1 /*****************************************************************************
2 * vlc_threads.h : threads implementation for the VideoLAN client
3 * This header provides portable declarations for mutexes & conditions
4 *****************************************************************************
5 * Copyright (C) 1999, 2002 the VideoLAN team
6 * Copyright © 2007-2008 Rémi Denis-Courmont
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>
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.
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.
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 *****************************************************************************/
28 #ifndef VLC_THREADS_H_
29 #define VLC_THREADS_H_
33 * This file defines structures and functions for handling threads in vlc
37 #if defined( UNDER_CE )
39 #elif defined( WIN32 )
40 # include <process.h> /* Win32 API */
43 #elif defined( SYS_BEOS ) /* BeOS */
44 # include <kernel/OS.h>
45 # include <kernel/scheduler.h>
46 # include <byteorder.h>
48 #else /* pthreads (like Linux & BSD) */
49 # define LIBVLC_USE_PTHREAD 1
50 # define _APPLE_C_SOURCE 1 /* Proper pthread semantics on OSX */
52 # include <stdlib.h> /* lldiv_t definition (only in C99) */
53 # include <unistd.h> /* _POSIX_SPIN_LOCKS */
55 /* Needed for pthread_cond_timedwait */
61 /*****************************************************************************
63 *****************************************************************************/
65 /* Thread priorities */
67 # define VLC_THREAD_PRIORITY_LOW 0
68 # define VLC_THREAD_PRIORITY_INPUT 22
69 # define VLC_THREAD_PRIORITY_AUDIO 22
70 # define VLC_THREAD_PRIORITY_VIDEO 0
71 # define VLC_THREAD_PRIORITY_OUTPUT 22
72 # define VLC_THREAD_PRIORITY_HIGHEST 22
74 #elif defined(SYS_BEOS)
75 # define VLC_THREAD_PRIORITY_LOW 5
76 # define VLC_THREAD_PRIORITY_INPUT 10
77 # define VLC_THREAD_PRIORITY_AUDIO 10
78 # define VLC_THREAD_PRIORITY_VIDEO 5
79 # define VLC_THREAD_PRIORITY_OUTPUT 15
80 # define VLC_THREAD_PRIORITY_HIGHEST 15
82 #elif defined(LIBVLC_USE_PTHREAD)
83 # define VLC_THREAD_PRIORITY_LOW 0
84 # define VLC_THREAD_PRIORITY_INPUT 10
85 # define VLC_THREAD_PRIORITY_AUDIO 5
86 # define VLC_THREAD_PRIORITY_VIDEO 0
87 # define VLC_THREAD_PRIORITY_OUTPUT 15
88 # define VLC_THREAD_PRIORITY_HIGHEST 20
90 #elif defined(WIN32) || defined(UNDER_CE)
91 /* Define different priorities for WinNT/2K/XP and Win9x/Me */
92 # define VLC_THREAD_PRIORITY_LOW 0
93 # define VLC_THREAD_PRIORITY_INPUT \
94 (IS_WINNT ? THREAD_PRIORITY_ABOVE_NORMAL : 0)
95 # define VLC_THREAD_PRIORITY_AUDIO \
96 (IS_WINNT ? THREAD_PRIORITY_HIGHEST : 0)
97 # define VLC_THREAD_PRIORITY_VIDEO \
98 (IS_WINNT ? 0 : THREAD_PRIORITY_BELOW_NORMAL )
99 # define VLC_THREAD_PRIORITY_OUTPUT \
100 (IS_WINNT ? THREAD_PRIORITY_ABOVE_NORMAL : 0)
101 # define VLC_THREAD_PRIORITY_HIGHEST \
102 (IS_WINNT ? THREAD_PRIORITY_TIME_CRITICAL : 0)
105 # define VLC_THREAD_PRIORITY_LOW 0
106 # define VLC_THREAD_PRIORITY_INPUT 0
107 # define VLC_THREAD_PRIORITY_AUDIO 0
108 # define VLC_THREAD_PRIORITY_VIDEO 0
109 # define VLC_THREAD_PRIORITY_OUTPUT 0
110 # define VLC_THREAD_PRIORITY_HIGHEST 0
114 /*****************************************************************************
116 *****************************************************************************/
118 #if defined (LIBVLC_USE_PTHREAD)
119 typedef pthread_t vlc_thread_t;
120 typedef pthread_mutex_t vlc_mutex_t;
121 typedef pthread_cond_t vlc_cond_t;
122 typedef pthread_key_t vlc_threadvar_t;
124 #elif defined( WIN32 ) || defined( UNDER_CE )
128 void *(*entry) (void *);
132 typedef HANDLE vlc_mutex_t;
133 typedef HANDLE vlc_cond_t;
134 typedef DWORD vlc_threadvar_t;
136 #elif defined( SYS_BEOS )
137 /* This is the BeOS implementation of the vlc threads, note that the mutex is
138 * not a real mutex and the cond_var is not like a pthread cond_var but it is
139 * enough for what we need */
141 typedef thread_id vlc_thread_t;
161 #if defined( WIN32 ) && !defined ETIMEDOUT
162 # define ETIMEDOUT 10060 /* This is the value in winsock.h. */
165 /*****************************************************************************
166 * Function definitions
167 *****************************************************************************/
168 VLC_EXPORT( int, vlc_mutex_init, ( vlc_mutex_t * ) );
169 VLC_EXPORT( int, vlc_mutex_init_recursive, ( vlc_mutex_t * ) );
170 VLC_EXPORT( void, __vlc_mutex_destroy, ( const char *, int, vlc_mutex_t * ) );
171 VLC_EXPORT( int, __vlc_cond_init, ( vlc_cond_t * ) );
172 VLC_EXPORT( void, __vlc_cond_destroy, ( const char *, int, vlc_cond_t * ) );
173 VLC_EXPORT( int, vlc_threadvar_create, (vlc_threadvar_t * , void (*) (void *) ) );
174 VLC_EXPORT( void, vlc_threadvar_delete, (vlc_threadvar_t *) );
175 VLC_EXPORT( int, __vlc_thread_create, ( vlc_object_t *, const char *, int, const char *, void * ( * ) ( vlc_object_t * ), int, bool ) );
176 VLC_EXPORT( int, __vlc_thread_set_priority, ( vlc_object_t *, const char *, int, int ) );
177 VLC_EXPORT( void, __vlc_thread_join, ( vlc_object_t *, const char *, int ) );
179 VLC_EXPORT( int, vlc_clone, (vlc_thread_t *, void * (*) (void *), void *, int) );
180 VLC_EXPORT( void, vlc_cancel, (vlc_thread_t) );
181 VLC_EXPORT( int, vlc_join, (vlc_thread_t, void **) );
182 VLC_EXPORT (void, vlc_control_cancel, (int cmd, ...));
184 #ifndef LIBVLC_USE_PTHREAD
193 #define vlc_thread_ready vlc_object_signal
195 /*****************************************************************************
196 * vlc_mutex_lock: lock a mutex
197 *****************************************************************************/
198 #define vlc_mutex_lock( P_MUTEX ) \
199 __vlc_mutex_lock( __FILE__, __LINE__, P_MUTEX )
201 VLC_EXPORT(void, vlc_pthread_fatal, (const char *action, int error, const char *file, unsigned line));
203 #if defined(LIBVLC_USE_PTHREAD)
204 # define VLC_THREAD_ASSERT( action ) \
206 vlc_pthread_fatal (action, val, psz_file, i_line)
208 # define VLC_THREAD_ASSERT ((void)(val))
211 static inline void __vlc_mutex_lock( const char * psz_file, int i_line,
212 vlc_mutex_t * p_mutex )
214 #if defined(LIBVLC_USE_PTHREAD)
215 # define vlc_assert_locked( m ) \
216 assert (pthread_mutex_lock (m) == EDEADLK)
217 int val = pthread_mutex_lock( p_mutex );
218 VLC_THREAD_ASSERT ("locking mutex");
220 #elif defined( UNDER_CE )
221 (void)psz_file; (void)i_line;
223 EnterCriticalSection( &p_mutex->csection );
225 #elif defined( WIN32 )
226 (void)psz_file; (void)i_line;
228 WaitForSingleObject( *p_mutex, INFINITE );
230 #elif defined( SYS_BEOS )
231 acquire_sem( p_mutex->lock );
236 #ifndef vlc_assert_locked
237 # define vlc_assert_locked( m ) (void)m
240 /*****************************************************************************
241 * vlc_mutex_unlock: unlock a mutex
242 *****************************************************************************/
243 #define vlc_mutex_unlock( P_MUTEX ) \
244 __vlc_mutex_unlock( __FILE__, __LINE__, P_MUTEX )
246 static inline void __vlc_mutex_unlock( const char * psz_file, int i_line,
247 vlc_mutex_t *p_mutex )
249 #if defined(LIBVLC_USE_PTHREAD)
250 int val = pthread_mutex_unlock( p_mutex );
251 VLC_THREAD_ASSERT ("unlocking mutex");
253 #elif defined( UNDER_CE )
254 (void)psz_file; (void)i_line;
256 LeaveCriticalSection( &p_mutex->csection );
258 #elif defined( WIN32 )
259 (void)psz_file; (void)i_line;
261 ReleaseMutex( *p_mutex );
263 #elif defined( SYS_BEOS )
264 release_sem( p_mutex->lock );
269 /*****************************************************************************
270 * vlc_mutex_destroy: destroy a mutex
271 *****************************************************************************/
272 #define vlc_mutex_destroy( P_MUTEX ) \
273 __vlc_mutex_destroy( __FILE__, __LINE__, P_MUTEX )
276 * Save the cancellation state and disable cancellation for the calling thread.
277 * This function must be called before entering a piece of code that is not
279 * @return Previous cancellation state (opaque value).
281 static inline int vlc_savecancel (void)
284 #if defined (LIBVLC_USE_PTHREAD)
285 (void) pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
287 vlc_control_cancel (VLC_SAVE_CANCEL, &state);
293 * Restore the cancellation state for the calling thread.
294 * @param state previous state as returned by vlc_savecancel().
295 * @return Nothing, always succeeds.
297 static inline void vlc_restorecancel (int state)
299 #if defined (LIBVLC_USE_PTHREAD)
300 (void) pthread_setcancelstate (state, NULL);
302 vlc_control_cancel (VLC_RESTORE_CANCEL, state);
307 * Issues an explicit deferred cancellation point.
308 * This has no effect if thread cancellation is disabled.
309 * This can be called when there is a rather slow non-sleeping operation.
311 static inline void vlc_testcancel (void)
313 #if defined (LIBVLC_USE_PTHREAD)
314 pthread_testcancel ();
316 vlc_control_cancel (VLC_TEST_CANCEL);
320 /*****************************************************************************
321 * vlc_cond_init: initialize a condition
322 *****************************************************************************/
323 #define vlc_cond_init( P_THIS, P_COND ) \
324 __vlc_cond_init( P_COND )
326 /*****************************************************************************
327 * vlc_cond_signal: start a thread on condition completion
328 *****************************************************************************/
329 #define vlc_cond_signal( P_COND ) \
330 __vlc_cond_signal( __FILE__, __LINE__, P_COND )
332 static inline void __vlc_cond_signal( const char * psz_file, int i_line,
333 vlc_cond_t *p_condvar )
335 #if defined(LIBVLC_USE_PTHREAD)
336 int val = pthread_cond_signal( p_condvar );
337 VLC_THREAD_ASSERT ("signaling condition variable");
339 #elif defined( UNDER_CE ) || defined( WIN32 )
340 (void)psz_file; (void)i_line;
342 /* Release one waiting thread if one is available. */
343 /* For this trick to work properly, the vlc_cond_signal must be surrounded
344 * by a mutex. This will prevent another thread from stealing the signal */
345 /* PulseEvent() only works if none of the waiting threads is suspended.
346 * This is particularily problematic under a debug session.
347 * as documented in http://support.microsoft.com/kb/q173260/ */
348 PulseEvent( *p_condvar );
350 #elif defined( SYS_BEOS )
351 while( p_condvar->thread != -1 )
354 if( get_thread_info(p_condvar->thread, &info) == B_BAD_VALUE )
357 if( info.state != B_THREAD_SUSPENDED )
359 /* The waiting thread is not suspended so it could
360 * have been interrupted beetwen the unlock and the
361 * suspend_thread line. That is why we sleep a little
362 * before retesting p_condver->thread. */
367 /* Ok, we have to wake up that thread */
368 resume_thread( p_condvar->thread );
375 /*****************************************************************************
376 * vlc_cond_wait: wait until condition completion
377 *****************************************************************************/
378 #define vlc_cond_wait( P_COND, P_MUTEX ) \
379 __vlc_cond_wait( __FILE__, __LINE__, P_COND, P_MUTEX )
381 static inline void __vlc_cond_wait( const char * psz_file, int i_line,
382 vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex )
384 #if defined(LIBVLC_USE_PTHREAD)
385 int val = pthread_cond_wait( p_condvar, p_mutex );
386 VLC_THREAD_ASSERT ("waiting on condition");
388 #elif defined( UNDER_CE )
389 LeaveCriticalSection( &p_mutex->csection );
390 WaitForSingleObject( *p_condvar, INFINITE );
392 /* Reacquire the mutex before returning. */
393 vlc_mutex_lock( p_mutex );
395 #elif defined( WIN32 )
401 result = SignalObjectAndWait (*p_mutex, *p_condvar, INFINITE, TRUE);
403 /* Reacquire the mutex before returning. */
404 vlc_mutex_lock( p_mutex );
406 while (result == WAIT_IO_COMPLETION);
410 (void)psz_file; (void)i_line;
412 #elif defined( SYS_BEOS )
413 /* The p_condvar->thread var is initialized before the unlock because
414 * it enables to identify when the thread is interrupted beetwen the
415 * unlock line and the suspend_thread line */
416 p_condvar->thread = find_thread( NULL );
417 vlc_mutex_unlock( p_mutex );
418 suspend_thread( p_condvar->thread );
419 p_condvar->thread = -1;
421 vlc_mutex_lock( p_mutex );
427 /*****************************************************************************
428 * vlc_cond_timedwait: wait until condition completion or expiration
429 *****************************************************************************
430 * Returns 0 if object signaled, an error code in case of timeout or error.
431 *****************************************************************************/
432 #define vlc_cond_timedwait( P_COND, P_MUTEX, DEADLINE ) \
433 __vlc_cond_timedwait( __FILE__, __LINE__, P_COND, P_MUTEX, DEADLINE )
435 static inline int __vlc_cond_timedwait( const char * psz_file, int i_line,
436 vlc_cond_t *p_condvar,
437 vlc_mutex_t *p_mutex,
440 #if defined(LIBVLC_USE_PTHREAD)
441 lldiv_t d = lldiv( deadline, 1000000 );
442 struct timespec ts = { d.quot, d.rem * 1000 };
444 int val = pthread_cond_timedwait (p_condvar, p_mutex, &ts);
445 if (val != ETIMEDOUT)
446 VLC_THREAD_ASSERT ("timed-waiting on condition");
449 #elif defined( UNDER_CE )
450 mtime_t delay_ms = (deadline - mdate())/1000;
455 LeaveCriticalSection( &p_mutex->csection );
456 result = WaitForSingleObject( *p_condvar, delay_ms );
458 /* Reacquire the mutex before returning. */
459 vlc_mutex_lock( p_mutex );
461 (void)psz_file; (void)i_line;
463 return (result == WAIT_TIMEOUT) ? ETIMEDOUT : 0;
465 #elif defined( WIN32 )
467 DWORD result = WAIT_TIMEOUT;
469 (void)psz_file; (void)i_line;
472 while ((total = (deadline - mdate ()) > 0))
474 DWORD delay = (total > 0x7fffffff) ? 0x7fffffff : total;
475 result = SignalObjectAndWait( *p_mutex, *p_condvar,
478 /* Reacquire the mutex before return/cancel. */
479 vlc_mutex_lock (p_mutex);
480 if (result == WAIT_OBJECT_0)
481 return 0; /* Condition signaled! */
486 #elif defined( SYS_BEOS )
487 # error Unimplemented
492 /*****************************************************************************
493 * vlc_cond_destroy: destroy a condition
494 *****************************************************************************/
495 #define vlc_cond_destroy( P_COND ) \
496 __vlc_cond_destroy( __FILE__, __LINE__, P_COND )
498 /*****************************************************************************
499 * vlc_threadvar_set: create: set the value of a thread-local variable
500 *****************************************************************************/
501 static inline int vlc_threadvar_set( vlc_threadvar_t * p_tls, void *p_value )
505 #if defined(LIBVLC_USE_PTHREAD)
506 i_ret = pthread_setspecific( *p_tls, p_value );
508 #elif defined( SYS_BEOS )
511 #elif defined( UNDER_CE ) || defined( WIN32 )
512 i_ret = TlsSetValue( *p_tls, p_value ) ? EINVAL : 0;
519 /*****************************************************************************
520 * vlc_threadvar_get: create: get the value of a thread-local variable
521 *****************************************************************************/
522 static inline void* vlc_threadvar_get( vlc_threadvar_t * p_tls )
526 #if defined(LIBVLC_USE_PTHREAD)
527 p_ret = pthread_getspecific( *p_tls );
529 #elif defined( SYS_BEOS )
532 #elif defined( UNDER_CE ) || defined( WIN32 )
533 p_ret = TlsGetValue( *p_tls );
540 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
541 typedef pthread_spinlock_t vlc_spinlock_t;
544 * Initializes a spinlock.
546 static inline int vlc_spin_init (vlc_spinlock_t *spin)
548 return pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE);
552 * Acquires a spinlock.
554 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
556 pthread_spin_lock (spin);
560 * Releases a spinlock.
562 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
564 pthread_spin_unlock (spin);
568 * Deinitializes a spinlock.
570 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
572 pthread_spin_destroy (spin);
575 #elif defined( WIN32 )
577 typedef CRITICAL_SECTION vlc_spinlock_t;
580 * Initializes a spinlock.
582 static inline int vlc_spin_init (vlc_spinlock_t *spin)
584 return !InitializeCriticalSectionAndSpinCount(spin, 4000);
588 * Acquires a spinlock.
590 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
592 EnterCriticalSection(spin);
596 * Releases a spinlock.
598 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
600 LeaveCriticalSection(spin);
604 * Deinitializes a spinlock.
606 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
608 DeleteCriticalSection(spin);
613 /* Fallback to plain mutexes if spinlocks are not available */
614 typedef vlc_mutex_t vlc_spinlock_t;
616 static inline int vlc_spin_init (vlc_spinlock_t *spin)
618 return vlc_mutex_init (spin);
621 # define vlc_spin_lock vlc_mutex_lock
622 # define vlc_spin_unlock vlc_mutex_unlock
623 # define vlc_spin_destroy vlc_mutex_destroy
627 * Issues a full memory barrier.
629 #if defined (__APPLE__)
630 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
632 static inline void barrier (void)
634 #if defined (__GNUC__) && (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)
635 __sync_synchronize ();
636 #elif defined(__APPLE__)
638 #elif defined(__powerpc__)
639 asm volatile ("sync":::"memory");
640 #elif defined(__i386__)
641 asm volatile ("mfence":::"memory");
644 vlc_spin_init (&spin);
645 vlc_spin_lock (&spin);
646 vlc_spin_unlock (&spin);
647 vlc_spin_destroy (&spin);
651 /*****************************************************************************
652 * vlc_thread_create: create a thread
653 *****************************************************************************/
654 #define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY, WAIT ) \
655 __vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, FUNC, PRIORITY, WAIT )
657 /*****************************************************************************
658 * vlc_thread_set_priority: set the priority of the calling thread
659 *****************************************************************************/
660 #define vlc_thread_set_priority( P_THIS, PRIORITY ) \
661 __vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
663 /*****************************************************************************
664 * vlc_thread_join: wait until a thread exits
665 *****************************************************************************/
666 #define vlc_thread_join( P_THIS ) \
667 __vlc_thread_join( VLC_OBJECT(P_THIS), __FILE__, __LINE__ )
669 #endif /* !_VLC_THREADS_H */