git.sesse.net Git - vlc/blob - include/vlc_threads_funcs.h

   1 /*****************************************************************************
   2  * vlc_threads_funcs.h : threads implementation for the VideoLAN client
   3  * This header provides a portable threads implementation.
   4  *****************************************************************************
   5  * Copyright (C) 1999, 2002 the VideoLAN team
   6  * $Id$
   7  *
   8  * Authors: Jean-Marc Dressler <polux@via.ecp.fr>
   9  *          Samuel Hocevar <sam@via.ecp.fr>
  10  *          Gildas Bazin <gbazin@netcourrier.com>
  11  *          Christophe Massiot <massiot@via.ecp.fr>
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  26  *****************************************************************************/
  27
  28 /*****************************************************************************
  29  * Function definitions
  30  *****************************************************************************/
  31 VLC_EXPORT( int,  __vlc_threads_init,  ( vlc_object_t * ) );
  32 VLC_EXPORT( int,  __vlc_threads_end,   ( vlc_object_t * ) );
  33 VLC_EXPORT( int,  __vlc_mutex_init,    ( vlc_object_t *, vlc_mutex_t * ) );
  34 VLC_EXPORT( int,  __vlc_mutex_destroy, ( char *, int, vlc_mutex_t * ) );
  35 VLC_EXPORT( int,  __vlc_cond_init,     ( vlc_object_t *, vlc_cond_t * ) );
  36 VLC_EXPORT( int,  __vlc_cond_destroy,  ( char *, int, vlc_cond_t * ) );
  37 VLC_EXPORT( int,  __vlc_thread_create, ( vlc_object_t *, char *, int, char *, void * ( * ) ( void * ), int, vlc_bool_t ) );
  38 VLC_EXPORT( int,  __vlc_thread_set_priority, ( vlc_object_t *, char *, int, int ) );
  39 VLC_EXPORT( void, __vlc_thread_ready,  ( vlc_object_t * ) );
  40 VLC_EXPORT( void, __vlc_thread_join,   ( vlc_object_t *, char *, int ) );
  41
  42
  43 /*****************************************************************************
  44  * vlc_threads_init: initialize threads system
  45  *****************************************************************************/
  46 #define vlc_threads_init( P_THIS )                                          \
  47     __vlc_threads_init( VLC_OBJECT(P_THIS) )
  48
  49 /*****************************************************************************
  50  * vlc_threads_end: deinitialize threads system
  51  *****************************************************************************/
  52 #define vlc_threads_end( P_THIS )                                           \
  53     __vlc_threads_end( VLC_OBJECT(P_THIS) )
  54
  55 /*****************************************************************************
  56  * vlc_mutex_init: initialize a mutex
  57  *****************************************************************************/
  58 #define vlc_mutex_init( P_THIS, P_MUTEX )                                   \
  59     __vlc_mutex_init( VLC_OBJECT(P_THIS), P_MUTEX )
  60
  61 /*****************************************************************************
  62  * vlc_mutex_lock: lock a mutex
  63  *****************************************************************************/
  64 #define vlc_mutex_lock( P_MUTEX )                                           \
  65     __vlc_mutex_lock( __FILE__, __LINE__, P_MUTEX )
  66
  67 static inline int __vlc_mutex_lock( const char * psz_file, int i_line,
  68                                     vlc_mutex_t * p_mutex )
  69 {
  70     int i_result;
  71     /* In case of error : */
  72     int i_thread = -1;
  73     const char * psz_error = "";
  74
  75 #if defined( PTH_INIT_IN_PTH_H )
  76     i_result = ( pth_mutex_acquire( &p_mutex->mutex, FALSE, NULL ) == FALSE );
  77
  78 #elif defined( ST_INIT_IN_ST_H )
  79     i_result = st_mutex_lock( p_mutex->mutex );
  80
  81 #elif defined( UNDER_CE )
  82     EnterCriticalSection( &p_mutex->csection );
  83     i_result = 0;
  84
  85 #elif defined( WIN32 )
  86     if( p_mutex->mutex )
  87     {
  88         WaitForSingleObject( p_mutex->mutex, INFINITE );
  89     }
  90     else
  91     {
  92         EnterCriticalSection( &p_mutex->csection );
  93     }
  94     i_result = 0;
  95
  96 #elif defined( HAVE_KERNEL_SCHEDULER_H )
  97     if( p_mutex == NULL )
  98     {
  99         i_result = B_BAD_VALUE;
 100     }
 101     else if( p_mutex->init < 2000 )
 102     {
 103         i_result = B_NO_INIT;
 104     }
 105     else
 106     {
 107         i_result = acquire_sem( p_mutex->lock );
 108     }
 109
 110 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 111     i_result = pthread_mutex_lock( &p_mutex->mutex );
 112     if ( i_result )
 113     {
 114         i_thread = (int)pthread_self();
 115         psz_error = strerror(i_result);
 116     }
 117
 118 #elif defined( HAVE_CTHREADS_H )
 119     mutex_lock( p_mutex->mutex );
 120     i_result = 0;
 121
 122 #endif
 123
 124     if( i_result )
 125     {
 126         msg_Err( p_mutex->p_this,
 127                  "thread %u: mutex_lock failed at %s:%d (%d:%s)",
 128                  i_thread, psz_file, i_line, i_result, psz_error );
 129     }
 130     return i_result;
 131 }
 132
 133 /*****************************************************************************
 134  * vlc_mutex_unlock: unlock a mutex
 135  *****************************************************************************/
 136 #define vlc_mutex_unlock( P_MUTEX )                                         \
 137     __vlc_mutex_unlock( __FILE__, __LINE__, P_MUTEX )
 138
 139 static inline int __vlc_mutex_unlock( const char * psz_file, int i_line,
 140                                       vlc_mutex_t *p_mutex )
 141 {
 142     int i_result;
 143     /* In case of error : */
 144     int i_thread = -1;
 145     const char * psz_error = "";
 146
 147 #if defined( PTH_INIT_IN_PTH_H )
 148     i_result = ( pth_mutex_release( &p_mutex->mutex ) == FALSE );
 149
 150 #elif defined( ST_INIT_IN_ST_H )
 151     i_result = st_mutex_unlock( p_mutex->mutex );
 152
 153 #elif defined( UNDER_CE )
 154     LeaveCriticalSection( &p_mutex->csection );
 155     i_result = 0;
 156
 157 #elif defined( WIN32 )
 158     if( p_mutex->mutex )
 159     {
 160         ReleaseMutex( p_mutex->mutex );
 161     }
 162     else
 163     {
 164         LeaveCriticalSection( &p_mutex->csection );
 165     }
 166     i_result = 0;
 167
 168 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 169     if( p_mutex == NULL )
 170     {
 171         i_result = B_BAD_VALUE;
 172     }
 173     else if( p_mutex->init < 2000 )
 174     {
 175         i_result = B_NO_INIT;
 176     }
 177     else
 178     {
 179         release_sem( p_mutex->lock );
 180         return B_OK;
 181     }
 182
 183 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 184     i_result = pthread_mutex_unlock( &p_mutex->mutex );
 185     if ( i_result )
 186     {
 187         i_thread = (int)pthread_self();
 188         psz_error = strerror(i_result);
 189     }
 190
 191 #elif defined( HAVE_CTHREADS_H )
 192     mutex_unlock( p_mutex );
 193     i_result = 0;
 194
 195 #endif
 196
 197     if( i_result )
 198     {
 199         msg_Err( p_mutex->p_this,
 200                  "thread %u: mutex_unlock failed at %s:%d (%d:%s)",
 201                  i_thread, psz_file, i_line, i_result, psz_error );
 202     }
 203
 204     return i_result;
 205 }
 206
 207 /*****************************************************************************
 208  * vlc_mutex_destroy: destroy a mutex
 209  *****************************************************************************/
 210 #define vlc_mutex_destroy( P_MUTEX )                                        \
 211     __vlc_mutex_destroy( __FILE__, __LINE__, P_MUTEX )
 212
 213 /*****************************************************************************
 214  * vlc_cond_init: initialize a condition
 215  *****************************************************************************/
 216 #define vlc_cond_init( P_THIS, P_COND )                                     \
 217     __vlc_cond_init( VLC_OBJECT(P_THIS), P_COND )
 218
 219 /*****************************************************************************
 220  * vlc_cond_signal: start a thread on condition completion
 221  *****************************************************************************/
 222 #define vlc_cond_signal( P_COND )                                           \
 223     __vlc_cond_signal( __FILE__, __LINE__, P_COND )
 224
 225 static inline int __vlc_cond_signal( const char * psz_file, int i_line,
 226                                      vlc_cond_t *p_condvar )
 227 {
 228     int i_result;
 229     /* In case of error : */
 230     int i_thread = -1;
 231     const char * psz_error = "";
 232
 233 #if defined( PTH_INIT_IN_PTH_H )
 234     i_result = ( pth_cond_notify( &p_condvar->cond, FALSE ) == FALSE );
 235
 236 #elif defined( ST_INIT_IN_ST_H )
 237     i_result = st_cond_signal( p_condvar->cond );
 238
 239 #elif defined( UNDER_CE )
 240     PulseEvent( p_condvar->event );
 241     i_result = 0;
 242
 243 #elif defined( WIN32 )
 244     /* Release one waiting thread if one is available. */
 245     /* For this trick to work properly, the vlc_cond_signal must be surrounded
 246      * by a mutex. This will prevent another thread from stealing the signal */
 247     if( !p_condvar->semaphore )
 248     {
 249         PulseEvent( p_condvar->event );
 250     }
 251     else if( p_condvar->i_win9x_cv == 1 )
 252     {
 253         /* Wait for the gate to be open */
 254         WaitForSingleObject( p_condvar->event, INFINITE );
 255
 256         if( p_condvar->i_waiting_threads )
 257         {
 258             /* Using a semaphore exposes us to a race condition. It is
 259              * possible for another thread to start waiting on the semaphore
 260              * just after we signaled it and thus steal the signal.
 261              * We have to prevent new threads from entering the cond_wait(). */
 262             ResetEvent( p_condvar->event );
 263
 264             /* A semaphore is used here because Win9x doesn't have
 265              * SignalObjectAndWait() and thus a race condition exists
 266              * during the time we release the mutex and the time we start
 267              * waiting on the event (more precisely, the signal can sometimes
 268              * be missed by the waiting thread if we use PulseEvent()). */
 269             ReleaseSemaphore( p_condvar->semaphore, 1, 0 );
 270         }
 271     }
 272     else
 273     {
 274         if( p_condvar->i_waiting_threads )
 275         {
 276             ReleaseSemaphore( p_condvar->semaphore, 1, 0 );
 277
 278             /* Wait for the last thread to be awakened */
 279             WaitForSingleObject( p_condvar->event, INFINITE );
 280         }
 281     }
 282     i_result = 0;
 283
 284 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 285     if( p_condvar == NULL )
 286     {
 287         i_result = B_BAD_VALUE;
 288     }
 289     else if( p_condvar->init < 2000 )
 290     {
 291         i_result = B_NO_INIT;
 292     }
 293     else
 294     {
 295         while( p_condvar->thread != -1 )
 296         {
 297             thread_info info;
 298             if( get_thread_info(p_condvar->thread, &info) == B_BAD_VALUE )
 299             {
 300                 return 0;
 301             }
 302
 303             if( info.state != B_THREAD_SUSPENDED )
 304             {
 305                 /* The  waiting thread is not suspended so it could
 306                  * have been interrupted beetwen the unlock and the
 307                  * suspend_thread line. That is why we sleep a little
 308                  * before retesting p_condver->thread. */
 309                 snooze( 10000 );
 310             }
 311             else
 312             {
 313                 /* Ok, we have to wake up that thread */
 314                 resume_thread( p_condvar->thread );
 315                 return 0;
 316             }
 317         }
 318         i_result = 0;
 319     }
 320
 321 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 322     i_result = pthread_cond_signal( &p_condvar->cond );
 323     if ( i_result )
 324     {
 325         i_thread = (int)pthread_self();
 326         psz_error = strerror(i_result);
 327     }
 328
 329 #elif defined( HAVE_CTHREADS_H )
 330     /* condition_signal() */
 331     if ( p_condvar->queue.head || p_condvar->implications )
 332     {
 333         cond_signal( (condition_t)p_condvar );
 334     }
 335     i_result = 0;
 336
 337 #endif
 338
 339     if( i_result )
 340     {
 341         msg_Err( p_condvar->p_this,
 342                  "thread %u: cond_signal failed at %s:%d (%d:%s)",
 343                  i_thread, psz_file, i_line, i_result, psz_error );
 344     }
 345
 346     return i_result;
 347 }
 348
 349 /*****************************************************************************
 350  * vlc_cond_wait: wait until condition completion
 351  *****************************************************************************/
 352 #define vlc_cond_wait( P_COND, P_MUTEX )                                     \
 353     __vlc_cond_wait( __FILE__, __LINE__, P_COND, P_MUTEX  )
 354
 355 static inline int __vlc_cond_wait( const char * psz_file, int i_line,
 356                                    vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex )
 357 {
 358     int i_result;
 359     /* In case of error : */
 360     int i_thread = -1;
 361     const char * psz_error = "";
 362
 363 #if defined( PTH_INIT_IN_PTH_H )
 364     i_result = ( pth_cond_await( &p_condvar->cond, &p_mutex->mutex, NULL )
 365                  == FALSE );
 366
 367 #elif defined( ST_INIT_IN_ST_H )
 368     st_mutex_unlock( p_mutex->mutex );
 369     i_result = st_cond_wait( p_condvar->cond );
 370     st_mutex_lock( p_mutex->mutex );
 371
 372 #elif defined( UNDER_CE )
 373     p_condvar->i_waiting_threads++;
 374     LeaveCriticalSection( &p_mutex->csection );
 375     WaitForSingleObject( p_condvar->event, INFINITE );
 376     p_condvar->i_waiting_threads--;
 377
 378     /* Reacquire the mutex before returning. */
 379     vlc_mutex_lock( p_mutex );
 380
 381     i_result = 0;
 382
 383 #elif defined( WIN32 )
 384     if( !p_condvar->semaphore )
 385     {
 386         /* Increase our wait count */
 387         p_condvar->i_waiting_threads++;
 388
 389         if( p_mutex->mutex )
 390         {
 391             /* It is only possible to atomically release the mutex and
 392              * initiate the waiting on WinNT/2K/XP. Win9x doesn't have
 393              * SignalObjectAndWait(). */
 394             p_condvar->SignalObjectAndWait( p_mutex->mutex,
 395                                             p_condvar->event,
 396                                             INFINITE, FALSE );
 397         }
 398         else
 399         {
 400             LeaveCriticalSection( &p_mutex->csection );
 401             WaitForSingleObject( p_condvar->event, INFINITE );
 402         }
 403
 404         p_condvar->i_waiting_threads--;
 405     }
 406     else if( p_condvar->i_win9x_cv == 1 )
 407     {
 408         int i_waiting_threads;
 409
 410         /* Wait for the gate to be open */
 411         WaitForSingleObject( p_condvar->event, INFINITE );
 412
 413         /* Increase our wait count */
 414         p_condvar->i_waiting_threads++;
 415
 416         LeaveCriticalSection( &p_mutex->csection );
 417         WaitForSingleObject( p_condvar->semaphore, INFINITE );
 418
 419         /* Decrement and test must be atomic */
 420         EnterCriticalSection( &p_condvar->csection );
 421
 422         /* Decrease our wait count */
 423         i_waiting_threads = --p_condvar->i_waiting_threads;
 424
 425         LeaveCriticalSection( &p_condvar->csection );
 426
 427         /* Reopen the gate if we were the last waiting thread */
 428         if( !i_waiting_threads )
 429             SetEvent( p_condvar->event );
 430     }
 431     else
 432     {
 433         int i_waiting_threads;
 434
 435         /* Increase our wait count */
 436         p_condvar->i_waiting_threads++;
 437
 438         LeaveCriticalSection( &p_mutex->csection );
 439         WaitForSingleObject( p_condvar->semaphore, INFINITE );
 440
 441         /* Decrement and test must be atomic */
 442         EnterCriticalSection( &p_condvar->csection );
 443
 444         /* Decrease our wait count */
 445         i_waiting_threads = --p_condvar->i_waiting_threads;
 446
 447         LeaveCriticalSection( &p_condvar->csection );
 448
 449         /* Signal that the last waiting thread just went through */
 450         if( !i_waiting_threads )
 451             SetEvent( p_condvar->event );
 452     }
 453
 454     /* Reacquire the mutex before returning. */
 455     vlc_mutex_lock( p_mutex );
 456
 457     i_result = 0;
 458
 459 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 460     if( p_condvar == NULL )
 461     {
 462         i_result = B_BAD_VALUE;
 463     }
 464     else if( p_mutex == NULL )
 465     {
 466         i_result = B_BAD_VALUE;
 467     }
 468     else if( p_condvar->init < 2000 )
 469     {
 470         i_result = B_NO_INIT;
 471     }
 472
 473     /* The p_condvar->thread var is initialized before the unlock because
 474      * it enables to identify when the thread is interrupted beetwen the
 475      * unlock line and the suspend_thread line */
 476     p_condvar->thread = find_thread( NULL );
 477     vlc_mutex_unlock( p_mutex );
 478     suspend_thread( p_condvar->thread );
 479     p_condvar->thread = -1;
 480
 481     vlc_mutex_lock( p_mutex );
 482     i_result = 0;
 483
 484 #elif defined( PTHREAD_COND_T_IN_PTHREAD_H )
 485
 486 #   ifdef DEBUG
 487     /* In debug mode, timeout */
 488     struct timeval now;
 489     struct timespec timeout;
 490
 491     gettimeofday( &now, NULL );
 492     timeout.tv_sec = now.tv_sec + THREAD_COND_TIMEOUT;
 493     timeout.tv_nsec = now.tv_usec * 1000;
 494
 495     i_result = pthread_cond_timedwait( &p_condvar->cond, &p_mutex->mutex,
 496                                        &timeout );
 497
 498     if( i_result == ETIMEDOUT )
 499     {
 500         /* People keep pissing me off with this. --Meuuh */
 501         msg_Dbg( p_condvar->p_this,
 502                   "thread %u: secret message triggered "
 503                   "at %s:%d (%s)", (int)pthread_self(),
 504                   psz_file, i_line, strerror(i_result) );
 505
 506         i_result = pthread_cond_wait( &p_condvar->cond, &p_mutex->mutex );
 507     }
 508
 509 #   else
 510     i_result = pthread_cond_wait( &p_condvar->cond, &p_mutex->mutex );
 511 #   endif
 512
 513     if ( i_result )
 514     {
 515         i_thread = (int)pthread_self();
 516         psz_error = strerror(i_result);
 517     }
 518
 519 #elif defined( HAVE_CTHREADS_H )
 520     condition_wait( (condition_t)p_condvar, (mutex_t)p_mutex );
 521     i_result = 0;
 522
 523 #endif
 524
 525     if( i_result )
 526     {
 527         msg_Err( p_condvar->p_this,
 528                  "thread %u: cond_wait failed at %s:%d (%d:%s)",
 529                  i_thread, psz_file, i_line, i_result, psz_error );
 530     }
 531
 532     return i_result;
 533 }
 534
 535 /*****************************************************************************
 536  * vlc_cond_destroy: destroy a condition
 537  *****************************************************************************/
 538 #define vlc_cond_destroy( P_COND )                                          \
 539     __vlc_cond_destroy( __FILE__, __LINE__, P_COND )
 540
 541 /*****************************************************************************
 542  * vlc_thread_create: create a thread
 543  *****************************************************************************/
 544 #define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY, WAIT )         \
 545     __vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, (void * ( * ) ( void * ))FUNC, PRIORITY, WAIT )
 546
 547 /*****************************************************************************
 548  * vlc_thread_set_priority: set the priority of the calling thread
 549  *****************************************************************************/
 550 #define vlc_thread_set_priority( P_THIS, PRIORITY )                         \
 551     __vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
 552
 553 /*****************************************************************************
 554  * vlc_thread_ready: tell the parent thread we were successfully spawned
 555  *****************************************************************************/
 556 #define vlc_thread_ready( P_THIS )                                          \
 557     __vlc_thread_ready( VLC_OBJECT(P_THIS) )
 558
 559 /*****************************************************************************
 560  * vlc_thread_join: wait until a thread exits
 561  *****************************************************************************/
 562 #define vlc_thread_join( P_THIS )                                           \
 563     __vlc_thread_join( VLC_OBJECT(P_THIS), __FILE__, __LINE__ )