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;
49 #if defined( LIBVLC_USE_PTHREAD )
50 static pthread_mutex_t once_mutex = PTHREAD_MUTEX_INITIALIZER;
54 * Global process-wide VLC object.
55 * Contains inter-instance data, such as the module cache and global mutexes.
57 static libvlc_global_data_t *p_root;
59 libvlc_global_data_t *vlc_global( void )
61 assert( i_initializations > 0 );
66 vlc_threadvar_t msg_context_global_key;
68 #if defined(LIBVLC_USE_PTHREAD)
69 static inline unsigned long vlc_threadid (void)
71 union { pthread_t th; unsigned long int i; } v = { };
72 v.th = pthread_self ();
77 /*****************************************************************************
78 * vlc_thread_fatal: Report an error from the threading layer
79 *****************************************************************************
80 * This is mostly meant for debugging.
81 *****************************************************************************/
82 void vlc_pthread_fatal (const char *action, int error,
83 const char *file, unsigned line)
85 fprintf (stderr, "LibVLC fatal error %s in thread %lu at %s:%u: %d\n",
86 action, vlc_threadid (), file, line, error);
89 /* Sometimes strerror_r() crashes too, so make sure we print an error
90 * message before we invoke it */
92 /* Avoid the strerror_r() prototype brain damage in glibc */
94 fprintf (stderr, " Error message: %m\n");
99 switch (strerror_r (error, buf, sizeof (buf)))
104 case ERANGE: /* should never happen */
105 msg = "unknwon (too big to display)";
108 msg = "unknown (invalid error number)";
111 fprintf (stderr, " Error message: %s\n", msg);
120 /*****************************************************************************
121 * vlc_threads_init: initialize threads system
122 *****************************************************************************
123 * This function requires lazy initialization of a global lock in order to
124 * keep the library really thread-safe. Some architectures don't support this
125 * and thus do not guarantee the complete reentrancy.
126 *****************************************************************************/
127 int vlc_threads_init( void )
129 int i_ret = VLC_SUCCESS;
131 /* If we have lazy mutex initialization, use it. Otherwise, we just
132 * hope nothing wrong happens. */
133 #if defined( LIBVLC_USE_PTHREAD )
134 pthread_mutex_lock( &once_mutex );
137 if( i_initializations == 0 )
139 p_root = vlc_custom_create( NULL, sizeof( *p_root ),
140 VLC_OBJECT_GENERIC, "root" );
147 /* We should be safe now. Do all the initialization stuff we want. */
148 vlc_threadvar_create( p_root, &msg_context_global_key );
153 /* If we have lazy mutex initialization support, unlock the mutex.
154 * Otherwize, we are screwed. */
155 #if defined( LIBVLC_USE_PTHREAD )
156 pthread_mutex_unlock( &once_mutex );
162 /*****************************************************************************
163 * vlc_threads_end: stop threads system
164 *****************************************************************************
165 * FIXME: This function is far from being threadsafe.
166 *****************************************************************************/
167 void vlc_threads_end( void )
169 #if defined( LIBVLC_USE_PTHREAD )
170 pthread_mutex_lock( &once_mutex );
173 assert( i_initializations > 0 );
175 if( i_initializations == 1 )
176 vlc_object_release( p_root );
179 #if defined( LIBVLC_USE_PTHREAD )
180 pthread_mutex_unlock( &once_mutex );
184 #if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
185 /* This is not prototyped under glibc, though it exists. */
186 int pthread_mutexattr_setkind_np( pthread_mutexattr_t *attr, int kind );
189 /*****************************************************************************
190 * vlc_mutex_init: initialize a mutex
191 *****************************************************************************/
192 int vlc_mutex_init( vlc_mutex_t *p_mutex )
194 #if defined( LIBVLC_USE_PTHREAD )
195 pthread_mutexattr_t attr;
198 pthread_mutexattr_init( &attr );
201 /* Create error-checking mutex to detect problems more easily. */
202 # if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
203 pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_ERRORCHECK_NP );
205 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ERRORCHECK );
208 i_result = pthread_mutex_init( p_mutex, &attr );
209 pthread_mutexattr_destroy( &attr );
211 #elif defined( UNDER_CE )
212 InitializeCriticalSection( &p_mutex->csection );
215 #elif defined( WIN32 )
216 *p_mutex = CreateMutex( 0, FALSE, 0 );
217 return (*p_mutex != NULL) ? 0 : ENOMEM;
219 #elif defined( HAVE_KERNEL_SCHEDULER_H )
220 /* check the arguments and whether it's already been initialized */
221 if( p_mutex == NULL )
226 if( p_mutex->init == 9999 )
231 p_mutex->lock = create_sem( 1, "BeMutex" );
232 if( p_mutex->lock < B_NO_ERROR )
237 p_mutex->init = 9999;
243 /*****************************************************************************
244 * vlc_mutex_init: initialize a recursive mutex (Do not use)
245 *****************************************************************************/
246 int vlc_mutex_init_recursive( vlc_mutex_t *p_mutex )
248 #if defined( LIBVLC_USE_PTHREAD )
249 pthread_mutexattr_t attr;
252 pthread_mutexattr_init( &attr );
253 # if defined (__GLIBC__) && (__GLIBC_MINOR__ < 6)
254 pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_RECURSIVE_NP );
256 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_RECURSIVE );
258 i_result = pthread_mutex_init( p_mutex, &attr );
259 pthread_mutexattr_destroy( &attr );
261 #elif defined( WIN32 )
262 /* Create mutex returns a recursive mutex */
263 *p_mutex = CreateMutex( 0, FALSE, 0 );
264 return (*p_mutex != NULL) ? 0 : ENOMEM;
266 # error Unimplemented!
271 /*****************************************************************************
272 * vlc_mutex_destroy: destroy a mutex, inner version
273 *****************************************************************************/
274 void __vlc_mutex_destroy( const char * psz_file, int i_line, vlc_mutex_t *p_mutex )
276 #if defined( LIBVLC_USE_PTHREAD )
277 int val = pthread_mutex_destroy( p_mutex );
278 VLC_THREAD_ASSERT ("destroying mutex");
280 #elif defined( UNDER_CE )
281 VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
283 DeleteCriticalSection( &p_mutex->csection );
285 #elif defined( WIN32 )
286 VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
288 CloseHandle( *p_mutex );
290 #elif defined( HAVE_KERNEL_SCHEDULER_H )
291 if( p_mutex->init == 9999 )
292 delete_sem( p_mutex->lock );
299 /*****************************************************************************
300 * vlc_cond_init: initialize a condition
301 *****************************************************************************/
302 int __vlc_cond_init( vlc_cond_t *p_condvar )
304 #if defined( LIBVLC_USE_PTHREAD )
305 pthread_condattr_t attr;
308 ret = pthread_condattr_init (&attr);
312 # if !defined (_POSIX_CLOCK_SELECTION)
313 /* Fairly outdated POSIX support (that was defined in 2001) */
314 # define _POSIX_CLOCK_SELECTION (-1)
316 # if (_POSIX_CLOCK_SELECTION >= 0)
317 /* NOTE: This must be the same clock as the one in mtime.c */
318 pthread_condattr_setclock (&attr, CLOCK_MONOTONIC);
321 ret = pthread_cond_init (p_condvar, &attr);
322 pthread_condattr_destroy (&attr);
325 #elif defined( UNDER_CE ) || defined( WIN32 )
326 /* Initialize counter */
327 p_condvar->i_waiting_threads = 0;
329 /* Create an auto-reset event. */
330 p_condvar->event = CreateEvent( NULL, /* no security */
331 FALSE, /* auto-reset event */
332 FALSE, /* start non-signaled */
333 NULL ); /* unnamed */
334 return !p_condvar->event;
336 #elif defined( HAVE_KERNEL_SCHEDULER_H )
342 if( p_condvar->init == 9999 )
347 p_condvar->thread = -1;
348 p_condvar->init = 9999;
354 /*****************************************************************************
355 * vlc_cond_destroy: destroy a condition, inner version
356 *****************************************************************************/
357 void __vlc_cond_destroy( const char * psz_file, int i_line, vlc_cond_t *p_condvar )
359 #if defined( LIBVLC_USE_PTHREAD )
360 int val = pthread_cond_destroy( p_condvar );
361 VLC_THREAD_ASSERT ("destroying condition");
363 #elif defined( UNDER_CE ) || defined( WIN32 )
364 VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
366 CloseHandle( p_condvar->event );
368 #elif defined( HAVE_KERNEL_SCHEDULER_H )
374 /*****************************************************************************
375 * vlc_tls_create: create a thread-local variable
376 *****************************************************************************/
377 int __vlc_threadvar_create( vlc_threadvar_t *p_tls )
381 #if defined( LIBVLC_USE_PTHREAD )
382 i_ret = pthread_key_create( p_tls, NULL );
383 #elif defined( UNDER_CE )
384 #elif defined( WIN32 )
386 i_ret = (*p_tls == TLS_OUT_OF_INDEXES) ? EAGAIN : 0;
388 # error Unimplemented!
393 /*****************************************************************************
394 * vlc_thread_create: create a thread, inner version
395 *****************************************************************************
396 * Note that i_priority is only taken into account on platforms supporting
397 * userland real-time priority threads.
398 *****************************************************************************/
399 int __vlc_thread_create( vlc_object_t *p_this, const char * psz_file, int i_line,
400 const char *psz_name, void * ( *func ) ( void * ),
401 int i_priority, bool b_wait )
404 void *p_data = (void *)p_this;
405 vlc_object_internals_t *p_priv = vlc_internals( p_this );
407 vlc_mutex_lock( &p_this->object_lock );
409 #if defined( LIBVLC_USE_PTHREAD )
410 i_ret = pthread_create( &p_priv->thread_id, NULL, func, p_data );
413 if( config_GetInt( p_this, "rt-priority" ) > 0 )
416 int i_error, i_policy;
417 struct sched_param param;
419 memset( ¶m, 0, sizeof(struct sched_param) );
420 if( config_GetType( p_this, "rt-offset" ) )
421 i_priority += config_GetInt( p_this, "rt-offset" );
422 if( i_priority <= 0 )
424 param.sched_priority = (-1) * i_priority;
425 i_policy = SCHED_OTHER;
429 param.sched_priority = i_priority;
432 if( (i_error = pthread_setschedparam( p_priv->thread_id,
433 i_policy, ¶m )) )
436 msg_Warn( p_this, "couldn't set thread priority (%s:%d): %m",
446 #elif defined( WIN32 ) || defined( UNDER_CE )
448 /* When using the MSVCRT C library you have to use the _beginthreadex
449 * function instead of CreateThread, otherwise you'll end up with
450 * memory leaks and the signal functions not working (see Microsoft
451 * Knowledge Base, article 104641) */
452 #if defined( UNDER_CE )
453 HANDLE hThread = CreateThread( NULL, 0, (LPTHREAD_START_ROUTINE)func,
454 (LPVOID)p_data, CREATE_SUSPENDED,
457 HANDLE hThread = (HANDLE)(uintptr_t)
458 _beginthreadex( NULL, 0, (LPTHREAD_START_ROUTINE)func,
459 (void *)p_data, CREATE_SUSPENDED, NULL );
461 p_priv->thread_id = hThread;
462 ResumeThread(hThread);
465 i_ret = ( p_priv->thread_id ? 0 : errno );
467 if( !i_ret && i_priority )
469 if( !SetThreadPriority(p_priv->thread_id, i_priority) )
471 msg_Warn( p_this, "couldn't set a faster priority" );
476 #elif defined( HAVE_KERNEL_SCHEDULER_H )
477 p_priv->thread_id = spawn_thread( (thread_func)func, psz_name,
478 i_priority, p_data );
479 i_ret = resume_thread( p_priv->thread_id );
487 msg_Dbg( p_this, "waiting for thread completion" );
488 vlc_object_wait( p_this );
491 p_priv->b_thread = true;
492 msg_Dbg( p_this, "thread %lu (%s) created at priority %d (%s:%d)",
493 (unsigned long)p_priv->thread_id, psz_name, i_priority,
499 msg_Err( p_this, "%s thread could not be created at %s:%d (%m)",
500 psz_name, psz_file, i_line );
503 vlc_mutex_unlock( &p_this->object_lock );
507 /*****************************************************************************
508 * vlc_thread_set_priority: set the priority of the current thread when we
509 * couldn't set it in vlc_thread_create (for instance for the main thread)
510 *****************************************************************************/
511 int __vlc_thread_set_priority( vlc_object_t *p_this, const char * psz_file,
512 int i_line, int i_priority )
514 vlc_object_internals_t *p_priv = vlc_internals( p_this );
516 #if defined( LIBVLC_USE_PTHREAD )
518 if( config_GetInt( p_this, "rt-priority" ) > 0 )
521 int i_error, i_policy;
522 struct sched_param param;
524 memset( ¶m, 0, sizeof(struct sched_param) );
525 if( config_GetType( p_this, "rt-offset" ) )
526 i_priority += config_GetInt( p_this, "rt-offset" );
527 if( i_priority <= 0 )
529 param.sched_priority = (-1) * i_priority;
530 i_policy = SCHED_OTHER;
534 param.sched_priority = i_priority;
537 if( !p_priv->thread_id )
538 p_priv->thread_id = pthread_self();
539 if( (i_error = pthread_setschedparam( p_priv->thread_id,
540 i_policy, ¶m )) )
543 msg_Warn( p_this, "couldn't set thread priority (%s:%d): %m",
549 #elif defined( WIN32 ) || defined( UNDER_CE )
550 VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
552 if( !p_priv->thread_id )
553 p_priv->thread_id = GetCurrentThread();
554 if( !SetThreadPriority(p_priv->thread_id, i_priority) )
556 msg_Warn( p_this, "couldn't set a faster priority" );
565 /*****************************************************************************
566 * vlc_thread_ready: tell the parent thread we were successfully spawned
567 *****************************************************************************/
568 void __vlc_thread_ready( vlc_object_t *p_this )
570 vlc_object_signal( p_this );
573 /*****************************************************************************
574 * vlc_thread_join: wait until a thread exits, inner version
575 *****************************************************************************/
576 void __vlc_thread_join( vlc_object_t *p_this, const char * psz_file, int i_line )
578 vlc_object_internals_t *p_priv = vlc_internals( p_this );
581 #if defined( LIBVLC_USE_PTHREAD )
582 /* Make sure we do return if we are calling vlc_thread_join()
583 * from the joined thread */
584 if (pthread_equal (pthread_self (), p_priv->thread_id))
585 i_ret = pthread_detach (p_priv->thread_id);
587 i_ret = pthread_join (p_priv->thread_id, NULL);
589 #elif defined( UNDER_CE ) || defined( WIN32 )
591 BOOL (WINAPI *OurGetThreadTimes)( HANDLE, FILETIME*, FILETIME*,
592 FILETIME*, FILETIME* );
593 FILETIME create_ft, exit_ft, kernel_ft, user_ft;
594 int64_t real_time, kernel_time, user_time;
598 ** object will close its thread handle when destroyed, duplicate it here
599 ** to be on the safe side
601 if( ! DuplicateHandle(GetCurrentProcess(),
607 DUPLICATE_SAME_ACCESS) )
609 p_priv->b_thread = false;
610 i_ret = GetLastError();
614 WaitForSingleObject( hThread, INFINITE );
616 #if defined( UNDER_CE )
617 hmodule = GetModuleHandle( _T("COREDLL") );
619 hmodule = GetModuleHandle( _T("KERNEL32") );
621 OurGetThreadTimes = (BOOL (WINAPI*)( HANDLE, FILETIME*, FILETIME*,
622 FILETIME*, FILETIME* ))
623 GetProcAddress( hmodule, _T("GetThreadTimes") );
625 if( OurGetThreadTimes &&
626 OurGetThreadTimes( hThread,
627 &create_ft, &exit_ft, &kernel_ft, &user_ft ) )
630 ((((int64_t)exit_ft.dwHighDateTime)<<32)| exit_ft.dwLowDateTime) -
631 ((((int64_t)create_ft.dwHighDateTime)<<32)| create_ft.dwLowDateTime);
635 ((((int64_t)kernel_ft.dwHighDateTime)<<32)|
636 kernel_ft.dwLowDateTime) / 10;
639 ((((int64_t)user_ft.dwHighDateTime)<<32)|
640 user_ft.dwLowDateTime) / 10;
642 msg_Dbg( p_this, "thread times: "
643 "real %"PRId64"m%fs, kernel %"PRId64"m%fs, user %"PRId64"m%fs",
644 real_time/60/1000000,
645 (double)((real_time%(60*1000000))/1000000.0),
646 kernel_time/60/1000000,
647 (double)((kernel_time%(60*1000000))/1000000.0),
648 user_time/60/1000000,
649 (double)((user_time%(60*1000000))/1000000.0) );
651 CloseHandle( hThread );
654 #elif defined( HAVE_KERNEL_SCHEDULER_H )
656 i_ret = (B_OK == wait_for_thread( p_priv->thread_id, &exit_value ));
663 msg_Err( p_this, "thread_join(%lu) failed at %s:%d (%m)",
664 (unsigned long)p_priv->thread_id, psz_file, i_line );
667 msg_Dbg( p_this, "thread %lu joined (%s:%d)",
668 (unsigned long)p_priv->thread_id, psz_file, i_line );
670 p_priv->b_thread = false;