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;
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);
355 #if defined(LIBVLC_USE_PTHREAD) && !defined(NDEBUG)
356 # ifdef HAVE_VALGRIND_VALGRIND_H
357 # include <valgrind/valgrind.h>
359 # define RUNNING_ON_VALGRIND (0)
362 void vlc_assert_locked (vlc_mutex_t *p_mutex)
364 if (RUNNING_ON_VALGRIND > 0)
366 assert (pthread_mutex_lock (p_mutex) == EDEADLK);
371 * Acquires a mutex. If needed, waits for any other thread to release it.
372 * Beware of deadlocks when locking multiple mutexes at the same time,
373 * or when using mutexes from callbacks.
374 * This function is not a cancellation-point.
376 * @param p_mutex mutex initialized with vlc_mutex_init() or
377 * vlc_mutex_init_recursive()
379 void vlc_mutex_lock (vlc_mutex_t *p_mutex)
381 #if defined(LIBVLC_USE_PTHREAD)
382 int val = pthread_mutex_lock( p_mutex );
383 VLC_THREAD_ASSERT ("locking mutex");
385 #elif defined( WIN32 )
386 if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
387 { /* ^^ We could also lock super_mutex all the time... sluggish */
388 assert (p_mutex != &super_mutex); /* this one cannot be static */
390 vlc_mutex_lock (&super_mutex);
391 if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
392 vlc_mutex_init (p_mutex);
393 /* FIXME: destroy the mutex some time... */
394 vlc_mutex_unlock (&super_mutex);
396 assert (InterlockedExchange (&p_mutex->initialized, 1) == 1);
397 EnterCriticalSection (&p_mutex->mutex);
403 * Acquires a mutex if and only if it is not currently held by another thread.
404 * This function never sleeps and can be used in delay-critical code paths.
405 * This function is not a cancellation-point.
407 * <b>Beware</b>: If this function fails, then the mutex is held... by another
408 * thread. The calling thread must deal with the error appropriately. That
409 * typically implies postponing the operations that would have required the
410 * mutex. If the thread cannot defer those operations, then it must use
411 * vlc_mutex_lock(). If in doubt, use vlc_mutex_lock() instead.
413 * @param p_mutex mutex initialized with vlc_mutex_init() or
414 * vlc_mutex_init_recursive()
415 * @return 0 if the mutex could be acquired, an error code otherwise.
417 int vlc_mutex_trylock (vlc_mutex_t *p_mutex)
419 #if defined(LIBVLC_USE_PTHREAD)
420 int val = pthread_mutex_trylock( p_mutex );
423 VLC_THREAD_ASSERT ("locking mutex");
426 #elif defined( WIN32 )
427 if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
428 { /* ^^ We could also lock super_mutex all the time... sluggish */
429 assert (p_mutex != &super_mutex); /* this one cannot be static */
431 vlc_mutex_lock (&super_mutex);
432 if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
433 vlc_mutex_init (p_mutex);
434 /* FIXME: destroy the mutex some time... */
435 vlc_mutex_unlock (&super_mutex);
437 assert (InterlockedExchange (&p_mutex->initialized, 1) == 1);
438 return TryEnterCriticalSection (&p_mutex->mutex) ? 0 : EBUSY;
444 * Releases a mutex (or crashes if the mutex is not locked by the caller).
445 * @param p_mutex mutex locked with vlc_mutex_lock().
447 void vlc_mutex_unlock (vlc_mutex_t *p_mutex)
449 #if defined(LIBVLC_USE_PTHREAD)
450 int val = pthread_mutex_unlock( p_mutex );
451 VLC_THREAD_ASSERT ("unlocking mutex");
453 #elif defined( WIN32 )
454 assert (InterlockedExchange (&p_mutex->initialized, 1) == 1);
455 LeaveCriticalSection (&p_mutex->mutex);
460 /*****************************************************************************
461 * vlc_cond_init: initialize a condition variable
462 *****************************************************************************/
463 int vlc_cond_init( vlc_cond_t *p_condvar )
465 #if defined( LIBVLC_USE_PTHREAD )
466 pthread_condattr_t attr;
469 ret = pthread_condattr_init (&attr);
473 # if !defined (_POSIX_CLOCK_SELECTION)
474 /* Fairly outdated POSIX support (that was defined in 2001) */
475 # define _POSIX_CLOCK_SELECTION (-1)
477 # if (_POSIX_CLOCK_SELECTION >= 0)
478 /* NOTE: This must be the same clock as the one in mtime.c */
479 pthread_condattr_setclock (&attr, CLOCK_MONOTONIC);
482 ret = pthread_cond_init (p_condvar, &attr);
483 pthread_condattr_destroy (&attr);
486 #elif defined( WIN32 )
487 /* Create a manual-reset event (manual reset is needed for broadcast). */
488 *p_condvar = CreateEvent( NULL, TRUE, FALSE, NULL );
489 return *p_condvar ? 0 : ENOMEM;
495 * Destroys a condition variable. No threads shall be waiting or signaling the
497 * @param p_condvar condition variable to destroy
499 void vlc_cond_destroy (vlc_cond_t *p_condvar)
501 #if defined( LIBVLC_USE_PTHREAD )
502 int val = pthread_cond_destroy( p_condvar );
503 VLC_THREAD_ASSERT ("destroying condition");
505 #elif defined( WIN32 )
506 CloseHandle( *p_condvar );
512 * Wakes up one thread waiting on a condition variable, if any.
513 * @param p_condvar condition variable
515 void vlc_cond_signal (vlc_cond_t *p_condvar)
517 #if defined(LIBVLC_USE_PTHREAD)
518 int val = pthread_cond_signal( p_condvar );
519 VLC_THREAD_ASSERT ("signaling condition variable");
521 #elif defined( WIN32 )
522 /* NOTE: This will cause a broadcast, that is wrong.
523 * This will also wake up the next waiting thread if no thread are yet
524 * waiting, which is also wrong. However both of these issues are allowed
525 * by the provision for spurious wakeups. Better have too many wakeups
526 * than too few (= deadlocks). */
527 SetEvent (*p_condvar);
533 * Wakes up all threads (if any) waiting on a condition variable.
534 * @param p_cond condition variable
536 void vlc_cond_broadcast (vlc_cond_t *p_condvar)
538 #if defined (LIBVLC_USE_PTHREAD)
539 pthread_cond_broadcast (p_condvar);
541 #elif defined (WIN32)
542 SetEvent (*p_condvar);
548 * Waits for a condition variable. The calling thread will be suspended until
549 * another thread calls vlc_cond_signal() or vlc_cond_broadcast() on the same
550 * condition variable, the thread is cancelled with vlc_cancel(), or the
551 * system causes a "spurious" unsolicited wake-up.
553 * A mutex is needed to wait on a condition variable. It must <b>not</b> be
554 * a recursive mutex. Although it is possible to use the same mutex for
555 * multiple condition, it is not valid to use different mutexes for the same
556 * condition variable at the same time from different threads.
558 * In case of thread cancellation, the mutex is always locked before
559 * cancellation proceeds.
561 * The canonical way to use a condition variable to wait for event foobar is:
563 vlc_mutex_lock (&lock);
564 mutex_cleanup_push (&lock); // release the mutex in case of cancellation
567 vlc_cond_wait (&wait, &lock);
569 --- foobar is now true, do something about it here --
571 vlc_cleanup_run (); // release the mutex
574 * @param p_condvar condition variable to wait on
575 * @param p_mutex mutex which is unlocked while waiting,
576 * then locked again when waking up.
577 * @param deadline <b>absolute</b> timeout
579 * @return 0 if the condition was signaled, an error code in case of timeout.
581 void vlc_cond_wait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex)
583 #if defined(LIBVLC_USE_PTHREAD)
584 int val = pthread_cond_wait( p_condvar, p_mutex );
585 VLC_THREAD_ASSERT ("waiting on condition");
587 #elif defined( WIN32 )
593 LeaveCriticalSection (&p_mutex->mutex);
594 result = WaitForSingleObjectEx (*p_condvar, INFINITE, TRUE);
595 EnterCriticalSection (&p_mutex->mutex);
597 while (result == WAIT_IO_COMPLETION);
599 ResetEvent (*p_condvar);
605 * Waits for a condition variable up to a certain date.
606 * This works like vlc_cond_wait(), except for the additional timeout.
608 * @param p_condvar condition variable to wait on
609 * @param p_mutex mutex which is unlocked while waiting,
610 * then locked again when waking up.
611 * @param deadline <b>absolute</b> timeout
613 * @return 0 if the condition was signaled, an error code in case of timeout.
615 int vlc_cond_timedwait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex,
618 #if defined(LIBVLC_USE_PTHREAD)
620 /* mdate() is mac_absolute_time on osx, which we must convert to do
621 * the same base than gettimeofday() on which pthread_cond_timedwait
623 mtime_t oldbase = mdate();
625 gettimeofday(&tv, NULL);
626 mtime_t newbase = (mtime_t)tv.tv_sec * 1000000 + (mtime_t) tv.tv_usec;
627 deadline = deadline - oldbase + newbase;
629 lldiv_t d = lldiv( deadline, CLOCK_FREQ );
630 struct timespec ts = { d.quot, d.rem * (1000000000 / CLOCK_FREQ) };
632 int val = pthread_cond_timedwait (p_condvar, p_mutex, &ts);
633 if (val != ETIMEDOUT)
634 VLC_THREAD_ASSERT ("timed-waiting on condition");
637 #elif defined( WIN32 )
644 mtime_t total = (deadline - mdate ())/1000;
648 DWORD delay = (total > 0x7fffffff) ? 0x7fffffff : total;
649 LeaveCriticalSection (&p_mutex->mutex);
650 result = WaitForSingleObjectEx (*p_condvar, delay, TRUE);
651 EnterCriticalSection (&p_mutex->mutex);
653 while (result == WAIT_IO_COMPLETION);
655 ResetEvent (*p_condvar);
657 return (result == WAIT_OBJECT_0) ? 0 : ETIMEDOUT;
662 /*****************************************************************************
663 * vlc_tls_create: create a thread-local variable
664 *****************************************************************************/
665 int vlc_threadvar_create( vlc_threadvar_t *p_tls, void (*destr) (void *) )
669 #if defined( LIBVLC_USE_PTHREAD )
670 i_ret = pthread_key_create( p_tls, destr );
671 #elif defined( WIN32 )
672 /* FIXME: remember/use the destr() callback and stop leaking whatever */
674 i_ret = (*p_tls == TLS_OUT_OF_INDEXES) ? EAGAIN : 0;
676 # error Unimplemented!
681 void vlc_threadvar_delete (vlc_threadvar_t *p_tls)
683 #if defined( LIBVLC_USE_PTHREAD )
684 pthread_key_delete (*p_tls);
685 #elif defined( WIN32 )
688 # error Unimplemented!
693 * Sets a thread-local variable.
694 * @param key thread-local variable key (created with vlc_threadvar_create())
695 * @param value new value for the variable for the calling thread
696 * @return 0 on success, a system error code otherwise.
698 int vlc_threadvar_set (vlc_threadvar_t key, void *value)
700 #if defined(LIBVLC_USE_PTHREAD)
701 return pthread_setspecific (key, value);
702 #elif defined( UNDER_CE ) || defined( WIN32 )
703 return TlsSetValue (key, value) ? ENOMEM : 0;
705 # error Unimplemented!
710 * Gets the value of a thread-local variable for the calling thread.
711 * This function cannot fail.
712 * @return the value associated with the given variable for the calling
713 * or NULL if there is no value.
715 void *vlc_threadvar_get (vlc_threadvar_t key)
717 #if defined(LIBVLC_USE_PTHREAD)
718 return pthread_getspecific (key);
719 #elif defined( UNDER_CE ) || defined( WIN32 )
720 return TlsGetValue (key);
722 # error Unimplemented!
726 #if defined (LIBVLC_USE_PTHREAD)
727 #elif defined (WIN32)
728 static unsigned __stdcall vlc_entry (void *data)
730 vlc_cancel_t cancel_data = VLC_CANCEL_INIT;
731 vlc_thread_t self = data;
733 cancel_data.cancel_event = self->cancel_event;
736 vlc_threadvar_set (cancel_key, &cancel_data);
737 self->data = self->entry (self->data);
743 * Creates and starts new thread.
745 * @param p_handle [OUT] pointer to write the handle of the created thread to
746 * @param entry entry point for the thread
747 * @param data data parameter given to the entry point
748 * @param priority thread priority value
749 * @return 0 on success, a standard error code on error.
751 int vlc_clone (vlc_thread_t *p_handle, void * (*entry) (void *), void *data,
756 #if defined( LIBVLC_USE_PTHREAD )
758 pthread_attr_init (&attr);
760 /* Block the signals that signals interface plugin handles.
761 * If the LibVLC caller wants to handle some signals by itself, it should
762 * block these before whenever invoking LibVLC. And it must obviously not
763 * start the VLC signals interface plugin.
765 * LibVLC will normally ignore any interruption caused by an asynchronous
766 * signal during a system call. But there may well be some buggy cases
767 * where it fails to handle EINTR (bug reports welcome). Some underlying
768 * libraries might also not handle EINTR properly.
774 sigdelset (&set, SIGHUP);
775 sigaddset (&set, SIGINT);
776 sigaddset (&set, SIGQUIT);
777 sigaddset (&set, SIGTERM);
779 sigaddset (&set, SIGPIPE); /* We don't want this one, really! */
780 pthread_sigmask (SIG_BLOCK, &set, &oldset);
783 #if (_POSIX_THREAD_PRIORITY_SCHEDULING >= 0)
785 struct sched_param sp = { .sched_priority = priority, };
788 if (sp.sched_priority <= 0)
789 sp.sched_priority += sched_get_priority_max (policy = SCHED_OTHER);
791 sp.sched_priority += sched_get_priority_min (policy = SCHED_RR);
793 pthread_attr_setschedpolicy (&attr, policy);
794 pthread_attr_setschedparam (&attr, &sp);
800 /* The thread stack size.
801 * The lower the value, the less address space per thread, the highest
802 * maximum simultaneous threads per process. Too low values will cause
803 * stack overflows and weird crashes. Set with caution. Also keep in mind
804 * that 64-bits platforms consume more stack than 32-bits one.
806 * Thanks to on-demand paging, thread stack size only affects address space
807 * consumption. In terms of memory, threads only use what they need
808 * (rounded up to the page boundary).
810 * For example, on Linux i386, the default is 2 mega-bytes, which supports
811 * about 320 threads per processes. */
812 #define VLC_STACKSIZE (128 * sizeof (void *) * 1024)
815 ret = pthread_attr_setstacksize (&attr, VLC_STACKSIZE);
816 assert (ret == 0); /* fails iif VLC_STACKSIZE is invalid */
819 ret = pthread_create (p_handle, &attr, entry, data);
820 pthread_sigmask (SIG_SETMASK, &oldset, NULL);
821 pthread_attr_destroy (&attr);
823 #elif defined( WIN32 ) || defined( UNDER_CE )
824 /* When using the MSVCRT C library you have to use the _beginthreadex
825 * function instead of CreateThread, otherwise you'll end up with
826 * memory leaks and the signal functions not working (see Microsoft
827 * Knowledge Base, article 104641) */
829 vlc_thread_t th = malloc (sizeof (*th));
836 #if defined( UNDER_CE )
837 th->cancel_event = CreateEvent (NULL, FALSE, FALSE, NULL);
838 if (th->cancel_event == NULL)
843 hThread = CreateThread (NULL, 128*1024, vlc_entry, th, CREATE_SUSPENDED, NULL);
845 hThread = (HANDLE)(uintptr_t)
846 _beginthreadex (NULL, 0, vlc_entry, th, CREATE_SUSPENDED, NULL);
852 /* Thread closes the handle when exiting, duplicate it here
853 * to be on the safe side when joining. */
854 if (!DuplicateHandle (GetCurrentProcess (), hThread,
855 GetCurrentProcess (), &th->handle, 0, FALSE,
856 DUPLICATE_SAME_ACCESS))
858 CloseHandle (hThread);
863 th->handle = hThread;
866 ResumeThread (hThread);
868 SetThreadPriority (hThread, priority);
884 /* APC procedure for thread cancellation */
885 static void CALLBACK vlc_cancel_self (ULONG_PTR dummy)
888 vlc_control_cancel (VLC_DO_CANCEL);
893 * Marks a thread as cancelled. Next time the target thread reaches a
894 * cancellation point (while not having disabled cancellation), it will
895 * run its cancellation cleanup handler, the thread variable destructors, and
896 * terminate. vlc_join() must be used afterward regardless of a thread being
899 void vlc_cancel (vlc_thread_t thread_id)
901 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
902 pthread_cancel (thread_id);
903 #elif defined (UNDER_CE)
904 SetEvent (thread_id->cancel_event);
905 #elif defined (WIN32)
906 QueueUserAPC (vlc_cancel_self, thread_id->handle, 0);
908 # warning vlc_cancel is not implemented!
913 * Waits for a thread to complete (if needed), and destroys it.
914 * This is a cancellation point; in case of cancellation, the join does _not_
917 * @param handle thread handle
918 * @param p_result [OUT] pointer to write the thread return value or NULL
919 * @return 0 on success, a standard error code otherwise.
921 void vlc_join (vlc_thread_t handle, void **result)
923 #if defined( LIBVLC_USE_PTHREAD )
924 int val = pthread_join (handle, result);
925 VLC_THREAD_ASSERT ("joining thread");
927 #elif defined( UNDER_CE ) || defined( WIN32 )
930 while (WaitForSingleObjectEx (handle->handle, INFINITE, TRUE)
931 == WAIT_IO_COMPLETION);
933 CloseHandle (handle->handle);
935 *result = handle->data;
936 #if defined( UNDER_CE )
937 CloseHandle (handle->cancel_event);
945 * Save the current cancellation state (enabled or disabled), then disable
946 * cancellation for the calling thread.
947 * This function must be called before entering a piece of code that is not
948 * cancellation-safe, unless it can be proven that the calling thread will not
950 * @return Previous cancellation state (opaque value for vlc_restorecancel()).
952 int vlc_savecancel (void)
956 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
957 int val = pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
958 VLC_THREAD_ASSERT ("saving cancellation");
961 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
963 return false; /* Main thread - cannot be cancelled anyway */
965 state = nfo->killable;
966 nfo->killable = false;
973 * Restore the cancellation state for the calling thread.
974 * @param state previous state as returned by vlc_savecancel().
975 * @return Nothing, always succeeds.
977 void vlc_restorecancel (int state)
979 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
983 val = pthread_setcancelstate (state, &oldstate);
984 /* This should fail if an invalid value for given for state */
985 VLC_THREAD_ASSERT ("restoring cancellation");
987 if (oldstate != PTHREAD_CANCEL_DISABLE)
988 vlc_thread_fatal ("restoring cancellation while not disabled", EINVAL,
989 __func__, __FILE__, __LINE__);
991 pthread_setcancelstate (state, NULL);
995 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
996 assert (state == false || state == true);
999 return; /* Main thread - cannot be cancelled anyway */
1001 assert (!nfo->killable);
1002 nfo->killable = state != 0;
1008 * Issues an explicit deferred cancellation point.
1009 * This has no effect if thread cancellation is disabled.
1010 * This can be called when there is a rather slow non-sleeping operation.
1011 * This is also used to force a cancellation point in a function that would
1012 * otherwise "not always" be a one (block_FifoGet() is an example).
1014 void vlc_testcancel (void)
1016 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
1017 pthread_testcancel ();
1020 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
1022 return; /* Main thread - cannot be cancelled anyway */
1024 if (nfo->killable && nfo->killed)
1026 for (vlc_cleanup_t *p = nfo->cleaners; p != NULL; p = p->next)
1028 # if defined (LIBVLC_USE_PTHREAD)
1029 pthread_exit (PTHREAD_CANCELLED);
1030 # elif defined (UNDER_CE)
1032 # elif defined (WIN32)
1035 # error Not implemented!
1042 struct vlc_thread_boot
1044 void * (*entry) (vlc_object_t *);
1045 vlc_object_t *object;
1048 static void *thread_entry (void *data)
1050 vlc_object_t *obj = ((struct vlc_thread_boot *)data)->object;
1051 void *(*func) (vlc_object_t *) = ((struct vlc_thread_boot *)data)->entry;
1054 msg_Dbg (obj, "thread started");
1056 msg_Dbg (obj, "thread ended");
1061 #undef vlc_thread_create
1062 /*****************************************************************************
1063 * vlc_thread_create: create a thread
1064 *****************************************************************************
1065 * Note that i_priority is only taken into account on platforms supporting
1066 * userland real-time priority threads.
1067 *****************************************************************************/
1068 int vlc_thread_create( vlc_object_t *p_this, const char * psz_file, int i_line,
1069 const char *psz_name, void *(*func) ( vlc_object_t * ),
1073 vlc_object_internals_t *p_priv = vlc_internals( p_this );
1075 struct vlc_thread_boot *boot = malloc (sizeof (*boot));
1079 boot->object = p_this;
1081 /* Make sure we don't re-create a thread if the object has already one */
1082 assert( !p_priv->b_thread );
1084 #if defined( LIBVLC_USE_PTHREAD )
1086 if( config_GetInt( p_this, "rt-priority" ) > 0 )
1089 /* Hack to avoid error msg */
1090 if( config_GetType( p_this, "rt-offset" ) )
1091 i_priority += config_GetInt( p_this, "rt-offset" );
1095 p_priv->b_thread = true;
1096 i_ret = vlc_clone( &p_priv->thread_id, thread_entry, boot, i_priority );
1098 msg_Dbg( p_this, "thread (%s) created at priority %d (%s:%d)",
1099 psz_name, i_priority, psz_file, i_line );
1102 p_priv->b_thread = false;
1104 msg_Err( p_this, "%s thread could not be created at %s:%d (%m)",
1105 psz_name, psz_file, i_line );
1111 /*****************************************************************************
1112 * vlc_thread_set_priority: set the priority of the current thread when we
1113 * couldn't set it in vlc_thread_create (for instance for the main thread)
1114 *****************************************************************************/
1115 int __vlc_thread_set_priority( vlc_object_t *p_this, const char * psz_file,
1116 int i_line, int i_priority )
1118 vlc_object_internals_t *p_priv = vlc_internals( p_this );
1120 if( !p_priv->b_thread )
1122 msg_Err( p_this, "couldn't set priority of non-existent thread" );
1126 #if defined( LIBVLC_USE_PTHREAD )
1128 if( config_GetInt( p_this, "rt-priority" ) > 0 )
1131 int i_error, i_policy;
1132 struct sched_param param;
1134 memset( ¶m, 0, sizeof(struct sched_param) );
1135 if( config_GetType( p_this, "rt-offset" ) )
1136 i_priority += config_GetInt( p_this, "rt-offset" );
1137 if( i_priority <= 0 )
1139 param.sched_priority = (-1) * i_priority;
1140 i_policy = SCHED_OTHER;
1144 param.sched_priority = i_priority;
1145 i_policy = SCHED_RR;
1147 if( (i_error = pthread_setschedparam( p_priv->thread_id,
1148 i_policy, ¶m )) )
1151 msg_Warn( p_this, "couldn't set thread priority (%s:%d): %m",
1157 #elif defined( WIN32 ) || defined( UNDER_CE )
1158 VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
1160 if( !SetThreadPriority(p_priv->thread_id->handle, i_priority) )
1162 msg_Warn( p_this, "couldn't set a faster priority" );
1171 /*****************************************************************************
1172 * vlc_thread_join: wait until a thread exits, inner version
1173 *****************************************************************************/
1174 void __vlc_thread_join( vlc_object_t *p_this )
1176 vlc_object_internals_t *p_priv = vlc_internals( p_this );
1178 #if defined( LIBVLC_USE_PTHREAD )
1179 vlc_join (p_priv->thread_id, NULL);
1181 #elif defined( UNDER_CE ) || defined( WIN32 )
1183 FILETIME create_ft, exit_ft, kernel_ft, user_ft;
1184 int64_t real_time, kernel_time, user_time;
1187 if( ! DuplicateHandle(GetCurrentProcess(),
1188 p_priv->thread_id->handle,
1189 GetCurrentProcess(),
1193 DUPLICATE_SAME_ACCESS) )
1195 p_priv->b_thread = false;
1196 return; /* We have a problem! */
1199 hThread = p_priv->thread_id->handle;
1202 vlc_join( p_priv->thread_id, NULL );
1204 if( GetThreadTimes( hThread, &create_ft, &exit_ft, &kernel_ft, &user_ft ) )
1207 ((((int64_t)exit_ft.dwHighDateTime)<<32)| exit_ft.dwLowDateTime) -
1208 ((((int64_t)create_ft.dwHighDateTime)<<32)| create_ft.dwLowDateTime);
1212 ((((int64_t)kernel_ft.dwHighDateTime)<<32)|
1213 kernel_ft.dwLowDateTime) / 10;
1216 ((((int64_t)user_ft.dwHighDateTime)<<32)|
1217 user_ft.dwLowDateTime) / 10;
1219 msg_Dbg( p_this, "thread times: "
1220 "real %"PRId64"m%fs, kernel %"PRId64"m%fs, user %"PRId64"m%fs",
1221 real_time/60/1000000,
1222 (double)((real_time%(60*1000000))/1000000.0),
1223 kernel_time/60/1000000,
1224 (double)((kernel_time%(60*1000000))/1000000.0),
1225 user_time/60/1000000,
1226 (double)((user_time%(60*1000000))/1000000.0) );
1228 CloseHandle( hThread );
1231 vlc_join( p_priv->thread_id, NULL );
1235 p_priv->b_thread = false;
1238 void vlc_thread_cancel (vlc_object_t *obj)
1240 vlc_object_internals_t *priv = vlc_internals (obj);
1243 vlc_cancel (priv->thread_id);
1246 void vlc_control_cancel (int cmd, ...)
1248 /* NOTE: This function only modifies thread-specific data, so there is no
1249 * need to lock anything. */
1250 #ifdef LIBVLC_USE_PTHREAD_CANCEL
1256 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
1260 /* Main thread - cannot be cancelled anyway */
1263 nfo = malloc (sizeof (*nfo));
1265 return; /* Uho! Expect problems! */
1266 *nfo = VLC_CANCEL_INIT;
1267 vlc_threadvar_set (cancel_key, nfo);
1278 case VLC_CLEANUP_PUSH:
1280 /* cleaner is a pointer to the caller stack, no need to allocate
1281 * and copy anything. As a nice side effect, this cannot fail. */
1282 vlc_cleanup_t *cleaner = va_arg (ap, vlc_cleanup_t *);
1283 cleaner->next = nfo->cleaners;
1284 nfo->cleaners = cleaner;
1288 case VLC_CLEANUP_POP:
1290 nfo->cleaners = nfo->cleaners->next;