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1// -*- C++ -*-
2//===--------------------------- mutex ------------------------------------===//
3//
4// The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_MUTEX
12#define _LIBCPP_MUTEX
13
14/*
15 mutex synopsis
16
17namespace std
18{
19
20class mutex
21{
22public:
23 constexpr mutex() noexcept;
24 ~mutex();
25
26 mutex(const mutex&) = delete;
27 mutex& operator=(const mutex&) = delete;
28
29 void lock();
30 bool try_lock();
31 void unlock();
32
33 typedef pthread_mutex_t* native_handle_type;
34 native_handle_type native_handle();
35};
36
37class recursive_mutex
38{
39public:
40 recursive_mutex();
41 ~recursive_mutex();
42
43 recursive_mutex(const recursive_mutex&) = delete;
44 recursive_mutex& operator=(const recursive_mutex&) = delete;
45
46 void lock();
47 bool try_lock() noexcept;
48 void unlock();
49
50 typedef pthread_mutex_t* native_handle_type;
51 native_handle_type native_handle();
52};
53
54class timed_mutex
55{
56public:
57 timed_mutex();
58 ~timed_mutex();
59
60 timed_mutex(const timed_mutex&) = delete;
61 timed_mutex& operator=(const timed_mutex&) = delete;
62
63 void lock();
64 bool try_lock();
65 template <class Rep, class Period>
66 bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
67 template <class Clock, class Duration>
68 bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
69 void unlock();
70};
71
72class recursive_timed_mutex
73{
74public:
75 recursive_timed_mutex();
76 ~recursive_timed_mutex();
77
78 recursive_timed_mutex(const recursive_timed_mutex&) = delete;
79 recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete;
80
81 void lock();
82 bool try_lock() noexcept;
83 template <class Rep, class Period>
84 bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
85 template <class Clock, class Duration>
86 bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
87 void unlock();
88};
89
90struct defer_lock_t {};
91struct try_to_lock_t {};
92struct adopt_lock_t {};
93
94constexpr defer_lock_t defer_lock{};
95constexpr try_to_lock_t try_to_lock{};
96constexpr adopt_lock_t adopt_lock{};
97
98template <class Mutex>
99class lock_guard
100{
101public:
102 typedef Mutex mutex_type;
103
104 explicit lock_guard(mutex_type& m);
105 lock_guard(mutex_type& m, adopt_lock_t);
106 ~lock_guard();
107
108 lock_guard(lock_guard const&) = delete;
109 lock_guard& operator=(lock_guard const&) = delete;
110};
111
112template <class... MutexTypes>
113class scoped_lock // C++17
114{
115public:
116 using mutex_type = Mutex; // If MutexTypes... consists of the single type Mutex
117
118 explicit scoped_lock(MutexTypes&... m);
119 scoped_lock(MutexTypes&... m, adopt_lock_t);
120 ~scoped_lock();
121 scoped_lock(scoped_lock const&) = delete;
122 scoped_lock& operator=(scoped_lock const&) = delete;
123private:
124 tuple<MutexTypes&...> pm; // exposition only
125};
126
127template <class Mutex>
128class unique_lock
129{
130public:
131 typedef Mutex mutex_type;
132 unique_lock() noexcept;
133 explicit unique_lock(mutex_type& m);
134 unique_lock(mutex_type& m, defer_lock_t) noexcept;
135 unique_lock(mutex_type& m, try_to_lock_t);
136 unique_lock(mutex_type& m, adopt_lock_t);
137 template <class Clock, class Duration>
138 unique_lock(mutex_type& m, const chrono::time_point<Clock, Duration>& abs_time);
139 template <class Rep, class Period>
140 unique_lock(mutex_type& m, const chrono::duration<Rep, Period>& rel_time);
141 ~unique_lock();
142
143 unique_lock(unique_lock const&) = delete;
144 unique_lock& operator=(unique_lock const&) = delete;
145
146 unique_lock(unique_lock&& u) noexcept;
147 unique_lock& operator=(unique_lock&& u) noexcept;
148
149 void lock();
150 bool try_lock();
151
152 template <class Rep, class Period>
153 bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
154 template <class Clock, class Duration>
155 bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
156
157 void unlock();
158
159 void swap(unique_lock& u) noexcept;
160 mutex_type* release() noexcept;
161
162 bool owns_lock() const noexcept;
163 explicit operator bool () const noexcept;
164 mutex_type* mutex() const noexcept;
165};
166
167template <class Mutex>
168 void swap(unique_lock<Mutex>& x, unique_lock<Mutex>& y) noexcept;
169
170template <class L1, class L2, class... L3>
171 int try_lock(L1&, L2&, L3&...);
172template <class L1, class L2, class... L3>
173 void lock(L1&, L2&, L3&...);
174
175struct once_flag
176{
177 constexpr once_flag() noexcept;
178
179 once_flag(const once_flag&) = delete;
180 once_flag& operator=(const once_flag&) = delete;
181};
182
183template<class Callable, class ...Args>
184 void call_once(once_flag& flag, Callable&& func, Args&&... args);
185
186} // std
187
188*/
189
190#include <__config>
191#include <__mutex_base>
192#include <functional>
193#include <memory>
194#ifndef _LIBCPP_CXX03_LANG
195#include <tuple>
196#endif
197#include <__threading_support>
198
199#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
200#pragma GCC system_header
201#endif
202
203_LIBCPP_PUSH_MACROS
204#include <__undef_macros>
205
206
207_LIBCPP_BEGIN_NAMESPACE_STD
208
209#ifndef _LIBCPP_HAS_NO_THREADS
210
211class _LIBCPP_TYPE_VIS recursive_mutex
212{
213 __libcpp_recursive_mutex_t __m_;
214
215public:
216 recursive_mutex();
217 ~recursive_mutex();
218
219private:
220 recursive_mutex(const recursive_mutex&); // = delete;
221 recursive_mutex& operator=(const recursive_mutex&); // = delete;
222
223public:
224 void lock();
225 bool try_lock() _NOEXCEPT;
226 void unlock() _NOEXCEPT;
227
228 typedef __libcpp_recursive_mutex_t* native_handle_type;
229
230 _LIBCPP_INLINE_VISIBILITY
231 native_handle_type native_handle() {return &__m_;}
232};
233
234class _LIBCPP_TYPE_VIS timed_mutex
235{
236 mutex __m_;
237 condition_variable __cv_;
238 bool __locked_;
239public:
240 timed_mutex();
241 ~timed_mutex();
242
243private:
244 timed_mutex(const timed_mutex&); // = delete;
245 timed_mutex& operator=(const timed_mutex&); // = delete;
246
247public:
248 void lock();
249 bool try_lock() _NOEXCEPT;
250 template <class _Rep, class _Period>
251 _LIBCPP_INLINE_VISIBILITY
252 bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
253 {return try_lock_until(chrono::steady_clock::now() + __d);}
254 template <class _Clock, class _Duration>
255 _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
256 bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
257 void unlock() _NOEXCEPT;
258};
259
260template <class _Clock, class _Duration>
261bool
262timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
263{
264 using namespace chrono;
265 unique_lock<mutex> __lk(__m_);
266 bool no_timeout = _Clock::now() < __t;
267 while (no_timeout && __locked_)
268 no_timeout = __cv_.wait_until(__lk, __t) == cv_status::no_timeout;
269 if (!__locked_)
270 {
271 __locked_ = true;
272 return true;
273 }
274 return false;
275}
276
277class _LIBCPP_TYPE_VIS recursive_timed_mutex
278{
279 mutex __m_;
280 condition_variable __cv_;
281 size_t __count_;
282 __libcpp_thread_id __id_;
283public:
284 recursive_timed_mutex();
285 ~recursive_timed_mutex();
286
287private:
288 recursive_timed_mutex(const recursive_timed_mutex&); // = delete;
289 recursive_timed_mutex& operator=(const recursive_timed_mutex&); // = delete;
290
291public:
292 void lock();
293 bool try_lock() _NOEXCEPT;
294 template <class _Rep, class _Period>
295 _LIBCPP_INLINE_VISIBILITY
296 bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
297 {return try_lock_until(chrono::steady_clock::now() + __d);}
298 template <class _Clock, class _Duration>
299 _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
300 bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
301 void unlock() _NOEXCEPT;
302};
303
304template <class _Clock, class _Duration>
305bool
306recursive_timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
307{
308 using namespace chrono;
309 __libcpp_thread_id __id = __libcpp_thread_get_current_id();
310 unique_lock<mutex> lk(__m_);
311 if (__libcpp_thread_id_equal(__id, __id_))
312 {
313 if (__count_ == numeric_limits<size_t>::max())
314 return false;
315 ++__count_;
316 return true;
317 }
318 bool no_timeout = _Clock::now() < __t;
319 while (no_timeout && __count_ != 0)
320 no_timeout = __cv_.wait_until(lk, __t) == cv_status::no_timeout;
321 if (__count_ == 0)
322 {
323 __count_ = 1;
324 __id_ = __id;
325 return true;
326 }
327 return false;
328}
329
330template <class _L0, class _L1>
331int
332try_lock(_L0& __l0, _L1& __l1)
333{
334 unique_lock<_L0> __u0(__l0, try_to_lock);
335 if (__u0.owns_lock())
336 {
337 if (__l1.try_lock())
338 {
339 __u0.release();
340 return -1;
341 }
342 else
343 return 1;
344 }
345 return 0;
346}
347
348#ifndef _LIBCPP_CXX03_LANG
349
350template <class _L0, class _L1, class _L2, class... _L3>
351int
352try_lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3)
353{
354 int __r = 0;
355 unique_lock<_L0> __u0(__l0, try_to_lock);
356 if (__u0.owns_lock())
357 {
358 __r = try_lock(__l1, __l2, __l3...);
359 if (__r == -1)
360 __u0.release();
361 else
362 ++__r;
363 }
364 return __r;
365}
366
367#endif // _LIBCPP_CXX03_LANG
368
369template <class _L0, class _L1>
370void
371lock(_L0& __l0, _L1& __l1)
372{
373 while (true)
374 {
375 {
376 unique_lock<_L0> __u0(__l0);
377 if (__l1.try_lock())
378 {
379 __u0.release();
380 break;
381 }
382 }
383 __libcpp_thread_yield();
384 {
385 unique_lock<_L1> __u1(__l1);
386 if (__l0.try_lock())
387 {
388 __u1.release();
389 break;
390 }
391 }
392 __libcpp_thread_yield();
393 }
394}
395
396#ifndef _LIBCPP_CXX03_LANG
397
398template <class _L0, class _L1, class _L2, class ..._L3>
399void
400__lock_first(int __i, _L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3)
401{
402 while (true)
403 {
404 switch (__i)
405 {
406 case 0:
407 {
408 unique_lock<_L0> __u0(__l0);
409 __i = try_lock(__l1, __l2, __l3...);
410 if (__i == -1)
411 {
412 __u0.release();
413 return;
414 }
415 }
416 ++__i;
417 __libcpp_thread_yield();
418 break;
419 case 1:
420 {
421 unique_lock<_L1> __u1(__l1);
422 __i = try_lock(__l2, __l3..., __l0);
423 if (__i == -1)
424 {
425 __u1.release();
426 return;
427 }
428 }
429 if (__i == sizeof...(_L3) + 1)
430 __i = 0;
431 else
432 __i += 2;
433 __libcpp_thread_yield();
434 break;
435 default:
436 __lock_first(__i - 2, __l2, __l3..., __l0, __l1);
437 return;
438 }
439 }
440}
441
442template <class _L0, class _L1, class _L2, class ..._L3>
443inline _LIBCPP_INLINE_VISIBILITY
444void
445lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3)
446{
447 __lock_first(0, __l0, __l1, __l2, __l3...);
448}
449
450template <class _L0>
451inline _LIBCPP_INLINE_VISIBILITY
452void __unlock(_L0& __l0) {
453 __l0.unlock();
454}
455
456template <class _L0, class _L1>
457inline _LIBCPP_INLINE_VISIBILITY
458void __unlock(_L0& __l0, _L1& __l1) {
459 __l0.unlock();
460 __l1.unlock();
461}
462
463template <class _L0, class _L1, class _L2, class ..._L3>
464inline _LIBCPP_INLINE_VISIBILITY
465void __unlock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3) {
466 __l0.unlock();
467 __l1.unlock();
468 _VSTD::__unlock(__l2, __l3...);
469}
470
471#endif // _LIBCPP_CXX03_LANG
472
473#if _LIBCPP_STD_VER > 14
474template <class ..._Mutexes>
475class _LIBCPP_TEMPLATE_VIS scoped_lock;
476
477template <>
478class _LIBCPP_TEMPLATE_VIS scoped_lock<> {
479public:
480 explicit scoped_lock() {}
481 ~scoped_lock() = default;
482
483 _LIBCPP_INLINE_VISIBILITY
484 explicit scoped_lock(adopt_lock_t) {}
485
486 scoped_lock(scoped_lock const&) = delete;
487 scoped_lock& operator=(scoped_lock const&) = delete;
488};
489
490template <class _Mutex>
491class _LIBCPP_TEMPLATE_VIS scoped_lock<_Mutex> {
492public:
493 typedef _Mutex mutex_type;
494private:
495 mutex_type& __m_;
496public:
497 explicit scoped_lock(mutex_type & __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
498 : __m_(__m) {__m_.lock();}
499
500 ~scoped_lock() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) {__m_.unlock();}
501
502 _LIBCPP_INLINE_VISIBILITY
503 explicit scoped_lock(mutex_type& __m, adopt_lock_t) _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
504 : __m_(__m) {}
505
506 scoped_lock(scoped_lock const&) = delete;
507 scoped_lock& operator=(scoped_lock const&) = delete;
508};
509
510template <class ..._MArgs>
511class _LIBCPP_TEMPLATE_VIS scoped_lock
512{
513 static_assert(sizeof...(_MArgs) > 1, "At least 2 lock types required");
514 typedef tuple<_MArgs&...> _MutexTuple;
515
516public:
517 _LIBCPP_INLINE_VISIBILITY
518 explicit scoped_lock(_MArgs&... __margs)
519 : __t_(__margs...)
520 {
521 _VSTD::lock(__margs...);
522 }
523
524 _LIBCPP_INLINE_VISIBILITY
525 scoped_lock(_MArgs&... __margs, adopt_lock_t)
526 : __t_(__margs...)
527 {
528 }
529
530 _LIBCPP_INLINE_VISIBILITY
531 ~scoped_lock() {
532 typedef typename __make_tuple_indices<sizeof...(_MArgs)>::type _Indices;
533 __unlock_unpack(_Indices{}, __t_);
534 }
535
536 scoped_lock(scoped_lock const&) = delete;
537 scoped_lock& operator=(scoped_lock const&) = delete;
538
539private:
540 template <size_t ..._Indx>
541 _LIBCPP_INLINE_VISIBILITY
542 static void __unlock_unpack(__tuple_indices<_Indx...>, _MutexTuple& __mt) {
543 _VSTD::__unlock(_VSTD::get<_Indx>(__mt)...);
544 }
545
546 _MutexTuple __t_;
547};
548
549#endif // _LIBCPP_STD_VER > 14
550#endif // !_LIBCPP_HAS_NO_THREADS
551
552struct _LIBCPP_TEMPLATE_VIS once_flag;
553
554#ifndef _LIBCPP_CXX03_LANG
555
556template<class _Callable, class... _Args>
557_LIBCPP_INLINE_VISIBILITY
558void call_once(once_flag&, _Callable&&, _Args&&...);
559
560#else // _LIBCPP_CXX03_LANG
561
562template<class _Callable>
563_LIBCPP_INLINE_VISIBILITY
564void call_once(once_flag&, _Callable&);
565
566template<class _Callable>
567_LIBCPP_INLINE_VISIBILITY
568void call_once(once_flag&, const _Callable&);
569
570#endif // _LIBCPP_CXX03_LANG
571
572struct _LIBCPP_TEMPLATE_VIS once_flag
573{
574 _LIBCPP_INLINE_VISIBILITY
575 _LIBCPP_CONSTEXPR
576 once_flag() _NOEXCEPT : __state_(0) {}
577
578private:
579 once_flag(const once_flag&); // = delete;
580 once_flag& operator=(const once_flag&); // = delete;
581
582 unsigned long __state_;
583
584#ifndef _LIBCPP_CXX03_LANG
585 template<class _Callable, class... _Args>
586 friend
587 void call_once(once_flag&, _Callable&&, _Args&&...);
588#else // _LIBCPP_CXX03_LANG
589 template<class _Callable>
590 friend
591 void call_once(once_flag&, _Callable&);
592
593 template<class _Callable>
594 friend
595 void call_once(once_flag&, const _Callable&);
596#endif // _LIBCPP_CXX03_LANG
597};
598
599#ifndef _LIBCPP_CXX03_LANG
600
601template <class _Fp>
602class __call_once_param
603{
604 _Fp& __f_;
605public:
606 _LIBCPP_INLINE_VISIBILITY
607 explicit __call_once_param(_Fp& __f) : __f_(__f) {}
608
609 _LIBCPP_INLINE_VISIBILITY
610 void operator()()
611 {
612 typedef typename __make_tuple_indices<tuple_size<_Fp>::value, 1>::type _Index;
613 __execute(_Index());
614 }
615
616private:
617 template <size_t ..._Indices>
618 _LIBCPP_INLINE_VISIBILITY
619 void __execute(__tuple_indices<_Indices...>)
620 {
621 __invoke(_VSTD::get<0>(_VSTD::move(__f_)), _VSTD::get<_Indices>(_VSTD::move(__f_))...);
622 }
623};
624
625#else
626
627template <class _Fp>
628class __call_once_param
629{
630 _Fp& __f_;
631public:
632 _LIBCPP_INLINE_VISIBILITY
633 explicit __call_once_param(_Fp& __f) : __f_(__f) {}
634
635 _LIBCPP_INLINE_VISIBILITY
636 void operator()()
637 {
638 __f_();
639 }
640};
641
642#endif
643
644template <class _Fp>
645void
646__call_once_proxy(void* __vp)
647{
648 __call_once_param<_Fp>* __p = static_cast<__call_once_param<_Fp>*>(__vp);
649 (*__p)();
650}
651
652_LIBCPP_FUNC_VIS void __call_once(volatile unsigned long&, void*, void(*)(void*));
653
654#ifndef _LIBCPP_CXX03_LANG
655
656template<class _Callable, class... _Args>
657inline _LIBCPP_INLINE_VISIBILITY
658void
659call_once(once_flag& __flag, _Callable&& __func, _Args&&... __args)
660{
661 if (__libcpp_acquire_load(&__flag.__state_) != ~0ul)
662 {
663 typedef tuple<_Callable&&, _Args&&...> _Gp;
664 _Gp __f(_VSTD::forward<_Callable>(__func), _VSTD::forward<_Args>(__args)...);
665 __call_once_param<_Gp> __p(__f);
666 __call_once(__flag.__state_, &__p, &__call_once_proxy<_Gp>);
667 }
668}
669
670#else // _LIBCPP_CXX03_LANG
671
672template<class _Callable>
673inline _LIBCPP_INLINE_VISIBILITY
674void
675call_once(once_flag& __flag, _Callable& __func)
676{
677 if (__libcpp_acquire_load(&__flag.__state_) != ~0ul)
678 {
679 __call_once_param<_Callable> __p(__func);
680 __call_once(__flag.__state_, &__p, &__call_once_proxy<_Callable>);
681 }
682}
683
684template<class _Callable>
685inline _LIBCPP_INLINE_VISIBILITY
686void
687call_once(once_flag& __flag, const _Callable& __func)
688{
689 if (__libcpp_acquire_load(&__flag.__state_) != ~0ul)
690 {
691 __call_once_param<const _Callable> __p(__func);
692 __call_once(__flag.__state_, &__p, &__call_once_proxy<const _Callable>);
693 }
694}
695
696#endif // _LIBCPP_CXX03_LANG
697
698_LIBCPP_END_NAMESPACE_STD
699
700_LIBCPP_POP_MACROS
701
702#endif // _LIBCPP_MUTEX