1 /*****************************************************************************
2 * threads.c : threads implementation for the VideoLAN client
3 *****************************************************************************
4 * Copyright (C) 1999-2008 the VideoLAN team
7 * Authors: Jean-Marc Dressler <polux@via.ecp.fr>
8 * Samuel Hocevar <sam@zoy.org>
9 * Gildas Bazin <gbazin@netcourrier.com>
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
26 *****************************************************************************/
32 #include <vlc_common.h>
42 #if defined( LIBVLC_USE_PTHREAD )
45 # include <sys/syscall.h> /* SYS_gettid */
48 static vlc_threadvar_t cancel_key;
51 #ifdef HAVE_EXECINFO_H
52 # include <execinfo.h>
56 # include <sys/time.h> /* gettimeofday in vlc_cond_timedwait */
60 * Print a backtrace to the standard error for debugging purpose.
62 void vlc_trace (const char *fn, const char *file, unsigned line)
64 fprintf (stderr, "at %s:%u in %s\n", file, line, fn);
65 fflush (stderr); /* needed before switch to low-level I/O */
68 int len = backtrace (stack, sizeof (stack) / sizeof (stack[0]));
69 backtrace_symbols_fd (stack, len, 2);
76 static inline unsigned long vlc_threadid (void)
78 #if defined (LIBVLC_USE_PTHREAD)
79 # if defined (__linux__)
80 return syscall (SYS_gettid);
83 union { pthread_t th; unsigned long int i; } v = { };
84 v.th = pthread_self ();
89 return GetCurrentThreadId ();
98 /*****************************************************************************
99 * vlc_thread_fatal: Report an error from the threading layer
100 *****************************************************************************
101 * This is mostly meant for debugging.
102 *****************************************************************************/
104 vlc_thread_fatal (const char *action, int error,
105 const char *function, const char *file, unsigned line)
107 fprintf (stderr, "LibVLC fatal error %s (%d) in thread %lu ",
108 action, error, vlc_threadid ());
109 vlc_trace (function, file, line);
111 /* Sometimes strerror_r() crashes too, so make sure we print an error
112 * message before we invoke it */
114 /* Avoid the strerror_r() prototype brain damage in glibc */
116 fprintf (stderr, " Error message: %m\n");
117 #elif !defined (WIN32)
121 switch (strerror_r (error, buf, sizeof (buf)))
126 case ERANGE: /* should never happen */
127 msg = "unknwon (too big to display)";
130 msg = "unknown (invalid error number)";
133 fprintf (stderr, " Error message: %s\n", msg);
140 # define VLC_THREAD_ASSERT( action ) \
141 if (val) vlc_thread_fatal (action, val, __func__, __FILE__, __LINE__)
143 # define VLC_THREAD_ASSERT( action ) ((void)val)
147 * Per-thread cancellation data
149 #ifndef LIBVLC_USE_PTHREAD_CANCEL
150 typedef struct vlc_cancel_t
152 vlc_cleanup_t *cleaners;
161 # define VLC_CANCEL_INIT { NULL, true, false }
163 # define VLC_CANCEL_INIT { NULL, true, false, NULL }
168 static void CALLBACK vlc_cancel_self (ULONG_PTR dummy);
170 static DWORD vlc_cancelable_wait (DWORD count, const HANDLE *handles,
173 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
176 /* Main thread - cannot be cancelled anyway */
177 return WaitForMultipleObjects (count, handles, FALSE, delay);
179 HANDLE new_handles[count + 1];
180 memcpy(new_handles, handles, count * sizeof(HANDLE));
181 new_handles[count] = nfo->cancel_event;
182 DWORD result = WaitForMultipleObjects (count + 1, new_handles, FALSE,
184 if (result == WAIT_OBJECT_0 + count)
186 vlc_cancel_self (NULL);
187 return WAIT_IO_COMPLETION;
195 DWORD SleepEx (DWORD dwMilliseconds, BOOL bAlertable)
199 DWORD result = vlc_cancelable_wait (0, NULL, dwMilliseconds);
200 return (result == WAIT_TIMEOUT) ? 0 : WAIT_IO_COMPLETION;
204 Sleep(dwMilliseconds);
209 DWORD WaitForSingleObjectEx (HANDLE hHandle, DWORD dwMilliseconds,
214 /* The MSDN documentation specifies different return codes,
215 * but in practice they are the same. We just check that it
217 #if WAIT_ABANDONED != WAIT_ABANDONED_0
218 # error Windows headers changed, code needs to be rewritten!
220 return vlc_cancelable_wait (1, &hHandle, dwMilliseconds);
224 return WaitForSingleObject (hHandle, dwMilliseconds);
228 DWORD WaitForMultipleObjectsEx (DWORD nCount, const HANDLE *lpHandles,
229 BOOL bWaitAll, DWORD dwMilliseconds,
234 /* We do not support the bWaitAll case */
236 return vlc_cancelable_wait (nCount, lpHandles, dwMilliseconds);
240 return WaitForMultipleObjects (nCount, lpHandles, bWaitAll,
247 static vlc_mutex_t super_mutex, tls_mutex;
248 static struct vlc_threadvar *tls_list = NULL;
250 BOOL WINAPI DllMain (HINSTANCE hinstDll, DWORD fdwReason, LPVOID lpvReserved)
257 case DLL_PROCESS_ATTACH:
258 vlc_mutex_init (&super_mutex);
259 vlc_mutex_init (&tls_mutex);
260 vlc_threadvar_create (&cancel_key, free);
263 case DLL_PROCESS_DETACH:
264 vlc_threadvar_delete( &cancel_key );
265 assert (tls_list == NULL);
266 vlc_mutex_destroy (&tls_mutex);
267 vlc_mutex_destroy (&super_mutex);
274 #if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
275 /* This is not prototyped under glibc, though it exists. */
276 int pthread_mutexattr_setkind_np( pthread_mutexattr_t *attr, int kind );
279 /*****************************************************************************
280 * vlc_mutex_init: initialize a mutex
281 *****************************************************************************/
282 int vlc_mutex_init( vlc_mutex_t *p_mutex )
284 #if defined( LIBVLC_USE_PTHREAD )
285 pthread_mutexattr_t attr;
288 pthread_mutexattr_init( &attr );
291 /* Create error-checking mutex to detect problems more easily. */
292 # if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
293 pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_ERRORCHECK_NP );
295 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ERRORCHECK );
298 i_result = pthread_mutex_init( p_mutex, &attr );
299 pthread_mutexattr_destroy( &attr );
302 #elif defined( WIN32 )
303 /* This creates a recursive mutex. This is OK as fast mutexes have
304 * no defined behavior in case of recursive locking. */
305 InitializeCriticalSection (&p_mutex->mutex);
306 p_mutex->initialized = 1;
312 /*****************************************************************************
313 * vlc_mutex_init: initialize a recursive mutex (Do not use)
314 *****************************************************************************/
315 int vlc_mutex_init_recursive( vlc_mutex_t *p_mutex )
317 #if defined( LIBVLC_USE_PTHREAD )
318 pthread_mutexattr_t attr;
321 pthread_mutexattr_init( &attr );
322 # if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
323 pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_RECURSIVE_NP );
325 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_RECURSIVE );
327 i_result = pthread_mutex_init( p_mutex, &attr );
328 pthread_mutexattr_destroy( &attr );
331 #elif defined( WIN32 )
332 InitializeCriticalSection( &p_mutex->mutex );
333 p_mutex->initialized = 1;
341 * Destroys a mutex. The mutex must not be locked.
343 * @param p_mutex mutex to destroy
344 * @return always succeeds
346 void vlc_mutex_destroy (vlc_mutex_t *p_mutex)
348 #if defined( LIBVLC_USE_PTHREAD )
349 int val = pthread_mutex_destroy( p_mutex );
350 VLC_THREAD_ASSERT ("destroying mutex");
352 #elif defined( WIN32 )
353 assert (InterlockedExchange (&p_mutex->initialized, -1) == 1);
354 DeleteCriticalSection (&p_mutex->mutex);
359 #if defined(LIBVLC_USE_PTHREAD) && !defined(NDEBUG)
360 # ifdef HAVE_VALGRIND_VALGRIND_H
361 # include <valgrind/valgrind.h>
363 # define RUNNING_ON_VALGRIND (0)
366 void vlc_assert_locked (vlc_mutex_t *p_mutex)
368 if (RUNNING_ON_VALGRIND > 0)
370 assert (pthread_mutex_lock (p_mutex) == EDEADLK);
375 * Acquires a mutex. If needed, waits for any other thread to release it.
376 * Beware of deadlocks when locking multiple mutexes at the same time,
377 * or when using mutexes from callbacks.
378 * This function is not a cancellation-point.
380 * @param p_mutex mutex initialized with vlc_mutex_init() or
381 * vlc_mutex_init_recursive()
383 void vlc_mutex_lock (vlc_mutex_t *p_mutex)
385 #if defined(LIBVLC_USE_PTHREAD)
386 int val = pthread_mutex_lock( p_mutex );
387 VLC_THREAD_ASSERT ("locking mutex");
389 #elif defined( WIN32 )
390 if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
391 { /* ^^ We could also lock super_mutex all the time... sluggish */
392 assert (p_mutex != &super_mutex); /* this one cannot be static */
394 vlc_mutex_lock (&super_mutex);
395 if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
396 vlc_mutex_init (p_mutex);
397 /* FIXME: destroy the mutex some time... */
398 vlc_mutex_unlock (&super_mutex);
400 assert (InterlockedExchange (&p_mutex->initialized, 1) == 1);
401 EnterCriticalSection (&p_mutex->mutex);
407 * Acquires a mutex if and only if it is not currently held by another thread.
408 * This function never sleeps and can be used in delay-critical code paths.
409 * This function is not a cancellation-point.
411 * <b>Beware</b>: If this function fails, then the mutex is held... by another
412 * thread. The calling thread must deal with the error appropriately. That
413 * typically implies postponing the operations that would have required the
414 * mutex. If the thread cannot defer those operations, then it must use
415 * vlc_mutex_lock(). If in doubt, use vlc_mutex_lock() instead.
417 * @param p_mutex mutex initialized with vlc_mutex_init() or
418 * vlc_mutex_init_recursive()
419 * @return 0 if the mutex could be acquired, an error code otherwise.
421 int vlc_mutex_trylock (vlc_mutex_t *p_mutex)
423 #if defined(LIBVLC_USE_PTHREAD)
424 int val = pthread_mutex_trylock( p_mutex );
427 VLC_THREAD_ASSERT ("locking mutex");
430 #elif defined( WIN32 )
431 if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
432 { /* ^^ We could also lock super_mutex all the time... sluggish */
433 assert (p_mutex != &super_mutex); /* this one cannot be static */
435 vlc_mutex_lock (&super_mutex);
436 if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
437 vlc_mutex_init (p_mutex);
438 /* FIXME: destroy the mutex some time... */
439 vlc_mutex_unlock (&super_mutex);
441 assert (InterlockedExchange (&p_mutex->initialized, 1) == 1);
442 return TryEnterCriticalSection (&p_mutex->mutex) ? 0 : EBUSY;
448 * Releases a mutex (or crashes if the mutex is not locked by the caller).
449 * @param p_mutex mutex locked with vlc_mutex_lock().
451 void vlc_mutex_unlock (vlc_mutex_t *p_mutex)
453 #if defined(LIBVLC_USE_PTHREAD)
454 int val = pthread_mutex_unlock( p_mutex );
455 VLC_THREAD_ASSERT ("unlocking mutex");
457 #elif defined( WIN32 )
458 assert (InterlockedExchange (&p_mutex->initialized, 1) == 1);
459 LeaveCriticalSection (&p_mutex->mutex);
464 /*****************************************************************************
465 * vlc_cond_init: initialize a condition variable
466 *****************************************************************************/
467 int vlc_cond_init( vlc_cond_t *p_condvar )
469 #if defined( LIBVLC_USE_PTHREAD )
470 pthread_condattr_t attr;
473 ret = pthread_condattr_init (&attr);
477 # if !defined (_POSIX_CLOCK_SELECTION)
478 /* Fairly outdated POSIX support (that was defined in 2001) */
479 # define _POSIX_CLOCK_SELECTION (-1)
481 # if (_POSIX_CLOCK_SELECTION >= 0)
482 /* NOTE: This must be the same clock as the one in mtime.c */
483 pthread_condattr_setclock (&attr, CLOCK_MONOTONIC);
486 ret = pthread_cond_init (p_condvar, &attr);
487 pthread_condattr_destroy (&attr);
490 #elif defined( WIN32 )
491 /* Create a manual-reset event (manual reset is needed for broadcast). */
492 *p_condvar = CreateEvent( NULL, TRUE, FALSE, NULL );
493 return *p_condvar ? 0 : ENOMEM;
499 * Destroys a condition variable. No threads shall be waiting or signaling the
501 * @param p_condvar condition variable to destroy
503 void vlc_cond_destroy (vlc_cond_t *p_condvar)
505 #if defined( LIBVLC_USE_PTHREAD )
506 int val = pthread_cond_destroy( p_condvar );
507 VLC_THREAD_ASSERT ("destroying condition");
509 #elif defined( WIN32 )
510 CloseHandle( *p_condvar );
516 * Wakes up one thread waiting on a condition variable, if any.
517 * @param p_condvar condition variable
519 void vlc_cond_signal (vlc_cond_t *p_condvar)
521 #if defined(LIBVLC_USE_PTHREAD)
522 int val = pthread_cond_signal( p_condvar );
523 VLC_THREAD_ASSERT ("signaling condition variable");
525 #elif defined( WIN32 )
526 /* NOTE: This will cause a broadcast, that is wrong.
527 * This will also wake up the next waiting thread if no thread are yet
528 * waiting, which is also wrong. However both of these issues are allowed
529 * by the provision for spurious wakeups. Better have too many wakeups
530 * than too few (= deadlocks). */
531 SetEvent (*p_condvar);
537 * Wakes up all threads (if any) waiting on a condition variable.
538 * @param p_cond condition variable
540 void vlc_cond_broadcast (vlc_cond_t *p_condvar)
542 #if defined (LIBVLC_USE_PTHREAD)
543 pthread_cond_broadcast (p_condvar);
545 #elif defined (WIN32)
546 SetEvent (*p_condvar);
552 * Waits for a condition variable. The calling thread will be suspended until
553 * another thread calls vlc_cond_signal() or vlc_cond_broadcast() on the same
554 * condition variable, the thread is cancelled with vlc_cancel(), or the
555 * system causes a "spurious" unsolicited wake-up.
557 * A mutex is needed to wait on a condition variable. It must <b>not</b> be
558 * a recursive mutex. Although it is possible to use the same mutex for
559 * multiple condition, it is not valid to use different mutexes for the same
560 * condition variable at the same time from different threads.
562 * In case of thread cancellation, the mutex is always locked before
563 * cancellation proceeds.
565 * The canonical way to use a condition variable to wait for event foobar is:
567 vlc_mutex_lock (&lock);
568 mutex_cleanup_push (&lock); // release the mutex in case of cancellation
571 vlc_cond_wait (&wait, &lock);
573 --- foobar is now true, do something about it here --
575 vlc_cleanup_run (); // release the mutex
578 * @param p_condvar condition variable to wait on
579 * @param p_mutex mutex which is unlocked while waiting,
580 * then locked again when waking up.
581 * @param deadline <b>absolute</b> timeout
583 * @return 0 if the condition was signaled, an error code in case of timeout.
585 void vlc_cond_wait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex)
587 #if defined(LIBVLC_USE_PTHREAD)
588 int val = pthread_cond_wait( p_condvar, p_mutex );
589 VLC_THREAD_ASSERT ("waiting on condition");
591 #elif defined( WIN32 )
597 LeaveCriticalSection (&p_mutex->mutex);
598 result = WaitForSingleObjectEx (*p_condvar, INFINITE, TRUE);
599 EnterCriticalSection (&p_mutex->mutex);
601 while (result == WAIT_IO_COMPLETION);
603 ResetEvent (*p_condvar);
609 * Waits for a condition variable up to a certain date.
610 * This works like vlc_cond_wait(), except for the additional timeout.
612 * @param p_condvar condition variable to wait on
613 * @param p_mutex mutex which is unlocked while waiting,
614 * then locked again when waking up.
615 * @param deadline <b>absolute</b> timeout
617 * @return 0 if the condition was signaled, an error code in case of timeout.
619 int vlc_cond_timedwait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex,
622 #if defined(LIBVLC_USE_PTHREAD)
624 /* mdate() is mac_absolute_time on osx, which we must convert to do
625 * the same base than gettimeofday() on which pthread_cond_timedwait
627 mtime_t oldbase = mdate();
629 gettimeofday(&tv, NULL);
630 mtime_t newbase = (mtime_t)tv.tv_sec * 1000000 + (mtime_t) tv.tv_usec;
631 deadline = deadline - oldbase + newbase;
633 lldiv_t d = lldiv( deadline, CLOCK_FREQ );
634 struct timespec ts = { d.quot, d.rem * (1000000000 / CLOCK_FREQ) };
636 int val = pthread_cond_timedwait (p_condvar, p_mutex, &ts);
637 if (val != ETIMEDOUT)
638 VLC_THREAD_ASSERT ("timed-waiting on condition");
641 #elif defined( WIN32 )
648 mtime_t total = (deadline - mdate ())/1000;
652 DWORD delay = (total > 0x7fffffff) ? 0x7fffffff : total;
653 LeaveCriticalSection (&p_mutex->mutex);
654 result = WaitForSingleObjectEx (*p_condvar, delay, TRUE);
655 EnterCriticalSection (&p_mutex->mutex);
657 while (result == WAIT_IO_COMPLETION);
659 ResetEvent (*p_condvar);
661 return (result == WAIT_OBJECT_0) ? 0 : ETIMEDOUT;
667 #if defined (LIBVLC_USE_PTHREAD)
668 #elif defined (WIN32)
672 void (*cleanup) (void *);
673 struct vlc_threadvar *prev, *next;
676 static void vlc_threadvar_cleanup (void)
678 struct vlc_threadvar *p;
680 vlc_mutex_lock (&tls_mutex);
681 for (p = tls_list; p != NULL; p = p->next)
683 void *value = TlsGetValue (p->handle);
687 vlc_mutex_unlock (&tls_mutex);
691 /*****************************************************************************
692 * vlc_tls_create: create a thread-local variable
693 *****************************************************************************/
694 int vlc_threadvar_create( vlc_threadvar_t *p_tls, void (*destr) (void *) )
696 #if defined( LIBVLC_USE_PTHREAD )
697 return pthread_key_create( p_tls, destr );
699 #elif defined( WIN32 )
700 struct vlc_threadvar *tls = malloc (sizeof (*tls));
704 tls->handle = TlsAlloc();
705 if (tls->handle == TLS_OUT_OF_INDEXES)
710 tls->cleanup = destr;
712 vlc_mutex_lock (&tls_mutex);
713 tls->next = tls_list;
715 tls_list->prev = tls;
717 vlc_mutex_unlock (&tls_mutex);
722 # error Unimplemented!
726 void vlc_threadvar_delete (vlc_threadvar_t *p_tls)
728 #if defined( LIBVLC_USE_PTHREAD )
729 pthread_key_delete (*p_tls);
731 #elif defined( WIN32 )
732 struct vlc_threadvar *tls = *p_tls;
734 TlsFree (tls->handle);
735 vlc_mutex_lock (&tls_mutex);
737 tls->prev->next = tls->next;
739 tls->next->prev = tls->prev;
740 vlc_mutex_unlock (&tls_mutex);
744 # error Unimplemented!
749 * Sets a thread-local variable.
750 * @param key thread-local variable key (created with vlc_threadvar_create())
751 * @param value new value for the variable for the calling thread
752 * @return 0 on success, a system error code otherwise.
754 int vlc_threadvar_set (vlc_threadvar_t key, void *value)
756 #if defined(LIBVLC_USE_PTHREAD)
757 return pthread_setspecific (key, value);
758 #elif defined( UNDER_CE ) || defined( WIN32 )
759 return TlsSetValue (key->handle, value) ? ENOMEM : 0;
761 # error Unimplemented!
766 * Gets the value of a thread-local variable for the calling thread.
767 * This function cannot fail.
768 * @return the value associated with the given variable for the calling
769 * or NULL if there is no value.
771 void *vlc_threadvar_get (vlc_threadvar_t key)
773 #if defined(LIBVLC_USE_PTHREAD)
774 return pthread_getspecific (key);
775 #elif defined( UNDER_CE ) || defined( WIN32 )
776 return TlsGetValue (key->handle);
778 # error Unimplemented!
782 #if defined (LIBVLC_USE_PTHREAD)
783 #elif defined (WIN32)
784 static unsigned __stdcall vlc_entry (void *data)
786 vlc_cancel_t cancel_data = VLC_CANCEL_INIT;
787 vlc_thread_t self = data;
789 cancel_data.cancel_event = self->cancel_event;
792 vlc_threadvar_set (cancel_key, &cancel_data);
793 self->data = self->entry (self->data);
794 vlc_threadvar_cleanup ();
800 * Creates and starts new thread.
802 * @param p_handle [OUT] pointer to write the handle of the created thread to
803 * @param entry entry point for the thread
804 * @param data data parameter given to the entry point
805 * @param priority thread priority value
806 * @return 0 on success, a standard error code on error.
808 int vlc_clone (vlc_thread_t *p_handle, void * (*entry) (void *), void *data,
813 #if defined( LIBVLC_USE_PTHREAD )
815 pthread_attr_init (&attr);
817 /* Block the signals that signals interface plugin handles.
818 * If the LibVLC caller wants to handle some signals by itself, it should
819 * block these before whenever invoking LibVLC. And it must obviously not
820 * start the VLC signals interface plugin.
822 * LibVLC will normally ignore any interruption caused by an asynchronous
823 * signal during a system call. But there may well be some buggy cases
824 * where it fails to handle EINTR (bug reports welcome). Some underlying
825 * libraries might also not handle EINTR properly.
831 sigdelset (&set, SIGHUP);
832 sigaddset (&set, SIGINT);
833 sigaddset (&set, SIGQUIT);
834 sigaddset (&set, SIGTERM);
836 sigaddset (&set, SIGPIPE); /* We don't want this one, really! */
837 pthread_sigmask (SIG_BLOCK, &set, &oldset);
840 struct sched_param sp = { .sched_priority = priority, };
843 if (sp.sched_priority <= 0)
844 sp.sched_priority += sched_get_priority_max (policy = SCHED_OTHER);
846 sp.sched_priority += sched_get_priority_min (policy = SCHED_RR);
848 pthread_attr_setschedpolicy (&attr, policy);
849 pthread_attr_setschedparam (&attr, &sp);
852 /* The thread stack size.
853 * The lower the value, the less address space per thread, the highest
854 * maximum simultaneous threads per process. Too low values will cause
855 * stack overflows and weird crashes. Set with caution. Also keep in mind
856 * that 64-bits platforms consume more stack than 32-bits one.
858 * Thanks to on-demand paging, thread stack size only affects address space
859 * consumption. In terms of memory, threads only use what they need
860 * (rounded up to the page boundary).
862 * For example, on Linux i386, the default is 2 mega-bytes, which supports
863 * about 320 threads per processes. */
864 #define VLC_STACKSIZE (128 * sizeof (void *) * 1024)
867 ret = pthread_attr_setstacksize (&attr, VLC_STACKSIZE);
868 assert (ret == 0); /* fails iif VLC_STACKSIZE is invalid */
871 ret = pthread_create (p_handle, &attr, entry, data);
872 pthread_sigmask (SIG_SETMASK, &oldset, NULL);
873 pthread_attr_destroy (&attr);
875 #elif defined( WIN32 ) || defined( UNDER_CE )
876 /* When using the MSVCRT C library you have to use the _beginthreadex
877 * function instead of CreateThread, otherwise you'll end up with
878 * memory leaks and the signal functions not working (see Microsoft
879 * Knowledge Base, article 104641) */
881 vlc_thread_t th = malloc (sizeof (*th));
888 #if defined( UNDER_CE )
889 th->cancel_event = CreateEvent (NULL, FALSE, FALSE, NULL);
890 if (th->cancel_event == NULL)
895 hThread = CreateThread (NULL, 128*1024, vlc_entry, th, CREATE_SUSPENDED, NULL);
897 hThread = (HANDLE)(uintptr_t)
898 _beginthreadex (NULL, 0, vlc_entry, th, CREATE_SUSPENDED, NULL);
904 /* Thread closes the handle when exiting, duplicate it here
905 * to be on the safe side when joining. */
906 if (!DuplicateHandle (GetCurrentProcess (), hThread,
907 GetCurrentProcess (), &th->handle, 0, FALSE,
908 DUPLICATE_SAME_ACCESS))
910 CloseHandle (hThread);
915 th->handle = hThread;
918 ResumeThread (hThread);
920 SetThreadPriority (hThread, priority);
936 /* APC procedure for thread cancellation */
937 static void CALLBACK vlc_cancel_self (ULONG_PTR dummy)
940 vlc_control_cancel (VLC_DO_CANCEL);
945 * Marks a thread as cancelled. Next time the target thread reaches a
946 * cancellation point (while not having disabled cancellation), it will
947 * run its cancellation cleanup handler, the thread variable destructors, and
948 * terminate. vlc_join() must be used afterward regardless of a thread being
951 void vlc_cancel (vlc_thread_t thread_id)
953 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
954 pthread_cancel (thread_id);
955 #elif defined (UNDER_CE)
956 SetEvent (thread_id->cancel_event);
957 #elif defined (WIN32)
958 QueueUserAPC (vlc_cancel_self, thread_id->handle, 0);
960 # warning vlc_cancel is not implemented!
965 * Waits for a thread to complete (if needed), and destroys it.
966 * This is a cancellation point; in case of cancellation, the join does _not_
969 * @param handle thread handle
970 * @param p_result [OUT] pointer to write the thread return value or NULL
971 * @return 0 on success, a standard error code otherwise.
973 void vlc_join (vlc_thread_t handle, void **result)
975 #if defined( LIBVLC_USE_PTHREAD )
976 int val = pthread_join (handle, result);
977 VLC_THREAD_ASSERT ("joining thread");
979 #elif defined( UNDER_CE ) || defined( WIN32 )
982 while (WaitForSingleObjectEx (handle->handle, INFINITE, TRUE)
983 == WAIT_IO_COMPLETION);
985 CloseHandle (handle->handle);
987 *result = handle->data;
988 #if defined( UNDER_CE )
989 CloseHandle (handle->cancel_event);
997 * Save the current cancellation state (enabled or disabled), then disable
998 * cancellation for the calling thread.
999 * This function must be called before entering a piece of code that is not
1000 * cancellation-safe, unless it can be proven that the calling thread will not
1002 * @return Previous cancellation state (opaque value for vlc_restorecancel()).
1004 int vlc_savecancel (void)
1008 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
1009 int val = pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
1010 VLC_THREAD_ASSERT ("saving cancellation");
1013 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
1015 return false; /* Main thread - cannot be cancelled anyway */
1017 state = nfo->killable;
1018 nfo->killable = false;
1025 * Restore the cancellation state for the calling thread.
1026 * @param state previous state as returned by vlc_savecancel().
1027 * @return Nothing, always succeeds.
1029 void vlc_restorecancel (int state)
1031 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
1035 val = pthread_setcancelstate (state, &oldstate);
1036 /* This should fail if an invalid value for given for state */
1037 VLC_THREAD_ASSERT ("restoring cancellation");
1039 if (oldstate != PTHREAD_CANCEL_DISABLE)
1040 vlc_thread_fatal ("restoring cancellation while not disabled", EINVAL,
1041 __func__, __FILE__, __LINE__);
1043 pthread_setcancelstate (state, NULL);
1047 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
1048 assert (state == false || state == true);
1051 return; /* Main thread - cannot be cancelled anyway */
1053 assert (!nfo->killable);
1054 nfo->killable = state != 0;
1060 * Issues an explicit deferred cancellation point.
1061 * This has no effect if thread cancellation is disabled.
1062 * This can be called when there is a rather slow non-sleeping operation.
1063 * This is also used to force a cancellation point in a function that would
1064 * otherwise "not always" be a one (block_FifoGet() is an example).
1066 void vlc_testcancel (void)
1068 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
1069 pthread_testcancel ();
1072 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
1074 return; /* Main thread - cannot be cancelled anyway */
1076 if (nfo->killable && nfo->killed)
1078 for (vlc_cleanup_t *p = nfo->cleaners; p != NULL; p = p->next)
1080 # if defined (LIBVLC_USE_PTHREAD)
1081 pthread_exit (PTHREAD_CANCELLED);
1082 # elif defined (UNDER_CE)
1083 vlc_threadvar_cleanup ();
1085 # elif defined (WIN32)
1086 vlc_threadvar_cleanup ();
1089 # error Not implemented!
1096 struct vlc_thread_boot
1098 void * (*entry) (vlc_object_t *);
1099 vlc_object_t *object;
1102 static void *thread_entry (void *data)
1104 vlc_object_t *obj = ((struct vlc_thread_boot *)data)->object;
1105 void *(*func) (vlc_object_t *) = ((struct vlc_thread_boot *)data)->entry;
1108 msg_Dbg (obj, "thread started");
1110 msg_Dbg (obj, "thread ended");
1115 #undef vlc_thread_create
1116 /*****************************************************************************
1117 * vlc_thread_create: create a thread
1118 *****************************************************************************
1119 * Note that i_priority is only taken into account on platforms supporting
1120 * userland real-time priority threads.
1121 *****************************************************************************/
1122 int vlc_thread_create( vlc_object_t *p_this, const char * psz_file, int i_line,
1123 const char *psz_name, void *(*func) ( vlc_object_t * ),
1127 vlc_object_internals_t *p_priv = vlc_internals( p_this );
1129 struct vlc_thread_boot *boot = malloc (sizeof (*boot));
1133 boot->object = p_this;
1135 /* Make sure we don't re-create a thread if the object has already one */
1136 assert( !p_priv->b_thread );
1138 #if defined( LIBVLC_USE_PTHREAD )
1140 if( config_GetInt( p_this, "rt-priority" ) > 0 )
1143 /* Hack to avoid error msg */
1144 if( config_GetType( p_this, "rt-offset" ) )
1145 i_priority += config_GetInt( p_this, "rt-offset" );
1149 p_priv->b_thread = true;
1150 i_ret = vlc_clone( &p_priv->thread_id, thread_entry, boot, i_priority );
1152 msg_Dbg( p_this, "thread (%s) created at priority %d (%s:%d)",
1153 psz_name, i_priority, psz_file, i_line );
1156 p_priv->b_thread = false;
1158 msg_Err( p_this, "%s thread could not be created at %s:%d (%m)",
1159 psz_name, psz_file, i_line );
1165 /*****************************************************************************
1166 * vlc_thread_set_priority: set the priority of the current thread when we
1167 * couldn't set it in vlc_thread_create (for instance for the main thread)
1168 *****************************************************************************/
1169 int __vlc_thread_set_priority( vlc_object_t *p_this, const char * psz_file,
1170 int i_line, int i_priority )
1172 vlc_object_internals_t *p_priv = vlc_internals( p_this );
1174 if( !p_priv->b_thread )
1176 msg_Err( p_this, "couldn't set priority of non-existent thread" );
1180 #if defined( LIBVLC_USE_PTHREAD )
1182 if( config_GetInt( p_this, "rt-priority" ) > 0 )
1185 int i_error, i_policy;
1186 struct sched_param param;
1188 memset( ¶m, 0, sizeof(struct sched_param) );
1189 if( config_GetType( p_this, "rt-offset" ) )
1190 i_priority += config_GetInt( p_this, "rt-offset" );
1191 if( i_priority <= 0 )
1193 param.sched_priority = (-1) * i_priority;
1194 i_policy = SCHED_OTHER;
1198 param.sched_priority = i_priority;
1199 i_policy = SCHED_RR;
1201 if( (i_error = pthread_setschedparam( p_priv->thread_id,
1202 i_policy, ¶m )) )
1205 msg_Warn( p_this, "couldn't set thread priority (%s:%d): %m",
1211 #elif defined( WIN32 ) || defined( UNDER_CE )
1212 VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
1214 if( !SetThreadPriority(p_priv->thread_id->handle, i_priority) )
1216 msg_Warn( p_this, "couldn't set a faster priority" );
1225 /*****************************************************************************
1226 * vlc_thread_join: wait until a thread exits, inner version
1227 *****************************************************************************/
1228 void __vlc_thread_join( vlc_object_t *p_this )
1230 vlc_object_internals_t *p_priv = vlc_internals( p_this );
1232 #if defined( LIBVLC_USE_PTHREAD )
1233 vlc_join (p_priv->thread_id, NULL);
1235 #elif defined( UNDER_CE ) || defined( WIN32 )
1237 FILETIME create_ft, exit_ft, kernel_ft, user_ft;
1238 int64_t real_time, kernel_time, user_time;
1241 if( ! DuplicateHandle(GetCurrentProcess(),
1242 p_priv->thread_id->handle,
1243 GetCurrentProcess(),
1247 DUPLICATE_SAME_ACCESS) )
1249 p_priv->b_thread = false;
1250 return; /* We have a problem! */
1253 hThread = p_priv->thread_id->handle;
1256 vlc_join( p_priv->thread_id, NULL );
1258 if( GetThreadTimes( hThread, &create_ft, &exit_ft, &kernel_ft, &user_ft ) )
1261 ((((int64_t)exit_ft.dwHighDateTime)<<32)| exit_ft.dwLowDateTime) -
1262 ((((int64_t)create_ft.dwHighDateTime)<<32)| create_ft.dwLowDateTime);
1266 ((((int64_t)kernel_ft.dwHighDateTime)<<32)|
1267 kernel_ft.dwLowDateTime) / 10;
1270 ((((int64_t)user_ft.dwHighDateTime)<<32)|
1271 user_ft.dwLowDateTime) / 10;
1273 msg_Dbg( p_this, "thread times: "
1274 "real %"PRId64"m%fs, kernel %"PRId64"m%fs, user %"PRId64"m%fs",
1275 real_time/60/1000000,
1276 (double)((real_time%(60*1000000))/1000000.0),
1277 kernel_time/60/1000000,
1278 (double)((kernel_time%(60*1000000))/1000000.0),
1279 user_time/60/1000000,
1280 (double)((user_time%(60*1000000))/1000000.0) );
1282 CloseHandle( hThread );
1285 vlc_join( p_priv->thread_id, NULL );
1289 p_priv->b_thread = false;
1292 void vlc_thread_cancel (vlc_object_t *obj)
1294 vlc_object_internals_t *priv = vlc_internals (obj);
1297 vlc_cancel (priv->thread_id);
1300 void vlc_control_cancel (int cmd, ...)
1302 /* NOTE: This function only modifies thread-specific data, so there is no
1303 * need to lock anything. */
1304 #ifdef LIBVLC_USE_PTHREAD_CANCEL
1310 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
1314 /* Main thread - cannot be cancelled anyway */
1317 nfo = malloc (sizeof (*nfo));
1319 return; /* Uho! Expect problems! */
1320 *nfo = VLC_CANCEL_INIT;
1321 vlc_threadvar_set (cancel_key, nfo);
1332 case VLC_CLEANUP_PUSH:
1334 /* cleaner is a pointer to the caller stack, no need to allocate
1335 * and copy anything. As a nice side effect, this cannot fail. */
1336 vlc_cleanup_t *cleaner = va_arg (ap, vlc_cleanup_t *);
1337 cleaner->next = nfo->cleaners;
1338 nfo->cleaners = cleaner;
1342 case VLC_CLEANUP_POP:
1344 nfo->cleaners = nfo->cleaners->next;