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 1.9 2002/07/16 21:29:10 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_s
  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( (GetVersion() < 0x80000000) && !p_this->p_vlc->b_fast_pthread )
 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 //X        intf_ErrMsg( "thread %d error: mutex_destroy failed at %s:%d (%s)",
 316 //X                     pthread_self(), psz_file, i_line, strerror(i_return) );
 317     }
 318     return i_return;
 319
 320 #elif defined( HAVE_CTHREADS_H )
 321     return 0;
 322
 323 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 324     if( p_mutex->init == 9999 )
 325     {
 326         delete_sem( p_mutex->lock );
 327     }
 328
 329     p_mutex->init = 0;
 330     return B_OK;
 331
 332 #endif
 333 }
 334
 335 /*****************************************************************************
 336  * vlc_cond_init: initialize a condition
 337  *****************************************************************************/
 338 int __vlc_cond_init( vlc_object_t *p_this, vlc_cond_t *p_condvar )
 339 {
 340 #if defined( PTH_INIT_IN_PTH_H )
 341     return pth_cond_init( p_condvar );
 342
 343 #elif defined( ST_INIT_IN_ST_H )
 344     *p_condvar = st_cond_new();
 345     return ( *p_condvar == NULL ) ? errno : 0;
 346
 347 #elif defined( WIN32 )
 348     /* Initialize counter */
 349     p_condvar->i_waiting_threads = 0;
 350
 351     if( (GetVersion() < 0x80000000) && !p_this->p_vlc->b_fast_pthread )
 352     {
 353         /* Create an auto-reset event and a semaphore. */
 354         p_condvar->signal = CreateEvent( NULL, FALSE, FALSE, NULL );
 355         p_condvar->semaphore = CreateSemaphore( NULL, 0, 0x7fffffff, NULL );
 356
 357         p_condvar->b_broadcast = 0;
 358
 359         /* We are running on NT/2K/XP, we can use SignalObjectAndWait */
 360         p_condvar->SignalObjectAndWait = p_this->p_vlc->SignalObjectAndWait;
 361
 362         return !p_condvar->signal || !p_condvar->semaphore;
 363     }
 364     else
 365     {
 366         p_condvar->signal = NULL;
 367
 368         /* Create an auto-reset event and a manual-reset event. */
 369         p_condvar->p_events[0] = CreateEvent( NULL, FALSE, FALSE, NULL );
 370         p_condvar->p_events[1] = CreateEvent( NULL, TRUE, FALSE, NULL );
 371
 372         return !p_condvar->p_events[0] || !p_condvar->p_events[1];
 373     }
 374
 375 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 376     return pthread_cond_init( p_condvar, NULL );
 377
 378 #elif defined( HAVE_CTHREADS_H )
 379     /* condition_init() */
 380     spin_lock_init( &p_condvar->lock );
 381     cthread_queue_init( &p_condvar->queue );
 382     p_condvar->name = 0;
 383     p_condvar->implications = 0;
 384
 385     return 0;
 386
 387 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 388     if( !p_condvar )
 389     {
 390         return B_BAD_VALUE;
 391     }
 392
 393     if( p_condvar->init == 9999 )
 394     {
 395         return EALREADY;
 396     }
 397
 398     p_condvar->thread = -1;
 399     p_condvar->init = 9999;
 400     return 0;
 401
 402 #endif
 403 }
 404
 405 /*****************************************************************************
 406  * vlc_cond_destroy: destroy a condition, inner version
 407  *****************************************************************************/
 408 int __vlc_cond_destroy( char * psz_file, int i_line, vlc_cond_t *p_condvar )
 409 {
 410 #if defined( PTH_INIT_IN_PTH_H )
 411     return 0;
 412
 413 #elif defined( ST_INIT_IN_ST_H )
 414     return st_cond_destroy( *p_condvar );
 415
 416 #elif defined( WIN32 )
 417     if( p_condvar->signal )
 418     {
 419         return !CloseHandle( p_condvar->signal )
 420                  || !CloseHandle( p_condvar->semaphore );
 421     }
 422     else
 423     {
 424         return !CloseHandle( p_condvar->p_events[0] )
 425                  || !CloseHandle( p_condvar->p_events[1] );
 426     }
 427
 428 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 429     int i_result = pthread_cond_destroy( p_condvar );
 430     if( i_result )
 431     {
 432 //X        intf_ErrMsg( "thread %d error: cond_destroy failed at %s:%d (%s)",
 433 //X                     pthread_self(), psz_file, i_line, strerror(i_result) );
 434     }
 435     return i_result;
 436
 437 #elif defined( HAVE_CTHREADS_H )
 438     return 0;
 439
 440 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 441     p_condvar->init = 0;
 442     return 0;
 443
 444 #endif
 445 }
 446
 447 /*****************************************************************************
 448  * vlc_thread_create: create a thread, inner version
 449  *****************************************************************************/
 450 int __vlc_thread_create( vlc_object_t *p_this, char * psz_file, int i_line,
 451                          char *psz_name, void * ( *func ) ( void * ),
 452                          vlc_bool_t b_wait )
 453 {
 454     int i_ret;
 455
 456     vlc_mutex_lock( &p_this->object_lock );
 457
 458 #ifdef GPROF
 459     wrapper_t wrapper;
 460
 461     /* Initialize the wrapper structure */
 462     wrapper.func = func;
 463     wrapper.p_data = (void *)p_this;
 464     getitimer( ITIMER_PROF, &wrapper.itimer );
 465     vlc_mutex_init( p_this, &wrapper.lock );
 466     vlc_cond_init( p_this, &wrapper.wait );
 467     vlc_mutex_lock( &wrapper.lock );
 468
 469     /* Alter user-passed data so that we call the wrapper instead
 470      * of the real function */
 471     p_data = &wrapper;
 472     func = vlc_thread_wrapper;
 473 #endif
 474
 475 #if defined( PTH_INIT_IN_PTH_H )
 476     p_this->thread_id = pth_spawn( PTH_ATTR_DEFAULT, func, (void *)p_this );
 477     i_ret = 0;
 478
 479 #elif defined( ST_INIT_IN_ST_H )
 480     p_this->thread_id = st_thread_create( func, (void *)p_this, 1, 0 );
 481     i_ret = 0;
 482
 483 #elif defined( WIN32 )
 484     {
 485         unsigned threadID;
 486         /* When using the MSVCRT C library you have to use the _beginthreadex
 487          * function instead of CreateThread, otherwise you'll end up with
 488          * memory leaks and the signal functions not working */
 489         p_this->thread_id =
 490                 (HANDLE)_beginthreadex( NULL, 0, (PTHREAD_START) func,
 491                                         (void *)p_this, 0, &threadID );
 492     }
 493
 494     i_ret = ( p_this->thread_id ? 0 : 1 );
 495
 496 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 497     i_ret = pthread_create( &p_this->thread_id, NULL, func, (void *)p_this );
 498
 499 #elif defined( HAVE_CTHREADS_H )
 500     p_this->thread_id = cthread_fork( (cthread_fn_t)func, (any_t)p_this );
 501     i_ret = 0;
 502
 503 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 504     p_this->thread_id = spawn_thread( (thread_func)func, psz_name,
 505                                       B_NORMAL_PRIORITY, (void *)p_this );
 506     i_ret = resume_thread( p_this->thread_id );
 507
 508 #endif
 509
 510 #ifdef GPROF
 511     if( i_ret == 0 )
 512     {
 513         vlc_cond_wait( &wrapper.wait, &wrapper.lock );
 514     }
 515
 516     vlc_mutex_unlock( &wrapper.lock );
 517     vlc_mutex_destroy( &wrapper.lock );
 518     vlc_cond_destroy( &wrapper.wait );
 519 #endif
 520
 521     if( i_ret == 0 )
 522     {
 523         if( b_wait )
 524         {
 525             msg_Dbg( p_this, "waiting for thread completion" );
 526             vlc_cond_wait( &p_this->object_wait, &p_this->object_lock );
 527         }
 528
 529         p_this->b_thread = 1;
 530
 531         msg_Dbg( p_this, "thread %d (%s) created (%s:%d)",
 532                          p_this->thread_id, psz_name, psz_file, i_line );
 533
 534         vlc_mutex_unlock( &p_this->object_lock );
 535     }
 536     else
 537     {
 538         msg_Err( p_this, "%s thread could not be created at %s:%d (%s)",
 539                          psz_name, psz_file, i_line, strerror(i_ret) );
 540         vlc_mutex_unlock( &p_this->object_lock );
 541     }
 542
 543     return i_ret;
 544 }
 545
 546 /*****************************************************************************
 547  * vlc_thread_ready: tell the parent thread we were successfully spawned
 548  *****************************************************************************/
 549 void __vlc_thread_ready( vlc_object_t *p_this )
 550 {
 551     vlc_mutex_lock( &p_this->object_lock );
 552     vlc_cond_signal( &p_this->object_wait );
 553     vlc_mutex_unlock( &p_this->object_lock );
 554 }
 555
 556 /*****************************************************************************
 557  * vlc_thread_join: wait until a thread exits, inner version
 558  *****************************************************************************/
 559 void __vlc_thread_join( vlc_object_t *p_this, char * psz_file, int i_line )
 560 {
 561     int i_ret = 0;
 562
 563 #if defined( PTH_INIT_IN_PTH_H )
 564     i_ret = pth_join( p_this->thread_id, NULL );
 565
 566 #elif defined( ST_INIT_IN_ST_H )
 567     i_ret = st_thread_join( p_this->thread_id, NULL );
 568
 569 #elif defined( WIN32 )
 570     WaitForSingleObject( p_this->thread_id, INFINITE );
 571
 572 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 573     i_ret = pthread_join( p_this->thread_id, NULL );
 574
 575 #elif defined( HAVE_CTHREADS_H )
 576     cthread_join( p_this->thread_id );
 577     i_ret = 1;
 578
 579 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 580     int32 exit_value;
 581     wait_for_thread( p_this->thread_id, &exit_value );
 582
 583 #endif
 584
 585     if( i_ret )
 586     {
 587         msg_Err( p_this, "thread_join(%d) failed at %s:%d (%s)",
 588                          p_this->thread_id, psz_file, i_line, strerror(i_ret) );
 589     }
 590     else
 591     {
 592         msg_Dbg( p_this, "thread %d joined (%s:%d)",
 593                          p_this->thread_id, psz_file, i_line );
 594     }
 595
 596     p_this->b_thread = 0;
 597 }
 598
 599 /*****************************************************************************
 600  * vlc_thread_wrapper: wrapper around thread functions used when profiling.
 601  *****************************************************************************/
 602 #ifdef GPROF
 603 static void *vlc_thread_wrapper( void *p_wrapper )
 604 {
 605     /* Put user data in thread-local variables */
 606     void *            p_data = ((wrapper_t*)p_wrapper)->p_data;
 607     vlc_thread_func_t func   = ((wrapper_t*)p_wrapper)->func;
 608
 609     /* Set the profile timer value */
 610     setitimer( ITIMER_PROF, &((wrapper_t*)p_wrapper)->itimer, NULL );
 611
 612     /* Tell the calling thread that we don't need its data anymore */
 613     vlc_mutex_lock( &((wrapper_t*)p_wrapper)->lock );
 614     vlc_cond_signal( &((wrapper_t*)p_wrapper)->wait );
 615     vlc_mutex_unlock( &((wrapper_t*)p_wrapper)->lock );
 616
 617     /* Call the real function */
 618     return func( p_data );
 619 }
 620 #endif