1// -*- C++ -*-
2//===--------------------------- mutex ------------------------------------===//
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 {};
90struct try_to_lock_t {};
91struct adopt_lock_t {};
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; // If MutexTypes... consists of the single type Mutex
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 <__config>
190#include <__mutex_base>
191#include <cstdint>
192#include <functional>
193#include <memory>
194#ifndef _LIBCPP_CXX03_LANG
195#include <tuple>
196#endif
197#include <version>
198#include <__threading_support>
199
200#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
201#pragma GCC system_header
202#endif
203
204_LIBCPP_PUSH_MACROS
205#include <__undef_macros>
206
207
208_LIBCPP_BEGIN_NAMESPACE_STD
209
210#ifndef _LIBCPP_HAS_NO_THREADS
211
212class _LIBCPP_TYPE_VIS recursive_mutex
213{
214 __libcpp_recursive_mutex_t __m_;
215
216public:
217 recursive_mutex();
218 ~recursive_mutex();
219
220private:
221 recursive_mutex(const recursive_mutex&); // = delete;
222 recursive_mutex& operator=(const recursive_mutex&); // = delete;
223
224public:
225 void lock();
226 bool try_lock() _NOEXCEPT;
227 void unlock() _NOEXCEPT;
228
229 typedef __libcpp_recursive_mutex_t* native_handle_type;
230
231 _LIBCPP_INLINE_VISIBILITY
232 native_handle_type native_handle() {return &__m_;}
233};
234
235class _LIBCPP_TYPE_VIS timed_mutex
236{
237 mutex __m_;
238 condition_variable __cv_;
239 bool __locked_;
240public:
241 timed_mutex();
242 ~timed_mutex();
243
244private:
245 timed_mutex(const timed_mutex&); // = delete;
246 timed_mutex& operator=(const timed_mutex&); // = delete;
247
248public:
249 void lock();
250 bool try_lock() _NOEXCEPT;
251 template <class _Rep, class _Period>
252 _LIBCPP_INLINE_VISIBILITY
253 bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
254 {return try_lock_until(chrono::steady_clock::now() + __d);}
255 template <class _Clock, class _Duration>
256 _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
257 bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
258 void unlock() _NOEXCEPT;
259};
260
261template <class _Clock, class _Duration>
262bool
263timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
264{
265 using namespace chrono;
266 unique_lock<mutex> __lk(__m_);
267 bool no_timeout = _Clock::now() < __t;
268 while (no_timeout && __locked_)
269 no_timeout = __cv_.wait_until(__lk, __t) == cv_status::no_timeout;
270 if (!__locked_)
271 {
272 __locked_ = true;
273 return true;
274 }
275 return false;
276}
277
278class _LIBCPP_TYPE_VIS recursive_timed_mutex
279{
280 mutex __m_;
281 condition_variable __cv_;
282 size_t __count_;
283 __libcpp_thread_id __id_;
284public:
285 recursive_timed_mutex();
286 ~recursive_timed_mutex();
287
288private:
289 recursive_timed_mutex(const recursive_timed_mutex&); // = delete;
290 recursive_timed_mutex& operator=(const recursive_timed_mutex&); // = delete;
291
292public:
293 void lock();
294 bool try_lock() _NOEXCEPT;
295 template <class _Rep, class _Period>
296 _LIBCPP_INLINE_VISIBILITY
297 bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
298 {return try_lock_until(chrono::steady_clock::now() + __d);}
299 template <class _Clock, class _Duration>
300 _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
301 bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
302 void unlock() _NOEXCEPT;
303};
304
305template <class _Clock, class _Duration>
306bool
307recursive_timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
308{
309 using namespace chrono;
310 __libcpp_thread_id __id = __libcpp_thread_get_current_id();
311 unique_lock<mutex> lk(__m_);
312 if (__libcpp_thread_id_equal(__id, __id_))
313 {
314 if (__count_ == numeric_limits<size_t>::max())
315 return false;
316 ++__count_;
317 return true;
318 }
319 bool no_timeout = _Clock::now() < __t;
320 while (no_timeout && __count_ != 0)
321 no_timeout = __cv_.wait_until(lk, __t) == cv_status::no_timeout;
322 if (__count_ == 0)
323 {
324 __count_ = 1;
325 __id_ = __id;
326 return true;
327 }
328 return false;
329}
330
331template <class _L0, class _L1>
332int
333try_lock(_L0& __l0, _L1& __l1)
334{
335 unique_lock<_L0> __u0(__l0, try_to_lock);
336 if (__u0.owns_lock())
337 {
338 if (__l1.try_lock())
339 {
340 __u0.release();
341 return -1;
342 }
343 else
344 return 1;
345 }
346 return 0;
347}
348
349#ifndef _LIBCPP_CXX03_LANG
350
351template <class _L0, class _L1, class _L2, class... _L3>
352int
353try_lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3)
354{
355 int __r = 0;
356 unique_lock<_L0> __u0(__l0, try_to_lock);
357 if (__u0.owns_lock())
358 {
359 __r = try_lock(__l1, __l2, __l3...);
360 if (__r == -1)
361 __u0.release();
362 else
363 ++__r;
364 }
365 return __r;
366}
367
368#endif // _LIBCPP_CXX03_LANG
369
370template <class _L0, class _L1>
371void
372lock(_L0& __l0, _L1& __l1)
373{
374 while (true)
375 {
376 {
377 unique_lock<_L0> __u0(__l0);
378 if (__l1.try_lock())
379 {
380 __u0.release();
381 break;
382 }
383 }
384 __libcpp_thread_yield();
385 {
386 unique_lock<_L1> __u1(__l1);
387 if (__l0.try_lock())
388 {
389 __u1.release();
390 break;
391 }
392 }
393 __libcpp_thread_yield();
394 }
395}
396
397#ifndef _LIBCPP_CXX03_LANG
398
399template <class _L0, class _L1, class _L2, class ..._L3>
400void
401__lock_first(int __i, _L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3)
402{
403 while (true)
404 {
405 switch (__i)
406 {
407 case 0:
408 {
409 unique_lock<_L0> __u0(__l0);
410 __i = try_lock(__l1, __l2, __l3...);
411 if (__i == -1)
412 {
413 __u0.release();
414 return;
415 }
416 }
417 ++__i;
418 __libcpp_thread_yield();
419 break;
420 case 1:
421 {
422 unique_lock<_L1> __u1(__l1);
423 __i = try_lock(__l2, __l3..., __l0);
424 if (__i == -1)
425 {
426 __u1.release();
427 return;
428 }
429 }
430 if (__i == sizeof...(_L3) + 1)
431 __i = 0;
432 else
433 __i += 2;
434 __libcpp_thread_yield();
435 break;
436 default:
437 __lock_first(__i - 2, __l2, __l3..., __l0, __l1);
438 return;
439 }
440 }
441}
442
443template <class _L0, class _L1, class _L2, class ..._L3>
444inline _LIBCPP_INLINE_VISIBILITY
445void
446lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3)
447{
448 __lock_first(0, __l0, __l1, __l2, __l3...);
449}
450
451template <class _L0>
452inline _LIBCPP_INLINE_VISIBILITY
453void __unlock(_L0& __l0) {
454 __l0.unlock();
455}
456
457template <class _L0, class _L1>
458inline _LIBCPP_INLINE_VISIBILITY
459void __unlock(_L0& __l0, _L1& __l1) {
460 __l0.unlock();
461 __l1.unlock();
462}
463
464template <class _L0, class _L1, class _L2, class ..._L3>
465inline _LIBCPP_INLINE_VISIBILITY
466void __unlock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3) {
467 __l0.unlock();
468 __l1.unlock();
469 _VSTD::__unlock(__l2, __l3...);
470}
471
472#endif // _LIBCPP_CXX03_LANG
473
474#if _LIBCPP_STD_VER > 14
475template <class ..._Mutexes>
476class _LIBCPP_TEMPLATE_VIS scoped_lock;
477
478template <>
479class _LIBCPP_TEMPLATE_VIS scoped_lock<> {
480public:
481 explicit scoped_lock() {}
482 ~scoped_lock() = default;
483
484 _LIBCPP_INLINE_VISIBILITY
485 explicit scoped_lock(adopt_lock_t) {}
486
487 scoped_lock(scoped_lock const&) = delete;
488 scoped_lock& operator=(scoped_lock const&) = delete;
489};
490
491template <class _Mutex>
492class _LIBCPP_TEMPLATE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(scoped_lockable) scoped_lock<_Mutex> {
493public:
494 typedef _Mutex mutex_type;
495private:
496 mutex_type& __m_;
497public:
498 explicit scoped_lock(mutex_type & __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
499 : __m_(__m) {__m_.lock();}
500
501 ~scoped_lock() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) {__m_.unlock();}
502
503 _LIBCPP_INLINE_VISIBILITY
504 explicit scoped_lock(adopt_lock_t, mutex_type& __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
505 : __m_(__m) {}
506
507 scoped_lock(scoped_lock const&) = delete;
508 scoped_lock& operator=(scoped_lock const&) = delete;
509};
510
511template <class ..._MArgs>
512class _LIBCPP_TEMPLATE_VIS scoped_lock
513{
514 static_assert(sizeof...(_MArgs) > 1, "At least 2 lock types required");
515 typedef tuple<_MArgs&...> _MutexTuple;
516
517public:
518 _LIBCPP_INLINE_VISIBILITY
519 explicit scoped_lock(_MArgs&... __margs)
520 : __t_(__margs...)
521 {
522 _VSTD::lock(__margs...);
523 }
524
525 _LIBCPP_INLINE_VISIBILITY
526 scoped_lock(adopt_lock_t, _MArgs&... __margs)
527 : __t_(__margs...)
528 {
529 }
530
531 _LIBCPP_INLINE_VISIBILITY
532 ~scoped_lock() {
533 typedef typename __make_tuple_indices<sizeof...(_MArgs)>::type _Indices;
534 __unlock_unpack(_Indices{}, __t_);
535 }
536
537 scoped_lock(scoped_lock const&) = delete;
538 scoped_lock& operator=(scoped_lock const&) = delete;
539
540private:
541 template <size_t ..._Indx>
542 _LIBCPP_INLINE_VISIBILITY
543 static void __unlock_unpack(__tuple_indices<_Indx...>, _MutexTuple& __mt) {
544 _VSTD::__unlock(_VSTD::get<_Indx>(__mt)...);
545 }
546
547 _MutexTuple __t_;
548};
549
550#endif // _LIBCPP_STD_VER > 14
551#endif // !_LIBCPP_HAS_NO_THREADS
552
553struct _LIBCPP_TEMPLATE_VIS once_flag;
554
555#ifndef _LIBCPP_CXX03_LANG
556
557template<class _Callable, class... _Args>
558_LIBCPP_INLINE_VISIBILITY
559void call_once(once_flag&, _Callable&&, _Args&&...);
560
561#else // _LIBCPP_CXX03_LANG
562
563template<class _Callable>
564_LIBCPP_INLINE_VISIBILITY
565void call_once(once_flag&, _Callable&);
566
567template<class _Callable>
568_LIBCPP_INLINE_VISIBILITY
569void call_once(once_flag&, const _Callable&);
570
571#endif // _LIBCPP_CXX03_LANG
572
573struct _LIBCPP_TEMPLATE_VIS once_flag
574{
575 _LIBCPP_INLINE_VISIBILITY
576 _LIBCPP_CONSTEXPR
577 once_flag() _NOEXCEPT : __state_(0) {}
578
579#if defined(_LIBCPP_ABI_MICROSOFT)
580 typedef uintptr_t _State_type;
581#else
582 typedef unsigned long _State_type;
583#endif
584
585
586private:
587 once_flag(const once_flag&); // = delete;
588 once_flag& operator=(const once_flag&); // = delete;
589
590 _State_type __state_;
591
592#ifndef _LIBCPP_CXX03_LANG
593 template<class _Callable, class... _Args>
594 friend
595 void call_once(once_flag&, _Callable&&, _Args&&...);
596#else // _LIBCPP_CXX03_LANG
597 template<class _Callable>
598 friend
599 void call_once(once_flag&, _Callable&);
600
601 template<class _Callable>
602 friend
603 void call_once(once_flag&, const _Callable&);
604#endif // _LIBCPP_CXX03_LANG
605};
606
607#ifndef _LIBCPP_CXX03_LANG
608
609template <class _Fp>
610class __call_once_param
611{
612 _Fp& __f_;
613public:
614 _LIBCPP_INLINE_VISIBILITY
615 explicit __call_once_param(_Fp& __f) : __f_(__f) {}
616
617 _LIBCPP_INLINE_VISIBILITY
618 void operator()()
619 {
620 typedef typename __make_tuple_indices<tuple_size<_Fp>::value, 1>::type _Index;
621 __execute(_Index());
622 }
623
624private:
625 template <size_t ..._Indices>
626 _LIBCPP_INLINE_VISIBILITY
627 void __execute(__tuple_indices<_Indices...>)
628 {
629 __invoke(_VSTD::get<0>(_VSTD::move(__f_)), _VSTD::get<_Indices>(_VSTD::move(__f_))...);
630 }
631};
632
633#else
634
635template <class _Fp>
636class __call_once_param
637{
638 _Fp& __f_;
639public:
640 _LIBCPP_INLINE_VISIBILITY
641 explicit __call_once_param(_Fp& __f) : __f_(__f) {}
642
643 _LIBCPP_INLINE_VISIBILITY
644 void operator()()
645 {
646 __f_();
647 }
648};
649
650#endif
651
652template <class _Fp>
653void
654__call_once_proxy(void* __vp)
655{
656 __call_once_param<_Fp>* __p = static_cast<__call_once_param<_Fp>*>(__vp);
657 (*__p)();
658}
659
660_LIBCPP_FUNC_VIS void __call_once(volatile once_flag::_State_type&, void*,
661 void (*)(void*));
662
663#ifndef _LIBCPP_CXX03_LANG
664
665template<class _Callable, class... _Args>
666inline _LIBCPP_INLINE_VISIBILITY
667void
668call_once(once_flag& __flag, _Callable&& __func, _Args&&... __args)
669{
670 if (__libcpp_acquire_load(&__flag.__state_) != ~once_flag::_State_type(0))
671 {
672 typedef tuple<_Callable&&, _Args&&...> _Gp;
673 _Gp __f(_VSTD::forward<_Callable>(__func), _VSTD::forward<_Args>(__args)...);
674 __call_once_param<_Gp> __p(__f);
675 __call_once(__flag.__state_, &__p, &__call_once_proxy<_Gp>);
676 }
677}
678
679#else // _LIBCPP_CXX03_LANG
680
681template<class _Callable>
682inline _LIBCPP_INLINE_VISIBILITY
683void
684call_once(once_flag& __flag, _Callable& __func)
685{
686 if (__libcpp_acquire_load(&__flag.__state_) != ~once_flag::_State_type(0))
687 {
688 __call_once_param<_Callable> __p(__func);
689 __call_once(__flag.__state_, &__p, &__call_once_proxy<_Callable>);
690 }
691}
692
693template<class _Callable>
694inline _LIBCPP_INLINE_VISIBILITY
695void
696call_once(once_flag& __flag, const _Callable& __func)
697{
698 if (__libcpp_acquire_load(&__flag.__state_) != ~once_flag::_State_type(0))
699 {
700 __call_once_param<const _Callable> __p(__func);
701 __call_once(__flag.__state_, &__p, &__call_once_proxy<const _Callable>);
702 }
703}
704
705#endif // _LIBCPP_CXX03_LANG
706
707_LIBCPP_END_NAMESPACE_STD
708
709_LIBCPP_POP_MACROS
710
711#endif // _LIBCPP_MUTEX
712