aba753da7a64062bee8faf2cef1ce708cd9913d7
[vlc.git] / src / misc / threads.c
1 /*****************************************************************************
2  * threads.c : threads implementation for the VideoLAN client
3  *****************************************************************************
4  * Copyright (C) 1999, 2000, 2001, 2002 VideoLAN
5  * $Id: threads.c,v 1.18 2002/10/03 13:21:55 sam Exp $
6  *
7  * Authors: Jean-Marc Dressler <polux@via.ecp.fr>
8  *          Samuel Hocevar <sam@zoy.org>
9  *          Gildas Bazin <gbazin@netcourrier.com>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  * 
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with this program; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
24  *****************************************************************************/
25
26 #include <vlc/vlc.h>
27
28 #define VLC_THREADS_UNINITIALIZED  0
29 #define VLC_THREADS_PENDING        1
30 #define VLC_THREADS_ERROR          2
31 #define VLC_THREADS_READY          3
32
33 /*****************************************************************************
34  * Global mutex for lazy initialization of the threads system
35  *****************************************************************************/
36 static volatile int i_initializations = 0;
37
38 #if defined( PTH_INIT_IN_PTH_H )
39 #elif defined( ST_INIT_IN_ST_H )
40 #elif defined( WIN32 )
41 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
42     static pthread_mutex_t once_mutex = PTHREAD_MUTEX_INITIALIZER;
43 #elif defined( HAVE_CTHREADS_H )
44 #elif defined( HAVE_KERNEL_SCHEDULER_H )
45 #endif
46
47 /*****************************************************************************
48  * vlc_threads_init: initialize threads system
49  *****************************************************************************
50  * This function requires lazy initialization of a global lock in order to
51  * keep the library really thread-safe. Some architectures don't support this
52  * and thus do not guarantee the complete reentrancy.
53  *****************************************************************************/
54 int __vlc_threads_init( vlc_object_t *p_this )
55 {
56     static volatile int i_status = VLC_THREADS_UNINITIALIZED;
57
58     libvlc_t *p_libvlc = (libvlc_t *)p_this;
59     int i_ret = VLC_SUCCESS;
60
61     /* If we have lazy mutex initialization, use it. Otherwise, we just
62      * hope nothing wrong happens. */
63 #if defined( PTH_INIT_IN_PTH_H )
64 #elif defined( ST_INIT_IN_ST_H )
65 #elif defined( WIN32 )
66     HINSTANCE hInstLib;
67 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
68     pthread_mutex_lock( &once_mutex );
69 #elif defined( HAVE_CTHREADS_H )
70 #elif defined( HAVE_KERNEL_SCHEDULER_H )
71 #endif
72
73     if( i_status == VLC_THREADS_UNINITIALIZED )
74     {
75         i_status = VLC_THREADS_PENDING;
76
77         /* We should be safe now. Do all the initialization stuff we want. */
78         vlc_object_create( p_libvlc, VLC_OBJECT_ROOT );
79         p_libvlc->b_ready = VLC_FALSE;
80
81 #if defined( PTH_INIT_IN_PTH_H )
82         i_ret = pth_init();
83
84 #elif defined( ST_INIT_IN_ST_H )
85         i_ret = st_init();
86
87 #elif defined( WIN32 )
88         /* Dynamically get the address of SignalObjectAndWait */
89         if( GetVersion() < 0x80000000 )
90         {
91             /* We are running on NT/2K/XP, we can use SignalObjectAndWait */
92             hInstLib = LoadLibrary( "kernel32" );
93             if( hInstLib )
94             {
95                 p_libvlc->SignalObjectAndWait =
96                     (SIGNALOBJECTANDWAIT)GetProcAddress( hInstLib,
97                                                      "SignalObjectAndWait" );
98             }
99         }
100         else
101         {
102             p_libvlc->SignalObjectAndWait = NULL;
103         }
104
105         p_libvlc->b_fast_mutex = 0;
106         p_libvlc->i_win9x_cv = 0;
107
108 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
109 #elif defined( HAVE_CTHREADS_H )
110 #elif defined( HAVE_KERNEL_SCHEDULER_H )
111 #endif
112
113         vlc_mutex_init( p_libvlc, &p_libvlc->global_lock );
114
115         if( i_ret )
116         {
117             i_status = VLC_THREADS_ERROR;
118         }
119         else
120         {
121             i_initializations++;
122             i_status = VLC_THREADS_READY;
123         }
124     }
125     else
126     {
127         /* Just increment the initialization count */
128         i_initializations++;
129     }
130
131     /* If we have lazy mutex initialization support, unlock the mutex;
132      * otherwize, do a naive wait loop. */
133 #if defined( PTH_INIT_IN_PTH_H )
134     while( i_status == VLC_THREADS_PENDING ) msleep( THREAD_SLEEP );
135 #elif defined( ST_INIT_IN_ST_H )
136     while( i_status == VLC_THREADS_PENDING ) msleep( THREAD_SLEEP );
137 #elif defined( WIN32 )
138     while( i_status == VLC_THREADS_PENDING ) msleep( THREAD_SLEEP );
139 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
140     pthread_mutex_unlock( &once_mutex );
141 #elif defined( HAVE_CTHREADS_H )
142     while( i_status == VLC_THREADS_PENDING ) msleep( THREAD_SLEEP );
143 #elif defined( HAVE_KERNEL_SCHEDULER_H )
144     while( i_status == VLC_THREADS_PENDING ) msleep( THREAD_SLEEP );
145 #endif
146
147     if( i_status != VLC_THREADS_READY )
148     {
149         return VLC_ETHREAD;
150     }
151
152     return i_ret;
153 }
154
155 /*****************************************************************************
156  * vlc_threads_end: stop threads system
157  *****************************************************************************
158  * FIXME: This function is far from being threadsafe. We should undo exactly
159  * what we did above in vlc_threads_init.
160  *****************************************************************************/
161 int __vlc_threads_end( vlc_object_t *p_this )
162 {
163 #if defined( PTH_INIT_IN_PTH_H )
164     i_initializations--;
165     if( i_initializations == 0 )
166     {
167         return pth_kill();
168     }
169
170 #elif defined( ST_INIT_IN_ST_H )
171     i_initializations--;
172
173 #elif defined( WIN32 )
174     i_initializations--;
175
176 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
177     pthread_mutex_lock( &once_mutex );
178     i_initializations--;
179     pthread_mutex_unlock( &once_mutex );
180
181 #elif defined( HAVE_CTHREADS_H )
182     i_initializations--;
183
184 #elif defined( HAVE_KERNEL_SCHEDULER_H )
185     i_initializations--;
186
187 #endif
188     return VLC_SUCCESS;
189 }
190
191 /*****************************************************************************
192  * Prototype for GPROF wrapper
193  *****************************************************************************/
194 #ifdef GPROF
195 /* Wrapper function for profiling */
196 static void *      vlc_thread_wrapper ( void *p_wrapper );
197
198 #   ifdef WIN32
199
200 #       define ITIMER_REAL 1
201 #       define ITIMER_PROF 2
202
203 struct itimerval
204 {
205     struct timeval it_value;
206     struct timeval it_interval;
207 };  
208
209 int setitimer(int kind, const struct itimerval* itnew, struct itimerval* itold);
210 #   endif /* WIN32 */
211
212 typedef struct wrapper_t
213 {
214     /* Data lock access */
215     vlc_mutex_t lock;
216     vlc_cond_t  wait;
217     
218     /* Data used to spawn the real thread */
219     vlc_thread_func_t func;
220     void *p_data;
221     
222     /* Profiling timer passed to the thread */
223     struct itimerval itimer;
224     
225 } wrapper_t;
226
227 #endif /* GPROF */
228
229 /*****************************************************************************
230  * vlc_mutex_init: initialize a mutex
231  *****************************************************************************/
232 int __vlc_mutex_init( vlc_object_t *p_this, vlc_mutex_t *p_mutex )
233 {
234     p_mutex->p_this = p_this;
235
236 #if defined( PTH_INIT_IN_PTH_H )
237     return pth_mutex_init( &p_mutex->mutex );
238
239 #elif defined( ST_INIT_IN_ST_H )
240     p_mutex->mutex = st_mutex_new();
241     return ( p_mutex->mutex == NULL ) ? errno : 0;
242
243 #elif defined( WIN32 )
244     /* We use mutexes on WinNT/2K/XP because we can use the SignalObjectAndWait
245      * function and have a 100% correct vlc_cond_wait() implementation.
246      * As this function is not available on Win9x, we can use the faster
247      * CriticalSections */
248     if( p_this->p_vlc->SignalObjectAndWait && !p_this->p_vlc->b_fast_mutex )
249     {
250         /* We are running on NT/2K/XP, we can use SignalObjectAndWait */
251         p_mutex->mutex = CreateMutex( 0, FALSE, 0 );
252         return ( p_mutex->mutex != NULL ? 0 : 1 );
253     }
254     else
255     {
256         p_mutex->mutex = NULL;
257         InitializeCriticalSection( &p_mutex->csection );
258         return 0;
259     }
260
261 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
262 #   if defined(DEBUG) && defined(SYS_LINUX)
263     {
264         /* Create error-checking mutex to detect problems more easily. */
265         pthread_mutexattr_t attr;
266         int                 i_result;
267
268         pthread_mutexattr_init( &attr );
269         pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_ERRORCHECK_NP );
270         i_result = pthread_mutex_init( &p_mutex->mutex, &attr );
271         pthread_mutexattr_destroy( &attr );
272         return( i_result );
273     }
274 #   endif
275     return pthread_mutex_init( &p_mutex->mutex, NULL );
276
277 #elif defined( HAVE_CTHREADS_H )
278     mutex_init( p_mutex );
279     return 0;
280
281 #elif defined( HAVE_KERNEL_SCHEDULER_H )
282     /* check the arguments and whether it's already been initialized */
283     if( p_mutex == NULL )
284     {
285         return B_BAD_VALUE;
286     }
287
288     if( p_mutex->init == 9999 )
289     {
290         return EALREADY;
291     }
292
293     p_mutex->lock = create_sem( 1, "BeMutex" );
294     if( p_mutex->lock < B_NO_ERROR )
295     {
296         return( -1 );
297     }
298
299     p_mutex->init = 9999;
300     return B_OK;
301
302 #endif
303 }
304
305 /*****************************************************************************
306  * vlc_mutex_destroy: destroy a mutex, inner version
307  *****************************************************************************/
308 int __vlc_mutex_destroy( char * psz_file, int i_line, vlc_mutex_t *p_mutex )
309 {
310     int i_result;
311     /* In case of error : */
312     int i_thread = -1;
313     const char * psz_error = "";
314
315 #if defined( PTH_INIT_IN_PTH_H )
316     return 0;
317
318 #elif defined( ST_INIT_IN_ST_H )
319     i_result = st_mutex_destroy( p_mutex->mutex );
320
321 #elif defined( WIN32 )
322     if( p_mutex->mutex )
323     {
324         CloseHandle( p_mutex->mutex );
325     }
326     else
327     {
328         DeleteCriticalSection( &p_mutex->csection );
329     }
330     return 0;
331
332 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )    
333     i_result = pthread_mutex_destroy( &p_mutex->mutex );
334     if ( i_result )
335     {
336         i_thread = (int)pthread_self();
337         psz_error = strerror(i_result);
338     }
339
340 #elif defined( HAVE_CTHREADS_H )
341     return 0;
342
343 #elif defined( HAVE_KERNEL_SCHEDULER_H )
344     if( p_mutex->init == 9999 )
345     {
346         delete_sem( p_mutex->lock );
347     }
348
349     p_mutex->init = 0;
350     return B_OK;
351 #endif    
352
353     if( i_result )
354     {
355         msg_Err( p_mutex->p_this,
356                  "thread %d: mutex_destroy failed at %s:%d (%d:%s)",
357                  i_thread, psz_file, i_line, i_result, psz_error );
358     }
359     return i_result;
360 }
361
362 /*****************************************************************************
363  * vlc_cond_init: initialize a condition
364  *****************************************************************************/
365 int __vlc_cond_init( vlc_object_t *p_this, vlc_cond_t *p_condvar )
366 {
367     p_condvar->p_this = p_this;
368
369 #if defined( PTH_INIT_IN_PTH_H )
370     return pth_cond_init( &p_condvar->cond );
371
372 #elif defined( ST_INIT_IN_ST_H )
373     p_condvar->cond = st_cond_new();
374     return ( p_condvar->cond == NULL ) ? errno : 0;
375
376 #elif defined( WIN32 )
377     /* Initialize counter */
378     p_condvar->i_waiting_threads = 0;
379
380     /* Misc init */
381     p_condvar->i_win9x_cv = p_this->p_vlc->i_win9x_cv;
382     p_condvar->SignalObjectAndWait = p_this->p_vlc->SignalObjectAndWait;
383
384     if( p_this->p_vlc->i_win9x_cv == 0 )
385     {
386         /* Create an auto-reset event. */
387         p_condvar->event = CreateEvent( NULL,   /* no security */
388                                         FALSE,  /* auto-reset event */
389                                         FALSE,  /* start non-signaled */
390                                         NULL ); /* unnamed */
391
392         p_condvar->semaphore = NULL;
393         return !p_condvar->event;
394     }
395     else
396     {
397         p_condvar->semaphore = CreateSemaphore( NULL,       /* no security */
398                                                 0,          /* initial count */
399                                                 0x7fffffff, /* max count */
400                                                 NULL );     /* unnamed */
401
402         if( p_this->p_vlc->i_win9x_cv == 1 )
403             /* Create a manual-reset event initially signaled. */
404             p_condvar->event = CreateEvent( NULL, TRUE, TRUE, NULL );
405         else
406             /* Create a auto-reset event. */
407             p_condvar->event = CreateEvent( NULL, FALSE, FALSE, NULL );
408
409         InitializeCriticalSection( &p_condvar->csection );
410
411         return !p_condvar->semaphore || !p_condvar->event;
412     }
413
414 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
415     return pthread_cond_init( &p_condvar->cond, NULL );
416
417 #elif defined( HAVE_CTHREADS_H )
418     /* condition_init() */
419     spin_lock_init( &p_condvar->lock );
420     cthread_queue_init( &p_condvar->queue );
421     p_condvar->name = 0;
422     p_condvar->implications = 0;
423
424     return 0;
425
426 #elif defined( HAVE_KERNEL_SCHEDULER_H )
427     if( !p_condvar )
428     {
429         return B_BAD_VALUE;
430     }
431
432     if( p_condvar->init == 9999 )
433     {
434         return EALREADY;
435     }
436
437     p_condvar->thread = -1;
438     p_condvar->init = 9999;
439     return 0;
440 #endif
441 }
442
443 /*****************************************************************************
444  * vlc_cond_destroy: destroy a condition, inner version
445  *****************************************************************************/
446 int __vlc_cond_destroy( char * psz_file, int i_line, vlc_cond_t *p_condvar )
447 {
448     int i_result;
449     /* In case of error : */
450     int i_thread = -1;
451     const char * psz_error = "";
452
453 #if defined( PTH_INIT_IN_PTH_H )
454     return 0;
455
456 #elif defined( ST_INIT_IN_ST_H )
457     i_result = st_cond_destroy( p_condvar->cond );
458
459 #elif defined( WIN32 )
460     if( !p_condvar->semaphore )
461         i_result = !CloseHandle( p_condvar->event );
462     else
463         i_result = !CloseHandle( p_condvar->event )
464           || !CloseHandle( p_condvar->semaphore );
465
466 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
467     i_result = pthread_cond_destroy( &p_condvar->cond );
468     if ( i_result )
469     {
470         i_thread = (int)pthread_self();
471         psz_error = strerror(i_result);
472     }
473
474 #elif defined( HAVE_CTHREADS_H )
475     return 0;
476
477 #elif defined( HAVE_KERNEL_SCHEDULER_H )
478     p_condvar->init = 0;
479     return 0;
480 #endif
481
482     if( i_result )
483     {
484         msg_Err( p_condvar->p_this,
485                  "thread %d: cond_destroy failed at %s:%d (%d:%s)",
486                  i_thread, psz_file, i_line, i_result, psz_error );
487     }
488     return i_result;
489 }
490
491 /*****************************************************************************
492  * vlc_thread_create: create a thread, inner version
493  *****************************************************************************
494  * Note that i_priority is only taken into account on platforms supporting
495  * userland real-time priority threads.
496  *****************************************************************************/
497 int __vlc_thread_create( vlc_object_t *p_this, char * psz_file, int i_line,
498                          char *psz_name, void * ( *func ) ( void * ),
499                          int i_priority, vlc_bool_t b_wait )
500 {
501     int i_ret;
502
503     vlc_mutex_lock( &p_this->object_lock );
504
505 #ifdef GPROF
506     wrapper_t wrapper;
507
508     /* Initialize the wrapper structure */
509     wrapper.func = func;
510     wrapper.p_data = (void *)p_this;
511     getitimer( ITIMER_PROF, &wrapper.itimer );
512     vlc_mutex_init( p_this, &wrapper.lock );
513     vlc_cond_init( p_this, &wrapper.wait );
514     vlc_mutex_lock( &wrapper.lock );
515
516     /* Alter user-passed data so that we call the wrapper instead
517      * of the real function */
518     p_data = &wrapper;
519     func = vlc_thread_wrapper;
520 #endif
521
522 #if defined( PTH_INIT_IN_PTH_H )
523     p_this->thread_id = pth_spawn( PTH_ATTR_DEFAULT, func, (void *)p_this );
524     i_ret = 0;
525
526 #elif defined( ST_INIT_IN_ST_H )
527     p_this->thread_id = st_thread_create( func, (void *)p_this, 1, 0 );
528     i_ret = 0;
529     
530 #elif defined( WIN32 )
531     {
532         unsigned threadID;
533         /* When using the MSVCRT C library you have to use the _beginthreadex
534          * function instead of CreateThread, otherwise you'll end up with
535          * memory leaks and the signal functions not working */
536         p_this->thread_id =
537                 (HANDLE)_beginthreadex( NULL, 0, (PTHREAD_START) func, 
538                                         (void *)p_this, 0, &threadID );
539     }
540
541     if ( p_this->thread_id && i_priority )
542     {
543         if ( !SetThreadPriority(p_this->thread_id, i_priority) )
544         {
545             msg_Warn( p_this, "couldn't set a faster priority" );
546             i_priority = 0;
547         }
548     }
549
550     i_ret = ( p_this->thread_id ? 0 : 1 );
551
552 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
553     i_ret = pthread_create( &p_this->thread_id, NULL, func, (void *)p_this );
554
555     if ( i_priority )
556     {
557         struct sched_param param;
558         memset( &param, 0, sizeof(struct sched_param) );
559         param.sched_priority = i_priority;
560         if ( pthread_setschedparam( p_this->thread_id, SCHED_RR, &param ) )
561         {
562             msg_Warn( p_this, "couldn't go to real-time priority" );
563             i_priority = 0;
564         }
565     }
566
567 #elif defined( HAVE_CTHREADS_H )
568     p_this->thread_id = cthread_fork( (cthread_fn_t)func, (any_t)p_this );
569     i_ret = 0;
570
571 #elif defined( HAVE_KERNEL_SCHEDULER_H )
572     p_this->thread_id = spawn_thread( (thread_func)func, psz_name,
573                                       B_NORMAL_PRIORITY, (void *)p_this );
574     i_ret = resume_thread( p_this->thread_id );
575
576 #endif
577
578 #ifdef GPROF
579     if( i_ret == 0 )
580     {
581         vlc_cond_wait( &wrapper.wait, &wrapper.lock );
582     }
583
584     vlc_mutex_unlock( &wrapper.lock );
585     vlc_mutex_destroy( &wrapper.lock );
586     vlc_cond_destroy( &wrapper.wait );
587 #endif
588
589     if( i_ret == 0 )
590     {
591         if( b_wait )
592         {
593             msg_Dbg( p_this, "waiting for thread completion" );
594             vlc_cond_wait( &p_this->object_wait, &p_this->object_lock );
595         }
596
597         p_this->b_thread = 1;
598
599         msg_Dbg( p_this, "thread %d (%s) created at priority %d (%s:%d)",
600                  p_this->thread_id, psz_name, i_priority,
601                  psz_file, i_line );
602
603         vlc_mutex_unlock( &p_this->object_lock );
604     }
605     else
606     {
607         msg_Err( p_this, "%s thread could not be created at %s:%d (%s)",
608                          psz_name, psz_file, i_line, strerror(i_ret) );
609         vlc_mutex_unlock( &p_this->object_lock );
610     }
611
612     return i_ret;
613 }
614
615 /*****************************************************************************
616  * vlc_thread_ready: tell the parent thread we were successfully spawned
617  *****************************************************************************/
618 void __vlc_thread_ready( vlc_object_t *p_this )
619 {
620     vlc_mutex_lock( &p_this->object_lock );
621     vlc_cond_signal( &p_this->object_wait );
622     vlc_mutex_unlock( &p_this->object_lock );
623 }
624
625 /*****************************************************************************
626  * vlc_thread_join: wait until a thread exits, inner version
627  *****************************************************************************/
628 void __vlc_thread_join( vlc_object_t *p_this, char * psz_file, int i_line )
629 {
630     int i_ret = 0;
631
632 #if defined( PTH_INIT_IN_PTH_H )
633     i_ret = pth_join( p_this->thread_id, NULL );
634
635 #elif defined( ST_INIT_IN_ST_H )
636     i_ret = st_thread_join( p_this->thread_id, NULL );
637     
638 #elif defined( WIN32 )
639     WaitForSingleObject( p_this->thread_id, INFINITE );
640
641 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
642     i_ret = pthread_join( p_this->thread_id, NULL );
643
644 #elif defined( HAVE_CTHREADS_H )
645     cthread_join( p_this->thread_id );
646     i_ret = 1;
647
648 #elif defined( HAVE_KERNEL_SCHEDULER_H )
649     int32 exit_value;
650     wait_for_thread( p_this->thread_id, &exit_value );
651
652 #endif
653
654     if( i_ret )
655     {
656         msg_Err( p_this, "thread_join(%d) failed at %s:%d (%s)",
657                          p_this->thread_id, psz_file, i_line, strerror(i_ret) );
658     }
659     else
660     {
661         msg_Dbg( p_this, "thread %d joined (%s:%d)",
662                          p_this->thread_id, psz_file, i_line );
663     }
664
665     p_this->b_thread = 0;
666 }
667
668 /*****************************************************************************
669  * vlc_thread_wrapper: wrapper around thread functions used when profiling.
670  *****************************************************************************/
671 #ifdef GPROF
672 static void *vlc_thread_wrapper( void *p_wrapper )
673 {
674     /* Put user data in thread-local variables */
675     void *            p_data = ((wrapper_t*)p_wrapper)->p_data;
676     vlc_thread_func_t func   = ((wrapper_t*)p_wrapper)->func;
677
678     /* Set the profile timer value */
679     setitimer( ITIMER_PROF, &((wrapper_t*)p_wrapper)->itimer, NULL );
680
681     /* Tell the calling thread that we don't need its data anymore */
682     vlc_mutex_lock( &((wrapper_t*)p_wrapper)->lock );
683     vlc_cond_signal( &((wrapper_t*)p_wrapper)->wait );
684     vlc_mutex_unlock( &((wrapper_t*)p_wrapper)->lock );
685
686     /* Call the real function */
687     return func( p_data );
688 }
689 #endif