1 /*****************************************************************************
2 * pthread.c : pthread back-end for LibVLC
3 *****************************************************************************
4 * Copyright (C) 1999-2009 the VideoLAN team
6 * Authors: Jean-Marc Dressler <polux@via.ecp.fr>
7 * Samuel Hocevar <sam@zoy.org>
8 * Gildas Bazin <gbazin@netcourrier.com>
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
25 *****************************************************************************/
31 #include <vlc_common.h>
36 #include <unistd.h> /* fsync() */
42 # include <sys/syscall.h> /* SYS_gettid */
45 #ifdef HAVE_EXECINFO_H
46 # include <execinfo.h>
50 # include <sys/time.h> /* gettimeofday in vlc_cond_timedwait */
54 * Print a backtrace to the standard error for debugging purpose.
56 void vlc_trace (const char *fn, const char *file, unsigned line)
58 fprintf (stderr, "at %s:%u in %s\n", file, line, fn);
59 fflush (stderr); /* needed before switch to low-level I/O */
62 int len = backtrace (stack, sizeof (stack) / sizeof (stack[0]));
63 backtrace_symbols_fd (stack, len, 2);
68 static inline unsigned long vlc_threadid (void)
70 #if defined (__linux__)
71 /* glibc does not provide a call for this */
72 return syscall (SYS_gettid);
75 union { pthread_t th; unsigned long int i; } v = { };
76 v.th = pthread_self ();
83 /*****************************************************************************
84 * vlc_thread_fatal: Report an error from the threading layer
85 *****************************************************************************
86 * This is mostly meant for debugging.
87 *****************************************************************************/
89 vlc_thread_fatal (const char *action, int error,
90 const char *function, const char *file, unsigned line)
92 int canc = vlc_savecancel ();
93 fprintf (stderr, "LibVLC fatal error %s (%d) in thread %lu ",
94 action, error, vlc_threadid ());
95 vlc_trace (function, file, line);
97 /* Sometimes strerror_r() crashes too, so make sure we print an error
98 * message before we invoke it */
100 /* Avoid the strerror_r() prototype brain damage in glibc */
102 fprintf (stderr, " Error message: %m\n");
107 switch (strerror_r (error, buf, sizeof (buf)))
112 case ERANGE: /* should never happen */
113 msg = "unknwon (too big to display)";
116 msg = "unknown (invalid error number)";
119 fprintf (stderr, " Error message: %s\n", msg);
123 vlc_restorecancel (canc);
127 # define VLC_THREAD_ASSERT( action ) \
128 if (val) vlc_thread_fatal (action, val, __func__, __FILE__, __LINE__)
130 # define VLC_THREAD_ASSERT( action ) ((void)val)
133 #if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
134 /* This is not prototyped under glibc, though it exists. */
135 int pthread_mutexattr_setkind_np( pthread_mutexattr_t *attr, int kind );
138 /*****************************************************************************
139 * vlc_mutex_init: initialize a mutex
140 *****************************************************************************/
141 void vlc_mutex_init( vlc_mutex_t *p_mutex )
143 pthread_mutexattr_t attr;
145 if( pthread_mutexattr_init( &attr ) )
148 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_NORMAL );
150 /* Create error-checking mutex to detect problems more easily. */
151 # if defined (__GLIBC__) && (__GLIBC__ == 2) && (__GLIBC_MINOR__ < 6)
152 pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_ERRORCHECK_NP );
154 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ERRORCHECK );
157 if( pthread_mutex_init( p_mutex, &attr ) )
159 pthread_mutexattr_destroy( &attr );
162 /*****************************************************************************
163 * vlc_mutex_init: initialize a recursive mutex (Do not use)
164 *****************************************************************************/
165 void vlc_mutex_init_recursive( vlc_mutex_t *p_mutex )
167 pthread_mutexattr_t attr;
169 pthread_mutexattr_init( &attr );
170 #if defined (__GLIBC__) && (__GLIBC__ == 2) && (__GLIBC_MINOR__ < 6)
171 pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_RECURSIVE_NP );
173 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_RECURSIVE );
175 if( pthread_mutex_init( p_mutex, &attr ) )
177 pthread_mutexattr_destroy( &attr );
182 * Destroys a mutex. The mutex must not be locked.
184 * @param p_mutex mutex to destroy
185 * @return always succeeds
187 void vlc_mutex_destroy (vlc_mutex_t *p_mutex)
189 int val = pthread_mutex_destroy( p_mutex );
190 VLC_THREAD_ASSERT ("destroying mutex");
194 # ifdef HAVE_VALGRIND_VALGRIND_H
195 # include <valgrind/valgrind.h>
197 # define RUNNING_ON_VALGRIND (0)
200 void vlc_assert_locked (vlc_mutex_t *p_mutex)
202 if (RUNNING_ON_VALGRIND > 0)
204 assert (pthread_mutex_lock (p_mutex) == EDEADLK);
209 * Acquires a mutex. If needed, waits for any other thread to release it.
210 * Beware of deadlocks when locking multiple mutexes at the same time,
211 * or when using mutexes from callbacks.
212 * This function is not a cancellation-point.
214 * @param p_mutex mutex initialized with vlc_mutex_init() or
215 * vlc_mutex_init_recursive()
217 void vlc_mutex_lock (vlc_mutex_t *p_mutex)
219 int val = pthread_mutex_lock( p_mutex );
220 VLC_THREAD_ASSERT ("locking mutex");
224 * Acquires a mutex if and only if it is not currently held by another thread.
225 * This function never sleeps and can be used in delay-critical code paths.
226 * This function is not a cancellation-point.
228 * <b>Beware</b>: If this function fails, then the mutex is held... by another
229 * thread. The calling thread must deal with the error appropriately. That
230 * typically implies postponing the operations that would have required the
231 * mutex. If the thread cannot defer those operations, then it must use
232 * vlc_mutex_lock(). If in doubt, use vlc_mutex_lock() instead.
234 * @param p_mutex mutex initialized with vlc_mutex_init() or
235 * vlc_mutex_init_recursive()
236 * @return 0 if the mutex could be acquired, an error code otherwise.
238 int vlc_mutex_trylock (vlc_mutex_t *p_mutex)
240 int val = pthread_mutex_trylock( p_mutex );
243 VLC_THREAD_ASSERT ("locking mutex");
248 * Releases a mutex (or crashes if the mutex is not locked by the caller).
249 * @param p_mutex mutex locked with vlc_mutex_lock().
251 void vlc_mutex_unlock (vlc_mutex_t *p_mutex)
253 int val = pthread_mutex_unlock( p_mutex );
254 VLC_THREAD_ASSERT ("unlocking mutex");
257 /*****************************************************************************
258 * vlc_cond_init: initialize a condition variable
259 *****************************************************************************/
260 void vlc_cond_init( vlc_cond_t *p_condvar )
262 pthread_condattr_t attr;
264 if (pthread_condattr_init (&attr))
266 #if !defined (_POSIX_CLOCK_SELECTION)
267 /* Fairly outdated POSIX support (that was defined in 2001) */
268 # define _POSIX_CLOCK_SELECTION (-1)
270 #if (_POSIX_CLOCK_SELECTION >= 0)
271 /* NOTE: This must be the same clock as the one in mtime.c */
272 pthread_condattr_setclock (&attr, CLOCK_MONOTONIC);
275 if (pthread_cond_init (p_condvar, &attr))
277 pthread_condattr_destroy (&attr);
281 * Destroys a condition variable. No threads shall be waiting or signaling the
283 * @param p_condvar condition variable to destroy
285 void vlc_cond_destroy (vlc_cond_t *p_condvar)
287 int val = pthread_cond_destroy( p_condvar );
288 VLC_THREAD_ASSERT ("destroying condition");
292 * Wakes up one thread waiting on a condition variable, if any.
293 * @param p_condvar condition variable
295 void vlc_cond_signal (vlc_cond_t *p_condvar)
297 int val = pthread_cond_signal( p_condvar );
298 VLC_THREAD_ASSERT ("signaling condition variable");
302 * Wakes up all threads (if any) waiting on a condition variable.
303 * @param p_cond condition variable
305 void vlc_cond_broadcast (vlc_cond_t *p_condvar)
307 pthread_cond_broadcast (p_condvar);
311 * Waits for a condition variable. The calling thread will be suspended until
312 * another thread calls vlc_cond_signal() or vlc_cond_broadcast() on the same
313 * condition variable, the thread is cancelled with vlc_cancel(), or the
314 * system causes a "spurious" unsolicited wake-up.
316 * A mutex is needed to wait on a condition variable. It must <b>not</b> be
317 * a recursive mutex. Although it is possible to use the same mutex for
318 * multiple condition, it is not valid to use different mutexes for the same
319 * condition variable at the same time from different threads.
321 * In case of thread cancellation, the mutex is always locked before
322 * cancellation proceeds.
324 * The canonical way to use a condition variable to wait for event foobar is:
326 vlc_mutex_lock (&lock);
327 mutex_cleanup_push (&lock); // release the mutex in case of cancellation
330 vlc_cond_wait (&wait, &lock);
332 --- foobar is now true, do something about it here --
334 vlc_cleanup_run (); // release the mutex
337 * @param p_condvar condition variable to wait on
338 * @param p_mutex mutex which is unlocked while waiting,
339 * then locked again when waking up.
340 * @param deadline <b>absolute</b> timeout
342 * @return 0 if the condition was signaled, an error code in case of timeout.
344 void vlc_cond_wait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex)
346 int val = pthread_cond_wait( p_condvar, p_mutex );
347 VLC_THREAD_ASSERT ("waiting on condition");
351 * Waits for a condition variable up to a certain date.
352 * This works like vlc_cond_wait(), except for the additional timeout.
354 * @param p_condvar condition variable to wait on
355 * @param p_mutex mutex which is unlocked while waiting,
356 * then locked again when waking up.
357 * @param deadline <b>absolute</b> timeout
359 * @return 0 if the condition was signaled, an error code in case of timeout.
361 int vlc_cond_timedwait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex,
364 #if defined(__APPLE__) && !defined(__powerpc__) && !defined( __ppc__ ) && !defined( __ppc64__ )
365 /* mdate() is mac_absolute_time on OSX, which we must convert to do
366 * the same base than gettimeofday() which pthread_cond_timedwait
368 mtime_t oldbase = mdate();
370 gettimeofday(&tv, NULL);
371 mtime_t newbase = (mtime_t)tv.tv_sec * 1000000 + (mtime_t) tv.tv_usec;
372 deadline = deadline - oldbase + newbase;
374 lldiv_t d = lldiv( deadline, CLOCK_FREQ );
375 struct timespec ts = { d.quot, d.rem * (1000000000 / CLOCK_FREQ) };
377 int val = pthread_cond_timedwait (p_condvar, p_mutex, &ts);
378 if (val != ETIMEDOUT)
379 VLC_THREAD_ASSERT ("timed-waiting on condition");
384 * Initializes a semaphore.
386 void vlc_sem_init (vlc_sem_t *sem, unsigned value)
388 if (sem_init (sem, 0, value))
393 * Destroys a semaphore.
395 void vlc_sem_destroy (vlc_sem_t *sem)
397 int val = sem_destroy (sem);
398 VLC_THREAD_ASSERT ("destroying semaphore");
402 * Increments the value of a semaphore.
404 int vlc_sem_post (vlc_sem_t *sem)
406 int val = sem_post (sem);
407 if (val != EOVERFLOW)
408 VLC_THREAD_ASSERT ("unlocking semaphore");
413 * Atomically wait for the semaphore to become non-zero (if needed),
414 * then decrements it.
416 void vlc_sem_wait (vlc_sem_t *sem)
420 val = sem_wait (sem);
421 while (val == EINTR);
422 VLC_THREAD_ASSERT ("locking semaphore");
426 * Initializes a read/write lock.
428 void vlc_rwlock_init (vlc_rwlock_t *lock)
430 if (pthread_rwlock_init (lock, NULL))
435 * Destroys an initialized unused read/write lock.
437 void vlc_rwlock_destroy (vlc_rwlock_t *lock)
439 int val = pthread_rwlock_destroy (lock);
440 VLC_THREAD_ASSERT ("destroying R/W lock");
444 * Acquires a read/write lock for reading. Recursion is allowed.
446 void vlc_rwlock_rdlock (vlc_rwlock_t *lock)
448 int val = pthread_rwlock_rdlock (lock);
449 VLC_THREAD_ASSERT ("acquiring R/W lock for reading");
453 * Acquires a read/write lock for writing. Recursion is not allowed.
455 void vlc_rwlock_wrlock (vlc_rwlock_t *lock)
457 int val = pthread_rwlock_wrlock (lock);
458 VLC_THREAD_ASSERT ("acquiring R/W lock for writing");
462 * Releases a read/write lock.
464 void vlc_rwlock_unlock (vlc_rwlock_t *lock)
466 int val = pthread_rwlock_unlock (lock);
467 VLC_THREAD_ASSERT ("releasing R/W lock");
471 * Allocates a thread-specific variable.
472 * @param key where to store the thread-specific variable handle
473 * @param destr a destruction callback. It is called whenever a thread exits
474 * and the thread-specific variable has a non-NULL value.
475 * @return 0 on success, a system error code otherwise. This function can
476 * actually fail because there is a fixed limit on the number of
477 * thread-specific variable in a process on most systems.
479 int vlc_threadvar_create (vlc_threadvar_t *key, void (*destr) (void *))
481 return pthread_key_create (key, destr);
484 void vlc_threadvar_delete (vlc_threadvar_t *p_tls)
486 pthread_key_delete (*p_tls);
490 * Sets a thread-specific variable.
491 * @param key thread-local variable key (created with vlc_threadvar_create())
492 * @param value new value for the variable for the calling thread
493 * @return 0 on success, a system error code otherwise.
495 int vlc_threadvar_set (vlc_threadvar_t key, void *value)
497 return pthread_setspecific (key, value);
501 * Gets the value of a thread-local variable for the calling thread.
502 * This function cannot fail.
503 * @return the value associated with the given variable for the calling
504 * or NULL if there is no value.
506 void *vlc_threadvar_get (vlc_threadvar_t key)
508 return pthread_getspecific (key);
511 static bool rt_priorities = false;
512 static int rt_offset;
514 void vlc_threads_setup (libvlc_int_t *p_libvlc)
516 static vlc_mutex_t lock = VLC_STATIC_MUTEX;
517 static bool initialized = false;
519 vlc_mutex_lock (&lock);
520 /* Initializes real-time priorities before any thread is created,
521 * just once per process. */
525 if (config_GetInt (p_libvlc, "rt-priority"))
528 rt_offset = config_GetInt (p_libvlc, "rt-offset");
529 rt_priorities = true;
533 vlc_mutex_unlock (&lock);
537 * Creates and starts new thread.
539 * @param p_handle [OUT] pointer to write the handle of the created thread to
540 * @param entry entry point for the thread
541 * @param data data parameter given to the entry point
542 * @param priority thread priority value
543 * @return 0 on success, a standard error code on error.
545 int vlc_clone (vlc_thread_t *p_handle, void * (*entry) (void *), void *data,
551 pthread_attr_init (&attr);
553 /* Block the signals that signals interface plugin handles.
554 * If the LibVLC caller wants to handle some signals by itself, it should
555 * block these before whenever invoking LibVLC. And it must obviously not
556 * start the VLC signals interface plugin.
558 * LibVLC will normally ignore any interruption caused by an asynchronous
559 * signal during a system call. But there may well be some buggy cases
560 * where it fails to handle EINTR (bug reports welcome). Some underlying
561 * libraries might also not handle EINTR properly.
567 sigdelset (&set, SIGHUP);
568 sigaddset (&set, SIGINT);
569 sigaddset (&set, SIGQUIT);
570 sigaddset (&set, SIGTERM);
572 sigaddset (&set, SIGPIPE); /* We don't want this one, really! */
573 pthread_sigmask (SIG_BLOCK, &set, &oldset);
576 #if defined (_POSIX_PRIORITY_SCHEDULING) && (_POSIX_PRIORITY_SCHEDULING >= 0) \
577 && defined (_POSIX_THREAD_PRIORITY_SCHEDULING) \
578 && (_POSIX_THREAD_PRIORITY_SCHEDULING >= 0)
581 struct sched_param sp = { .sched_priority = priority + rt_offset, };
584 if (sp.sched_priority <= 0)
585 sp.sched_priority += sched_get_priority_max (policy = SCHED_OTHER);
587 sp.sched_priority += sched_get_priority_min (policy = SCHED_RR);
589 pthread_attr_setschedpolicy (&attr, policy);
590 pthread_attr_setschedparam (&attr, &sp);
596 /* The thread stack size.
597 * The lower the value, the less address space per thread, the highest
598 * maximum simultaneous threads per process. Too low values will cause
599 * stack overflows and weird crashes. Set with caution. Also keep in mind
600 * that 64-bits platforms consume more stack than 32-bits one.
602 * Thanks to on-demand paging, thread stack size only affects address space
603 * consumption. In terms of memory, threads only use what they need
604 * (rounded up to the page boundary).
606 * For example, on Linux i386, the default is 2 mega-bytes, which supports
607 * about 320 threads per processes. */
608 #define VLC_STACKSIZE (128 * sizeof (void *) * 1024)
611 ret = pthread_attr_setstacksize (&attr, VLC_STACKSIZE);
612 assert (ret == 0); /* fails iif VLC_STACKSIZE is invalid */
615 ret = pthread_create (p_handle, &attr, entry, data);
616 pthread_sigmask (SIG_SETMASK, &oldset, NULL);
617 pthread_attr_destroy (&attr);
622 * Marks a thread as cancelled. Next time the target thread reaches a
623 * cancellation point (while not having disabled cancellation), it will
624 * run its cancellation cleanup handler, the thread variable destructors, and
625 * terminate. vlc_join() must be used afterward regardless of a thread being
628 void vlc_cancel (vlc_thread_t thread_id)
630 pthread_cancel (thread_id);
634 * Waits for a thread to complete (if needed), then destroys it.
635 * This is a cancellation point; in case of cancellation, the join does _not_
638 * A thread cannot join itself (normally VLC will abort if this is attempted).
639 * Also, a detached thread <b>cannot</b> be joined.
641 * @param handle thread handle
642 * @param p_result [OUT] pointer to write the thread return value or NULL
644 void vlc_join (vlc_thread_t handle, void **result)
646 int val = pthread_join (handle, result);
647 VLC_THREAD_ASSERT ("joining thread");
651 * Detaches a thread. When the specified thread completes, it will be
652 * automatically destroyed (in particular, its stack will be reclaimed),
653 * instead of waiting for another thread to call vlc_join(). If the thread has
654 * already completed, it will be destroyed immediately.
656 * When a thread performs some work asynchronously and may complete much
657 * earlier than it can be joined, detaching the thread can save memory.
658 * However, care must be taken that any resources used by a detached thread
659 * remains valid until the thread completes. This will typically involve some
660 * kind of thread-safe signaling.
662 * A thread may detach itself.
664 * @param handle thread handle
666 void vlc_detach (vlc_thread_t handle)
668 int val = pthread_detach (handle);
669 VLC_THREAD_ASSERT ("detaching thread");
673 * Save the current cancellation state (enabled or disabled), then disable
674 * cancellation for the calling thread.
675 * This function must be called before entering a piece of code that is not
676 * cancellation-safe, unless it can be proven that the calling thread will not
678 * @return Previous cancellation state (opaque value for vlc_restorecancel()).
680 int vlc_savecancel (void)
683 int val = pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
685 VLC_THREAD_ASSERT ("saving cancellation");
690 * Restore the cancellation state for the calling thread.
691 * @param state previous state as returned by vlc_savecancel().
692 * @return Nothing, always succeeds.
694 void vlc_restorecancel (int state)
699 val = pthread_setcancelstate (state, &oldstate);
700 /* This should fail if an invalid value for given for state */
701 VLC_THREAD_ASSERT ("restoring cancellation");
703 if (oldstate != PTHREAD_CANCEL_DISABLE)
704 vlc_thread_fatal ("restoring cancellation while not disabled", EINVAL,
705 __func__, __FILE__, __LINE__);
707 pthread_setcancelstate (state, NULL);
712 * Issues an explicit deferred cancellation point.
713 * This has no effect if thread cancellation is disabled.
714 * This can be called when there is a rather slow non-sleeping operation.
715 * This is also used to force a cancellation point in a function that would
716 * otherwise "not always" be a one (block_FifoGet() is an example).
718 void vlc_testcancel (void)
720 pthread_testcancel ();
723 void vlc_control_cancel (int cmd, ...)
735 void (*func) (void *);
737 mtime_t value, interval;
742 static void *vlc_timer_do (void *data)
744 struct vlc_timer *timer = data;
746 timer->func (timer->data);
748 vlc_mutex_lock (&timer->lock);
749 assert (timer->users > 0);
750 if (--timer->users == 0)
751 vlc_cond_signal (&timer->wait);
752 vlc_mutex_unlock (&timer->lock);
756 static void *vlc_timer_thread (void *data)
758 struct vlc_timer *timer = data;
759 mtime_t value, interval;
761 vlc_mutex_lock (&timer->lock);
762 value = timer->value;
763 interval = timer->interval;
764 vlc_mutex_unlock (&timer->lock);
772 vlc_mutex_lock (&timer->lock);
773 if (vlc_clone (&th, vlc_timer_do, timer, VLC_THREAD_PRIORITY_INPUT))
780 vlc_mutex_unlock (&timer->lock);
790 * Initializes an asynchronous timer.
791 * @warning Asynchronous timers are processed from an unspecified thread.
792 * Also, multiple occurences of an interval timer can run concurrently.
794 * @param id pointer to timer to be initialized
795 * @param func function that the timer will call
796 * @param data parameter for the timer function
797 * @return 0 on success, a system error code otherwise.
799 int vlc_timer_create (vlc_timer_t *id, void (*func) (void *), void *data)
801 struct vlc_timer *timer = malloc (sizeof (*timer));
805 vlc_mutex_init (&timer->lock);
806 vlc_cond_init (&timer->wait);
819 * Destroys an initialized timer. If needed, the timer is first disarmed.
820 * This function is undefined if the specified timer is not initialized.
822 * @warning This function <b>must</b> be called before the timer data can be
823 * freed and before the timer callback function can be unloaded.
825 * @param timer timer to destroy
827 void vlc_timer_destroy (vlc_timer_t timer)
829 vlc_timer_schedule (timer, false, 0, 0);
830 vlc_mutex_lock (&timer->lock);
831 while (timer->users != 0)
832 vlc_cond_wait (&timer->wait, &timer->lock);
833 vlc_mutex_unlock (&timer->lock);
835 vlc_cond_destroy (&timer->wait);
836 vlc_mutex_destroy (&timer->lock);
841 * Arm or disarm an initialized timer.
842 * This functions overrides any previous call to itself.
844 * @note A timer can fire later than requested due to system scheduling
845 * limitations. An interval timer can fail to trigger sometimes, either because
846 * the system is busy or suspended, or because a previous iteration of the
847 * timer is still running. See also vlc_timer_getoverrun().
849 * @param timer initialized timer
850 * @param absolute the timer value origin is the same as mdate() if true,
851 * the timer value is relative to now if false.
852 * @param value zero to disarm the timer, otherwise the initial time to wait
853 * before firing the timer.
854 * @param interval zero to fire the timer just once, otherwise the timer
855 * repetition interval.
857 void vlc_timer_schedule (vlc_timer_t timer, bool absolute,
858 mtime_t value, mtime_t interval)
860 static vlc_mutex_t lock = VLC_STATIC_MUTEX;
862 vlc_mutex_lock (&lock);
863 vlc_mutex_lock (&timer->lock);
866 vlc_mutex_unlock (&timer->lock);
867 vlc_cancel (timer->thread);
868 vlc_join (timer->thread, NULL);
869 vlc_mutex_lock (&timer->lock);
873 && (vlc_clone (&timer->thread, vlc_timer_thread, timer,
874 VLC_THREAD_PRIORITY_INPUT) == 0))
876 timer->value = (absolute ? 0 : mdate ()) + value;
877 timer->interval = interval;
879 vlc_mutex_unlock (&timer->lock);
880 vlc_mutex_unlock (&lock);
884 * Fetch and reset the overrun counter for a timer.
885 * @param timer initialized timer
886 * @return the timer overrun counter, i.e. the number of times that the timer
887 * should have run but did not since the last actual run. If all is well, this
890 unsigned vlc_timer_getoverrun (vlc_timer_t timer)
894 vlc_mutex_lock (&timer->lock);
895 ret = timer->overruns;
897 vlc_mutex_unlock (&timer->lock);