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#include <__chrono/steady_clock.h>
190#include <__chrono/time_point.h>
191#include <__condition_variable/condition_variable.h>
192#include <__config>
193#include <__memory/shared_ptr.h>
194#include <__mutex/lock_guard.h>
195#include <__mutex/mutex.h>
196#include <__mutex/once_flag.h>
197#include <__mutex/tag_types.h>
198#include <__mutex/unique_lock.h>
199#include <__thread/id.h>
200#include <__thread/support.h>
201#include <__utility/forward.h>
202#include <cstddef>
203#include <limits>
204#ifndef _LIBCPP_CXX03_LANG
205# include <tuple>
206#endif
207#include <version>
208
209#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
210# pragma GCC system_header
211#endif
212
213_LIBCPP_PUSH_MACROS
214#include <__undef_macros>
215
216_LIBCPP_BEGIN_NAMESPACE_STD
217
218#ifndef _LIBCPP_HAS_NO_THREADS
219
220class _LIBCPP_EXPORTED_FROM_ABI recursive_mutex {
221 __libcpp_recursive_mutex_t __m_;
222
223public:
224 recursive_mutex();
225 ~recursive_mutex();
226
227 recursive_mutex(const recursive_mutex&) = delete;
228 recursive_mutex& operator=(const recursive_mutex&) = delete;
229
230 void lock();
231 bool try_lock() _NOEXCEPT;
232 void unlock() _NOEXCEPT;
233
234 typedef __libcpp_recursive_mutex_t* native_handle_type;
235
236 _LIBCPP_HIDE_FROM_ABI native_handle_type native_handle() { return &__m_; }
237};
238
239class _LIBCPP_EXPORTED_FROM_ABI timed_mutex {
240 mutex __m_;
241 condition_variable __cv_;
242 bool __locked_;
243
244public:
245 timed_mutex();
246 ~timed_mutex();
247
248 timed_mutex(const timed_mutex&) = delete;
249 timed_mutex& operator=(const timed_mutex&) = delete;
250
251public:
252 void lock();
253 bool try_lock() _NOEXCEPT;
254 template <class _Rep, class _Period>
255 _LIBCPP_HIDE_FROM_ABI bool try_lock_for(const chrono::duration<_Rep, _Period>& __d) {
256 return try_lock_until(chrono::steady_clock::now() + __d);
257 }
258 template <class _Clock, class _Duration>
259 _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS bool
260 try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
261 void unlock() _NOEXCEPT;
262};
263
264template <class _Clock, class _Duration>
265bool timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t) {
266 using namespace chrono;
267 unique_lock<mutex> __lk(__m_);
268 bool __no_timeout = _Clock::now() < __t;
269 while (__no_timeout && __locked_)
270 __no_timeout = __cv_.wait_until(__lk, __t) == cv_status::no_timeout;
271 if (!__locked_) {
272 __locked_ = true;
273 return true;
274 }
275 return false;
276}
277
278class _LIBCPP_EXPORTED_FROM_ABI recursive_timed_mutex {
279 mutex __m_;
280 condition_variable __cv_;
281 size_t __count_;
282 __thread_id __id_;
283
284public:
285 recursive_timed_mutex();
286 ~recursive_timed_mutex();
287
288 recursive_timed_mutex(const recursive_timed_mutex&) = delete;
289 recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete;
290
291 void lock();
292 bool try_lock() _NOEXCEPT;
293 template <class _Rep, class _Period>
294 _LIBCPP_HIDE_FROM_ABI bool try_lock_for(const chrono::duration<_Rep, _Period>& __d) {
295 return try_lock_until(chrono::steady_clock::now() + __d);
296 }
297 template <class _Clock, class _Duration>
298 _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS bool
299 try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
300 void unlock() _NOEXCEPT;
301};
302
303template <class _Clock, class _Duration>
304bool recursive_timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t) {
305 using namespace chrono;
306 __thread_id __id = this_thread::get_id();
307 unique_lock<mutex> __lk(__m_);
308 if (__id == __id_) {
309 if (__count_ == numeric_limits<size_t>::max())
310 return false;
311 ++__count_;
312 return true;
313 }
314 bool __no_timeout = _Clock::now() < __t;
315 while (__no_timeout && __count_ != 0)
316 __no_timeout = __cv_.wait_until(__lk, __t) == cv_status::no_timeout;
317 if (__count_ == 0) {
318 __count_ = 1;
319 __id_ = __id;
320 return true;
321 }
322 return false;
323}
324
325template <class _L0, class _L1>
326_LIBCPP_HIDE_FROM_ABI int try_lock(_L0& __l0, _L1& __l1) {
327 unique_lock<_L0> __u0(__l0, try_to_lock_t());
328 if (__u0.owns_lock()) {
329 if (__l1.try_lock()) {
330 __u0.release();
331 return -1;
332 } else
333 return 1;
334 }
335 return 0;
336}
337
338# ifndef _LIBCPP_CXX03_LANG
339
340template <class _L0, class _L1, class _L2, class... _L3>
341_LIBCPP_HIDE_FROM_ABI int try_lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3) {
342 int __r = 0;
343 unique_lock<_L0> __u0(__l0, try_to_lock);
344 if (__u0.owns_lock()) {
345 __r = std::try_lock(__l1, __l2, __l3...);
346 if (__r == -1)
347 __u0.release();
348 else
349 ++__r;
350 }
351 return __r;
352}
353
354# endif // _LIBCPP_CXX03_LANG
355
356template <class _L0, class _L1>
357_LIBCPP_HIDE_FROM_ABI void lock(_L0& __l0, _L1& __l1) {
358 while (true) {
359 {
360 unique_lock<_L0> __u0(__l0);
361 if (__l1.try_lock()) {
362 __u0.release();
363 break;
364 }
365 }
366 __libcpp_thread_yield();
367 {
368 unique_lock<_L1> __u1(__l1);
369 if (__l0.try_lock()) {
370 __u1.release();
371 break;
372 }
373 }
374 __libcpp_thread_yield();
375 }
376}
377
378# ifndef _LIBCPP_CXX03_LANG
379
380template <class _L0, class _L1, class _L2, class... _L3>
381void __lock_first(int __i, _L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3) {
382 while (true) {
383 switch (__i) {
384 case 0: {
385 unique_lock<_L0> __u0(__l0);
386 __i = std::try_lock(__l1, __l2, __l3...);
387 if (__i == -1) {
388 __u0.release();
389 return;
390 }
391 }
392 ++__i;
393 __libcpp_thread_yield();
394 break;
395 case 1: {
396 unique_lock<_L1> __u1(__l1);
397 __i = std::try_lock(__l2, __l3..., __l0);
398 if (__i == -1) {
399 __u1.release();
400 return;
401 }
402 }
403 if (__i == sizeof...(_L3) + 1)
404 __i = 0;
405 else
406 __i += 2;
407 __libcpp_thread_yield();
408 break;
409 default:
410 std::__lock_first(__i - 2, __l2, __l3..., __l0, __l1);
411 return;
412 }
413 }
414}
415
416template <class _L0, class _L1, class _L2, class... _L3>
417inline _LIBCPP_HIDE_FROM_ABI void lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3) {
418 std::__lock_first(0, __l0, __l1, __l2, __l3...);
419}
420
421# endif // _LIBCPP_CXX03_LANG
422
423# if _LIBCPP_STD_VER >= 17
424template <class... _Mutexes>
425class _LIBCPP_TEMPLATE_VIS scoped_lock;
426
427template <>
428class _LIBCPP_TEMPLATE_VIS scoped_lock<> {
429public:
430 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI explicit scoped_lock() {}
431 ~scoped_lock() = default;
432
433 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI explicit scoped_lock(adopt_lock_t) {}
434
435 scoped_lock(scoped_lock const&) = delete;
436 scoped_lock& operator=(scoped_lock const&) = delete;
437};
438
439template <class _Mutex>
440class _LIBCPP_TEMPLATE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(scoped_lockable) scoped_lock<_Mutex> {
441public:
442 typedef _Mutex mutex_type;
443
444private:
445 mutex_type& __m_;
446
447public:
448 [[nodiscard]]
449 _LIBCPP_HIDE_FROM_ABI explicit scoped_lock(mutex_type& __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
450 : __m_(__m) {
451 __m_.lock();
452 }
453
454 ~scoped_lock() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) { __m_.unlock(); }
455
456 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI explicit scoped_lock(adopt_lock_t, mutex_type& __m)
457 _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
458 : __m_(__m) {}
459
460 scoped_lock(scoped_lock const&) = delete;
461 scoped_lock& operator=(scoped_lock const&) = delete;
462};
463
464template <class... _MArgs>
465class _LIBCPP_TEMPLATE_VIS scoped_lock {
466 static_assert(sizeof...(_MArgs) > 1, "At least 2 lock types required");
467 typedef tuple<_MArgs&...> _MutexTuple;
468
469public:
470 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI explicit scoped_lock(_MArgs&... __margs) : __t_(__margs...) {
471 std::lock(__margs...);
472 }
473
474 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI scoped_lock(adopt_lock_t, _MArgs&... __margs) : __t_(__margs...) {}
475
476 _LIBCPP_HIDE_FROM_ABI ~scoped_lock() {
477 typedef typename __make_tuple_indices<sizeof...(_MArgs)>::type _Indices;
478 __unlock_unpack(_Indices{}, __t_);
479 }
480
481 scoped_lock(scoped_lock const&) = delete;
482 scoped_lock& operator=(scoped_lock const&) = delete;
483
484private:
485 template <size_t... _Indx>
486 _LIBCPP_HIDE_FROM_ABI static void __unlock_unpack(__tuple_indices<_Indx...>, _MutexTuple& __mt) {
487 (std::get<_Indx>(__mt).unlock(), ...);
488 }
489
490 _MutexTuple __t_;
491};
492_LIBCPP_CTAD_SUPPORTED_FOR_TYPE(scoped_lock);
493
494# endif // _LIBCPP_STD_VER >= 17
495#endif // !_LIBCPP_HAS_NO_THREADS
496
497_LIBCPP_END_NAMESPACE_STD
498
499_LIBCPP_POP_MACROS
500
501#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
502# include <atomic>
503# include <concepts>
504# include <cstdlib>
505# include <cstring>
506# include <ctime>
507# include <initializer_list>
508# include <iosfwd>
509# include <new>
510# include <stdexcept>
511# include <system_error>
512# include <type_traits>
513# include <typeinfo>
514#endif
515
516#endif // _LIBCPP_MUTEX
517