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 ();
97 /*****************************************************************************
98 * vlc_thread_fatal: Report an error from the threading layer
99 *****************************************************************************
100 * This is mostly meant for debugging.
101 *****************************************************************************/
103 vlc_thread_fatal (const char *action, int error,
104 const char *function, const char *file, unsigned line)
106 fprintf (stderr, "LibVLC fatal error %s (%d) in thread %lu ",
107 action, error, vlc_threadid ());
108 vlc_trace (function, file, line);
110 /* Sometimes strerror_r() crashes too, so make sure we print an error
111 * message before we invoke it */
113 /* Avoid the strerror_r() prototype brain damage in glibc */
115 fprintf (stderr, " Error message: %m\n");
116 #elif !defined (WIN32)
120 switch (strerror_r (error, buf, sizeof (buf)))
125 case ERANGE: /* should never happen */
126 msg = "unknwon (too big to display)";
129 msg = "unknown (invalid error number)";
132 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;
249 BOOL WINAPI DllMain (HINSTANCE hinstDll, DWORD fdwReason, LPVOID lpvReserved)
256 case DLL_PROCESS_ATTACH:
257 vlc_mutex_init (&super_mutex);
258 vlc_threadvar_create (&cancel_key, free);
261 case DLL_PROCESS_DETACH:
262 vlc_threadvar_delete( &cancel_key );
263 vlc_mutex_destroy (&super_mutex);
270 #if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
271 /* This is not prototyped under glibc, though it exists. */
272 int pthread_mutexattr_setkind_np( pthread_mutexattr_t *attr, int kind );
275 /*****************************************************************************
276 * vlc_mutex_init: initialize a mutex
277 *****************************************************************************/
278 int vlc_mutex_init( vlc_mutex_t *p_mutex )
280 #if defined( LIBVLC_USE_PTHREAD )
281 pthread_mutexattr_t attr;
284 pthread_mutexattr_init( &attr );
287 /* Create error-checking mutex to detect problems more easily. */
288 # if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
289 pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_ERRORCHECK_NP );
291 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ERRORCHECK );
294 i_result = pthread_mutex_init( p_mutex, &attr );
295 pthread_mutexattr_destroy( &attr );
298 #elif defined( WIN32 )
299 /* This creates a recursive mutex. This is OK as fast mutexes have
300 * no defined behavior in case of recursive locking. */
301 InitializeCriticalSection (&p_mutex->mutex);
302 p_mutex->initialized = 1;
308 /*****************************************************************************
309 * vlc_mutex_init: initialize a recursive mutex (Do not use)
310 *****************************************************************************/
311 int vlc_mutex_init_recursive( vlc_mutex_t *p_mutex )
313 #if defined( LIBVLC_USE_PTHREAD )
314 pthread_mutexattr_t attr;
317 pthread_mutexattr_init( &attr );
318 # if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
319 pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_RECURSIVE_NP );
321 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_RECURSIVE );
323 i_result = pthread_mutex_init( p_mutex, &attr );
324 pthread_mutexattr_destroy( &attr );
327 #elif defined( WIN32 )
328 InitializeCriticalSection( &p_mutex->mutex );
329 p_mutex->initialized = 1;
337 * Destroys a mutex. The mutex must not be locked.
339 * @param p_mutex mutex to destroy
340 * @return always succeeds
342 void vlc_mutex_destroy (vlc_mutex_t *p_mutex)
344 #if defined( LIBVLC_USE_PTHREAD )
345 int val = pthread_mutex_destroy( p_mutex );
346 VLC_THREAD_ASSERT ("destroying mutex");
348 #elif defined( WIN32 )
349 assert (InterlockedExchange (&p_mutex->initialized, -1) == 1);
350 DeleteCriticalSection (&p_mutex->mutex);
356 * Acquires a mutex. If needed, waits for any other thread to release it.
357 * Beware of deadlocks when locking multiple mutexes at the same time,
358 * or when using mutexes from callbacks.
360 * @param p_mutex mutex initialized with vlc_mutex_init() or
361 * vlc_mutex_init_recursive()
363 void vlc_mutex_lock (vlc_mutex_t *p_mutex)
365 #if defined(LIBVLC_USE_PTHREAD)
366 int val = pthread_mutex_lock( p_mutex );
367 VLC_THREAD_ASSERT ("locking mutex");
369 #elif defined( WIN32 )
370 if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
371 { /* ^^ We could also lock super_mutex all the time... sluggish */
372 assert (p_mutex != &super_mutex); /* this one cannot be static */
374 vlc_mutex_lock (&super_mutex);
375 if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
376 vlc_mutex_init (p_mutex);
377 /* FIXME: destroy the mutex some time... */
378 vlc_mutex_unlock (&super_mutex);
380 assert (InterlockedExchange (&p_mutex->initialized, 1) == 1);
381 EnterCriticalSection (&p_mutex->mutex);
388 * Releases a mutex (or crashes if the mutex is not locked by the caller).
389 * @param p_mutex mutex locked with vlc_mutex_lock().
391 void vlc_mutex_unlock (vlc_mutex_t *p_mutex)
393 #if defined(LIBVLC_USE_PTHREAD)
394 int val = pthread_mutex_unlock( p_mutex );
395 VLC_THREAD_ASSERT ("unlocking mutex");
397 #elif defined( WIN32 )
398 assert (InterlockedExchange (&p_mutex->initialized, 1) == 1);
399 LeaveCriticalSection (&p_mutex->mutex);
404 /*****************************************************************************
405 * vlc_cond_init: initialize a condition variable
406 *****************************************************************************/
407 int vlc_cond_init( vlc_cond_t *p_condvar )
409 #if defined( LIBVLC_USE_PTHREAD )
410 pthread_condattr_t attr;
413 ret = pthread_condattr_init (&attr);
417 # if !defined (_POSIX_CLOCK_SELECTION)
418 /* Fairly outdated POSIX support (that was defined in 2001) */
419 # define _POSIX_CLOCK_SELECTION (-1)
421 # if (_POSIX_CLOCK_SELECTION >= 0)
422 /* NOTE: This must be the same clock as the one in mtime.c */
423 pthread_condattr_setclock (&attr, CLOCK_MONOTONIC);
426 ret = pthread_cond_init (p_condvar, &attr);
427 pthread_condattr_destroy (&attr);
430 #elif defined( WIN32 )
431 /* Create a manual-reset event (manual reset is needed for broadcast). */
432 *p_condvar = CreateEvent( NULL, TRUE, FALSE, NULL );
433 return *p_condvar ? 0 : ENOMEM;
439 * Destroys a condition variable. No threads shall be waiting or signaling the
441 * @param p_condvar condition variable to destroy
443 void vlc_cond_destroy (vlc_cond_t *p_condvar)
445 #if defined( LIBVLC_USE_PTHREAD )
446 int val = pthread_cond_destroy( p_condvar );
447 VLC_THREAD_ASSERT ("destroying condition");
449 #elif defined( WIN32 )
450 CloseHandle( *p_condvar );
456 * Wakes up one thread waiting on a condition variable, if any.
457 * @param p_condvar condition variable
459 void vlc_cond_signal (vlc_cond_t *p_condvar)
461 #if defined(LIBVLC_USE_PTHREAD)
462 int val = pthread_cond_signal( p_condvar );
463 VLC_THREAD_ASSERT ("signaling condition variable");
465 #elif defined( WIN32 )
466 /* NOTE: This will cause a broadcast, that is wrong.
467 * This will also wake up the next waiting thread if no thread are yet
468 * waiting, which is also wrong. However both of these issues are allowed
469 * by the provision for spurious wakeups. Better have too many wakeups
470 * than too few (= deadlocks). */
471 SetEvent (*p_condvar);
477 * Wakes up all threads (if any) waiting on a condition variable.
478 * @param p_cond condition variable
480 void vlc_cond_broadcast (vlc_cond_t *p_condvar)
482 #if defined (LIBVLC_USE_PTHREAD)
483 pthread_cond_broadcast (p_condvar);
485 #elif defined (WIN32)
486 SetEvent (*p_condvar);
492 * Waits for a condition variable. The calling thread will be suspended until
493 * another thread calls vlc_cond_signal() or vlc_cond_broadcast() on the same
494 * condition variable, the thread is cancelled with vlc_cancel(), or the
495 * system causes a "spurious" unsolicited wake-up.
497 * A mutex is needed to wait on a condition variable. It must <b>not</b> be
498 * a recursive mutex. Although it is possible to use the same mutex for
499 * multiple condition, it is not valid to use different mutexes for the same
500 * condition variable at the same time from different threads.
502 * In case of thread cancellation, the mutex is always locked before
503 * cancellation proceeds.
505 * The canonical way to use a condition variable to wait for event foobar is:
507 vlc_mutex_lock (&lock);
508 mutex_cleanup_push (&lock); // release the mutex in case of cancellation
511 vlc_cond_wait (&wait, &lock);
513 --- foobar is now true, do something about it here --
515 vlc_cleanup_run (); // release the mutex
518 * @param p_condvar condition variable to wait on
519 * @param p_mutex mutex which is unlocked while waiting,
520 * then locked again when waking up.
521 * @param deadline <b>absolute</b> timeout
523 * @return 0 if the condition was signaled, an error code in case of timeout.
525 void vlc_cond_wait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex)
527 #if defined(LIBVLC_USE_PTHREAD)
528 int val = pthread_cond_wait( p_condvar, p_mutex );
529 VLC_THREAD_ASSERT ("waiting on condition");
531 #elif defined( WIN32 )
537 LeaveCriticalSection (&p_mutex->mutex);
538 result = WaitForSingleObjectEx (*p_condvar, INFINITE, TRUE);
539 EnterCriticalSection (&p_mutex->mutex);
541 while (result == WAIT_IO_COMPLETION);
543 ResetEvent (*p_condvar);
549 * Waits for a condition variable up to a certain date.
550 * This works like vlc_cond_wait(), except for the additional timeout.
552 * @param p_condvar condition variable to wait on
553 * @param p_mutex mutex which is unlocked while waiting,
554 * then locked again when waking up.
555 * @param deadline <b>absolute</b> timeout
557 * @return 0 if the condition was signaled, an error code in case of timeout.
559 int vlc_cond_timedwait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex,
562 #if defined(LIBVLC_USE_PTHREAD)
564 /* mdate() is mac_absolute_time on osx, which we must convert to do
565 * the same base than gettimeofday() on which pthread_cond_timedwait
567 mtime_t oldbase = mdate();
569 gettimeofday(&tv, NULL);
570 mtime_t newbase = (mtime_t)tv.tv_sec * 1000000 + (mtime_t) tv.tv_usec;
571 deadline = deadline - oldbase + newbase;
573 lldiv_t d = lldiv( deadline, CLOCK_FREQ );
574 struct timespec ts = { d.quot, d.rem * (1000000000 / CLOCK_FREQ) };
576 int val = pthread_cond_timedwait (p_condvar, p_mutex, &ts);
577 if (val != ETIMEDOUT)
578 VLC_THREAD_ASSERT ("timed-waiting on condition");
581 #elif defined( WIN32 )
588 mtime_t total = (deadline - mdate ())/1000;
592 DWORD delay = (total > 0x7fffffff) ? 0x7fffffff : total;
593 LeaveCriticalSection (&p_mutex->mutex);
594 result = WaitForSingleObjectEx (*p_condvar, delay, TRUE);
595 EnterCriticalSection (&p_mutex->mutex);
597 while (result == WAIT_IO_COMPLETION);
599 ResetEvent (*p_condvar);
601 return (result == WAIT_OBJECT_0) ? 0 : ETIMEDOUT;
606 /*****************************************************************************
607 * vlc_tls_create: create a thread-local variable
608 *****************************************************************************/
609 int vlc_threadvar_create( vlc_threadvar_t *p_tls, void (*destr) (void *) )
613 #if defined( LIBVLC_USE_PTHREAD )
614 i_ret = pthread_key_create( p_tls, destr );
615 #elif defined( WIN32 )
616 /* FIXME: remember/use the destr() callback and stop leaking whatever */
618 i_ret = (*p_tls == TLS_OUT_OF_INDEXES) ? EAGAIN : 0;
620 # error Unimplemented!
625 void vlc_threadvar_delete (vlc_threadvar_t *p_tls)
627 #if defined( LIBVLC_USE_PTHREAD )
628 pthread_key_delete (*p_tls);
629 #elif defined( WIN32 )
632 # error Unimplemented!
636 #if defined (LIBVLC_USE_PTHREAD)
637 #elif defined (WIN32)
638 static unsigned __stdcall vlc_entry (void *data)
640 vlc_cancel_t cancel_data = VLC_CANCEL_INIT;
641 vlc_thread_t self = data;
643 cancel_data.cancel_event = self->cancel_event;
646 vlc_threadvar_set (&cancel_key, &cancel_data);
647 self->data = self->entry (self->data);
653 * Creates and starts new thread.
655 * @param p_handle [OUT] pointer to write the handle of the created thread to
656 * @param entry entry point for the thread
657 * @param data data parameter given to the entry point
658 * @param priority thread priority value
659 * @return 0 on success, a standard error code on error.
661 int vlc_clone (vlc_thread_t *p_handle, void * (*entry) (void *), void *data,
666 #if defined( LIBVLC_USE_PTHREAD )
668 pthread_attr_init (&attr);
670 /* Block the signals that signals interface plugin handles.
671 * If the LibVLC caller wants to handle some signals by itself, it should
672 * block these before whenever invoking LibVLC. And it must obviously not
673 * start the VLC signals interface plugin.
675 * LibVLC will normally ignore any interruption caused by an asynchronous
676 * signal during a system call. But there may well be some buggy cases
677 * where it fails to handle EINTR (bug reports welcome). Some underlying
678 * libraries might also not handle EINTR properly.
684 sigdelset (&set, SIGHUP);
685 sigaddset (&set, SIGINT);
686 sigaddset (&set, SIGQUIT);
687 sigaddset (&set, SIGTERM);
689 sigaddset (&set, SIGPIPE); /* We don't want this one, really! */
690 pthread_sigmask (SIG_BLOCK, &set, &oldset);
693 struct sched_param sp = { .sched_priority = priority, };
696 if (sp.sched_priority <= 0)
697 sp.sched_priority += sched_get_priority_max (policy = SCHED_OTHER);
699 sp.sched_priority += sched_get_priority_min (policy = SCHED_RR);
701 pthread_attr_setschedpolicy (&attr, policy);
702 pthread_attr_setschedparam (&attr, &sp);
705 /* The thread stack size.
706 * The lower the value, the less address space per thread, the highest
707 * maximum simultaneous threads per process. Too low values will cause
708 * stack overflows and weird crashes. Set with caution. Also keep in mind
709 * that 64-bits platforms consume more stack than 32-bits one.
711 * Thanks to on-demand paging, thread stack size only affects address space
712 * consumption. In terms of memory, threads only use what they need
713 * (rounded up to the page boundary).
715 * For example, on Linux i386, the default is 2 mega-bytes, which supports
716 * about 320 threads per processes. */
717 #define VLC_STACKSIZE (128 * sizeof (void *) * 1024)
720 ret = pthread_attr_setstacksize (&attr, VLC_STACKSIZE);
721 assert (ret == 0); /* fails iif VLC_STACKSIZE is invalid */
724 ret = pthread_create (p_handle, &attr, entry, data);
725 pthread_sigmask (SIG_SETMASK, &oldset, NULL);
726 pthread_attr_destroy (&attr);
728 #elif defined( WIN32 ) || defined( UNDER_CE )
729 /* When using the MSVCRT C library you have to use the _beginthreadex
730 * function instead of CreateThread, otherwise you'll end up with
731 * memory leaks and the signal functions not working (see Microsoft
732 * Knowledge Base, article 104641) */
734 vlc_thread_t th = malloc (sizeof (*th));
741 #if defined( UNDER_CE )
742 th->cancel_event = CreateEvent (NULL, FALSE, FALSE, NULL);
743 if (th->cancel_event == NULL)
748 hThread = CreateThread (NULL, 128*1024, vlc_entry, th, CREATE_SUSPENDED, NULL);
750 hThread = (HANDLE)(uintptr_t)
751 _beginthreadex (NULL, 0, vlc_entry, th, CREATE_SUSPENDED, NULL);
757 /* Thread closes the handle when exiting, duplicate it here
758 * to be on the safe side when joining. */
759 if (!DuplicateHandle (GetCurrentProcess (), hThread,
760 GetCurrentProcess (), &th->handle, 0, FALSE,
761 DUPLICATE_SAME_ACCESS))
763 CloseHandle (hThread);
768 th->handle = hThread;
771 ResumeThread (hThread);
773 SetThreadPriority (hThread, priority);
789 /* APC procedure for thread cancellation */
790 static void CALLBACK vlc_cancel_self (ULONG_PTR dummy)
793 vlc_control_cancel (VLC_DO_CANCEL);
798 * Marks a thread as cancelled. Next time the target thread reaches a
799 * cancellation point (while not having disabled cancellation), it will
800 * run its cancellation cleanup handler, the thread variable destructors, and
801 * terminate. vlc_join() must be used afterward regardless of a thread being
804 void vlc_cancel (vlc_thread_t thread_id)
806 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
807 pthread_cancel (thread_id);
808 #elif defined (UNDER_CE)
809 SetEvent (thread_id->cancel_event);
810 #elif defined (WIN32)
811 QueueUserAPC (vlc_cancel_self, thread_id->handle, 0);
813 # warning vlc_cancel is not implemented!
818 * Waits for a thread to complete (if needed), and destroys it.
819 * This is a cancellation point; in case of cancellation, the join does _not_
822 * @param handle thread handle
823 * @param p_result [OUT] pointer to write the thread return value or NULL
824 * @return 0 on success, a standard error code otherwise.
826 void vlc_join (vlc_thread_t handle, void **result)
828 #if defined( LIBVLC_USE_PTHREAD )
829 int val = pthread_join (handle, result);
830 VLC_THREAD_ASSERT ("joining thread");
832 #elif defined( UNDER_CE ) || defined( WIN32 )
835 while (WaitForSingleObjectEx (handle->handle, INFINITE, TRUE)
836 == WAIT_IO_COMPLETION);
838 CloseHandle (handle->handle);
840 *result = handle->data;
841 #if defined( UNDER_CE )
842 CloseHandle (handle->cancel_event);
850 * Save the current cancellation state (enabled or disabled), then disable
851 * cancellation for the calling thread.
852 * This function must be called before entering a piece of code that is not
853 * cancellation-safe, unless it can be proven that the calling thread will not
855 * @return Previous cancellation state (opaque value for vlc_restorecancel()).
857 int vlc_savecancel (void)
861 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
862 int val = pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
863 VLC_THREAD_ASSERT ("saving cancellation");
866 vlc_cancel_t *nfo = vlc_threadvar_get (&cancel_key);
868 return false; /* Main thread - cannot be cancelled anyway */
870 state = nfo->killable;
871 nfo->killable = false;
878 * Restore the cancellation state for the calling thread.
879 * @param state previous state as returned by vlc_savecancel().
880 * @return Nothing, always succeeds.
882 void vlc_restorecancel (int state)
884 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
888 val = pthread_setcancelstate (state, &oldstate);
889 /* This should fail if an invalid value for given for state */
890 VLC_THREAD_ASSERT ("restoring cancellation");
892 if (oldstate != PTHREAD_CANCEL_DISABLE)
893 vlc_thread_fatal ("restoring cancellation while not disabled", EINVAL,
894 __func__, __FILE__, __LINE__);
896 pthread_setcancelstate (state, NULL);
900 vlc_cancel_t *nfo = vlc_threadvar_get (&cancel_key);
901 assert (state == false || state == true);
904 return; /* Main thread - cannot be cancelled anyway */
906 assert (!nfo->killable);
907 nfo->killable = state != 0;
913 * Issues an explicit deferred cancellation point.
914 * This has no effect if thread cancellation is disabled.
915 * This can be called when there is a rather slow non-sleeping operation.
916 * This is also used to force a cancellation point in a function that would
917 * otherwise "not always" be a one (block_FifoGet() is an example).
919 void vlc_testcancel (void)
921 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
922 pthread_testcancel ();
925 vlc_cancel_t *nfo = vlc_threadvar_get (&cancel_key);
927 return; /* Main thread - cannot be cancelled anyway */
929 if (nfo->killable && nfo->killed)
931 for (vlc_cleanup_t *p = nfo->cleaners; p != NULL; p = p->next)
933 # if defined (LIBVLC_USE_PTHREAD)
934 pthread_exit (PTHREAD_CANCELLED);
935 # elif defined (UNDER_CE)
937 # elif defined (WIN32)
940 # error Not implemented!
947 struct vlc_thread_boot
949 void * (*entry) (vlc_object_t *);
950 vlc_object_t *object;
953 static void *thread_entry (void *data)
955 vlc_object_t *obj = ((struct vlc_thread_boot *)data)->object;
956 void *(*func) (vlc_object_t *) = ((struct vlc_thread_boot *)data)->entry;
959 msg_Dbg (obj, "thread started");
961 msg_Dbg (obj, "thread ended");
966 #undef vlc_thread_create
967 /*****************************************************************************
968 * vlc_thread_create: create a thread
969 *****************************************************************************
970 * Note that i_priority is only taken into account on platforms supporting
971 * userland real-time priority threads.
972 *****************************************************************************/
973 int vlc_thread_create( vlc_object_t *p_this, const char * psz_file, int i_line,
974 const char *psz_name, void *(*func) ( vlc_object_t * ),
978 vlc_object_internals_t *p_priv = vlc_internals( p_this );
980 struct vlc_thread_boot *boot = malloc (sizeof (*boot));
984 boot->object = p_this;
986 /* Make sure we don't re-create a thread if the object has already one */
987 assert( !p_priv->b_thread );
989 #if defined( LIBVLC_USE_PTHREAD )
991 if( config_GetInt( p_this, "rt-priority" ) > 0 )
994 /* Hack to avoid error msg */
995 if( config_GetType( p_this, "rt-offset" ) )
996 i_priority += config_GetInt( p_this, "rt-offset" );
1000 p_priv->b_thread = true;
1001 i_ret = vlc_clone( &p_priv->thread_id, thread_entry, boot, i_priority );
1003 msg_Dbg( p_this, "thread (%s) created at priority %d (%s:%d)",
1004 psz_name, i_priority, psz_file, i_line );
1007 p_priv->b_thread = false;
1009 msg_Err( p_this, "%s thread could not be created at %s:%d (%m)",
1010 psz_name, psz_file, i_line );
1016 /*****************************************************************************
1017 * vlc_thread_set_priority: set the priority of the current thread when we
1018 * couldn't set it in vlc_thread_create (for instance for the main thread)
1019 *****************************************************************************/
1020 int __vlc_thread_set_priority( vlc_object_t *p_this, const char * psz_file,
1021 int i_line, int i_priority )
1023 vlc_object_internals_t *p_priv = vlc_internals( p_this );
1025 if( !p_priv->b_thread )
1027 msg_Err( p_this, "couldn't set priority of non-existent thread" );
1031 #if defined( LIBVLC_USE_PTHREAD )
1033 if( config_GetInt( p_this, "rt-priority" ) > 0 )
1036 int i_error, i_policy;
1037 struct sched_param param;
1039 memset( ¶m, 0, sizeof(struct sched_param) );
1040 if( config_GetType( p_this, "rt-offset" ) )
1041 i_priority += config_GetInt( p_this, "rt-offset" );
1042 if( i_priority <= 0 )
1044 param.sched_priority = (-1) * i_priority;
1045 i_policy = SCHED_OTHER;
1049 param.sched_priority = i_priority;
1050 i_policy = SCHED_RR;
1052 if( (i_error = pthread_setschedparam( p_priv->thread_id,
1053 i_policy, ¶m )) )
1056 msg_Warn( p_this, "couldn't set thread priority (%s:%d): %m",
1062 #elif defined( WIN32 ) || defined( UNDER_CE )
1063 VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
1065 if( !SetThreadPriority(p_priv->thread_id->handle, i_priority) )
1067 msg_Warn( p_this, "couldn't set a faster priority" );
1076 /*****************************************************************************
1077 * vlc_thread_join: wait until a thread exits, inner version
1078 *****************************************************************************/
1079 void __vlc_thread_join( vlc_object_t *p_this )
1081 vlc_object_internals_t *p_priv = vlc_internals( p_this );
1083 #if defined( LIBVLC_USE_PTHREAD )
1084 vlc_join (p_priv->thread_id, NULL);
1086 #elif defined( UNDER_CE ) || defined( WIN32 )
1088 FILETIME create_ft, exit_ft, kernel_ft, user_ft;
1089 int64_t real_time, kernel_time, user_time;
1092 if( ! DuplicateHandle(GetCurrentProcess(),
1093 p_priv->thread_id->handle,
1094 GetCurrentProcess(),
1098 DUPLICATE_SAME_ACCESS) )
1100 p_priv->b_thread = false;
1101 return; /* We have a problem! */
1104 hThread = p_priv->thread_id->handle;
1107 vlc_join( p_priv->thread_id, NULL );
1109 if( GetThreadTimes( hThread, &create_ft, &exit_ft, &kernel_ft, &user_ft ) )
1112 ((((int64_t)exit_ft.dwHighDateTime)<<32)| exit_ft.dwLowDateTime) -
1113 ((((int64_t)create_ft.dwHighDateTime)<<32)| create_ft.dwLowDateTime);
1117 ((((int64_t)kernel_ft.dwHighDateTime)<<32)|
1118 kernel_ft.dwLowDateTime) / 10;
1121 ((((int64_t)user_ft.dwHighDateTime)<<32)|
1122 user_ft.dwLowDateTime) / 10;
1124 msg_Dbg( p_this, "thread times: "
1125 "real %"PRId64"m%fs, kernel %"PRId64"m%fs, user %"PRId64"m%fs",
1126 real_time/60/1000000,
1127 (double)((real_time%(60*1000000))/1000000.0),
1128 kernel_time/60/1000000,
1129 (double)((kernel_time%(60*1000000))/1000000.0),
1130 user_time/60/1000000,
1131 (double)((user_time%(60*1000000))/1000000.0) );
1133 CloseHandle( hThread );
1136 vlc_join( p_priv->thread_id, NULL );
1140 p_priv->b_thread = false;
1143 void vlc_thread_cancel (vlc_object_t *obj)
1145 vlc_object_internals_t *priv = vlc_internals (obj);
1148 vlc_cancel (priv->thread_id);
1151 void vlc_control_cancel (int cmd, ...)
1153 /* NOTE: This function only modifies thread-specific data, so there is no
1154 * need to lock anything. */
1155 #ifdef LIBVLC_USE_PTHREAD_CANCEL
1161 vlc_cancel_t *nfo = vlc_threadvar_get (&cancel_key);
1165 /* Main thread - cannot be cancelled anyway */
1168 nfo = malloc (sizeof (*nfo));
1170 return; /* Uho! Expect problems! */
1171 *nfo = VLC_CANCEL_INIT;
1172 vlc_threadvar_set (&cancel_key, nfo);
1183 case VLC_CLEANUP_PUSH:
1185 /* cleaner is a pointer to the caller stack, no need to allocate
1186 * and copy anything. As a nice side effect, this cannot fail. */
1187 vlc_cleanup_t *cleaner = va_arg (ap, vlc_cleanup_t *);
1188 cleaner->next = nfo->cleaners;
1189 nfo->cleaners = cleaner;
1193 case VLC_CLEANUP_POP:
1195 nfo->cleaners = nfo->cleaners->next;