1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
|
// <condition_variable> -*- C++ -*-
// Copyright (C) 2008-2022 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file include/condition_variable
* This is a Standard C++ Library header.
*/
#ifndef _GLIBCXX_CONDITION_VARIABLE
#define _GLIBCXX_CONDITION_VARIABLE 1
#pragma GCC system_header
#if __cplusplus < 201103L
# include <bits/c++0x_warning.h>
#else
#include <bits/chrono.h>
#include <bits/std_mutex.h>
#include <bits/unique_lock.h>
#include <bits/alloc_traits.h>
#include <bits/shared_ptr.h>
#include <bits/cxxabi_forced.h>
#if __cplusplus > 201703L
# include <stop_token>
#endif
#if defined(_GLIBCXX_HAS_GTHREADS)
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @defgroup condition_variables Condition Variables
* @ingroup concurrency
*
* Classes for condition_variable support.
* @{
*/
/// cv_status
enum class cv_status { no_timeout, timeout };
/// condition_variable
class condition_variable
{
using steady_clock = chrono::steady_clock;
using system_clock = chrono::system_clock;
#ifdef _GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT
using __clock_t = steady_clock;
#else
using __clock_t = system_clock;
#endif
__condvar _M_cond;
public:
typedef __gthread_cond_t* native_handle_type;
condition_variable() noexcept;
~condition_variable() noexcept;
condition_variable(const condition_variable&) = delete;
condition_variable& operator=(const condition_variable&) = delete;
void
notify_one() noexcept;
void
notify_all() noexcept;
void
wait(unique_lock<mutex>& __lock);
template<typename _Predicate>
void
wait(unique_lock<mutex>& __lock, _Predicate __p)
{
while (!__p())
wait(__lock);
}
#ifdef _GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT
template<typename _Duration>
cv_status
wait_until(unique_lock<mutex>& __lock,
const chrono::time_point<steady_clock, _Duration>& __atime)
{ return __wait_until_impl(__lock, __atime); }
#endif
template<typename _Duration>
cv_status
wait_until(unique_lock<mutex>& __lock,
const chrono::time_point<system_clock, _Duration>& __atime)
{ return __wait_until_impl(__lock, __atime); }
template<typename _Clock, typename _Duration>
cv_status
wait_until(unique_lock<mutex>& __lock,
const chrono::time_point<_Clock, _Duration>& __atime)
{
#if __cplusplus > 201703L
static_assert(chrono::is_clock_v<_Clock>);
#endif
using __s_dur = typename __clock_t::duration;
const typename _Clock::time_point __c_entry = _Clock::now();
const __clock_t::time_point __s_entry = __clock_t::now();
const auto __delta = __atime - __c_entry;
const auto __s_atime = __s_entry +
chrono::__detail::ceil<__s_dur>(__delta);
if (__wait_until_impl(__lock, __s_atime) == cv_status::no_timeout)
return cv_status::no_timeout;
// We got a timeout when measured against __clock_t but
// we need to check against the caller-supplied clock
// to tell whether we should return a timeout.
if (_Clock::now() < __atime)
return cv_status::no_timeout;
return cv_status::timeout;
}
template<typename _Clock, typename _Duration, typename _Predicate>
bool
wait_until(unique_lock<mutex>& __lock,
const chrono::time_point<_Clock, _Duration>& __atime,
_Predicate __p)
{
while (!__p())
if (wait_until(__lock, __atime) == cv_status::timeout)
return __p();
return true;
}
template<typename _Rep, typename _Period>
cv_status
wait_for(unique_lock<mutex>& __lock,
const chrono::duration<_Rep, _Period>& __rtime)
{
using __dur = typename steady_clock::duration;
return wait_until(__lock,
steady_clock::now() +
chrono::__detail::ceil<__dur>(__rtime));
}
template<typename _Rep, typename _Period, typename _Predicate>
bool
wait_for(unique_lock<mutex>& __lock,
const chrono::duration<_Rep, _Period>& __rtime,
_Predicate __p)
{
using __dur = typename steady_clock::duration;
return wait_until(__lock,
steady_clock::now() +
chrono::__detail::ceil<__dur>(__rtime),
std::move(__p));
}
native_handle_type
native_handle()
{ return _M_cond.native_handle(); }
private:
#ifdef _GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT
template<typename _Dur>
cv_status
__wait_until_impl(unique_lock<mutex>& __lock,
const chrono::time_point<steady_clock, _Dur>& __atime)
{
auto __s = chrono::time_point_cast<chrono::seconds>(__atime);
auto __ns = chrono::duration_cast<chrono::nanoseconds>(__atime - __s);
__gthread_time_t __ts =
{
static_cast<std::time_t>(__s.time_since_epoch().count()),
static_cast<long>(__ns.count())
};
_M_cond.wait_until(*__lock.mutex(), CLOCK_MONOTONIC, __ts);
return (steady_clock::now() < __atime
? cv_status::no_timeout : cv_status::timeout);
}
#endif
template<typename _Dur>
cv_status
__wait_until_impl(unique_lock<mutex>& __lock,
const chrono::time_point<system_clock, _Dur>& __atime)
{
auto __s = chrono::time_point_cast<chrono::seconds>(__atime);
auto __ns = chrono::duration_cast<chrono::nanoseconds>(__atime - __s);
__gthread_time_t __ts =
{
static_cast<std::time_t>(__s.time_since_epoch().count()),
static_cast<long>(__ns.count())
};
_M_cond.wait_until(*__lock.mutex(), __ts);
return (system_clock::now() < __atime
? cv_status::no_timeout : cv_status::timeout);
}
};
void
notify_all_at_thread_exit(condition_variable&, unique_lock<mutex>);
struct __at_thread_exit_elt
{
__at_thread_exit_elt* _M_next;
void (*_M_cb)(void*);
};
inline namespace _V2 {
/// condition_variable_any
// Like above, but mutex is not required to have try_lock.
class condition_variable_any
{
#ifdef _GLIBCXX_USE_PTHREAD_COND_CLOCKWAIT
using __clock_t = chrono::steady_clock;
#else
using __clock_t = chrono::system_clock;
#endif
condition_variable _M_cond;
shared_ptr<mutex> _M_mutex;
// scoped unlock - unlocks in ctor, re-locks in dtor
template<typename _Lock>
struct _Unlock
{
explicit _Unlock(_Lock& __lk) : _M_lock(__lk) { __lk.unlock(); }
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
~_Unlock() noexcept(false)
{
if (uncaught_exception())
{
__try
{ _M_lock.lock(); }
__catch(const __cxxabiv1::__forced_unwind&)
{ __throw_exception_again; }
__catch(...)
{ }
}
else
_M_lock.lock();
}
#pragma GCC diagnostic pop
_Unlock(const _Unlock&) = delete;
_Unlock& operator=(const _Unlock&) = delete;
_Lock& _M_lock;
};
public:
condition_variable_any() : _M_mutex(std::make_shared<mutex>()) { }
~condition_variable_any() = default;
condition_variable_any(const condition_variable_any&) = delete;
condition_variable_any& operator=(const condition_variable_any&) = delete;
void
notify_one() noexcept
{
lock_guard<mutex> __lock(*_M_mutex);
_M_cond.notify_one();
}
void
notify_all() noexcept
{
lock_guard<mutex> __lock(*_M_mutex);
_M_cond.notify_all();
}
template<typename _Lock>
void
wait(_Lock& __lock)
{
shared_ptr<mutex> __mutex = _M_mutex;
unique_lock<mutex> __my_lock(*__mutex);
_Unlock<_Lock> __unlock(__lock);
// *__mutex must be unlocked before re-locking __lock so move
// ownership of *__mutex lock to an object with shorter lifetime.
unique_lock<mutex> __my_lock2(std::move(__my_lock));
_M_cond.wait(__my_lock2);
}
template<typename _Lock, typename _Predicate>
void
wait(_Lock& __lock, _Predicate __p)
{
while (!__p())
wait(__lock);
}
template<typename _Lock, typename _Clock, typename _Duration>
cv_status
wait_until(_Lock& __lock,
const chrono::time_point<_Clock, _Duration>& __atime)
{
shared_ptr<mutex> __mutex = _M_mutex;
unique_lock<mutex> __my_lock(*__mutex);
_Unlock<_Lock> __unlock(__lock);
// *__mutex must be unlocked before re-locking __lock so move
// ownership of *__mutex lock to an object with shorter lifetime.
unique_lock<mutex> __my_lock2(std::move(__my_lock));
return _M_cond.wait_until(__my_lock2, __atime);
}
template<typename _Lock, typename _Clock,
typename _Duration, typename _Predicate>
bool
wait_until(_Lock& __lock,
const chrono::time_point<_Clock, _Duration>& __atime,
_Predicate __p)
{
while (!__p())
if (wait_until(__lock, __atime) == cv_status::timeout)
return __p();
return true;
}
template<typename _Lock, typename _Rep, typename _Period>
cv_status
wait_for(_Lock& __lock, const chrono::duration<_Rep, _Period>& __rtime)
{ return wait_until(__lock, __clock_t::now() + __rtime); }
template<typename _Lock, typename _Rep,
typename _Period, typename _Predicate>
bool
wait_for(_Lock& __lock,
const chrono::duration<_Rep, _Period>& __rtime, _Predicate __p)
{ return wait_until(__lock, __clock_t::now() + __rtime, std::move(__p)); }
#ifdef __cpp_lib_jthread
template <class _Lock, class _Predicate>
bool wait(_Lock& __lock,
stop_token __stoken,
_Predicate __p)
{
if (__stoken.stop_requested())
{
return __p();
}
std::stop_callback __cb(__stoken, [this] { notify_all(); });
shared_ptr<mutex> __mutex = _M_mutex;
while (!__p())
{
unique_lock<mutex> __my_lock(*__mutex);
if (__stoken.stop_requested())
{
return false;
}
// *__mutex must be unlocked before re-locking __lock so move
// ownership of *__mutex lock to an object with shorter lifetime.
_Unlock<_Lock> __unlock(__lock);
unique_lock<mutex> __my_lock2(std::move(__my_lock));
_M_cond.wait(__my_lock2);
}
return true;
}
template <class _Lock, class _Clock, class _Duration, class _Predicate>
bool wait_until(_Lock& __lock,
stop_token __stoken,
const chrono::time_point<_Clock, _Duration>& __abs_time,
_Predicate __p)
{
if (__stoken.stop_requested())
{
return __p();
}
std::stop_callback __cb(__stoken, [this] { notify_all(); });
shared_ptr<mutex> __mutex = _M_mutex;
while (!__p())
{
bool __stop;
{
unique_lock<mutex> __my_lock(*__mutex);
if (__stoken.stop_requested())
{
return false;
}
_Unlock<_Lock> __u(__lock);
unique_lock<mutex> __my_lock2(std::move(__my_lock));
const auto __status = _M_cond.wait_until(__my_lock2, __abs_time);
__stop = (__status == std::cv_status::timeout) || __stoken.stop_requested();
}
if (__stop)
{
return __p();
}
}
return true;
}
template <class _Lock, class _Rep, class _Period, class _Predicate>
bool wait_for(_Lock& __lock,
stop_token __stoken,
const chrono::duration<_Rep, _Period>& __rel_time,
_Predicate __p)
{
auto __abst = std::chrono::steady_clock::now() + __rel_time;
return wait_until(__lock,
std::move(__stoken),
__abst,
std::move(__p));
}
#endif
};
} // end inline namespace
/// @} group condition_variables
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif // _GLIBCXX_HAS_GTHREADS
#endif // C++11
#endif // _GLIBCXX_CONDITION_VARIABLE
|