1 /*****************************************************************************
2 * threads.c : threads implementation for the VideoLAN client
3 *****************************************************************************
4 * Copyright (C) 1999-2007 the VideoLAN team
7 * Authors: Jean-Marc Dressler <polux@via.ecp.fr>
8 * Samuel Hocevar <sam@zoy.org>
9 * Gildas Bazin <gbazin@netcourrier.com>
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
25 *****************************************************************************/
39 #define VLC_THREADS_UNINITIALIZED 0
40 #define VLC_THREADS_PENDING 1
41 #define VLC_THREADS_ERROR 2
42 #define VLC_THREADS_READY 3
44 /*****************************************************************************
45 * Global mutex for lazy initialization of the threads system
46 *****************************************************************************/
47 static volatile unsigned i_initializations = 0;
48 static volatile int i_status = VLC_THREADS_UNINITIALIZED;
49 static vlc_object_t *p_root;
51 #if defined( UNDER_CE )
52 #elif defined( WIN32 )
54 /* following is only available on NT/2000/XP and above */
55 static SIGNALOBJECTANDWAIT pf_SignalObjectAndWait = NULL;
58 ** On Windows NT/2K/XP we use a slow mutex implementation but which
59 ** allows us to correctly implement condition variables.
60 ** You can also use the faster Win9x implementation but you might
61 ** experience problems with it.
63 static vlc_bool_t b_fast_mutex = VLC_FALSE;
65 ** On Windows 9x/Me you can use a fast but incorrect condition variables
66 ** implementation (more precisely there is a possibility for a race
67 ** condition to happen).
68 ** However it is possible to use slower alternatives which are more robust.
69 ** Currently you can choose between implementation 0 (which is the
70 ** fastest but slightly incorrect), 1 (default) and 2.
72 static int i_win9x_cv = 1;
74 #elif defined( HAVE_KERNEL_SCHEDULER_H )
75 #elif defined( LIBVLC_USE_PTHREAD )
76 static pthread_mutex_t once_mutex = PTHREAD_MUTEX_INITIALIZER;
79 vlc_threadvar_t msg_context_global_key;
81 #if defined(LIBVLC_USE_PTHREAD)
82 static inline unsigned long vlc_threadid (void)
84 union { pthread_t th; unsigned long int i; } v = { };
85 v.th = pthread_self ();
90 /*****************************************************************************
91 * vlc_thread_fatal: Report an error from the threading layer
92 *****************************************************************************
93 * This is mostly meant for debugging.
94 *****************************************************************************/
95 void vlc_pthread_fatal (const char *action, int error,
96 const char *file, unsigned line)
101 fprintf (stderr, "LibVLC fatal error %s in thread %lu at %s:%u: %d\n",
102 action, vlc_threadid (), file, line, error);
105 /* Sometimes strerror_r() crashes too, so make sure we print an error
106 * message before we invoke it */
107 msg = strerror_r (error, buf, sizeof (buf));
108 fprintf (stderr, " %s\n", msg ? msg : "(null)");
115 /*****************************************************************************
116 * vlc_threads_init: initialize threads system
117 *****************************************************************************
118 * This function requires lazy initialization of a global lock in order to
119 * keep the library really thread-safe. Some architectures don't support this
120 * and thus do not guarantee the complete reentrancy.
121 *****************************************************************************/
122 int __vlc_threads_init( vlc_object_t *p_this )
124 libvlc_global_data_t *p_libvlc_global = (libvlc_global_data_t *)p_this;
125 int i_ret = VLC_SUCCESS;
127 /* If we have lazy mutex initialization, use it. Otherwise, we just
128 * hope nothing wrong happens. */
129 #if defined( UNDER_CE )
130 #elif defined( WIN32 )
131 if( IsDebuggerPresent() )
133 /* SignalObjectAndWait() is problematic under a debugger */
134 b_fast_mutex = VLC_TRUE;
137 #elif defined( HAVE_KERNEL_SCHEDULER_H )
138 #elif defined( LIBVLC_USE_PTHREAD )
139 pthread_mutex_lock( &once_mutex );
142 if( i_status == VLC_THREADS_UNINITIALIZED )
144 i_status = VLC_THREADS_PENDING;
146 /* We should be safe now. Do all the initialization stuff we want. */
147 p_libvlc_global->b_ready = VLC_FALSE;
149 #if defined( UNDER_CE )
150 /* Nothing to initialize */
152 #elif defined( WIN32 )
153 /* Dynamically get the address of SignalObjectAndWait */
154 if( GetVersion() < 0x80000000 )
158 /* We are running on NT/2K/XP, we can use SignalObjectAndWait */
159 hInstLib = LoadLibrary( "kernel32" );
162 pf_SignalObjectAndWait =
163 (SIGNALOBJECTANDWAIT)GetProcAddress( hInstLib,
164 "SignalObjectAndWait" );
168 #elif defined( HAVE_KERNEL_SCHEDULER_H )
169 #elif defined( LIBVLC_USE_PTHREAD )
172 p_root = vlc_object_create( p_libvlc_global, VLC_OBJECT_GLOBAL );
178 i_status = VLC_THREADS_ERROR;
183 i_status = VLC_THREADS_READY;
186 vlc_threadvar_create( p_root, &msg_context_global_key );
190 /* Just increment the initialization count */
194 /* If we have lazy mutex initialization support, unlock the mutex;
195 * otherwize, do a naive wait loop. */
196 #if defined( UNDER_CE )
197 while( i_status == VLC_THREADS_PENDING ) msleep( THREAD_SLEEP );
198 #elif defined( WIN32 )
199 while( i_status == VLC_THREADS_PENDING ) msleep( THREAD_SLEEP );
200 #elif defined( HAVE_KERNEL_SCHEDULER_H )
201 while( i_status == VLC_THREADS_PENDING ) msleep( THREAD_SLEEP );
202 #elif defined( LIBVLC_USE_PTHREAD )
203 pthread_mutex_unlock( &once_mutex );
206 if( i_status != VLC_THREADS_READY )
214 /*****************************************************************************
215 * vlc_threads_end: stop threads system
216 *****************************************************************************
217 * FIXME: This function is far from being threadsafe.
218 *****************************************************************************/
219 int __vlc_threads_end( vlc_object_t *p_this )
222 #if defined( UNDER_CE )
223 #elif defined( WIN32 )
224 #elif defined( HAVE_KERNEL_SCHEDULER_H )
225 #elif defined( LIBVLC_USE_PTHREAD )
226 pthread_mutex_lock( &once_mutex );
229 if( i_initializations == 0 )
233 if( i_initializations == 0 )
235 i_status = VLC_THREADS_UNINITIALIZED;
236 vlc_object_destroy( p_root );
239 #if defined( UNDER_CE )
240 #elif defined( WIN32 )
241 #elif defined( HAVE_KERNEL_SCHEDULER_H )
242 #elif defined( LIBVLC_USE_PTHREAD )
243 pthread_mutex_unlock( &once_mutex );
249 /* This is not prototyped under Linux, though it exists. */
250 int pthread_mutexattr_setkind_np( pthread_mutexattr_t *attr, int kind );
253 /*****************************************************************************
254 * vlc_mutex_init: initialize a mutex
255 *****************************************************************************/
256 int __vlc_mutex_init( vlc_mutex_t *p_mutex )
258 #if defined( UNDER_CE )
259 InitializeCriticalSection( &p_mutex->csection );
262 #elif defined( WIN32 )
263 /* We use mutexes on WinNT/2K/XP because we can use the SignalObjectAndWait
264 * function and have a 100% correct vlc_cond_wait() implementation.
265 * As this function is not available on Win9x, we can use the faster
266 * CriticalSections */
267 if( pf_SignalObjectAndWait && !b_fast_mutex )
269 /* We are running on NT/2K/XP, we can use SignalObjectAndWait */
270 p_mutex->mutex = CreateMutex( 0, FALSE, 0 );
271 return ( p_mutex->mutex != NULL ? 0 : 1 );
275 p_mutex->mutex = NULL;
276 InitializeCriticalSection( &p_mutex->csection );
280 #elif defined( HAVE_KERNEL_SCHEDULER_H )
281 /* check the arguments and whether it's already been initialized */
282 if( p_mutex == NULL )
287 if( p_mutex->init == 9999 )
292 p_mutex->lock = create_sem( 1, "BeMutex" );
293 if( p_mutex->lock < B_NO_ERROR )
298 p_mutex->init = 9999;
301 #elif defined( LIBVLC_USE_PTHREAD )
304 /* Create error-checking mutex to detect problems more easily. */
305 pthread_mutexattr_t attr;
308 pthread_mutexattr_init( &attr );
309 # if defined(SYS_LINUX)
310 pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_ERRORCHECK_NP );
312 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ERRORCHECK );
315 i_result = pthread_mutex_init( &p_mutex->mutex, &attr );
316 pthread_mutexattr_destroy( &attr );
320 return pthread_mutex_init( &p_mutex->mutex, NULL );
325 /*****************************************************************************
326 * vlc_mutex_init: initialize a recursive mutex (Do not use)
327 *****************************************************************************/
328 int __vlc_mutex_init_recursive( vlc_mutex_t *p_mutex )
331 /* Create mutex returns a recursive mutex */
332 p_mutex->mutex = CreateMutex( 0, FALSE, 0 );
333 return ( p_mutex->mutex != NULL ? 0 : 1 );
334 #elif defined( LIBVLC_USE_PTHREAD )
335 pthread_mutexattr_t attr;
338 pthread_mutexattr_init( &attr );
340 /* Create error-checking mutex to detect problems more easily. */
341 # if defined(SYS_LINUX)
342 pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_ERRORCHECK_NP );
344 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ERRORCHECK );
347 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_RECURSIVE );
348 i_result = pthread_mutex_init( &p_mutex->mutex, &attr );
349 pthread_mutexattr_destroy( &attr );
352 # error Unimplemented!
357 /*****************************************************************************
358 * vlc_mutex_destroy: destroy a mutex, inner version
359 *****************************************************************************/
360 void __vlc_mutex_destroy( const char * psz_file, int i_line, vlc_mutex_t *p_mutex )
362 #if defined( UNDER_CE )
363 DeleteCriticalSection( &p_mutex->csection );
365 #elif defined( WIN32 )
367 CloseHandle( p_mutex->mutex );
369 DeleteCriticalSection( &p_mutex->csection );
371 #elif defined( HAVE_KERNEL_SCHEDULER_H )
372 if( p_mutex->init == 9999 )
373 delete_sem( p_mutex->lock );
377 #elif defined( LIBVLC_USE_PTHREAD )
378 int val = pthread_mutex_destroy( &p_mutex->mutex );
379 VLC_THREAD_ASSERT ("destroying mutex");
384 /*****************************************************************************
385 * vlc_cond_init: initialize a condition
386 *****************************************************************************/
387 int __vlc_cond_init( vlc_cond_t *p_condvar )
389 #if defined( UNDER_CE )
390 /* Initialize counter */
391 p_condvar->i_waiting_threads = 0;
393 /* Create an auto-reset event. */
394 p_condvar->event = CreateEvent( NULL, /* no security */
395 FALSE, /* auto-reset event */
396 FALSE, /* start non-signaled */
397 NULL ); /* unnamed */
398 return !p_condvar->event;
400 #elif defined( WIN32 )
401 /* Initialize counter */
402 p_condvar->i_waiting_threads = 0;
405 p_condvar->i_win9x_cv = i_win9x_cv;
406 p_condvar->SignalObjectAndWait = pf_SignalObjectAndWait;
408 if( (p_condvar->SignalObjectAndWait && !b_fast_mutex)
409 || p_condvar->i_win9x_cv == 0 )
411 /* Create an auto-reset event. */
412 p_condvar->event = CreateEvent( NULL, /* no security */
413 FALSE, /* auto-reset event */
414 FALSE, /* start non-signaled */
415 NULL ); /* unnamed */
417 p_condvar->semaphore = NULL;
418 return !p_condvar->event;
422 p_condvar->semaphore = CreateSemaphore( NULL, /* no security */
423 0, /* initial count */
424 0x7fffffff, /* max count */
425 NULL ); /* unnamed */
427 if( p_condvar->i_win9x_cv == 1 )
428 /* Create a manual-reset event initially signaled. */
429 p_condvar->event = CreateEvent( NULL, TRUE, TRUE, NULL );
431 /* Create a auto-reset event. */
432 p_condvar->event = CreateEvent( NULL, FALSE, FALSE, NULL );
434 InitializeCriticalSection( &p_condvar->csection );
436 return !p_condvar->semaphore || !p_condvar->event;
439 #elif defined( HAVE_KERNEL_SCHEDULER_H )
445 if( p_condvar->init == 9999 )
450 p_condvar->thread = -1;
451 p_condvar->init = 9999;
454 #elif defined( LIBVLC_USE_PTHREAD )
455 pthread_condattr_t attr;
458 ret = pthread_condattr_init (&attr);
462 # if !defined (_POSIX_CLOCK_SELECTION)
463 /* Fairly outdated POSIX support (that was defined in 2001) */
464 # define _POSIX_CLOCK_SELECTION (-1)
466 # if (_POSIX_CLOCK_SELECTION >= 0)
467 /* NOTE: This must be the same clock as the one in mtime.c */
468 pthread_condattr_setclock (&attr, CLOCK_MONOTONIC);
471 ret = pthread_cond_init (&p_condvar->cond, &attr);
472 pthread_condattr_destroy (&attr);
478 /*****************************************************************************
479 * vlc_cond_destroy: destroy a condition, inner version
480 *****************************************************************************/
481 void __vlc_cond_destroy( const char * psz_file, int i_line, vlc_cond_t *p_condvar )
483 #if defined( UNDER_CE )
484 CloseHandle( p_condvar->event );
486 #elif defined( WIN32 )
487 if( !p_condvar->semaphore )
488 CloseHandle( p_condvar->event );
491 CloseHandle( p_condvar->event );
492 CloseHandle( p_condvar->semaphore );
495 if( p_condvar->semaphore != NULL )
496 DeleteCriticalSection( &p_condvar->csection );
498 #elif defined( HAVE_KERNEL_SCHEDULER_H )
501 #elif defined( LIBVLC_USE_PTHREAD )
502 int val = pthread_cond_destroy( &p_condvar->cond );
503 VLC_THREAD_ASSERT ("destroying condition");
508 /*****************************************************************************
509 * vlc_tls_create: create a thread-local variable
510 *****************************************************************************/
511 int __vlc_threadvar_create( vlc_threadvar_t *p_tls )
515 #if defined( HAVE_KERNEL_SCHEDULER_H )
516 # error Unimplemented!
517 #elif defined( UNDER_CE ) || defined( WIN32 )
518 #elif defined( WIN32 )
519 p_tls->handle = TlsAlloc();
520 i_ret = !( p_tls->handle == 0xFFFFFFFF );
522 #elif defined( LIBVLC_USE_PTHREAD )
523 i_ret = pthread_key_create( &p_tls->handle, NULL );
528 /*****************************************************************************
529 * vlc_thread_create: create a thread, inner version
530 *****************************************************************************
531 * Note that i_priority is only taken into account on platforms supporting
532 * userland real-time priority threads.
533 *****************************************************************************/
534 int __vlc_thread_create( vlc_object_t *p_this, const char * psz_file, int i_line,
535 const char *psz_name, void * ( *func ) ( void * ),
536 int i_priority, vlc_bool_t b_wait )
539 void *p_data = (void *)p_this;
540 vlc_object_internals_t *p_priv = p_this->p_internals;
542 vlc_mutex_lock( &p_this->object_lock );
544 #if defined( WIN32 ) || defined( UNDER_CE )
546 /* When using the MSVCRT C library you have to use the _beginthreadex
547 * function instead of CreateThread, otherwise you'll end up with
548 * memory leaks and the signal functions not working (see Microsoft
549 * Knowledge Base, article 104641) */
550 #if defined( UNDER_CE )
552 HANDLE hThread = CreateThread( NULL, 0, (LPTHREAD_START_ROUTINE)func,
553 (LPVOID)p_data, CREATE_SUSPENDED,
557 uintptr_t hThread = _beginthreadex( NULL, 0,
558 (LPTHREAD_START_ROUTINE)func,
559 (void*)p_data, CREATE_SUSPENDED,
562 p_priv->thread_id.id = (DWORD)threadId;
563 p_priv->thread_id.hThread = (HANDLE)hThread;
564 ResumeThread((HANDLE)hThread);
567 i_ret = ( p_priv->thread_id.hThread ? 0 : 1 );
569 if( !i_ret && i_priority )
571 if( !SetThreadPriority(p_priv->thread_id.hThread, i_priority) )
573 msg_Warn( p_this, "couldn't set a faster priority" );
578 #elif defined( HAVE_KERNEL_SCHEDULER_H )
579 p_priv->thread_id = spawn_thread( (thread_func)func, psz_name,
580 i_priority, p_data );
581 i_ret = resume_thread( p_priv->thread_id );
583 #elif defined( LIBVLC_USE_PTHREAD )
584 i_ret = pthread_create( &p_priv->thread_id, NULL, func, p_data );
587 if( config_GetInt( p_this, "rt-priority" ) )
590 int i_error, i_policy;
591 struct sched_param param;
593 memset( ¶m, 0, sizeof(struct sched_param) );
594 if( config_GetType( p_this, "rt-offset" ) )
596 i_priority += config_GetInt( p_this, "rt-offset" );
598 if( i_priority <= 0 )
600 param.sched_priority = (-1) * i_priority;
601 i_policy = SCHED_OTHER;
605 param.sched_priority = i_priority;
608 if( (i_error = pthread_setschedparam( p_priv->thread_id,
609 i_policy, ¶m )) )
612 msg_Warn( p_this, "couldn't set thread priority (%s:%d): %m",
630 msg_Dbg( p_this, "waiting for thread completion" );
631 vlc_object_wait( p_this );
634 p_priv->b_thread = VLC_TRUE;
636 #if defined( WIN32 ) || defined( UNDER_CE )
637 msg_Dbg( p_this, "thread %u (%s) created at priority %d (%s:%d)",
638 (unsigned int)p_priv->thread_id.id, psz_name,
639 i_priority, psz_file, i_line );
641 msg_Dbg( p_this, "thread %u (%s) created at priority %d (%s:%d)",
642 (unsigned int)p_priv->thread_id, psz_name, i_priority,
647 vlc_mutex_unlock( &p_this->object_lock );
652 msg_Err( p_this, "%s thread could not be created at %s:%d (%m)",
653 psz_name, psz_file, i_line );
654 vlc_mutex_unlock( &p_this->object_lock );
660 /*****************************************************************************
661 * vlc_thread_set_priority: set the priority of the current thread when we
662 * couldn't set it in vlc_thread_create (for instance for the main thread)
663 *****************************************************************************/
664 int __vlc_thread_set_priority( vlc_object_t *p_this, const char * psz_file,
665 int i_line, int i_priority )
667 vlc_object_internals_t *p_priv = p_this->p_internals;
668 #if defined( WIN32 ) || defined( UNDER_CE )
669 if( !p_priv->thread_id.hThread )
670 p_priv->thread_id.hThread = GetCurrentThread();
671 if( !SetThreadPriority(p_priv->thread_id.hThread, i_priority) )
673 msg_Warn( p_this, "couldn't set a faster priority" );
677 #elif defined( LIBVLC_USE_PTHREAD )
679 if( config_GetInt( p_this, "rt-priority" ) > 0 )
682 int i_error, i_policy;
683 struct sched_param param;
685 memset( ¶m, 0, sizeof(struct sched_param) );
686 if( config_GetType( p_this, "rt-offset" ) )
688 i_priority += config_GetInt( p_this, "rt-offset" );
690 if( i_priority <= 0 )
692 param.sched_priority = (-1) * i_priority;
693 i_policy = SCHED_OTHER;
697 param.sched_priority = i_priority;
700 if( !p_priv->thread_id )
701 p_priv->thread_id = pthread_self();
702 if( (i_error = pthread_setschedparam( p_priv->thread_id,
703 i_policy, ¶m )) )
706 msg_Warn( p_this, "couldn't set thread priority (%s:%d): %m",
716 /*****************************************************************************
717 * vlc_thread_ready: tell the parent thread we were successfully spawned
718 *****************************************************************************/
719 void __vlc_thread_ready( vlc_object_t *p_this )
721 vlc_object_signal( p_this );
724 /*****************************************************************************
725 * vlc_thread_join: wait until a thread exits, inner version
726 *****************************************************************************/
727 void __vlc_thread_join( vlc_object_t *p_this, const char * psz_file, int i_line )
729 vlc_object_internals_t *p_priv = p_this->p_internals;
731 #if defined( UNDER_CE ) || defined( WIN32 )
733 BOOL (WINAPI *OurGetThreadTimes)( HANDLE, FILETIME*, FILETIME*,
734 FILETIME*, FILETIME* );
735 FILETIME create_ft, exit_ft, kernel_ft, user_ft;
736 int64_t real_time, kernel_time, user_time;
740 ** object will close its thread handle when destroyed, duplicate it here
741 ** to be on the safe side
743 if( ! DuplicateHandle(GetCurrentProcess(),
744 p_priv->thread_id.hThread,
749 DUPLICATE_SAME_ACCESS) )
751 msg_Err( p_this, "thread_join(%u) failed at %s:%d (%s)",
752 (unsigned int)p_priv->thread_id.id,
753 psz_file, i_line, GetLastError() );
754 p_priv->b_thread = VLC_FALSE;
758 WaitForSingleObject( hThread, INFINITE );
760 msg_Dbg( p_this, "thread %u joined (%s:%d)",
761 (unsigned int)p_priv->thread_id.id,
763 #if defined( UNDER_CE )
764 hmodule = GetModuleHandle( _T("COREDLL") );
766 hmodule = GetModuleHandle( _T("KERNEL32") );
768 OurGetThreadTimes = (BOOL (WINAPI*)( HANDLE, FILETIME*, FILETIME*,
769 FILETIME*, FILETIME* ))
770 GetProcAddress( hmodule, _T("GetThreadTimes") );
772 if( OurGetThreadTimes &&
773 OurGetThreadTimes( hThread,
774 &create_ft, &exit_ft, &kernel_ft, &user_ft ) )
777 ((((int64_t)exit_ft.dwHighDateTime)<<32)| exit_ft.dwLowDateTime) -
778 ((((int64_t)create_ft.dwHighDateTime)<<32)| create_ft.dwLowDateTime);
782 ((((int64_t)kernel_ft.dwHighDateTime)<<32)|
783 kernel_ft.dwLowDateTime) / 10;
786 ((((int64_t)user_ft.dwHighDateTime)<<32)|
787 user_ft.dwLowDateTime) / 10;
789 msg_Dbg( p_this, "thread times: "
790 "real "I64Fd"m%fs, kernel "I64Fd"m%fs, user "I64Fd"m%fs",
791 real_time/60/1000000,
792 (double)((real_time%(60*1000000))/1000000.0),
793 kernel_time/60/1000000,
794 (double)((kernel_time%(60*1000000))/1000000.0),
795 user_time/60/1000000,
796 (double)((user_time%(60*1000000))/1000000.0) );
798 CloseHandle( hThread );
800 #else /* !defined(WIN32) */
804 #if defined( HAVE_KERNEL_SCHEDULER_H )
806 i_ret = (B_OK == wait_for_thread( p_priv->thread_id, &exit_value ));
808 #elif defined( LIBVLC_USE_PTHREAD )
809 i_ret = pthread_join( p_priv->thread_id, NULL );
816 msg_Err( p_this, "thread_join(%u) failed at %s:%d (%m)",
817 (unsigned int)p_priv->thread_id, psz_file, i_line );
821 msg_Dbg( p_this, "thread %u joined (%s:%d)",
822 (unsigned int)p_priv->thread_id, psz_file, i_line );
827 p_priv->b_thread = VLC_FALSE;