summaryrefslogtreecommitdiff
path: root/boost/thread/pthread/condition_variable.hpp
blob: 285785ff59deb4eee69df72b2f5c95f198bb5319 (plain)
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
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
#ifndef BOOST_THREAD_CONDITION_VARIABLE_PTHREAD_HPP
#define BOOST_THREAD_CONDITION_VARIABLE_PTHREAD_HPP
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
// (C) Copyright 2007-10 Anthony Williams
// (C) Copyright 2011-2012 Vicente J. Botet Escriba

#include <boost/thread/detail/platform_time.hpp>
#include <boost/thread/pthread/pthread_mutex_scoped_lock.hpp>
#include <boost/thread/pthread/pthread_helpers.hpp>

#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
#include <boost/thread/pthread/thread_data.hpp>
#endif
#include <boost/thread/pthread/condition_variable_fwd.hpp>
#ifdef BOOST_THREAD_USES_CHRONO
#include <boost/chrono/system_clocks.hpp>
#include <boost/chrono/ceil.hpp>
#endif
#include <boost/thread/detail/delete.hpp>

#include <algorithm>

#include <boost/config/abi_prefix.hpp>

namespace boost
{
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
    namespace this_thread
    {
        void BOOST_THREAD_DECL interruption_point();
    }
#endif

    namespace thread_cv_detail
    {
        template<typename MutexType>
        struct lock_on_exit
        {
            MutexType* m;

            lock_on_exit():
                m(0)
            {}

            void activate(MutexType& m_)
            {
                m_.unlock();
                m=&m_;
            }
            void deactivate()
            {
                if (m)
                {
                    m->lock();
                }
                m = 0;
            }
            ~lock_on_exit() BOOST_NOEXCEPT_IF(false)
            {
                if (m)
                {
                    m->lock();
                }
           }
        };
    }

    inline void condition_variable::wait(unique_lock<mutex>& m)
    {
#if defined BOOST_THREAD_THROW_IF_PRECONDITION_NOT_SATISFIED
        if(! m.owns_lock())
        {
            boost::throw_exception(condition_error(-1, "boost::condition_variable::wait() failed precondition mutex not owned"));
        }
#endif
        int res=0;
        {
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
            thread_cv_detail::lock_on_exit<unique_lock<mutex> > guard;
            detail::interruption_checker check_for_interruption(&internal_mutex,&cond);
            pthread_mutex_t* the_mutex = &internal_mutex;
            guard.activate(m);
            res = pthread_cond_wait(&cond,the_mutex);
            check_for_interruption.unlock_if_locked();
            guard.deactivate();
#else
            pthread_mutex_t* the_mutex = m.mutex()->native_handle();
            res = pthread_cond_wait(&cond,the_mutex);
#endif
        }
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
        this_thread::interruption_point();
#endif
        if(res && res != EINTR)
        {
            boost::throw_exception(condition_error(res, "boost::condition_variable::wait failed in pthread_cond_wait"));
        }
    }

    // When this function returns true:
    // * A notification (or sometimes a spurious OS signal) has been received
    // * Do not assume that the timeout has not been reached
    // * Do not assume that the predicate has been changed
    //
    // When this function returns false:
    // * The timeout has been reached
    // * Do not assume that a notification has not been received
    // * Do not assume that the predicate has not been changed
    inline bool condition_variable::do_wait_until(
                unique_lock<mutex>& m,
                detail::internal_platform_timepoint const &timeout)
    {
#if defined BOOST_THREAD_THROW_IF_PRECONDITION_NOT_SATISFIED
        if (!m.owns_lock())
        {
            boost::throw_exception(condition_error(EPERM, "boost::condition_variable::do_wait_until() failed precondition mutex not owned"));
        }
#endif
        int cond_res;
        {
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
            thread_cv_detail::lock_on_exit<unique_lock<mutex> > guard;
            detail::interruption_checker check_for_interruption(&internal_mutex,&cond);
            pthread_mutex_t* the_mutex = &internal_mutex;
            guard.activate(m);
            cond_res=pthread_cond_timedwait(&cond,the_mutex,&timeout.getTs());
            check_for_interruption.unlock_if_locked();
            guard.deactivate();
#else
            pthread_mutex_t* the_mutex = m.mutex()->native_handle();
            cond_res=pthread_cond_timedwait(&cond,the_mutex,&timeout.getTs());
#endif
        }
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
        this_thread::interruption_point();
#endif
        if(cond_res==ETIMEDOUT)
        {
            return false;
        }
        if(cond_res)
        {
            boost::throw_exception(condition_error(cond_res, "boost::condition_variable::do_wait_until failed in pthread_cond_timedwait"));
        }
        return true;
    }

    inline void condition_variable::notify_one() BOOST_NOEXCEPT
    {
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
        boost::pthread::pthread_mutex_scoped_lock internal_lock(&internal_mutex);
#endif
        BOOST_VERIFY(!pthread_cond_signal(&cond));
    }

    inline void condition_variable::notify_all() BOOST_NOEXCEPT
    {
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
        boost::pthread::pthread_mutex_scoped_lock internal_lock(&internal_mutex);
#endif
        BOOST_VERIFY(!pthread_cond_broadcast(&cond));
    }

    class condition_variable_any
    {
        pthread_mutex_t internal_mutex;
        pthread_cond_t cond;

    public:
        BOOST_THREAD_NO_COPYABLE(condition_variable_any)
        condition_variable_any()
        {
            int const res=pthread_mutex_init(&internal_mutex,NULL);
            if(res)
            {
                boost::throw_exception(thread_resource_error(res, "boost::condition_variable_any::condition_variable_any() failed in pthread_mutex_init"));
            }
            int const res2 = pthread::cond_init(cond);
            if(res2)
            {
                BOOST_VERIFY(!pthread_mutex_destroy(&internal_mutex));
                boost::throw_exception(thread_resource_error(res2, "boost::condition_variable_any::condition_variable_any() failed in pthread::cond_init"));
            }
        }
        ~condition_variable_any()
        {
            BOOST_VERIFY(!pthread_mutex_destroy(&internal_mutex));
            BOOST_VERIFY(!pthread_cond_destroy(&cond));
        }

        template<typename lock_type>
        void wait(lock_type& m)
        {
            int res=0;
            {
                thread_cv_detail::lock_on_exit<lock_type> guard;
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
                detail::interruption_checker check_for_interruption(&internal_mutex,&cond);
#else
                boost::pthread::pthread_mutex_scoped_lock check_for_interruption(&internal_mutex);
#endif
                guard.activate(m);
                res=pthread_cond_wait(&cond,&internal_mutex);
                check_for_interruption.unlock_if_locked();
                guard.deactivate();
            }
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
            this_thread::interruption_point();
#endif
            if(res)
            {
                boost::throw_exception(condition_error(res, "boost::condition_variable_any::wait() failed in pthread_cond_wait"));
            }
        }

        template<typename lock_type,typename predicate_type>
        void wait(lock_type& m,predicate_type pred)
        {
            while (!pred())
            {
                wait(m);
            }
        }

#if defined BOOST_THREAD_USES_DATETIME
        template<typename lock_type>
        bool timed_wait(lock_type& m,boost::system_time const& abs_time)
        {
#if defined BOOST_THREAD_WAIT_BUG
            const detail::real_platform_timepoint ts(abs_time + BOOST_THREAD_WAIT_BUG);
#else
            const detail::real_platform_timepoint ts(abs_time);
#endif
#if defined BOOST_THREAD_INTERNAL_CLOCK_IS_MONO
            // The system time may jump while this function is waiting. To compensate for this and time
            // out near the correct time, we could call do_wait_until() in a loop with a short timeout
            // and recheck the time remaining each time through the loop. However, because we can't
            // check the predicate each time do_wait_until() completes, this introduces the possibility
            // of not exiting the function when a notification occurs, since do_wait_until() may report
            // that it timed out even though a notification was received. The best this function can do
            // is report correctly whether or not it reached the timeout time.
            const detail::platform_duration d(ts - detail::real_platform_clock::now());
            do_wait_until(m, detail::internal_platform_clock::now() + d);
            return ts > detail::real_platform_clock::now();
#else
            return do_wait_until(m, ts);
#endif
        }
        template<typename lock_type>
        bool timed_wait(lock_type& m,xtime const& abs_time)
        {
            return timed_wait(m,system_time(abs_time));
        }

        template<typename lock_type,typename duration_type>
        bool timed_wait(lock_type& m,duration_type const& wait_duration)
        {
            if (wait_duration.is_pos_infinity())
            {
                wait(m);
                return true;
            }
            if (wait_duration.is_special())
            {
                return true;
            }
            detail::platform_duration d(wait_duration);
#if defined(BOOST_THREAD_HAS_MONO_CLOCK) && !defined(BOOST_THREAD_INTERNAL_CLOCK_IS_MONO)
            // The system time may jump while this function is waiting. To compensate for this and time
            // out near the correct time, we could call do_wait_until() in a loop with a short timeout
            // and recheck the time remaining each time through the loop. However, because we can't
            // check the predicate each time do_wait_until() completes, this introduces the possibility
            // of not exiting the function when a notification occurs, since do_wait_until() may report
            // that it timed out even though a notification was received. The best this function can do
            // is report correctly whether or not it reached the timeout time.
            const detail::mono_platform_timepoint ts(detail::mono_platform_clock::now() + d);
            do_wait_until(m, detail::internal_platform_clock::now() + d);
            return ts > detail::mono_platform_clock::now();
#else
            return do_wait_until(m, detail::internal_platform_clock::now() + d);
#endif
        }

        template<typename lock_type,typename predicate_type>
        bool timed_wait(lock_type& m,boost::system_time const& abs_time, predicate_type pred)
        {
#if defined BOOST_THREAD_WAIT_BUG
            const detail::real_platform_timepoint ts(abs_time + BOOST_THREAD_WAIT_BUG);
#else
            const detail::real_platform_timepoint ts(abs_time);
#endif
            while (!pred())
            {
#if defined BOOST_THREAD_INTERNAL_CLOCK_IS_MONO
                // The system time may jump while this function is waiting. To compensate for this
                // and time out near the correct time, we call do_wait_until() in a loop with a
                // short timeout and recheck the time remaining each time through the loop.
                detail::platform_duration d(ts - detail::real_platform_clock::now());
                if (d <= detail::platform_duration::zero()) break; // timeout occurred
                d = (std::min)(d, detail::platform_milliseconds(BOOST_THREAD_POLL_INTERVAL_MILLISECONDS));
                do_wait_until(m, detail::internal_platform_clock::now() + d);
#else
                if (!do_wait_until(m, ts)) break; // timeout occurred
#endif
            }
            return pred();
        }

        template<typename lock_type,typename predicate_type>
        bool timed_wait(lock_type& m,xtime const& abs_time, predicate_type pred)
        {
            return timed_wait(m,system_time(abs_time),pred);
        }

        template<typename lock_type,typename duration_type,typename predicate_type>
        bool timed_wait(lock_type& m,duration_type const& wait_duration,predicate_type pred)
        {
            if (wait_duration.is_pos_infinity())
            {
                while (!pred())
                {
                    wait(m);
                }
                return true;
            }
            if (wait_duration.is_special())
            {
                return pred();
            }
            detail::platform_duration d(wait_duration);
#if defined(BOOST_THREAD_HAS_MONO_CLOCK) && !defined(BOOST_THREAD_INTERNAL_CLOCK_IS_MONO)
            // The system time may jump while this function is waiting. To compensate for this
            // and time out near the correct time, we call do_wait_until() in a loop with a
            // short timeout and recheck the time remaining each time through the loop.
            const detail::mono_platform_timepoint ts(detail::mono_platform_clock::now() + d);
            while (!pred())
            {
                if (d <= detail::platform_duration::zero()) break; // timeout occurred
                d = (std::min)(d, detail::platform_milliseconds(BOOST_THREAD_POLL_INTERVAL_MILLISECONDS));
                do_wait_until(m, detail::internal_platform_clock::now() + d);
                d = ts - detail::mono_platform_clock::now();
            }
#else
            const detail::internal_platform_timepoint ts(detail::internal_platform_clock::now() + d);
            while (!pred())
            {
                if (!do_wait_until(m, ts)) break; // timeout occurred
            }
#endif
            return pred();
        }
#endif

#ifdef BOOST_THREAD_USES_CHRONO
        template <class lock_type,class Duration>
        cv_status
        wait_until(
                lock_type& lock,
                const chrono::time_point<detail::internal_chrono_clock, Duration>& t)
        {
            const boost::detail::internal_platform_timepoint ts(t);
            if (do_wait_until(lock, ts)) return cv_status::no_timeout;
            else return cv_status::timeout;
        }

        template <class lock_type, class Clock, class Duration>
        cv_status
        wait_until(
                lock_type& lock,
                const chrono::time_point<Clock, Duration>& t)
        {
            // The system time may jump while this function is waiting. To compensate for this and time
            // out near the correct time, we could call do_wait_until() in a loop with a short timeout
            // and recheck the time remaining each time through the loop. However, because we can't
            // check the predicate each time do_wait_until() completes, this introduces the possibility
            // of not exiting the function when a notification occurs, since do_wait_until() may report
            // that it timed out even though a notification was received. The best this function can do
            // is report correctly whether or not it reached the timeout time.
            typedef typename common_type<Duration, typename Clock::duration>::type common_duration;
            common_duration d(t - Clock::now());
            do_wait_until(lock, detail::internal_chrono_clock::now() + d);
            if (t > Clock::now()) return cv_status::no_timeout;
            else return cv_status::timeout;
        }

        template <class lock_type, class Rep, class Period>
        cv_status
        wait_for(
                lock_type& lock,
                const chrono::duration<Rep, Period>& d)
        {
            return wait_until(lock, chrono::steady_clock::now() + d);
        }

        template <class lock_type, class Duration, class Predicate>
        bool
        wait_until(
                lock_type& lock,
                const chrono::time_point<detail::internal_chrono_clock, Duration>& t,
                Predicate pred)
        {
            const detail::internal_platform_timepoint ts(t);
            while (!pred())
            {
                if (!do_wait_until(lock, ts)) break; // timeout occurred
            }
            return pred();
        }

        template <class lock_type, class Clock, class Duration, class Predicate>
        bool
        wait_until(
                lock_type& lock,
                const chrono::time_point<Clock, Duration>& t,
                Predicate pred)
        {
            // The system time may jump while this function is waiting. To compensate for this
            // and time out near the correct time, we call do_wait_until() in a loop with a
            // short timeout and recheck the time remaining each time through the loop.
            typedef typename common_type<Duration, typename Clock::duration>::type common_duration;
            while (!pred())
            {
                common_duration d(t - Clock::now());
                if (d <= common_duration::zero()) break; // timeout occurred
                d = (std::min)(d, common_duration(chrono::milliseconds(BOOST_THREAD_POLL_INTERVAL_MILLISECONDS)));
                do_wait_until(lock, detail::internal_platform_clock::now() + detail::platform_duration(d));
            }
            return pred();
        }

        template <class lock_type, class Rep, class Period, class Predicate>
        bool
        wait_for(
                lock_type& lock,
                const chrono::duration<Rep, Period>& d,
                Predicate pred)
        {
            return wait_until(lock, chrono::steady_clock::now() + d, boost::move(pred));
        }
#endif

        void notify_one() BOOST_NOEXCEPT
        {
            boost::pthread::pthread_mutex_scoped_lock internal_lock(&internal_mutex);
            BOOST_VERIFY(!pthread_cond_signal(&cond));
        }

        void notify_all() BOOST_NOEXCEPT
        {
            boost::pthread::pthread_mutex_scoped_lock internal_lock(&internal_mutex);
            BOOST_VERIFY(!pthread_cond_broadcast(&cond));
        }
    private:

        // When this function returns true:
        // * A notification (or sometimes a spurious OS signal) has been received
        // * Do not assume that the timeout has not been reached
        // * Do not assume that the predicate has been changed
        //
        // When this function returns false:
        // * The timeout has been reached
        // * Do not assume that a notification has not been received
        // * Do not assume that the predicate has not been changed
        template <class lock_type>
        bool do_wait_until(
          lock_type& m,
          detail::internal_platform_timepoint const &timeout)
        {
          int res=0;
          {
              thread_cv_detail::lock_on_exit<lock_type> guard;
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
              detail::interruption_checker check_for_interruption(&internal_mutex,&cond);
#else
              boost::pthread::pthread_mutex_scoped_lock check_for_interruption(&internal_mutex);
#endif
              guard.activate(m);
              res=pthread_cond_timedwait(&cond,&internal_mutex,&timeout.getTs());
              check_for_interruption.unlock_if_locked();
              guard.deactivate();
          }
#if defined BOOST_THREAD_PROVIDES_INTERRUPTIONS
          this_thread::interruption_point();
#endif
          if(res==ETIMEDOUT)
          {
              return false;
          }
          if(res)
          {
              boost::throw_exception(condition_error(res, "boost::condition_variable_any::do_wait_until() failed in pthread_cond_timedwait"));
          }
          return true;
        }
    };
}

#include <boost/config/abi_suffix.hpp>

#endif