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( UNDER_CE )
50 #elif defined( WIN32 )
51 #elif defined( HAVE_KERNEL_SCHEDULER_H )
52 #elif defined( LIBVLC_USE_PTHREAD )
53 static pthread_mutex_t once_mutex = PTHREAD_MUTEX_INITIALIZER;
57 * Global process-wide VLC object.
58 * Contains inter-instance data, such as the module cache and global mutexes.
60 static libvlc_global_data_t *p_root;
62 libvlc_global_data_t *vlc_global( void )
64 assert( i_initializations > 0 );
69 vlc_threadvar_t msg_context_global_key;
71 #if defined(LIBVLC_USE_PTHREAD)
72 static inline unsigned long vlc_threadid (void)
74 union { pthread_t th; unsigned long int i; } v = { };
75 v.th = pthread_self ();
80 /*****************************************************************************
81 * vlc_thread_fatal: Report an error from the threading layer
82 *****************************************************************************
83 * This is mostly meant for debugging.
84 *****************************************************************************/
85 void vlc_pthread_fatal (const char *action, int error,
86 const char *file, unsigned line)
88 fprintf (stderr, "LibVLC fatal error %s in thread %lu at %s:%u: %d\n",
89 action, vlc_threadid (), file, line, error);
92 /* Sometimes strerror_r() crashes too, so make sure we print an error
93 * message before we invoke it */
95 /* Avoid the strerror_r() prototype brain damage in glibc */
97 fprintf (stderr, " Error message: %m\n");
102 switch (strerror_r (error, buf, sizeof (buf)))
107 case ERANGE: /* should never happen */
108 msg = "unknwon (too big to display)";
111 msg = "unknown (invalid error number)";
114 fprintf (stderr, " Error message: %s\n", msg);
123 /*****************************************************************************
124 * vlc_threads_init: initialize threads system
125 *****************************************************************************
126 * This function requires lazy initialization of a global lock in order to
127 * keep the library really thread-safe. Some architectures don't support this
128 * and thus do not guarantee the complete reentrancy.
129 *****************************************************************************/
130 int vlc_threads_init( void )
132 int i_ret = VLC_SUCCESS;
134 /* If we have lazy mutex initialization, use it. Otherwise, we just
135 * hope nothing wrong happens. */
136 #if defined( UNDER_CE )
137 #elif defined( WIN32 )
138 #elif defined( HAVE_KERNEL_SCHEDULER_H )
139 #elif defined( LIBVLC_USE_PTHREAD )
140 pthread_mutex_lock( &once_mutex );
143 if( i_initializations == 0 )
145 p_root = vlc_custom_create( NULL, sizeof( *p_root ),
146 VLC_OBJECT_GENERIC, "root" );
153 /* We should be safe now. Do all the initialization stuff we want. */
154 p_root->b_ready = false;
155 vlc_threadvar_create( p_root, &msg_context_global_key );
160 /* If we have lazy mutex initialization support, unlock the mutex.
161 * Otherwize, we are screwed. */
162 #if defined( UNDER_CE )
163 #elif defined( WIN32 )
164 #elif defined( HAVE_KERNEL_SCHEDULER_H )
165 #elif defined( LIBVLC_USE_PTHREAD )
166 pthread_mutex_unlock( &once_mutex );
172 /*****************************************************************************
173 * vlc_threads_end: stop threads system
174 *****************************************************************************
175 * FIXME: This function is far from being threadsafe.
176 *****************************************************************************/
177 void vlc_threads_end( void )
179 #if defined( UNDER_CE )
180 #elif defined( WIN32 )
181 #elif defined( HAVE_KERNEL_SCHEDULER_H )
182 #elif defined( LIBVLC_USE_PTHREAD )
183 pthread_mutex_lock( &once_mutex );
186 assert( i_initializations > 0 );
187 if( i_initializations == 0 )
188 vlc_object_release( p_root );
191 #if defined( UNDER_CE )
192 #elif defined( WIN32 )
193 #elif defined( HAVE_KERNEL_SCHEDULER_H )
194 #elif defined( LIBVLC_USE_PTHREAD )
195 pthread_mutex_unlock( &once_mutex );
200 /* This is not prototyped under Linux, though it exists. */
201 int pthread_mutexattr_setkind_np( pthread_mutexattr_t *attr, int kind );
204 /*****************************************************************************
205 * vlc_mutex_init: initialize a mutex
206 *****************************************************************************/
207 int vlc_mutex_init( vlc_mutex_t *p_mutex )
209 #if defined( UNDER_CE )
210 InitializeCriticalSection( &p_mutex->csection );
213 #elif defined( WIN32 )
214 *p_mutex = CreateMutex( 0, FALSE, 0 );
215 return (*p_mutex != NULL) ? 0 : ENOMEM;
217 #elif defined( HAVE_KERNEL_SCHEDULER_H )
218 /* check the arguments and whether it's already been initialized */
219 if( p_mutex == NULL )
224 if( p_mutex->init == 9999 )
229 p_mutex->lock = create_sem( 1, "BeMutex" );
230 if( p_mutex->lock < B_NO_ERROR )
235 p_mutex->init = 9999;
238 #elif defined( LIBVLC_USE_PTHREAD )
239 pthread_mutexattr_t attr;
242 pthread_mutexattr_init( &attr );
245 /* Create error-checking mutex to detect problems more easily. */
246 # if defined(SYS_LINUX)
247 pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_ERRORCHECK_NP );
249 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ERRORCHECK );
252 i_result = pthread_mutex_init( p_mutex, &attr );
253 pthread_mutexattr_destroy( &attr );
258 /*****************************************************************************
259 * vlc_mutex_init: initialize a recursive mutex (Do not use)
260 *****************************************************************************/
261 int vlc_mutex_init_recursive( vlc_mutex_t *p_mutex )
264 /* Create mutex returns a recursive mutex */
265 *p_mutex = CreateMutex( 0, FALSE, 0 );
266 return (*p_mutex != NULL) ? 0 : ENOMEM;
267 #elif defined( LIBVLC_USE_PTHREAD )
268 pthread_mutexattr_t attr;
271 pthread_mutexattr_init( &attr );
273 /* Create error-checking mutex to detect problems more easily. */
274 # if defined(SYS_LINUX)
275 pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_ERRORCHECK_NP );
277 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_ERRORCHECK );
280 pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_RECURSIVE );
281 i_result = pthread_mutex_init( p_mutex, &attr );
282 pthread_mutexattr_destroy( &attr );
285 # error Unimplemented!
290 /*****************************************************************************
291 * vlc_mutex_destroy: destroy a mutex, inner version
292 *****************************************************************************/
293 void __vlc_mutex_destroy( const char * psz_file, int i_line, vlc_mutex_t *p_mutex )
295 #if defined( UNDER_CE )
296 VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
298 DeleteCriticalSection( &p_mutex->csection );
300 #elif defined( WIN32 )
301 VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
303 CloseHandle( *p_mutex );
305 #elif defined( HAVE_KERNEL_SCHEDULER_H )
306 if( p_mutex->init == 9999 )
307 delete_sem( p_mutex->lock );
311 #elif defined( LIBVLC_USE_PTHREAD )
312 int val = pthread_mutex_destroy( p_mutex );
313 VLC_THREAD_ASSERT ("destroying mutex");
318 /*****************************************************************************
319 * vlc_cond_init: initialize a condition
320 *****************************************************************************/
321 int __vlc_cond_init( vlc_cond_t *p_condvar )
323 #if defined( UNDER_CE ) || defined( WIN32 )
324 /* Initialize counter */
325 p_condvar->i_waiting_threads = 0;
327 /* Create an auto-reset event. */
328 p_condvar->event = CreateEvent( NULL, /* no security */
329 FALSE, /* auto-reset event */
330 FALSE, /* start non-signaled */
331 NULL ); /* unnamed */
332 return !p_condvar->event;
334 #elif defined( HAVE_KERNEL_SCHEDULER_H )
340 if( p_condvar->init == 9999 )
345 p_condvar->thread = -1;
346 p_condvar->init = 9999;
349 #elif defined( LIBVLC_USE_PTHREAD )
350 pthread_condattr_t attr;
353 ret = pthread_condattr_init (&attr);
357 # if !defined (_POSIX_CLOCK_SELECTION)
358 /* Fairly outdated POSIX support (that was defined in 2001) */
359 # define _POSIX_CLOCK_SELECTION (-1)
361 # if (_POSIX_CLOCK_SELECTION >= 0)
362 /* NOTE: This must be the same clock as the one in mtime.c */
363 pthread_condattr_setclock (&attr, CLOCK_MONOTONIC);
366 ret = pthread_cond_init (p_condvar, &attr);
367 pthread_condattr_destroy (&attr);
373 /*****************************************************************************
374 * vlc_cond_destroy: destroy a condition, inner version
375 *****************************************************************************/
376 void __vlc_cond_destroy( const char * psz_file, int i_line, vlc_cond_t *p_condvar )
378 #if defined( UNDER_CE ) || defined( WIN32 )
379 VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
381 CloseHandle( p_condvar->event );
383 #elif defined( HAVE_KERNEL_SCHEDULER_H )
386 #elif defined( LIBVLC_USE_PTHREAD )
387 int val = pthread_cond_destroy( p_condvar );
388 VLC_THREAD_ASSERT ("destroying condition");
393 /*****************************************************************************
394 * vlc_tls_create: create a thread-local variable
395 *****************************************************************************/
396 int __vlc_threadvar_create( vlc_threadvar_t *p_tls )
400 #if defined( HAVE_KERNEL_SCHEDULER_H )
401 # error Unimplemented!
402 #elif defined( UNDER_CE )
403 #elif defined( WIN32 )
405 i_ret = (*p_tls == INVALID_HANDLE_VALUE) ? EAGAIN : 0;
407 #elif defined( LIBVLC_USE_PTHREAD )
408 i_ret = pthread_key_create( p_tls, NULL );
413 /*****************************************************************************
414 * vlc_thread_create: create a thread, inner version
415 *****************************************************************************
416 * Note that i_priority is only taken into account on platforms supporting
417 * userland real-time priority threads.
418 *****************************************************************************/
419 int __vlc_thread_create( vlc_object_t *p_this, const char * psz_file, int i_line,
420 const char *psz_name, void * ( *func ) ( void * ),
421 int i_priority, bool b_wait )
424 void *p_data = (void *)p_this;
425 vlc_object_internals_t *p_priv = vlc_internals( p_this );
427 vlc_mutex_lock( &p_this->object_lock );
429 #if defined( WIN32 ) || defined( UNDER_CE )
431 /* When using the MSVCRT C library you have to use the _beginthreadex
432 * function instead of CreateThread, otherwise you'll end up with
433 * memory leaks and the signal functions not working (see Microsoft
434 * Knowledge Base, article 104641) */
435 #if defined( UNDER_CE )
437 HANDLE hThread = CreateThread( NULL, 0, (LPTHREAD_START_ROUTINE)func,
438 (LPVOID)p_data, CREATE_SUSPENDED,
442 uintptr_t hThread = _beginthreadex( NULL, 0,
443 (LPTHREAD_START_ROUTINE)func,
444 (void*)p_data, CREATE_SUSPENDED,
447 p_priv->thread_id.id = (DWORD)threadId;
448 p_priv->thread_id.hThread = (HANDLE)hThread;
449 ResumeThread((HANDLE)hThread);
452 i_ret = ( p_priv->thread_id.hThread ? 0 : 1 );
454 if( !i_ret && i_priority )
456 if( !SetThreadPriority(p_priv->thread_id.hThread, i_priority) )
458 msg_Warn( p_this, "couldn't set a faster priority" );
463 #elif defined( HAVE_KERNEL_SCHEDULER_H )
464 p_priv->thread_id = spawn_thread( (thread_func)func, psz_name,
465 i_priority, p_data );
466 i_ret = resume_thread( p_priv->thread_id );
468 #elif defined( LIBVLC_USE_PTHREAD )
469 i_ret = pthread_create( &p_priv->thread_id, NULL, func, p_data );
472 if( config_GetInt( p_this, "rt-priority" ) )
475 int i_error, i_policy;
476 struct sched_param param;
478 memset( ¶m, 0, sizeof(struct sched_param) );
479 if( config_GetType( p_this, "rt-offset" ) )
481 i_priority += config_GetInt( p_this, "rt-offset" );
483 if( i_priority <= 0 )
485 param.sched_priority = (-1) * i_priority;
486 i_policy = SCHED_OTHER;
490 param.sched_priority = i_priority;
493 if( (i_error = pthread_setschedparam( p_priv->thread_id,
494 i_policy, ¶m )) )
497 msg_Warn( p_this, "couldn't set thread priority (%s:%d): %m",
515 msg_Dbg( p_this, "waiting for thread completion" );
516 vlc_object_wait( p_this );
519 p_priv->b_thread = true;
521 #if defined( WIN32 ) || defined( UNDER_CE )
522 msg_Dbg( p_this, "thread %u (%s) created at priority %d (%s:%d)",
523 (unsigned int)p_priv->thread_id.id, psz_name,
524 i_priority, psz_file, i_line );
526 msg_Dbg( p_this, "thread %u (%s) created at priority %d (%s:%d)",
527 (unsigned int)p_priv->thread_id, psz_name, i_priority,
532 vlc_mutex_unlock( &p_this->object_lock );
537 msg_Err( p_this, "%s thread could not be created at %s:%d (%m)",
538 psz_name, psz_file, i_line );
539 vlc_mutex_unlock( &p_this->object_lock );
545 /*****************************************************************************
546 * vlc_thread_set_priority: set the priority of the current thread when we
547 * couldn't set it in vlc_thread_create (for instance for the main thread)
548 *****************************************************************************/
549 int __vlc_thread_set_priority( vlc_object_t *p_this, const char * psz_file,
550 int i_line, int i_priority )
552 vlc_object_internals_t *p_priv = vlc_internals( p_this );
553 #if defined( WIN32 ) || defined( UNDER_CE )
554 VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
556 if( !p_priv->thread_id.hThread )
557 p_priv->thread_id.hThread = GetCurrentThread();
558 if( !SetThreadPriority(p_priv->thread_id.hThread, i_priority) )
560 msg_Warn( p_this, "couldn't set a faster priority" );
564 #elif defined( LIBVLC_USE_PTHREAD )
566 if( config_GetInt( p_this, "rt-priority" ) > 0 )
569 int i_error, i_policy;
570 struct sched_param param;
572 memset( ¶m, 0, sizeof(struct sched_param) );
573 if( config_GetType( p_this, "rt-offset" ) )
575 i_priority += config_GetInt( p_this, "rt-offset" );
577 if( i_priority <= 0 )
579 param.sched_priority = (-1) * i_priority;
580 i_policy = SCHED_OTHER;
584 param.sched_priority = i_priority;
587 if( !p_priv->thread_id )
588 p_priv->thread_id = pthread_self();
589 if( (i_error = pthread_setschedparam( p_priv->thread_id,
590 i_policy, ¶m )) )
593 msg_Warn( p_this, "couldn't set thread priority (%s:%d): %m",
603 /*****************************************************************************
604 * vlc_thread_ready: tell the parent thread we were successfully spawned
605 *****************************************************************************/
606 void __vlc_thread_ready( vlc_object_t *p_this )
608 vlc_object_signal( p_this );
611 /*****************************************************************************
612 * vlc_thread_join: wait until a thread exits, inner version
613 *****************************************************************************/
614 void __vlc_thread_join( vlc_object_t *p_this, const char * psz_file, int i_line )
616 vlc_object_internals_t *p_priv = vlc_internals( p_this );
618 #if defined( UNDER_CE ) || defined( WIN32 )
620 BOOL (WINAPI *OurGetThreadTimes)( HANDLE, FILETIME*, FILETIME*,
621 FILETIME*, FILETIME* );
622 FILETIME create_ft, exit_ft, kernel_ft, user_ft;
623 int64_t real_time, kernel_time, user_time;
627 ** object will close its thread handle when destroyed, duplicate it here
628 ** to be on the safe side
630 if( ! DuplicateHandle(GetCurrentProcess(),
631 p_priv->thread_id.hThread,
636 DUPLICATE_SAME_ACCESS) )
638 msg_Err( p_this, "thread_join(%u) failed at %s:%d (%u)",
639 (unsigned int)p_priv->thread_id.id,
640 psz_file, i_line, (unsigned int)GetLastError() );
641 p_priv->b_thread = false;
645 WaitForSingleObject( hThread, INFINITE );
647 msg_Dbg( p_this, "thread %u joined (%s:%d)",
648 (unsigned int)p_priv->thread_id.id,
650 #if defined( UNDER_CE )
651 hmodule = GetModuleHandle( _T("COREDLL") );
653 hmodule = GetModuleHandle( _T("KERNEL32") );
655 OurGetThreadTimes = (BOOL (WINAPI*)( HANDLE, FILETIME*, FILETIME*,
656 FILETIME*, FILETIME* ))
657 GetProcAddress( hmodule, _T("GetThreadTimes") );
659 if( OurGetThreadTimes &&
660 OurGetThreadTimes( hThread,
661 &create_ft, &exit_ft, &kernel_ft, &user_ft ) )
664 ((((int64_t)exit_ft.dwHighDateTime)<<32)| exit_ft.dwLowDateTime) -
665 ((((int64_t)create_ft.dwHighDateTime)<<32)| create_ft.dwLowDateTime);
669 ((((int64_t)kernel_ft.dwHighDateTime)<<32)|
670 kernel_ft.dwLowDateTime) / 10;
673 ((((int64_t)user_ft.dwHighDateTime)<<32)|
674 user_ft.dwLowDateTime) / 10;
676 msg_Dbg( p_this, "thread times: "
677 "real %"PRId64"m%fs, kernel %"PRId64"m%fs, user %"PRId64"m%fs",
678 real_time/60/1000000,
679 (double)((real_time%(60*1000000))/1000000.0),
680 kernel_time/60/1000000,
681 (double)((kernel_time%(60*1000000))/1000000.0),
682 user_time/60/1000000,
683 (double)((user_time%(60*1000000))/1000000.0) );
685 CloseHandle( hThread );
687 #else /* !defined(WIN32) */
691 #if defined( HAVE_KERNEL_SCHEDULER_H )
693 i_ret = (B_OK == wait_for_thread( p_priv->thread_id, &exit_value ));
695 #elif defined( LIBVLC_USE_PTHREAD )
696 /* Make sure we do return if we are calling vlc_thread_join()
697 * from the joined thread */
698 if (pthread_equal (pthread_self (), p_priv->thread_id))
699 i_ret = pthread_detach (p_priv->thread_id);
701 i_ret = pthread_join (p_priv->thread_id, NULL);
707 msg_Err( p_this, "thread_join(%u) failed at %s:%d (%m)",
708 (unsigned int)p_priv->thread_id, psz_file, i_line );
712 msg_Dbg( p_this, "thread %u joined (%s:%d)",
713 (unsigned int)p_priv->thread_id, psz_file, i_line );
718 p_priv->b_thread = false;