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)
100 fprintf (stderr, "LibVLC fatal error %s in thread %lu at %s:%u: %d\n",
101 action, vlc_threadid (), file, line, error);
104 /* Sometimes strerror() crashes too, so make sure we print an error
105 * message before we invoke it */
106 msg = strerror (error);
107 fprintf (stderr, "Error description was: \"%s\"\n", msg ? msg : "(null)");
114 /*****************************************************************************
115 * vlc_threads_init: initialize threads system
116 *****************************************************************************
117 * This function requires lazy initialization of a global lock in order to
118 * keep the library really thread-safe. Some architectures don't support this
119 * and thus do not guarantee the complete reentrancy.
120 *****************************************************************************/
121 int __vlc_threads_init( vlc_object_t *p_this )
123 libvlc_global_data_t *p_libvlc_global = (libvlc_global_data_t *)p_this;
124 int i_ret = VLC_SUCCESS;
126 /* If we have lazy mutex initialization, use it. Otherwise, we just
127 * hope nothing wrong happens. */
128 #if defined( UNDER_CE )
129 #elif defined( WIN32 )
130 if( IsDebuggerPresent() )
132 /* SignalObjectAndWait() is problematic under a debugger */
133 b_fast_mutex = VLC_TRUE;
136 #elif defined( HAVE_KERNEL_SCHEDULER_H )
137 #elif defined( LIBVLC_USE_PTHREAD )
138 pthread_mutex_lock( &once_mutex );
141 if( i_status == VLC_THREADS_UNINITIALIZED )
143 i_status = VLC_THREADS_PENDING;
145 /* We should be safe now. Do all the initialization stuff we want. */
146 p_libvlc_global->b_ready = VLC_FALSE;
148 #if defined( UNDER_CE )
149 /* Nothing to initialize */
151 #elif defined( WIN32 )
152 /* Dynamically get the address of SignalObjectAndWait */
153 if( GetVersion() < 0x80000000 )
157 /* We are running on NT/2K/XP, we can use SignalObjectAndWait */
158 hInstLib = LoadLibrary( "kernel32" );
161 pf_SignalObjectAndWait =
162 (SIGNALOBJECTANDWAIT)GetProcAddress( hInstLib,
163 "SignalObjectAndWait" );
167 #elif defined( HAVE_KERNEL_SCHEDULER_H )
168 #elif defined( LIBVLC_USE_PTHREAD )
171 p_root = vlc_object_create( p_libvlc_global, VLC_OBJECT_GLOBAL );
177 i_status = VLC_THREADS_ERROR;
182 i_status = VLC_THREADS_READY;
185 vlc_threadvar_create( p_root, &msg_context_global_key );
189 /* Just increment the initialization count */
193 /* If we have lazy mutex initialization support, unlock the mutex;
194 * otherwize, do a naive wait loop. */
195 #if defined( UNDER_CE )
196 while( i_status == VLC_THREADS_PENDING ) msleep( THREAD_SLEEP );
197 #elif defined( WIN32 )
198 while( i_status == VLC_THREADS_PENDING ) msleep( THREAD_SLEEP );
199 #elif defined( HAVE_KERNEL_SCHEDULER_H )
200 while( i_status == VLC_THREADS_PENDING ) msleep( THREAD_SLEEP );
201 #elif defined( LIBVLC_USE_PTHREAD )
202 pthread_mutex_unlock( &once_mutex );
205 if( i_status != VLC_THREADS_READY )
213 /*****************************************************************************
214 * vlc_threads_end: stop threads system
215 *****************************************************************************
216 * FIXME: This function is far from being threadsafe.
217 *****************************************************************************/
218 int __vlc_threads_end( vlc_object_t *p_this )
221 #if defined( UNDER_CE )
222 #elif defined( WIN32 )
223 #elif defined( HAVE_KERNEL_SCHEDULER_H )
224 #elif defined( LIBVLC_USE_PTHREAD )
225 pthread_mutex_lock( &once_mutex );
228 if( i_initializations == 0 )
232 if( i_initializations == 0 )
234 i_status = VLC_THREADS_UNINITIALIZED;
235 vlc_object_destroy( p_root );
238 #if defined( UNDER_CE )
239 #elif defined( WIN32 )
240 #elif defined( HAVE_KERNEL_SCHEDULER_H )
241 #elif defined( LIBVLC_USE_PTHREAD )
242 pthread_mutex_unlock( &once_mutex );
248 /* This is not prototyped under Linux, though it exists. */
249 int pthread_mutexattr_setkind_np( pthread_mutexattr_t *attr, int kind );
252 /*****************************************************************************
253 * vlc_mutex_init: initialize a mutex
254 *****************************************************************************/
255 int __vlc_mutex_init( vlc_mutex_t *p_mutex )
257 #if defined( UNDER_CE )
258 InitializeCriticalSection( &p_mutex->csection );
261 #elif defined( WIN32 )
262 /* We use mutexes on WinNT/2K/XP because we can use the SignalObjectAndWait
263 * function and have a 100% correct vlc_cond_wait() implementation.
264 * As this function is not available on Win9x, we can use the faster
265 * CriticalSections */
266 if( pf_SignalObjectAndWait && !b_fast_mutex )
268 /* We are running on NT/2K/XP, we can use SignalObjectAndWait */
269 p_mutex->mutex = CreateMutex( 0, FALSE, 0 );
270 return ( p_mutex->mutex != NULL ? 0 : 1 );
274 p_mutex->mutex = NULL;
275 InitializeCriticalSection( &p_mutex->csection );
279 #elif defined( HAVE_KERNEL_SCHEDULER_H )
280 /* check the arguments and whether it's already been initialized */
281 if( p_mutex == NULL )
286 if( p_mutex->init == 9999 )
291 p_mutex->lock = create_sem( 1, "BeMutex" );
292 if( p_mutex->lock < B_NO_ERROR )
297 p_mutex->init = 9999;
300 #elif defined( LIBVLC_USE_PTHREAD )
303 /* Create error-checking mutex to detect problems more easily. */
304 pthread_mutexattr_t attr;
307 pthread_mutexattr_init( &attr );
308 # if defined(SYS_LINUX)
309 pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_ERRORCHECK_NP );
311 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ERRORCHECK );
314 i_result = pthread_mutex_init( &p_mutex->mutex, &attr );
315 pthread_mutexattr_destroy( &attr );
319 return pthread_mutex_init( &p_mutex->mutex, NULL );
324 /*****************************************************************************
325 * vlc_mutex_init: initialize a recursive mutex (Do not use)
326 *****************************************************************************/
327 int __vlc_mutex_init_recursive( vlc_mutex_t *p_mutex )
330 /* Create mutex returns a recursive mutex */
331 p_mutex->mutex = CreateMutex( 0, FALSE, 0 );
332 return ( p_mutex->mutex != NULL ? 0 : 1 );
333 #elif defined( LIBVLC_USE_PTHREAD )
334 pthread_mutexattr_t attr;
337 pthread_mutexattr_init( &attr );
339 /* Create error-checking mutex to detect problems more easily. */
340 # if defined(SYS_LINUX)
341 pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_ERRORCHECK_NP );
343 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ERRORCHECK );
346 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_RECURSIVE );
347 i_result = pthread_mutex_init( &p_mutex->mutex, &attr );
348 pthread_mutexattr_destroy( &attr );
351 # error Unimplemented!
356 /*****************************************************************************
357 * vlc_mutex_destroy: destroy a mutex, inner version
358 *****************************************************************************/
359 void __vlc_mutex_destroy( const char * psz_file, int i_line, vlc_mutex_t *p_mutex )
361 #if defined( UNDER_CE )
362 DeleteCriticalSection( &p_mutex->csection );
364 #elif defined( WIN32 )
366 CloseHandle( p_mutex->mutex );
368 DeleteCriticalSection( &p_mutex->csection );
370 #elif defined( HAVE_KERNEL_SCHEDULER_H )
371 if( p_mutex->init == 9999 )
372 delete_sem( p_mutex->lock );
376 #elif defined( LIBVLC_USE_PTHREAD )
377 int val = pthread_mutex_destroy( &p_mutex->mutex );
378 VLC_THREAD_ASSERT ("destroying mutex");
383 /*****************************************************************************
384 * vlc_cond_init: initialize a condition
385 *****************************************************************************/
386 int __vlc_cond_init( vlc_cond_t *p_condvar )
388 #if defined( UNDER_CE )
389 /* Initialize counter */
390 p_condvar->i_waiting_threads = 0;
392 /* Create an auto-reset event. */
393 p_condvar->event = CreateEvent( NULL, /* no security */
394 FALSE, /* auto-reset event */
395 FALSE, /* start non-signaled */
396 NULL ); /* unnamed */
397 return !p_condvar->event;
399 #elif defined( WIN32 )
400 /* Initialize counter */
401 p_condvar->i_waiting_threads = 0;
404 p_condvar->i_win9x_cv = i_win9x_cv;
405 p_condvar->SignalObjectAndWait = pf_SignalObjectAndWait;
407 if( (p_condvar->SignalObjectAndWait && !b_fast_mutex)
408 || p_condvar->i_win9x_cv == 0 )
410 /* Create an auto-reset event. */
411 p_condvar->event = CreateEvent( NULL, /* no security */
412 FALSE, /* auto-reset event */
413 FALSE, /* start non-signaled */
414 NULL ); /* unnamed */
416 p_condvar->semaphore = NULL;
417 return !p_condvar->event;
421 p_condvar->semaphore = CreateSemaphore( NULL, /* no security */
422 0, /* initial count */
423 0x7fffffff, /* max count */
424 NULL ); /* unnamed */
426 if( p_condvar->i_win9x_cv == 1 )
427 /* Create a manual-reset event initially signaled. */
428 p_condvar->event = CreateEvent( NULL, TRUE, TRUE, NULL );
430 /* Create a auto-reset event. */
431 p_condvar->event = CreateEvent( NULL, FALSE, FALSE, NULL );
433 InitializeCriticalSection( &p_condvar->csection );
435 return !p_condvar->semaphore || !p_condvar->event;
438 #elif defined( HAVE_KERNEL_SCHEDULER_H )
444 if( p_condvar->init == 9999 )
449 p_condvar->thread = -1;
450 p_condvar->init = 9999;
453 #elif defined( LIBVLC_USE_PTHREAD )
454 pthread_condattr_t attr;
457 ret = pthread_condattr_init (&attr);
461 # if !defined (_POSIX_CLOCK_SELECTION)
462 /* Fairly outdated POSIX support (that was defined in 2001) */
463 # define _POSIX_CLOCK_SELECTION (-1)
465 # if (_POSIX_CLOCK_SELECTION >= 0)
466 /* NOTE: This must be the same clock as the one in mtime.c */
467 pthread_condattr_setclock (&attr, CLOCK_MONOTONIC);
470 ret = pthread_cond_init (&p_condvar->cond, &attr);
471 pthread_condattr_destroy (&attr);
477 /*****************************************************************************
478 * vlc_cond_destroy: destroy a condition, inner version
479 *****************************************************************************/
480 void __vlc_cond_destroy( const char * psz_file, int i_line, vlc_cond_t *p_condvar )
482 #if defined( UNDER_CE )
483 CloseHandle( p_condvar->event );
485 #elif defined( WIN32 )
486 if( !p_condvar->semaphore )
487 CloseHandle( p_condvar->event );
490 CloseHandle( p_condvar->event );
491 CloseHandle( p_condvar->semaphore );
494 if( p_condvar->semaphore != NULL )
495 DeleteCriticalSection( &p_condvar->csection );
497 #elif defined( HAVE_KERNEL_SCHEDULER_H )
500 #elif defined( LIBVLC_USE_PTHREAD )
501 int val = pthread_cond_destroy( &p_condvar->cond );
502 VLC_THREAD_ASSERT ("destroying condition");
507 /*****************************************************************************
508 * vlc_tls_create: create a thread-local variable
509 *****************************************************************************/
510 int __vlc_threadvar_create( vlc_threadvar_t *p_tls )
514 #if defined( HAVE_KERNEL_SCHEDULER_H )
515 # error Unimplemented!
516 #elif defined( UNDER_CE ) || defined( WIN32 )
517 #elif defined( WIN32 )
518 p_tls->handle = TlsAlloc();
519 i_ret = !( p_tls->handle == 0xFFFFFFFF );
521 #elif defined( LIBVLC_USE_PTHREAD )
522 i_ret = pthread_key_create( &p_tls->handle, NULL );
527 /*****************************************************************************
528 * vlc_thread_create: create a thread, inner version
529 *****************************************************************************
530 * Note that i_priority is only taken into account on platforms supporting
531 * userland real-time priority threads.
532 *****************************************************************************/
533 int __vlc_thread_create( vlc_object_t *p_this, const char * psz_file, int i_line,
534 const char *psz_name, void * ( *func ) ( void * ),
535 int i_priority, vlc_bool_t b_wait )
538 void *p_data = (void *)p_this;
539 vlc_object_internals_t *p_priv = p_this->p_internals;
541 vlc_mutex_lock( &p_this->object_lock );
543 #if defined( WIN32 ) || defined( UNDER_CE )
545 /* When using the MSVCRT C library you have to use the _beginthreadex
546 * function instead of CreateThread, otherwise you'll end up with
547 * memory leaks and the signal functions not working (see Microsoft
548 * Knowledge Base, article 104641) */
549 #if defined( UNDER_CE )
551 HANDLE hThread = CreateThread( NULL, 0, (LPTHREAD_START_ROUTINE)func,
552 (LPVOID)p_data, CREATE_SUSPENDED,
556 uintptr_t hThread = _beginthreadex( NULL, 0,
557 (LPTHREAD_START_ROUTINE)func,
558 (void*)p_data, CREATE_SUSPENDED,
561 p_priv->thread_id.id = (DWORD)threadId;
562 p_priv->thread_id.hThread = (HANDLE)hThread;
563 ResumeThread((HANDLE)hThread);
566 i_ret = ( p_priv->thread_id.hThread ? 0 : 1 );
568 if( !i_ret && i_priority )
570 if( !SetThreadPriority(p_priv->thread_id.hThread, i_priority) )
572 msg_Warn( p_this, "couldn't set a faster priority" );
577 #elif defined( HAVE_KERNEL_SCHEDULER_H )
578 p_priv->thread_id = spawn_thread( (thread_func)func, psz_name,
579 i_priority, p_data );
580 i_ret = resume_thread( p_priv->thread_id );
582 #elif defined( LIBVLC_USE_PTHREAD )
583 i_ret = pthread_create( &p_priv->thread_id, NULL, func, p_data );
586 if( config_GetInt( p_this, "rt-priority" ) )
589 int i_error, i_policy;
590 struct sched_param param;
592 memset( ¶m, 0, sizeof(struct sched_param) );
593 if( config_GetType( p_this, "rt-offset" ) )
595 i_priority += config_GetInt( p_this, "rt-offset" );
597 if( i_priority <= 0 )
599 param.sched_priority = (-1) * i_priority;
600 i_policy = SCHED_OTHER;
604 param.sched_priority = i_priority;
607 if( (i_error = pthread_setschedparam( p_priv->thread_id,
608 i_policy, ¶m )) )
611 msg_Warn( p_this, "couldn't set thread priority (%s:%d): %m",
629 msg_Dbg( p_this, "waiting for thread completion" );
630 vlc_object_wait( p_this );
633 p_priv->b_thread = VLC_TRUE;
635 #if defined( WIN32 ) || defined( UNDER_CE )
636 msg_Dbg( p_this, "thread %u (%s) created at priority %d (%s:%d)",
637 (unsigned int)p_priv->thread_id.id, psz_name,
638 i_priority, psz_file, i_line );
640 msg_Dbg( p_this, "thread %u (%s) created at priority %d (%s:%d)",
641 (unsigned int)p_priv->thread_id, psz_name, i_priority,
646 vlc_mutex_unlock( &p_this->object_lock );
651 msg_Err( p_this, "%s thread could not be created at %s:%d (%m)",
652 psz_name, psz_file, i_line );
653 vlc_mutex_unlock( &p_this->object_lock );
659 /*****************************************************************************
660 * vlc_thread_set_priority: set the priority of the current thread when we
661 * couldn't set it in vlc_thread_create (for instance for the main thread)
662 *****************************************************************************/
663 int __vlc_thread_set_priority( vlc_object_t *p_this, const char * psz_file,
664 int i_line, int i_priority )
666 vlc_object_internals_t *p_priv = p_this->p_internals;
667 #if defined( WIN32 ) || defined( UNDER_CE )
668 if( !p_priv->thread_id.hThread )
669 p_priv->thread_id.hThread = GetCurrentThread();
670 if( !SetThreadPriority(p_priv->thread_id.hThread, i_priority) )
672 msg_Warn( p_this, "couldn't set a faster priority" );
676 #elif defined( LIBVLC_USE_PTHREAD )
678 if( config_GetInt( p_this, "rt-priority" ) > 0 )
681 int i_error, i_policy;
682 struct sched_param param;
684 memset( ¶m, 0, sizeof(struct sched_param) );
685 if( config_GetType( p_this, "rt-offset" ) )
687 i_priority += config_GetInt( p_this, "rt-offset" );
689 if( i_priority <= 0 )
691 param.sched_priority = (-1) * i_priority;
692 i_policy = SCHED_OTHER;
696 param.sched_priority = i_priority;
699 if( !p_priv->thread_id )
700 p_priv->thread_id = pthread_self();
701 if( (i_error = pthread_setschedparam( p_priv->thread_id,
702 i_policy, ¶m )) )
705 msg_Warn( p_this, "couldn't set thread priority (%s:%d): %m",
715 /*****************************************************************************
716 * vlc_thread_ready: tell the parent thread we were successfully spawned
717 *****************************************************************************/
718 void __vlc_thread_ready( vlc_object_t *p_this )
720 vlc_object_signal( p_this );
723 /*****************************************************************************
724 * vlc_thread_join: wait until a thread exits, inner version
725 *****************************************************************************/
726 void __vlc_thread_join( vlc_object_t *p_this, const char * psz_file, int i_line )
728 vlc_object_internals_t *p_priv = p_this->p_internals;
730 #if defined( UNDER_CE ) || defined( WIN32 )
732 BOOL (WINAPI *OurGetThreadTimes)( HANDLE, FILETIME*, FILETIME*,
733 FILETIME*, FILETIME* );
734 FILETIME create_ft, exit_ft, kernel_ft, user_ft;
735 int64_t real_time, kernel_time, user_time;
739 ** object will close its thread handle when destroyed, duplicate it here
740 ** to be on the safe side
742 if( ! DuplicateHandle(GetCurrentProcess(),
743 p_priv->thread_id.hThread,
748 DUPLICATE_SAME_ACCESS) )
750 msg_Err( p_this, "thread_join(%u) failed at %s:%d (%s)",
751 (unsigned int)p_priv->thread_id.id,
752 psz_file, i_line, GetLastError() );
753 p_priv->b_thread = VLC_FALSE;
757 WaitForSingleObject( hThread, INFINITE );
759 msg_Dbg( p_this, "thread %u joined (%s:%d)",
760 (unsigned int)p_priv->thread_id.id,
762 #if defined( UNDER_CE )
763 hmodule = GetModuleHandle( _T("COREDLL") );
765 hmodule = GetModuleHandle( _T("KERNEL32") );
767 OurGetThreadTimes = (BOOL (WINAPI*)( HANDLE, FILETIME*, FILETIME*,
768 FILETIME*, FILETIME* ))
769 GetProcAddress( hmodule, _T("GetThreadTimes") );
771 if( OurGetThreadTimes &&
772 OurGetThreadTimes( hThread,
773 &create_ft, &exit_ft, &kernel_ft, &user_ft ) )
776 ((((int64_t)exit_ft.dwHighDateTime)<<32)| exit_ft.dwLowDateTime) -
777 ((((int64_t)create_ft.dwHighDateTime)<<32)| create_ft.dwLowDateTime);
781 ((((int64_t)kernel_ft.dwHighDateTime)<<32)|
782 kernel_ft.dwLowDateTime) / 10;
785 ((((int64_t)user_ft.dwHighDateTime)<<32)|
786 user_ft.dwLowDateTime) / 10;
788 msg_Dbg( p_this, "thread times: "
789 "real "I64Fd"m%fs, kernel "I64Fd"m%fs, user "I64Fd"m%fs",
790 real_time/60/1000000,
791 (double)((real_time%(60*1000000))/1000000.0),
792 kernel_time/60/1000000,
793 (double)((kernel_time%(60*1000000))/1000000.0),
794 user_time/60/1000000,
795 (double)((user_time%(60*1000000))/1000000.0) );
797 CloseHandle( hThread );
799 #else /* !defined(WIN32) */
803 #if defined( HAVE_KERNEL_SCHEDULER_H )
805 i_ret = (B_OK == wait_for_thread( p_priv->thread_id, &exit_value ));
807 #elif defined( LIBVLC_USE_PTHREAD )
808 i_ret = pthread_join( p_priv->thread_id, NULL );
815 msg_Err( p_this, "thread_join(%u) failed at %s:%d (%m)",
816 (unsigned int)p_priv->thread_id, psz_file, i_line );
820 msg_Dbg( p_this, "thread %u joined (%s:%d)",
821 (unsigned int)p_priv->thread_id, psz_file, i_line );
826 p_priv->b_thread = VLC_FALSE;