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) 1999-2007 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 #if !defined( __LIBVLC__ )
  29   #error You are not libvlc or one of its plugins. You cannot include this file
  30 #endif
  31
  32 #ifndef _VLC_THREADFUNCS_H_
  33 #define _VLC_THREADFUNCS_H_
  34
  35 #if defined( WIN32 ) && !defined ETIMEDOUT
  36 #  define ETIMEDOUT 10060 /* This is the value in winsock.h. */
  37 #endif
  38
  39 /*****************************************************************************
  40  * Function definitions
  41  *****************************************************************************/
  42 VLC_EXPORT( int,  __vlc_mutex_init,    ( vlc_mutex_t * ) );
  43 VLC_EXPORT( int,  __vlc_mutex_init_recursive, ( vlc_mutex_t * ) );
  44 VLC_EXPORT( void,  __vlc_mutex_destroy, ( const char *, int, vlc_mutex_t * ) );
  45 VLC_EXPORT( int,  __vlc_cond_init,     ( vlc_cond_t * ) );
  46 VLC_EXPORT( void,  __vlc_cond_destroy,  ( const char *, int, vlc_cond_t * ) );
  47 VLC_EXPORT( int, __vlc_threadvar_create, (vlc_threadvar_t * ) );
  48 VLC_EXPORT( int,  __vlc_thread_create, ( vlc_object_t *, const char *, int, const char *, void * ( * ) ( void * ), int, bool ) );
  49 VLC_EXPORT( int,  __vlc_thread_set_priority, ( vlc_object_t *, const char *, int, int ) );
  50 VLC_EXPORT( void, __vlc_thread_ready,  ( vlc_object_t * ) );
  51 VLC_EXPORT( void, __vlc_thread_join,   ( vlc_object_t *, const char *, int ) );
  52
  53 /*****************************************************************************
  54  * vlc_threads_init: initialize threads system
  55  *****************************************************************************/
  56 #define vlc_threads_init( P_THIS )                                          \
  57     __vlc_threads_init( VLC_OBJECT(P_THIS) )
  58
  59 /*****************************************************************************
  60  * vlc_threads_end: deinitialize threads system
  61  *****************************************************************************/
  62 #define vlc_threads_end( P_THIS )                                           \
  63     __vlc_threads_end( VLC_OBJECT(P_THIS) )
  64
  65 /*****************************************************************************
  66  * vlc_mutex_init: initialize a mutex
  67  *****************************************************************************/
  68 #define vlc_mutex_init( P_THIS, P_MUTEX )                                   \
  69     __vlc_mutex_init( P_MUTEX )
  70
  71 /*****************************************************************************
  72  * vlc_mutex_init: initialize a recursive mutex (Don't use it)
  73  *****************************************************************************/
  74 #define vlc_mutex_init_recursive( P_THIS, P_MUTEX )                         \
  75     __vlc_mutex_init_recursive( P_MUTEX )
  76
  77 /*****************************************************************************
  78  * vlc_mutex_lock: lock a mutex
  79  *****************************************************************************/
  80 #define vlc_mutex_lock( P_MUTEX )                                           \
  81     __vlc_mutex_lock( __FILE__, __LINE__, P_MUTEX )
  82
  83 #if defined(LIBVLC_USE_PTHREAD)
  84 VLC_EXPORT(void, vlc_pthread_fatal, (const char *action, int error, const char *file, unsigned line));
  85
  86 # define VLC_THREAD_ASSERT( action ) \
  87     if (val) \
  88         vlc_pthread_fatal (action, val, psz_file, i_line)
  89 #else
  90 # define VLC_THREAD_ASSERT (void)0
  91 #endif
  92
  93 static inline void __vlc_mutex_lock( const char * psz_file, int i_line,
  94                                     vlc_mutex_t * p_mutex )
  95 {
  96 #if defined( UNDER_CE )
  97     VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
  98
  99     EnterCriticalSection( &p_mutex->csection );
 100
 101 #elif defined( WIN32 )
 102     VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
 103
 104     WaitForSingleObject( *p_mutex, INFINITE );
 105
 106 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 107     acquire_sem( p_mutex->lock );
 108
 109 #elif defined(LIBVLC_USE_PTHREAD)
 110 #   define vlc_assert_locked( m ) \
 111            assert (pthread_mutex_lock (m) == EDEADLK)
 112     int val = pthread_mutex_lock( p_mutex );
 113     VLC_THREAD_ASSERT ("locking mutex");
 114
 115 #endif
 116 }
 117
 118 #ifndef vlc_assert_locked
 119 # define vlc_assert_locked( m ) (void)0
 120 #endif
 121
 122 /*****************************************************************************
 123  * vlc_mutex_unlock: unlock a mutex
 124  *****************************************************************************/
 125 #define vlc_mutex_unlock( P_MUTEX )                                         \
 126     __vlc_mutex_unlock( __FILE__, __LINE__, P_MUTEX )
 127
 128 static inline void __vlc_mutex_unlock( const char * psz_file, int i_line,
 129                                       vlc_mutex_t *p_mutex )
 130 {
 131 #if defined( UNDER_CE )
 132     VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
 133
 134     LeaveCriticalSection( &p_mutex->csection );
 135
 136 #elif defined( WIN32 )
 137     VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
 138
 139     ReleaseMutex( *p_mutex );
 140
 141 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 142     release_sem( p_mutex->lock );
 143
 144 #elif defined(LIBVLC_USE_PTHREAD)
 145     int val = pthread_mutex_unlock( p_mutex );
 146     VLC_THREAD_ASSERT ("unlocking mutex");
 147
 148 #endif
 149 }
 150
 151 /*****************************************************************************
 152  * vlc_mutex_destroy: destroy a mutex
 153  *****************************************************************************/
 154 #define vlc_mutex_destroy( P_MUTEX )                                        \
 155     __vlc_mutex_destroy( __FILE__, __LINE__, P_MUTEX )
 156
 157 /*****************************************************************************
 158  * vlc_cond_init: initialize a condition
 159  *****************************************************************************/
 160 #define vlc_cond_init( P_THIS, P_COND )                                     \
 161     __vlc_cond_init( P_COND )
 162
 163 /*****************************************************************************
 164  * vlc_cond_signal: start a thread on condition completion
 165  *****************************************************************************/
 166 #define vlc_cond_signal( P_COND )                                           \
 167     __vlc_cond_signal( __FILE__, __LINE__, P_COND )
 168
 169 static inline void __vlc_cond_signal( const char * psz_file, int i_line,
 170                                       vlc_cond_t *p_condvar )
 171 {
 172 #if defined( UNDER_CE ) || defined( WIN32 )
 173     VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
 174
 175     /* Release one waiting thread if one is available. */
 176     /* For this trick to work properly, the vlc_cond_signal must be surrounded
 177      * by a mutex. This will prevent another thread from stealing the signal */
 178     /* PulseEvent() only works if none of the waiting threads is suspended.
 179      * This is particularily problematic under a debug session.
 180      * as documented in http://support.microsoft.com/kb/q173260/ */
 181     PulseEvent( p_condvar->event );
 182
 183 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 184     while( p_condvar->thread != -1 )
 185     {
 186         thread_info info;
 187         if( get_thread_info(p_condvar->thread, &info) == B_BAD_VALUE )
 188             return;
 189
 190         if( info.state != B_THREAD_SUSPENDED )
 191         {
 192             /* The  waiting thread is not suspended so it could
 193              * have been interrupted beetwen the unlock and the
 194              * suspend_thread line. That is why we sleep a little
 195              * before retesting p_condver->thread. */
 196             snooze( 10000 );
 197         }
 198         else
 199         {
 200             /* Ok, we have to wake up that thread */
 201             resume_thread( p_condvar->thread );
 202         }
 203     }
 204
 205 #elif defined(LIBVLC_USE_PTHREAD)
 206     int val = pthread_cond_signal( p_condvar );
 207     VLC_THREAD_ASSERT ("signaling condition variable");
 208
 209 #endif
 210 }
 211
 212 /*****************************************************************************
 213  * vlc_cond_wait: wait until condition completion
 214  *****************************************************************************/
 215 #define vlc_cond_wait( P_COND, P_MUTEX )                                     \
 216     __vlc_cond_wait( __FILE__, __LINE__, P_COND, P_MUTEX  )
 217
 218 static inline void __vlc_cond_wait( const char * psz_file, int i_line,
 219                                     vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex )
 220 {
 221 #if defined( UNDER_CE )
 222     p_condvar->i_waiting_threads++;
 223     LeaveCriticalSection( &p_mutex->csection );
 224     WaitForSingleObject( p_condvar->event, INFINITE );
 225     p_condvar->i_waiting_threads--;
 226
 227     /* Reacquire the mutex before returning. */
 228     vlc_mutex_lock( p_mutex );
 229
 230 #elif defined( WIN32 )
 231     VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
 232
 233     /* Increase our wait count */
 234     p_condvar->i_waiting_threads++;
 235     SignalObjectAndWait( *p_mutex, p_condvar->event, INFINITE, FALSE );
 236     p_condvar->i_waiting_threads--;
 237
 238     /* Reacquire the mutex before returning. */
 239     vlc_mutex_lock( p_mutex );
 240
 241 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 242     /* The p_condvar->thread var is initialized before the unlock because
 243      * it enables to identify when the thread is interrupted beetwen the
 244      * unlock line and the suspend_thread line */
 245     p_condvar->thread = find_thread( NULL );
 246     vlc_mutex_unlock( p_mutex );
 247     suspend_thread( p_condvar->thread );
 248     p_condvar->thread = -1;
 249
 250     vlc_mutex_lock( p_mutex );
 251
 252 #elif defined(LIBVLC_USE_PTHREAD)
 253     int val = pthread_cond_wait( p_condvar, p_mutex );
 254     VLC_THREAD_ASSERT ("waiting on condition");
 255
 256 #endif
 257 }
 258
 259
 260 /*****************************************************************************
 261  * vlc_cond_timedwait: wait until condition completion or expiration
 262  *****************************************************************************
 263  * Returns 0 if object signaled, an error code in case of timeout or error.
 264  *****************************************************************************/
 265 #define vlc_cond_timedwait( P_COND, P_MUTEX, DEADLINE )                      \
 266     __vlc_cond_timedwait( __FILE__, __LINE__, P_COND, P_MUTEX, DEADLINE  )
 267
 268 static inline int __vlc_cond_timedwait( const char * psz_file, int i_line,
 269                                         vlc_cond_t *p_condvar,
 270                                         vlc_mutex_t *p_mutex,
 271                                         mtime_t deadline )
 272 {
 273 #if defined( UNDER_CE )
 274     mtime_t delay_ms = (deadline - mdate())/1000;
 275
 276     DWORD result;
 277     if( delay_ms < 0 )
 278         delay_ms = 0;
 279
 280     p_condvar->i_waiting_threads++;
 281     LeaveCriticalSection( &p_mutex->csection );
 282     result = WaitForSingleObject( p_condvar->event, delay_ms );
 283     p_condvar->i_waiting_threads--;
 284
 285     /* Reacquire the mutex before returning. */
 286     vlc_mutex_lock( p_mutex );
 287
 288     if(result == WAIT_TIMEOUT)
 289        return ETIMEDOUT; /* this error is perfectly normal */
 290
 291 #elif defined( WIN32 )
 292     VLC_UNUSED( psz_file); VLC_UNUSED( i_line );
 293
 294     DWORD result;
 295
 296     mtime_t delay_ms = (deadline - mdate())/1000;
 297     if( delay_ms < 0 )
 298         delay_ms = 0;
 299
 300     /* Increase our wait count */
 301     p_condvar->i_waiting_threads++;
 302     result = SignalObjectAndWait( *p_mutex, p_condvar->event,
 303                                   delay_ms, FALSE );
 304     p_condvar->i_waiting_threads--;
 305
 306     /* Reacquire the mutex before returning. */
 307     vlc_mutex_lock( p_mutex );
 308     if(result == WAIT_TIMEOUT)
 309        return ETIMEDOUT; /* this error is perfectly normal */
 310
 311 #elif defined( HAVE_KERNEL_SCHEDULER_H )
 312 #   error Unimplemented
 313
 314 #elif defined(LIBVLC_USE_PTHREAD)
 315     lldiv_t d = lldiv( deadline, 1000000 );
 316     struct timespec ts = { d.quot, d.rem * 1000 };
 317
 318     int val = pthread_cond_timedwait (p_condvar, p_mutex, &ts);
 319     if (val == ETIMEDOUT)
 320         return ETIMEDOUT; /* this error is perfectly normal */
 321     VLC_THREAD_ASSERT ("timed-waiting on condition");
 322
 323 #endif
 324
 325     return 0;
 326 }
 327
 328 /*****************************************************************************
 329  * vlc_cond_destroy: destroy a condition
 330  *****************************************************************************/
 331 #define vlc_cond_destroy( P_COND )                                          \
 332     __vlc_cond_destroy( __FILE__, __LINE__, P_COND )
 333
 334 /*****************************************************************************
 335  * vlc_threadvar_create: create a thread-local variable
 336  *****************************************************************************/
 337 #define vlc_threadvar_create( PTHIS, P_TLS )                                 \
 338    __vlc_threadvar_create( P_TLS )
 339
 340 /*****************************************************************************
 341  * vlc_threadvar_set: create: set the value of a thread-local variable
 342  *****************************************************************************/
 343 static inline int vlc_threadvar_set( vlc_threadvar_t * p_tls, void *p_value )
 344 {
 345     int i_ret;
 346
 347 #if defined( HAVE_KERNEL_SCHEDULER_H )
 348     i_ret = EINVAL;
 349
 350 #elif defined( UNDER_CE ) || defined( WIN32 )
 351     i_ret = TlsSetValue( *p_tls, p_value ) ? EINVAL : 0;
 352
 353 #elif defined(LIBVLC_USE_PTHREAD)
 354     i_ret = pthread_setspecific( *p_tls, p_value );
 355
 356 #endif
 357
 358     return i_ret;
 359 }
 360
 361 /*****************************************************************************
 362  * vlc_threadvar_get: create: get the value of a thread-local variable
 363  *****************************************************************************/
 364 static inline void* vlc_threadvar_get( vlc_threadvar_t * p_tls )
 365 {
 366     void *p_ret;
 367
 368 #if defined( HAVE_KERNEL_SCHEDULER_H )
 369     p_ret = NULL;
 370
 371 #elif defined( UNDER_CE ) || defined( WIN32 )
 372     p_ret = TlsGetValue( *p_tls );
 373
 374 #elif defined(LIBVLC_USE_PTHREAD)
 375     p_ret = pthread_getspecific( *p_tls );
 376
 377 #endif
 378
 379     return p_ret;
 380 }
 381
 382 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
 383 typedef struct
 384 {
 385     pthread_spinlock_t  spin;
 386 } vlc_spinlock_t;
 387
 388 /**
 389  * Initializes a spinlock.
 390  */
 391 static inline int vlc_spin_init (vlc_spinlock_t *spin)
 392 {
 393     return pthread_spin_init (&spin->spin, PTHREAD_PROCESS_PRIVATE);
 394 }
 395
 396 /**
 397  * Acquires a spinlock.
 398  */
 399 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
 400 {
 401     int val = pthread_spin_lock (&spin->spin);
 402     assert (val == 0);
 403     (void)val;
 404 }
 405
 406 /**
 407  * Releases a spinlock.
 408  */
 409 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
 410 {
 411     int val = pthread_spin_unlock (&spin->spin);
 412     assert (val == 0);
 413     (void)val;
 414 }
 415
 416 /**
 417  * Deinitializes a spinlock.
 418  */
 419 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
 420 {
 421     int val = pthread_spin_destroy (&spin->spin);
 422     assert (val == 0);
 423     (void)val;
 424 }
 425
 426 #elif defined( WIN32 )
 427
 428 typedef CRITICAL_SECTION vlc_spinlock_t;
 429
 430 /**
 431  * Initializes a spinlock.
 432  */
 433 static inline int vlc_spin_init (vlc_spinlock_t *spin)
 434 {
 435     return !InitializeCriticalSectionAndSpinCount(spin, 4000);
 436 }
 437
 438 /**
 439  * Acquires a spinlock.
 440  */
 441 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
 442 {
 443     EnterCriticalSection(spin);
 444 }
 445
 446 /**
 447  * Releases a spinlock.
 448  */
 449 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
 450 {
 451     LeaveCriticalSection(spin);
 452 }
 453
 454 /**
 455  * Deinitializes a spinlock.
 456  */
 457 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
 458 {
 459     DeleteCriticalSection(spin);
 460 }
 461
 462
 463 #else
 464
 465 /* Fallback to plain mutexes if spinlocks are not available */
 466 typedef vlc_mutex_t vlc_spinlock_t;
 467
 468 static inline int vlc_spin_init (vlc_spinlock_t *spin)
 469 {
 470     return __vlc_mutex_init (spin);
 471 }
 472
 473 # define vlc_spin_lock    vlc_mutex_lock
 474 # define vlc_spin_unlock  vlc_mutex_unlock
 475 # define vlc_spin_destroy vlc_mutex_destroy
 476 #endif
 477
 478 /*****************************************************************************
 479  * vlc_thread_create: create a thread
 480  *****************************************************************************/
 481 #define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY, WAIT )         \
 482     __vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, (void * ( * ) ( void * ))FUNC, PRIORITY, WAIT )
 483
 484 /*****************************************************************************
 485  * vlc_thread_set_priority: set the priority of the calling thread
 486  *****************************************************************************/
 487 #define vlc_thread_set_priority( P_THIS, PRIORITY )                         \
 488     __vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
 489
 490 /*****************************************************************************
 491  * vlc_thread_ready: tell the parent thread we were successfully spawned
 492  *****************************************************************************/
 493 #define vlc_thread_ready( P_THIS )                                          \
 494     __vlc_thread_ready( VLC_OBJECT(P_THIS) )
 495
 496 /*****************************************************************************
 497  * vlc_thread_join: wait until a thread exits
 498  *****************************************************************************/
 499 #define vlc_thread_join( P_THIS )                                           \
 500     __vlc_thread_join( VLC_OBJECT(P_THIS), __FILE__, __LINE__ )
 501
 502 #endif