock_t) {}
431
432 scoped_lock(scoped_lock const&) = delete;
433 scoped_lock& operator=(scoped_lock const&) = delete;
434};
435
436template <class _Mutex>
437class _LIBCPP_SCOPED_LOCKABLE scoped_lock<_Mutex> {
438public:
439 typedef _Mutex mutex_type;
440
441private:
442 mutex_type& __m_;
443
444public:
445 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI explicit scoped_lock(mutex_type& __m) _LIBCPP_ACQUIRE_CAPABILITY(__m)
446 : __m_(__m) {
447 __m_.lock();
448 }
449
450 _LIBCPP_RELEASE_CAPABILITY _LIBCPP_HIDE_FROM_ABI ~scoped_lock() { __m_.unlock(); }
451
452 [[nodiscard]]
453 _LIBCPP_HIDE_FROM_ABI explicit scoped_lock(adopt_lock_t, mutex_type& __m) _LIBCPP_REQUIRES_CAPABILITY(__m)
454 : __m_(__m) {}
455
456 scoped_lock(scoped_lock const&) = delete;
457 scoped_lock& operator=(scoped_lock const&) = delete;
458};
459
460template <class... _MArgs>
461class scoped_lock {
462 static_assert(sizeof...(_MArgs) > 1, "At least 2 lock types required");
463 typedef tuple<_MArgs&...> _MutexTuple;
464
465public:
466 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI explicit scoped_lock(_MArgs&... __margs) : __t_(__margs...) {
467 std::lock(__margs...);
468 }
469
470 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI scoped_lock(adopt_lock_t, _MArgs&... __margs) : __t_(__margs...) {}
471
472 _LIBCPP_HIDE_FROM_ABI ~scoped_lock() {
473 typedef typename __make_tuple_indices<sizeof...(_MArgs)>::type _Indices;
474 __unlock_unpack(_Indices{}, __t_);
475 }
476
477 scoped_lock(scoped_lock const&) = delete;
478 scoped_lock& operator=(scoped_lock const&) = delete;
479
480private:
481 template <size_t... _Indx>
482 _LIBCPP_HIDE_FROM_ABI static void __unlock_unpack(__tuple_indices<_Indx...>, _MutexTuple& __mt) {
483 (std::get<_Indx>(__mt).unlock(), ...);
484 }
485
486 _MutexTuple __t_;
487};
488_LIBCPP_CTAD_SUPPORTED_FOR_TYPE(scoped_lock);
489
490# endif // _LIBCPP_STD_VER >= 17
491# endif // _LIBCPP_HAS_THREADS
492
493_LIBCPP_END_NAMESPACE_STD
494
495_LIBCPP_POP_MACROS
496
497# if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
498# include <atomic>
499# include <concepts>
500# include <cstdlib>
501# include <cstring>
502# include <ctime>
503# include <initializer_list>
504# include <iosfwd>
505# include <new>
506# include <optional>
507# include <stdexcept>
508# include <system_error>
509# include <type_traits>
510# include <typeinfo>
511# endif
512#endif // __cplusplus < 201103L && defined(_LIBCPP_USE_FROZEN_CXX03_HEADERS)
513
514#endif // _LIBCPP_MUTEX