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

   1 /*****************************************************************************
   2  * threads.h : threads implementation for the VideoLAN client
   3  * This header provides a portable threads implementation.
   4  *****************************************************************************
   5  * Copyright (C) 1999, 2000 VideoLAN
   6  * $Id: threads.h,v 1.17 2001/04/28 03:36:25 sam Exp $
   7  *
   8  * Authors: Jean-Marc Dressler <polux@via.ecp.fr>
   9  *          Samuel Hocevar <sam@via.ecp.fr>
  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 <stdio.h>
  27
  28 #if defined(PTHREAD_COND_T_IN_PTHREAD_H)      /* pthreads (like Linux & BSD) */
  29 #include <pthread.h>
  30
  31 #elif defined(HAVE_CTHREADS_H)                                    /* GNUMach */
  32 #include <cthreads.h>
  33
  34 #elif defined(HAVE_KERNEL_SCHEDULER_H) && defined(HAVE_KERNEL_OS_H)  /* BeOS */
  35 #undef MAX
  36 #undef MIN
  37 #include <kernel/OS.h>
  38 #include <kernel/scheduler.h>
  39 #include <byteorder.h>
  40
  41 #elif defined(WIN32)                          /* Win32 with MinGW32 compiler */
  42 #include <windows.h>
  43 #include <process.h>
  44
  45 #else
  46 #error no threads available on your system !
  47 #endif
  48
  49 /*****************************************************************************
  50  * Constants
  51  *****************************************************************************
  52  * These constants are used by all threads in *_CreateThread() and
  53  * *_DestroyThreads() functions. Since those calls are non-blocking, an integer
  54  * value is used as a shared flag to represent the status of the thread.
  55  *****************************************************************************/
  56
  57 /* Void status - this value can be used to make sure no operation is currently
  58  * in progress on the concerned thread in an array of recorded threads */
  59 #define THREAD_NOP          0                            /* nothing happened */
  60
  61 /* Creation status */
  62 #define THREAD_CREATE       10                     /* thread is initializing */
  63 #define THREAD_START        11                          /* thread has forked */
  64 #define THREAD_READY        19                            /* thread is ready */
  65
  66 /* Destructions status */
  67 #define THREAD_DESTROY      20            /* destruction order has been sent */
  68 #define THREAD_END          21        /* destruction order has been received */
  69 #define THREAD_OVER         29             /* thread does not exist any more */
  70
  71 /* Error status */
  72 #define THREAD_ERROR        30                           /* an error occured */
  73 #define THREAD_FATAL        31  /* an fatal error occured - program must end */
  74
  75 /*****************************************************************************
  76  * Types definition
  77  *****************************************************************************/
  78
  79 #if defined(PTHREAD_COND_T_IN_PTHREAD_H)
  80 typedef pthread_t        vlc_thread_t;
  81 typedef pthread_mutex_t  vlc_mutex_t;
  82 typedef pthread_cond_t   vlc_cond_t;
  83
  84 #elif defined(HAVE_CTHREADS_H)
  85 typedef cthread_t        vlc_thread_t;
  86
  87 /* Those structs are the ones defined in /include/cthreads.h but we need
  88  * to handle (*foo) where foo is a (mutex_t) while they handle (foo) where
  89  * foo is a (mutex_t*) */
  90 typedef struct s_mutex {
  91     spin_lock_t held;
  92     spin_lock_t lock;
  93     char *name;
  94     struct cthread_queue queue;
  95 } vlc_mutex_t;
  96
  97 typedef struct s_condition {
  98     spin_lock_t lock;
  99     struct cthread_queue queue;
 100     char *name;
 101     struct cond_imp *implications;
 102 } vlc_cond_t;
 103
 104 #elif defined(HAVE_KERNEL_SCHEDULER_H) && defined(HAVE_KERNEL_OS_H)
 105 /* This is the BeOS implementation of the vlc threads, note that the mutex is
 106  * not a real mutex and the cond_var is not like a pthread cond_var but it is
 107  * enough for what wee need */
 108
 109 typedef thread_id vlc_thread_t;
 110
 111 typedef struct
 112 {
 113     int32           init;
 114     sem_id          lock;
 115 } vlc_mutex_t;
 116
 117 typedef struct
 118 {
 119     int32           init;
 120     thread_id       thread;
 121 } vlc_cond_t;
 122
 123 #elif defined(WIN32)
 124 typedef HANDLE      vlc_thread_t;
 125 typedef HANDLE      vlc_mutex_t;
 126 typedef HANDLE      vlc_cond_t;
 127 typedef unsigned (__stdcall *PTHREAD_START) (void *);
 128
 129 #endif
 130
 131 typedef void *(*vlc_thread_func_t)(void *p_data);
 132
 133 /*****************************************************************************
 134  * Prototypes
 135  *****************************************************************************/
 136
 137 static __inline__ int  vlc_thread_create ( vlc_thread_t *, char *,
 138                                            vlc_thread_func_t, void * );
 139 static __inline__ void vlc_thread_exit   ( void );
 140 static __inline__ void vlc_thread_join   ( vlc_thread_t );
 141
 142 static __inline__ int  vlc_mutex_init    ( vlc_mutex_t * );
 143 static __inline__ int  vlc_mutex_lock    ( vlc_mutex_t * );
 144 static __inline__ int  vlc_mutex_unlock  ( vlc_mutex_t * );
 145 static __inline__ int  vlc_mutex_destroy ( vlc_mutex_t * );
 146
 147 static __inline__ int  vlc_cond_init     ( vlc_cond_t * );
 148 static __inline__ int  vlc_cond_signal   ( vlc_cond_t * );
 149 static __inline__ int  vlc_cond_wait     ( vlc_cond_t *, vlc_mutex_t * );
 150 static __inline__ int  vlc_cond_destroy  ( vlc_cond_t * );
 151
 152 #if 0
 153 static __inline__ int  vlc_cond_timedwait( vlc_cond_t *, vlc_mutex_t *,
 154                                            mtime_t );
 155 #endif
 156
 157 /*****************************************************************************
 158  * vlc_thread_create: create a thread
 159  *****************************************************************************/
 160 static __inline__ int vlc_thread_create( vlc_thread_t *p_thread,
 161                                          char *psz_name, vlc_thread_func_t func,
 162                                          void *p_data)
 163 {
 164 #if defined(PTHREAD_COND_T_IN_PTHREAD_H)
 165     return pthread_create( p_thread, NULL, func, p_data );
 166
 167 #elif defined(HAVE_CTHREADS_H)
 168     *p_thread = cthread_fork( (cthread_fn_t)func, (any_t)p_data );
 169     return 0;
 170
 171 #elif defined(HAVE_KERNEL_SCHEDULER_H) && defined(HAVE_KERNEL_OS_H)
 172     *p_thread = spawn_thread( (thread_func)func, psz_name,
 173                               B_NORMAL_PRIORITY, p_data );
 174     return resume_thread( *p_thread );
 175
 176 #elif defined(WIN32)
 177 #if 0
 178     DWORD threadID;
 179     /* This method is not recommended when using the MSVCRT C library,
 180      * so we'll have to use _beginthreadex instead */
 181     *p_thread = CreateThread(0, 0, (LPTHREAD_START_ROUTINE) func,
 182                              p_data, 0, &threadID);
 183 #endif
 184     unsigned threadID;
 185     /* When using the MSVCRT C library you have to use the _beginthreadex
 186      * function instead of CreateThread, otherwise you'll end up with memory
 187      * leaks and the signal function not working */
 188     *p_thread = (HANDLE)_beginthreadex(NULL, 0, (PTHREAD_START) func,
 189                              p_data, 0, &threadID);
 190
 191     return( *p_thread ? 0 : 1 );
 192
 193 #endif
 194 }
 195
 196 /*****************************************************************************
 197  * vlc_thread_exit: terminate a thread
 198  *****************************************************************************/
 199 static __inline__ void vlc_thread_exit( void )
 200 {
 201 #if defined(PTHREAD_COND_T_IN_PTHREAD_H)
 202     pthread_exit( 0 );
 203
 204 #elif defined(HAVE_CTHREADS_H)
 205     int result;
 206     cthread_exit( &result );
 207
 208 #elif defined(HAVE_KERNEL_SCHEDULER_H) && defined(HAVE_KERNEL_OS_H)
 209     exit_thread( 0 );
 210
 211 #elif defined(WIN32)
 212 #if 0
 213     ExitThread( 0 );
 214 #endif
 215     /* For now we don't close the thread handles (because of race conditions).
 216      * Need to be looked at. */
 217     _endthreadex(0);
 218
 219 #endif
 220 }
 221
 222 /*****************************************************************************
 223  * vlc_thread_join: wait until a thread exits
 224  *****************************************************************************/
 225 static __inline__ void vlc_thread_join( vlc_thread_t thread )
 226 {
 227 #if defined(PTHREAD_COND_T_IN_PTHREAD_H)
 228     pthread_join( thread, NULL );
 229
 230 #elif defined(HAVE_CTHREADS_H)
 231     cthread_join( thread );
 232
 233 #elif defined(HAVE_KERNEL_SCHEDULER_H) && defined(HAVE_KERNEL_OS_H)
 234     int32 exit_value;
 235     wait_for_thread( thread, &exit_value );
 236
 237 #elif defined(WIN32)
 238     WaitForSingleObject( thread, INFINITE);
 239
 240 #endif
 241 }
 242
 243 /*****************************************************************************
 244  * vlc_mutex_init: initialize a mutex
 245  *****************************************************************************/
 246 static __inline__ int vlc_mutex_init( vlc_mutex_t *p_mutex )
 247 {
 248 #if defined(PTHREAD_COND_T_IN_PTHREAD_H)
 249     return pthread_mutex_init( p_mutex, NULL );
 250
 251 #elif defined(HAVE_CTHREADS_H)
 252     mutex_init( p_mutex );
 253     return 0;
 254
 255 #elif defined(HAVE_KERNEL_SCHEDULER_H) && defined(HAVE_KERNEL_OS_H)
 256
 257     /* check the arguments and whether it's already been initialized */
 258     if( p_mutex == NULL )
 259     {
 260         return B_BAD_VALUE;
 261     }
 262
 263     if( p_mutex->init == 9999 )
 264     {
 265         return EALREADY;
 266     }
 267
 268     p_mutex->lock = create_sem( 1, "BeMutex" );
 269     if( p_mutex->lock < B_NO_ERROR )
 270     {
 271         return( -1 );
 272     }
 273
 274     p_mutex->init = 9999;
 275     return B_OK;
 276
 277 #elif defined(WIN32)
 278     *p_mutex = CreateMutex(0,FALSE,0);
 279     return (*p_mutex?0:1);
 280
 281 #endif
 282 }
 283
 284 /*****************************************************************************
 285  * vlc_mutex_lock: lock a mutex
 286  *****************************************************************************/
 287 static __inline__ int vlc_mutex_lock( vlc_mutex_t *p_mutex )
 288 {
 289 #if defined(PTHREAD_COND_T_IN_PTHREAD_H)
 290     return pthread_mutex_lock( p_mutex );
 291
 292 #elif defined(HAVE_CTHREADS_H)
 293     mutex_lock( p_mutex );
 294     return 0;
 295
 296 #elif defined(HAVE_KERNEL_SCHEDULER_H) && defined(HAVE_KERNEL_OS_H)
 297     status_t err;
 298
 299     if( !p_mutex )
 300     {
 301         return B_BAD_VALUE;
 302     }
 303
 304     if( p_mutex->init < 2000 )
 305     {
 306         return B_NO_INIT;
 307     }
 308
 309     err = acquire_sem( p_mutex->lock );
 310     return err;
 311
 312 #elif defined(WIN32)
 313     WaitForSingleObject( *p_mutex, INFINITE );
 314     return 0;
 315
 316 #endif
 317 }
 318
 319 /*****************************************************************************
 320  * vlc_mutex_unlock: unlock a mutex
 321  *****************************************************************************/
 322 static __inline__ int vlc_mutex_unlock( vlc_mutex_t *p_mutex )
 323 {
 324 #if defined(PTHREAD_COND_T_IN_PTHREAD_H)
 325     return pthread_mutex_unlock( p_mutex );
 326
 327 #elif defined(HAVE_CTHREADS_H)
 328     mutex_unlock( p_mutex );
 329     return 0;
 330
 331 #elif defined(HAVE_KERNEL_SCHEDULER_H) && defined(HAVE_KERNEL_OS_H)
 332     if( !p_mutex)
 333     {
 334         return B_BAD_VALUE;
 335     }
 336
 337     if( p_mutex->init < 2000 )
 338     {
 339         return B_NO_INIT;
 340     }
 341
 342     release_sem( p_mutex->lock );
 343     return B_OK;
 344
 345 #elif defined(WIN32)
 346     ReleaseMutex( *p_mutex );
 347     return 0;
 348
 349 #endif
 350 }
 351
 352 /*****************************************************************************
 353  * vlc_mutex_destroy: destroy a mutex
 354  *****************************************************************************/
 355 static __inline__ int vlc_mutex_destroy( vlc_mutex_t *p_mutex )
 356 {
 357 #if defined(PTHREAD_COND_T_IN_PTHREAD_H)
 358     return pthread_mutex_destroy( p_mutex );
 359
 360 #elif defined(HAVE_KERNEL_SCHEDULER_H) && defined(HAVE_KERNEL_OS_H)
 361     if( p_mutex->init == 9999 )
 362     {
 363         delete_sem( p_mutex->lock );
 364     }
 365
 366     p_mutex->init = 0;
 367     return B_OK;
 368
 369 #elif defined(WIN32)
 370     CloseHandle(*p_mutex);
 371     return 0;
 372
 373 #endif
 374 }
 375
 376 /*****************************************************************************
 377  * vlc_cond_init: initialize a condition
 378  *****************************************************************************/
 379 static __inline__ int vlc_cond_init( vlc_cond_t *p_condvar )
 380 {
 381 #if defined(PTHREAD_COND_T_IN_PTHREAD_H)
 382     return pthread_cond_init( p_condvar, NULL );
 383
 384 #elif defined(HAVE_CTHREADS_H)
 385     /* condition_init() */
 386     spin_lock_init( &p_condvar->lock );
 387     cthread_queue_init( &p_condvar->queue );
 388     p_condvar->name = 0;
 389     p_condvar->implications = 0;
 390
 391     return 0;
 392
 393 #elif defined(HAVE_KERNEL_SCHEDULER_H) && defined(HAVE_KERNEL_OS_H)
 394     if( !p_condvar )
 395     {
 396         return B_BAD_VALUE;
 397     }
 398
 399     if( p_condvar->init == 9999 )
 400     {
 401         return EALREADY;
 402     }
 403
 404     p_condvar->thread = -1;
 405     p_condvar->init = 9999;
 406     return 0;
 407
 408 #elif defined(WIN32)
 409     /* Create an auto-reset event. */
 410     *p_condvar = CreateEvent( NULL,   /* no security */
 411                               FALSE,  /* auto-reset event */
 412                               FALSE,  /* non-signaled initially */
 413                               NULL ); /* unnamed */
 414
 415     return( *p_condvar ? 0 : 1 );
 416
 417 #endif
 418 }
 419
 420 /*****************************************************************************
 421  * vlc_cond_signal: start a thread on condition completion
 422  *****************************************************************************/
 423 static __inline__ int vlc_cond_signal( vlc_cond_t *p_condvar )
 424 {
 425 #if defined(PTHREAD_COND_T_IN_PTHREAD_H)
 426     return pthread_cond_signal( p_condvar );
 427
 428 #elif defined(HAVE_CTHREADS_H)
 429     /* condition_signal() */
 430     if ( p_condvar->queue.head || p_condvar->implications )
 431     {
 432         cond_signal( (condition_t)p_condvar );
 433     }
 434     return 0;
 435
 436 #elif defined(HAVE_KERNEL_SCHEDULER_H) && defined(HAVE_KERNEL_OS_H)
 437     if( !p_condvar )
 438     {
 439         return B_BAD_VALUE;
 440     }
 441
 442     if( p_condvar->init < 2000 )
 443     {
 444         return B_NO_INIT;
 445     }
 446
 447     while( p_condvar->thread != -1 )
 448     {
 449         thread_info info;
 450         if( get_thread_info(p_condvar->thread, &info) == B_BAD_VALUE )
 451         {
 452             return 0;
 453         }
 454
 455         if( info.state != B_THREAD_SUSPENDED )
 456         {
 457             /* The  waiting thread is not suspended so it could
 458              * have been interrupted beetwen the unlock and the
 459              * suspend_thread line. That is why we sleep a little
 460              * before retesting p_condver->thread. */
 461             snooze( 10000 );
 462         }
 463         else
 464         {
 465             /* Ok, we have to wake up that thread */
 466             resume_thread( p_condvar->thread );
 467             return 0;
 468         }
 469     }
 470     return 0;
 471
 472 #elif defined(WIN32)
 473     /* Try to release one waiting thread. */
 474     PulseEvent ( *p_condvar );
 475     return 0;
 476
 477 #endif
 478 }
 479
 480 /*****************************************************************************
 481  * vlc_cond_wait: wait until condition completion
 482  *****************************************************************************/
 483 static __inline__ int vlc_cond_wait( vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex )
 484 {
 485 #if defined(PTHREAD_COND_T_IN_PTHREAD_H)
 486     return pthread_cond_wait( p_condvar, p_mutex );
 487
 488 #elif defined(HAVE_CTHREADS_H)
 489     condition_wait( (condition_t)p_condvar, (mutex_t)p_mutex );
 490     return 0;
 491
 492 #elif defined(HAVE_KERNEL_SCHEDULER_H) && defined(HAVE_KERNEL_OS_H)
 493     if( !p_condvar )
 494     {
 495         return B_BAD_VALUE;
 496     }
 497
 498     if( !p_mutex )
 499     {
 500         return B_BAD_VALUE;
 501     }
 502
 503     if( p_condvar->init < 2000 )
 504     {
 505         return B_NO_INIT;
 506     }
 507
 508     /* The p_condvar->thread var is initialized before the unlock because
 509      * it enables to identify when the thread is interrupted beetwen the
 510      * unlock line and the suspend_thread line */
 511     p_condvar->thread = find_thread( NULL );
 512     vlc_mutex_unlock( p_mutex );
 513     suspend_thread( p_condvar->thread );
 514     p_condvar->thread = -1;
 515
 516     vlc_mutex_lock( p_mutex );
 517     return 0;
 518
 519 #elif defined(WIN32)
 520     /* Release the <external_mutex> here and wait for the event
 521      * to become signaled, due to <pthread_cond_signal> being
 522      * called. */
 523     vlc_mutex_unlock( p_mutex );
 524
 525     WaitForSingleObject( *p_condvar, INFINITE );
 526
 527     /* Reacquire the mutex before returning. */
 528     vlc_mutex_lock( p_mutex );
 529     return 0;
 530
 531 #endif
 532 }
 533
 534 /*****************************************************************************
 535  * vlc_cond_destroy: destroy a condition
 536  *****************************************************************************/
 537 static __inline__ int vlc_cond_destroy( vlc_cond_t *p_condvar )
 538 {
 539 #if defined(PTHREAD_COND_T_IN_PTHREAD_H)
 540     return pthread_cond_destroy( p_condvar );
 541
 542 #elif defined(HAVE_KERNEL_SCHEDULER_H) && defined(HAVE_KERNEL_OS_H)
 543     p_condvar->init = 0;
 544     return 0;
 545
 546 #elif defined(WIN32)
 547     CloseHandle( *p_condvar );
 548     return 0;
 549
 550 #endif
 551 }
 552