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_BASE
11#define _LIBCPP___MUTEX_BASE
12
13#include <__config>
14#include <chrono>
15#include <system_error>
16#include <__threading_support>
17
18
19#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
20#pragma GCC system_header
21#endif
22
23_LIBCPP_PUSH_MACROS
24#include <__undef_macros>
25
26
27_LIBCPP_BEGIN_NAMESPACE_STD
28
29#ifndef _LIBCPP_HAS_NO_THREADS
30
31#ifndef _LIBCPP_THREAD_SAFETY_ANNOTATION
32# ifdef _LIBCPP_HAS_THREAD_SAFETY_ANNOTATIONS
33# define _LIBCPP_THREAD_SAFETY_ANNOTATION(x) __attribute__((x))
34# else
35# define _LIBCPP_THREAD_SAFETY_ANNOTATION(x)
36# endif
37#endif // _LIBCPP_THREAD_SAFETY_ANNOTATION
38
39
40class _LIBCPP_TYPE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(capability("mutex")) mutex
41{
42 __libcpp_mutex_t __m_ = _LIBCPP_MUTEX_INITIALIZER;
43
44public:
45 _LIBCPP_INLINE_VISIBILITY
46 _LIBCPP_CONSTEXPR mutex() = default;
47
48 mutex(const mutex&) = delete;
49 mutex& operator=(const mutex&) = delete;
50
51#if defined(_LIBCPP_HAS_TRIVIAL_MUTEX_DESTRUCTION)
52 ~mutex() = default;
53#else
54 ~mutex() _NOEXCEPT;
55#endif
56
57 void lock() _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability());
58 bool try_lock() _NOEXCEPT _LIBCPP_THREAD_SAFETY_ANNOTATION(try_acquire_capability(true));
59 void unlock() _NOEXCEPT _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability());
60
61 typedef __libcpp_mutex_t* native_handle_type;
62 _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() {return &__m_;}
63};
64
65static_assert(is_nothrow_default_constructible<mutex>::value,
66 "the default constructor for std::mutex must be nothrow");
67
68struct _LIBCPP_TYPE_VIS defer_lock_t {};
69struct _LIBCPP_TYPE_VIS try_to_lock_t {};
70struct _LIBCPP_TYPE_VIS adopt_lock_t {};
71
72#if defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)
73
74extern _LIBCPP_EXPORTED_FROM_ABI const defer_lock_t defer_lock;
75extern _LIBCPP_EXPORTED_FROM_ABI const try_to_lock_t try_to_lock;
76extern _LIBCPP_EXPORTED_FROM_ABI const adopt_lock_t adopt_lock;
77
78#else
79
80/* _LIBCPP_INLINE_VAR */ constexpr defer_lock_t defer_lock = defer_lock_t();
81/* _LIBCPP_INLINE_VAR */ constexpr try_to_lock_t try_to_lock = try_to_lock_t();
82/* _LIBCPP_INLINE_VAR */ constexpr adopt_lock_t adopt_lock = adopt_lock_t();
83
84#endif
85
86template <class _Mutex>
87class _LIBCPP_TEMPLATE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(scoped_lockable)
88lock_guard
89{
90public:
91 typedef _Mutex mutex_type;
92
93private:
94 mutex_type& __m_;
95public:
96
97 _LIBCPP_INLINE_VISIBILITY
98 explicit lock_guard(mutex_type& __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
99 : __m_(__m) {__m_.lock();}
100 _LIBCPP_INLINE_VISIBILITY
101 lock_guard(mutex_type& __m, adopt_lock_t) _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
102 : __m_(__m) {}
103 _LIBCPP_INLINE_VISIBILITY
104 ~lock_guard() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) {__m_.unlock();}
105
106private:
107 lock_guard(lock_guard const&) _LIBCPP_EQUAL_DELETE;
108 lock_guard& operator=(lock_guard const&) _LIBCPP_EQUAL_DELETE;
109};
110
111template <class _Mutex>
112class _LIBCPP_TEMPLATE_VIS unique_lock
113{
114public:
115 typedef _Mutex mutex_type;
116
117private:
118 mutex_type* __m_;
119 bool __owns_;
120
121public:
122 _LIBCPP_INLINE_VISIBILITY
123 unique_lock() _NOEXCEPT : __m_(nullptr), __owns_(false) {}
124 _LIBCPP_INLINE_VISIBILITY
125 explicit unique_lock(mutex_type& __m)
126 : __m_(_VSTD::addressof(__m)), __owns_(true) {__m_->lock();}
127 _LIBCPP_INLINE_VISIBILITY
128 unique_lock(mutex_type& __m, defer_lock_t) _NOEXCEPT
129 : __m_(_VSTD::addressof(__m)), __owns_(false) {}
130 _LIBCPP_INLINE_VISIBILITY
131 unique_lock(mutex_type& __m, try_to_lock_t)
132 : __m_(_VSTD::addressof(__m)), __owns_(__m.try_lock()) {}
133 _LIBCPP_INLINE_VISIBILITY
134 unique_lock(mutex_type& __m, adopt_lock_t)
135 : __m_(_VSTD::addressof(__m)), __owns_(true) {}
136 template <class _Clock, class _Duration>
137 _LIBCPP_INLINE_VISIBILITY
138 unique_lock(mutex_type& __m, const chrono::time_point<_Clock, _Duration>& __t)
139 : __m_(_VSTD::addressof(__m)), __owns_(__m.try_lock_until(__t)) {}
140 template <class _Rep, class _Period>
141 _LIBCPP_INLINE_VISIBILITY
142 unique_lock(mutex_type& __m, const chrono::duration<_Rep, _Period>& __d)
143 : __m_(_VSTD::addressof(__m)), __owns_(__m.try_lock_for(__d)) {}
144 _LIBCPP_INLINE_VISIBILITY
145 ~unique_lock()
146 {
147 if (__owns_)
148 __m_->unlock();
149 }
150
151private:
152 unique_lock(unique_lock const&); // = delete;
153 unique_lock& operator=(unique_lock const&); // = delete;
154
155public:
156#ifndef _LIBCPP_CXX03_LANG
157 _LIBCPP_INLINE_VISIBILITY
158 unique_lock(unique_lock&& __u) _NOEXCEPT
159 : __m_(__u.__m_), __owns_(__u.__owns_)
160 {__u.__m_ = nullptr; __u.__owns_ = false;}
161 _LIBCPP_INLINE_VISIBILITY
162 unique_lock& operator=(unique_lock&& __u) _NOEXCEPT
163 {
164 if (__owns_)
165 __m_->unlock();
166 __m_ = __u.__m_;
167 __owns_ = __u.__owns_;
168 __u.__m_ = nullptr;
169 __u.__owns_ = false;
170 return *this;
171 }
172
173#endif // _LIBCPP_CXX03_LANG
174
175 void lock();
176 bool try_lock();
177
178 template <class _Rep, class _Period>
179 bool try_lock_for(const chrono::duration<_Rep, _Period>& __d);
180 template <class _Clock, class _Duration>
181 bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
182
183 void unlock();
184
185 _LIBCPP_INLINE_VISIBILITY
186 void swap(unique_lock& __u) _NOEXCEPT
187 {
188 _VSTD::swap(__m_, __u.__m_);
189 _VSTD::swap(__owns_, __u.__owns_);
190 }
191 _LIBCPP_INLINE_VISIBILITY
192 mutex_type* release() _NOEXCEPT
193 {
194 mutex_type* __m = __m_;
195 __m_ = nullptr;
196 __owns_ = false;
197 return __m;
198 }
199
200 _LIBCPP_INLINE_VISIBILITY
201 bool owns_lock() const _NOEXCEPT {return __owns_;}
202 _LIBCPP_INLINE_VISIBILITY
203 _LIBCPP_EXPLICIT
204 operator bool () const _NOEXCEPT {return __owns_;}
205 _LIBCPP_INLINE_VISIBILITY
206 mutex_type* mutex() const _NOEXCEPT {return __m_;}
207};
208
209template <class _Mutex>
210void
211unique_lock<_Mutex>::lock()
212{
213 if (__m_ == nullptr)
214 __throw_system_error(EPERM, "unique_lock::lock: references null mutex");
215 if (__owns_)
216 __throw_system_error(EDEADLK, "unique_lock::lock: already locked");
217 __m_->lock();
218 __owns_ = true;
219}
220
221template <class _Mutex>
222bool
223unique_lock<_Mutex>::try_lock()
224{
225 if (__m_ == nullptr)
226 __throw_system_error(EPERM, "unique_lock::try_lock: references null mutex");
227 if (__owns_)
228 __throw_system_error(EDEADLK, "unique_lock::try_lock: already locked");
229 __owns_ = __m_->try_lock();
230 return __owns_;
231}
232
233template <class _Mutex>
234template <class _Rep, class _Period>
235bool
236unique_lock<_Mutex>::try_lock_for(const chrono::duration<_Rep, _Period>& __d)
237{
238 if (__m_ == nullptr)
239 __throw_system_error(EPERM, "unique_lock::try_lock_for: references null mutex");
240 if (__owns_)
241 __throw_system_error(EDEADLK, "unique_lock::try_lock_for: already locked");
242 __owns_ = __m_->try_lock_for(__d);
243 return __owns_;
244}
245
246template <class _Mutex>
247template <class _Clock, class _Duration>
248bool
249unique_lock<_Mutex>::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
250{
251 if (__m_ == nullptr)
252 __throw_system_error(EPERM, "unique_lock::try_lock_until: references null mutex");
253 if (__owns_)
254 __throw_system_error(EDEADLK, "unique_lock::try_lock_until: already locked");
255 __owns_ = __m_->try_lock_until(__t);
256 return __owns_;
257}
258
259template <class _Mutex>
260void
261unique_lock<_Mutex>::unlock()
262{
263 if (!__owns_)
264 __throw_system_error(EPERM, "unique_lock::unlock: not locked");
265 __m_->unlock();
266 __owns_ = false;
267}
268
269template <class _Mutex>
270inline _LIBCPP_INLINE_VISIBILITY
271void
272swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y) _NOEXCEPT
273 {__x.swap(__y);}
274
275//enum class cv_status
276_LIBCPP_DECLARE_STRONG_ENUM(cv_status)
277{
278 no_timeout,
279 timeout
280};
281_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(cv_status)
282
283class _LIBCPP_TYPE_VIS condition_variable
284{
285 __libcpp_condvar_t __cv_ = _LIBCPP_CONDVAR_INITIALIZER;
286public:
287 _LIBCPP_INLINE_VISIBILITY
288 _LIBCPP_CONSTEXPR condition_variable() _NOEXCEPT = default;
289
290#ifdef _LIBCPP_HAS_TRIVIAL_CONDVAR_DESTRUCTION
291 ~condition_variable() = default;
292#else
293 ~condition_variable();
294#endif
295
296 condition_variable(const condition_variable&) = delete;
297 condition_variable& operator=(const condition_variable&) = delete;
298
299 void notify_one() _NOEXCEPT;
300 void notify_all() _NOEXCEPT;
301
302 void wait(unique_lock<mutex>& __lk) _NOEXCEPT;
303 template <class _Predicate>
304 _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
305 void wait(unique_lock<mutex>& __lk, _Predicate __pred);
306
307 template <class _Clock, class _Duration>
308 _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
309 cv_status
310 wait_until(unique_lock<mutex>& __lk,
311 const chrono::time_point<_Clock, _Duration>& __t);
312
313 template <class _Clock, class _Duration, class _Predicate>
314 _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
315 bool
316 wait_until(unique_lock<mutex>& __lk,
317 const chrono::time_point<_Clock, _Duration>& __t,
318 _Predicate __pred);
319
320 template <class _Rep, class _Period>
321 _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
322 cv_status
323 wait_for(unique_lock<mutex>& __lk,
324 const chrono::duration<_Rep, _Period>& __d);
325
326 template <class _Rep, class _Period, class _Predicate>
327 bool
328 _LIBCPP_INLINE_VISIBILITY
329 wait_for(unique_lock<mutex>& __lk,
330 const chrono::duration<_Rep, _Period>& __d,
331 _Predicate __pred);
332
333 typedef __libcpp_condvar_t* native_handle_type;
334 _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() {return &__cv_;}
335
336private:
337 void __do_timed_wait(unique_lock<mutex>& __lk,
338 chrono::time_point<chrono::system_clock, chrono::nanoseconds>) _NOEXCEPT;
339};
340#endif // !_LIBCPP_HAS_NO_THREADS
341
342template <class _To, class _Rep, class _Period>
343inline _LIBCPP_INLINE_VISIBILITY
344typename enable_if
345<
346 chrono::__is_duration<_To>::value,
347 _To
348>::type
349__ceil(chrono::duration<_Rep, _Period> __d)
350{
351 using namespace chrono;
352 _To __r = duration_cast<_To>(__d);
353 if (__r < __d)
354 ++__r;
355 return __r;
356}
357
358#ifndef _LIBCPP_HAS_NO_THREADS
359template <class _Predicate>
360void
361condition_variable::wait(unique_lock<mutex>& __lk, _Predicate __pred)
362{
363 while (!__pred())
364 wait(__lk);
365}
366
367template <class _Clock, class _Duration>
368cv_status
369condition_variable::wait_until(unique_lock<mutex>& __lk,
370 const chrono::time_point<_Clock, _Duration>& __t)
371{
372 using namespace chrono;
373 wait_for(__lk, __t - _Clock::now());
374 return _Clock::now() < __t ? cv_status::no_timeout : cv_status::timeout;
375}
376
377template <class _Clock, class _Duration, class _Predicate>
378bool
379condition_variable::wait_until(unique_lock<mutex>& __lk,
380 const chrono::time_point<_Clock, _Duration>& __t,
381 _Predicate __pred)
382{
383 while (!__pred())
384 {
385 if (wait_until(__lk, __t) == cv_status::timeout)
386 return __pred();
387 }
388 return true;
389}
390
391template <class _Rep, class _Period>
392cv_status
393condition_variable::wait_for(unique_lock<mutex>& __lk,
394 const chrono::duration<_Rep, _Period>& __d)
395{
396 using namespace chrono;
397 if (__d <= __d.zero())
398 return cv_status::timeout;
399 typedef time_point<system_clock, duration<long double, nano> > __sys_tpf;
400 typedef time_point<system_clock, nanoseconds> __sys_tpi;
401 __sys_tpf _Max = __sys_tpi::max();
402 steady_clock::time_point __c_now = steady_clock::now();
403 system_clock::time_point __s_now = system_clock::now();
404 if (_Max - __d > __s_now)
405 __do_timed_wait(__lk, __s_now + __ceil<nanoseconds>(__d));
406 else
407 __do_timed_wait(__lk, __sys_tpi::max());
408 return steady_clock::now() - __c_now < __d ? cv_status::no_timeout :
409 cv_status::timeout;
410}
411
412template <class _Rep, class _Period, class _Predicate>
413inline
414bool
415condition_variable::wait_for(unique_lock<mutex>& __lk,
416 const chrono::duration<_Rep, _Period>& __d,
417 _Predicate __pred)
418{
419 return wait_until(__lk, chrono::steady_clock::now() + __d,
420 _VSTD::move(__pred));
421}
422
423#endif // !_LIBCPP_HAS_NO_THREADS
424
425_LIBCPP_END_NAMESPACE_STD
426
427_LIBCPP_POP_MACROS
428
429#endif // _LIBCPP___MUTEX_BASE
430