git.sesse.net Git - vlc/blob - 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 1.12 2002/08/08 00:35:11 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  * Prototype for GPROF wrapper
  35  *****************************************************************************/
  36 #ifdef GPROF
  37 /* Wrapper function for profiling */
  38 static void *      vlc_thread_wrapper ( void *p_wrapper );
  39
  40 #   ifdef WIN32
  41
  42 #       define ITIMER_REAL 1
  43 #       define ITIMER_PROF 2
  44
  45 struct itimerval
  46 {
  47     struct timeval it_value;
  48     struct timeval it_interval;
  49 };
  50
  51 int setitimer(int kind, const struct itimerval* itnew, struct itimerval* itold);
  52 #   endif /* WIN32 */
  53
  54 typedef struct wrapper_t
  55 {
  56     /* Data lock access */
  57     vlc_mutex_t lock;
  58     vlc_cond_t  wait;
  59
  60     /* Data used to spawn the real thread */
  61     vlc_thread_func_t func;
  62     void *p_data;
  63
  64     /* Profiling timer passed to the thread */
  65     struct itimerval itimer;
  66
  67 } wrapper_t;
  68
  69 #endif /* GPROF */
  70
  71 /*****************************************************************************
  72  * Global mutexes for lazy initialization of the threads system
  73  *****************************************************************************/
  74 static volatile int i_initializations = 0;
  75
  76 #if defined( PTH_INIT_IN_PTH_H )
  77     /* Unimplemented */
  78 #elif defined( ST_INIT_IN_ST_H )
  79     /* Unimplemented */
  80 #elif defined( WIN32 )
  81     /* Unimplemented */
  82 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
  83     static pthread_mutex_t once_mutex = PTHREAD_MUTEX_INITIALIZER;
  84 #elif defined( HAVE_CTHREADS_H )
  85     /* Unimplemented */
  86 #elif defined( HAVE_KERNEL_SCHEDULER_H )
  87     /* Unimplemented */
  88 #endif
  89
  90 /*****************************************************************************
  91  * vlc_threads_init: initialize threads system
  92  *****************************************************************************
  93  * This function requires lazy initialization of a global lock in order to
  94  * keep the library really thread-safe. Some architectures don't support this
  95  * and thus do not guarantee the complete reentrancy.
  96  *****************************************************************************/
  97 int __vlc_threads_init( vlc_object_t *p_this )
  98 {
  99     static volatile int i_status = VLC_THREADS_UNINITIALIZED;
 100     int i_ret = 0;
 101
 102 #if defined( PTH_INIT_IN_PTH_H )
 103     /* Unimplemented */
 104 #elif defined( ST_INIT_IN_ST_H )
 105     /* Unimplemented */
 106 #elif defined( WIN32 )
 107     /* Unimplemented */
 108 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 109     pthread_mutex_lock( &once_mutex );
 110 #elif defined( HAVE_CTHREADS_H )
 111     /* Unimplemented */
 112 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 113     /* Unimplemented */
 114 #endif
 115
 116     if( i_status == VLC_THREADS_UNINITIALIZED )
 117     {
 118         i_status = VLC_THREADS_PENDING;
 119
 120 #if defined( PTH_INIT_IN_PTH_H )
 121         i_ret = pth_init();
 122 #elif defined( ST_INIT_IN_ST_H )
 123         i_ret = st_init();
 124 #elif defined( WIN32 )
 125         /* Unimplemented */
 126 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 127         /* Unimplemented */
 128 #elif defined( HAVE_CTHREADS_H )
 129         /* Unimplemented */
 130 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 131         /* Unimplemented */
 132 #endif
 133
 134         if( i_ret )
 135         {
 136             i_status = VLC_THREADS_ERROR;
 137         }
 138         else
 139         {
 140             vlc_mutex_init( p_this, p_this->p_vlc->p_global_lock );
 141             i_status = VLC_THREADS_READY;
 142         }
 143     }
 144     else
 145     {
 146         i_ret = ( i_status == VLC_THREADS_READY );
 147     }
 148
 149     i_initializations++;
 150
 151 #if defined( PTH_INIT_IN_PTH_H )
 152     /* Unimplemented */
 153 #elif defined( ST_INIT_IN_ST_H )
 154     /* Unimplemented */
 155 #elif defined( WIN32 )
 156     /* Unimplemented */
 157 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 158     pthread_mutex_unlock( &once_mutex );
 159     return i_ret;
 160 #elif defined( HAVE_CTHREADS_H )
 161     /* Unimplemented */
 162 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 163     /* Unimplemented */
 164 #endif
 165
 166     /* Wait until the other thread has initialized the thread library */
 167     while( i_status == VLC_THREADS_PENDING )
 168     {
 169         msleep( THREAD_SLEEP );
 170     }
 171
 172     return i_status == VLC_THREADS_READY;
 173 }
 174
 175 /*****************************************************************************
 176  * vlc_threads_end: stop threads system
 177  *****************************************************************************
 178  * FIXME: This function is far from being threadsafe. We should undo exactly
 179  * what we did above in vlc_threads_init.
 180  *****************************************************************************/
 181 int __vlc_threads_end( vlc_object_t *p_this )
 182 {
 183 #if defined( PTH_INIT_IN_PTH_H )
 184     i_initializations--;
 185     if( i_initializations == 0 )
 186     {
 187         return pth_kill();
 188     }
 189     return 0;
 190
 191 #elif defined( ST_INIT_IN_ST_H )
 192     i_initializations--;
 193     return 0;
 194
 195 #elif defined( WIN32 )
 196     i_initializations--;
 197     return 0;
 198
 199 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 200     pthread_mutex_lock( &once_mutex );
 201     i_initializations--;
 202     pthread_mutex_unlock( &once_mutex );
 203     return 0;
 204
 205 #elif defined( HAVE_CTHREADS_H )
 206     i_initializations--;
 207     return 0;
 208
 209 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 210     i_initializations--;
 211     return 0;
 212
 213 #endif
 214 }
 215
 216 /*****************************************************************************
 217  * vlc_mutex_init: initialize a mutex
 218  *****************************************************************************/
 219 int __vlc_mutex_init( vlc_object_t *p_this, vlc_mutex_t *p_mutex )
 220 {
 221 #if defined( PTH_INIT_IN_PTH_H )
 222     return pth_mutex_init( p_mutex );
 223
 224 #elif defined( ST_INIT_IN_ST_H )
 225     *p_mutex = st_mutex_new();
 226     return ( *p_mutex == NULL ) ? errno : 0;
 227
 228 #elif defined( WIN32 )
 229     /* We use mutexes on WinNT/2K/XP because we can use the SignalObjectAndWait
 230      * function and have a 100% correct vlc_cond_wait() implementation.
 231      * As this function is not available on Win9x, we can use the faster
 232      * CriticalSections */
 233     if( p_this->p_vlc->SignalObjectAndWait && !p_this->p_vlc->b_fast_mutex )
 234     {
 235         /* We are running on NT/2K/XP, we can use SignalObjectAndWait */
 236         p_mutex->mutex = CreateMutex( 0, FALSE, 0 );
 237         return ( p_mutex->mutex ? 0 : 1 );
 238     }
 239     else
 240     {
 241         p_mutex->mutex = NULL;
 242         InitializeCriticalSection( &p_mutex->csection );
 243         return 0;
 244     }
 245
 246 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 247 #   if defined(DEBUG) && defined(SYS_LINUX)
 248     /* Create error-checking mutex to detect threads problems more easily. */
 249     pthread_mutexattr_t attr;
 250     int                 i_result;
 251
 252     pthread_mutexattr_init( &attr );
 253     pthread_mutexattr_setkind_np( &attr, PTHREAD_MUTEX_ERRORCHECK_NP );
 254     i_result = pthread_mutex_init( p_mutex, &attr );
 255     pthread_mutexattr_destroy( &attr );
 256     return( i_result );
 257 #   endif
 258     return pthread_mutex_init( p_mutex, NULL );
 259
 260 #elif defined( HAVE_CTHREADS_H )
 261     mutex_init( p_mutex );
 262     return 0;
 263
 264 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 265
 266     /* check the arguments and whether it's already been initialized */
 267     if( p_mutex == NULL )
 268     {
 269         return B_BAD_VALUE;
 270     }
 271
 272     if( p_mutex->init == 9999 )
 273     {
 274         return EALREADY;
 275     }
 276
 277     p_mutex->lock = create_sem( 1, "BeMutex" );
 278     if( p_mutex->lock < B_NO_ERROR )
 279     {
 280         return( -1 );
 281     }
 282
 283     p_mutex->init = 9999;
 284     return B_OK;
 285
 286 #endif
 287 }
 288
 289 /*****************************************************************************
 290  * vlc_mutex_destroy: destroy a mutex, inner version
 291  *****************************************************************************/
 292 int __vlc_mutex_destroy( char * psz_file, int i_line, vlc_mutex_t *p_mutex )
 293 {
 294 #if defined( PTH_INIT_IN_PTH_H )
 295     return 0;
 296
 297 #elif defined( ST_INIT_IN_ST_H )
 298     return st_mutex_destroy( *p_mutex );
 299
 300 #elif defined( WIN32 )
 301     if( p_mutex->mutex )
 302     {
 303         CloseHandle( p_mutex->mutex );
 304     }
 305     else
 306     {
 307         DeleteCriticalSection( &p_mutex->csection );
 308     }
 309     return 0;
 310
 311 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 312     int i_return = pthread_mutex_destroy( p_mutex );
 313     if( i_return )
 314     {
 315 #if 0
 316         intf_ErrMsg( "thread %d error: mutex_destroy failed at %s:%d (%s)",
 317                      pthread_self(), psz_file, i_line, strerror(i_return) );
 318 #endif
 319     }
 320     return i_return;
 321
 322 #elif defined( HAVE_CTHREADS_H )
 323     return 0;
 324
 325 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 326     if( p_mutex->init == 9999 )
 327     {
 328         delete_sem( p_mutex->lock );
 329     }
 330
 331     p_mutex->init = 0;
 332     return B_OK;
 333
 334 #endif
 335 }
 336
 337 /*****************************************************************************
 338  * vlc_cond_init: initialize a condition
 339  *****************************************************************************/
 340 int __vlc_cond_init( vlc_object_t *p_this, vlc_cond_t *p_condvar )
 341 {
 342 #if defined( PTH_INIT_IN_PTH_H )
 343     return pth_cond_init( p_condvar );
 344
 345 #elif defined( ST_INIT_IN_ST_H )
 346     *p_condvar = st_cond_new();
 347     return ( *p_condvar == NULL ) ? errno : 0;
 348
 349 #elif defined( WIN32 )
 350     /* Initialize counter */
 351     p_condvar->i_waiting_threads = 0;
 352
 353     /* Misc init */
 354     p_condvar->i_win9x_cv = p_this->p_vlc->i_win9x_cv;
 355     p_condvar->SignalObjectAndWait = p_this->p_vlc->SignalObjectAndWait;
 356
 357     if( p_this->p_vlc->i_win9x_cv == 0 )
 358     {
 359         /* Create an auto-reset event. */
 360         p_condvar->event = CreateEvent( NULL,   /* no security */
 361                                         FALSE,  /* auto-reset event */
 362                                         FALSE,  /* start non-signaled */
 363                                         NULL ); /* unnamed */
 364
 365         p_condvar->semaphore = NULL;
 366         return !p_condvar->event;
 367     }
 368     else
 369     {
 370         p_condvar->semaphore = CreateSemaphore( NULL,       /* no security */
 371                                                 0,          /* initial count */
 372                                                 0x7fffffff, /* max count */
 373                                                 NULL );     /* unnamed */
 374
 375         if( p_this->p_vlc->i_win9x_cv == 1 )
 376             /* Create a manual-reset event initially signaled. */
 377             p_condvar->event = CreateEvent( NULL, TRUE, TRUE, NULL );
 378         else
 379             /* Create a auto-reset event. */
 380             p_condvar->event = CreateEvent( NULL, FALSE, FALSE, NULL );
 381
 382         InitializeCriticalSection( &p_condvar->csection );
 383
 384         return !p_condvar->semaphore || !p_condvar->event;
 385     }
 386
 387 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 388     return pthread_cond_init( p_condvar, NULL );
 389
 390 #elif defined( HAVE_CTHREADS_H )
 391     /* condition_init() */
 392     spin_lock_init( &p_condvar->lock );
 393     cthread_queue_init( &p_condvar->queue );
 394     p_condvar->name = 0;
 395     p_condvar->implications = 0;
 396
 397     return 0;
 398
 399 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 400     if( !p_condvar )
 401     {
 402         return B_BAD_VALUE;
 403     }
 404
 405     if( p_condvar->init == 9999 )
 406     {
 407         return EALREADY;
 408     }
 409
 410     p_condvar->thread = -1;
 411     p_condvar->init = 9999;
 412     return 0;
 413
 414 #endif
 415 }
 416
 417 /*****************************************************************************
 418  * vlc_cond_destroy: destroy a condition, inner version
 419  *****************************************************************************/
 420 int __vlc_cond_destroy( char * psz_file, int i_line, vlc_cond_t *p_condvar )
 421 {
 422 #if defined( PTH_INIT_IN_PTH_H )
 423     return 0;
 424
 425 #elif defined( ST_INIT_IN_ST_H )
 426     return st_cond_destroy( *p_condvar );
 427
 428 #elif defined( WIN32 )
 429     if( !p_condvar->semaphore )
 430         return !CloseHandle( p_condvar->event );
 431     else
 432         return !CloseHandle( p_condvar->event )
 433           || !CloseHandle( p_condvar->semaphore );
 434
 435 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 436     int i_result = pthread_cond_destroy( p_condvar );
 437     if( i_result )
 438     {
 439 #if 0
 440         intf_ErrMsg( "thread %d error: cond_destroy failed at %s:%d (%s)",
 441                      pthread_self(), psz_file, i_line, strerror(i_result) );
 442 #endif
 443     }
 444     return i_result;
 445
 446 #elif defined( HAVE_CTHREADS_H )
 447     return 0;
 448
 449 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 450     p_condvar->init = 0;
 451     return 0;
 452
 453 #endif
 454 }
 455
 456 /*****************************************************************************
 457  * vlc_thread_create: create a thread, inner version
 458  *****************************************************************************/
 459 int __vlc_thread_create( vlc_object_t *p_this, char * psz_file, int i_line,
 460                          char *psz_name, void * ( *func ) ( void * ),
 461                          vlc_bool_t b_wait )
 462 {
 463     int i_ret;
 464
 465     vlc_mutex_lock( &p_this->object_lock );
 466
 467 #ifdef GPROF
 468     wrapper_t wrapper;
 469
 470     /* Initialize the wrapper structure */
 471     wrapper.func = func;
 472     wrapper.p_data = (void *)p_this;
 473     getitimer( ITIMER_PROF, &wrapper.itimer );
 474     vlc_mutex_init( p_this, &wrapper.lock );
 475     vlc_cond_init( p_this, &wrapper.wait );
 476     vlc_mutex_lock( &wrapper.lock );
 477
 478     /* Alter user-passed data so that we call the wrapper instead
 479      * of the real function */
 480     p_data = &wrapper;
 481     func = vlc_thread_wrapper;
 482 #endif
 483
 484 #if defined( PTH_INIT_IN_PTH_H )
 485     p_this->thread_id = pth_spawn( PTH_ATTR_DEFAULT, func, (void *)p_this );
 486     i_ret = 0;
 487
 488 #elif defined( ST_INIT_IN_ST_H )
 489     p_this->thread_id = st_thread_create( func, (void *)p_this, 1, 0 );
 490     i_ret = 0;
 491
 492 #elif defined( WIN32 )
 493     {
 494         unsigned threadID;
 495         /* When using the MSVCRT C library you have to use the _beginthreadex
 496          * function instead of CreateThread, otherwise you'll end up with
 497          * memory leaks and the signal functions not working */
 498         p_this->thread_id =
 499                 (HANDLE)_beginthreadex( NULL, 0, (PTHREAD_START) func,
 500                                         (void *)p_this, 0, &threadID );
 501     }
 502
 503     i_ret = ( p_this->thread_id ? 0 : 1 );
 504
 505 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 506     i_ret = pthread_create( &p_this->thread_id, NULL, func, (void *)p_this );
 507
 508 #elif defined( HAVE_CTHREADS_H )
 509     p_this->thread_id = cthread_fork( (cthread_fn_t)func, (any_t)p_this );
 510     i_ret = 0;
 511
 512 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 513     p_this->thread_id = spawn_thread( (thread_func)func, psz_name,
 514                                       B_NORMAL_PRIORITY, (void *)p_this );
 515     i_ret = resume_thread( p_this->thread_id );
 516
 517 #endif
 518
 519 #ifdef GPROF
 520     if( i_ret == 0 )
 521     {
 522         vlc_cond_wait( &wrapper.wait, &wrapper.lock );
 523     }
 524
 525     vlc_mutex_unlock( &wrapper.lock );
 526     vlc_mutex_destroy( &wrapper.lock );
 527     vlc_cond_destroy( &wrapper.wait );
 528 #endif
 529
 530     if( i_ret == 0 )
 531     {
 532         if( b_wait )
 533         {
 534             msg_Dbg( p_this, "waiting for thread completion" );
 535             vlc_cond_wait( &p_this->object_wait, &p_this->object_lock );
 536         }
 537
 538         p_this->b_thread = 1;
 539
 540         msg_Dbg( p_this, "thread %d (%s) created (%s:%d)",
 541                          p_this->thread_id, psz_name, psz_file, i_line );
 542
 543         vlc_mutex_unlock( &p_this->object_lock );
 544     }
 545     else
 546     {
 547         msg_Err( p_this, "%s thread could not be created at %s:%d (%s)",
 548                          psz_name, psz_file, i_line, strerror(i_ret) );
 549         vlc_mutex_unlock( &p_this->object_lock );
 550     }
 551
 552     return i_ret;
 553 }
 554
 555 /*****************************************************************************
 556  * vlc_thread_ready: tell the parent thread we were successfully spawned
 557  *****************************************************************************/
 558 void __vlc_thread_ready( vlc_object_t *p_this )
 559 {
 560     vlc_mutex_lock( &p_this->object_lock );
 561     vlc_cond_signal( &p_this->object_wait );
 562     vlc_mutex_unlock( &p_this->object_lock );
 563 }
 564
 565 /*****************************************************************************
 566  * vlc_thread_join: wait until a thread exits, inner version
 567  *****************************************************************************/
 568 void __vlc_thread_join( vlc_object_t *p_this, char * psz_file, int i_line )
 569 {
 570     int i_ret = 0;
 571
 572 #if defined( PTH_INIT_IN_PTH_H )
 573     i_ret = pth_join( p_this->thread_id, NULL );
 574
 575 #elif defined( ST_INIT_IN_ST_H )
 576     i_ret = st_thread_join( p_this->thread_id, NULL );
 577
 578 #elif defined( WIN32 )
 579     WaitForSingleObject( p_this->thread_id, INFINITE );
 580
 581 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 582     i_ret = pthread_join( p_this->thread_id, NULL );
 583
 584 #elif defined( HAVE_CTHREADS_H )
 585     cthread_join( p_this->thread_id );
 586     i_ret = 1;
 587
 588 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 589     int32 exit_value;
 590     wait_for_thread( p_this->thread_id, &exit_value );
 591
 592 #endif
 593
 594     if( i_ret )
 595     {
 596         msg_Err( p_this, "thread_join(%d) failed at %s:%d (%s)",
 597                          p_this->thread_id, psz_file, i_line, strerror(i_ret) );
 598     }
 599     else
 600     {
 601         msg_Dbg( p_this, "thread %d joined (%s:%d)",
 602                          p_this->thread_id, psz_file, i_line );
 603     }
 604
 605     p_this->b_thread = 0;
 606 }
 607
 608 /*****************************************************************************
 609  * vlc_thread_wrapper: wrapper around thread functions used when profiling.
 610  *****************************************************************************/
 611 #ifdef GPROF
 612 static void *vlc_thread_wrapper( void *p_wrapper )
 613 {
 614     /* Put user data in thread-local variables */
 615     void *            p_data = ((wrapper_t*)p_wrapper)->p_data;
 616     vlc_thread_func_t func   = ((wrapper_t*)p_wrapper)->func;
 617
 618     /* Set the profile timer value */
 619     setitimer( ITIMER_PROF, &((wrapper_t*)p_wrapper)->itimer, NULL );
 620
 621     /* Tell the calling thread that we don't need its data anymore */
 622     vlc_mutex_lock( &((wrapper_t*)p_wrapper)->lock );
 623     vlc_cond_signal( &((wrapper_t*)p_wrapper)->wait );
 624     vlc_mutex_unlock( &((wrapper_t*)p_wrapper)->lock );
 625
 626     /* Call the real function */
 627     return func( p_data );
 628 }
 629 #endif