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
195 #define vlc_thread_ready vlc_object_signal
197 /*****************************************************************************
198 * vlc_mutex_lock: lock a mutex
199 *****************************************************************************/
200 #define vlc_mutex_lock( P_MUTEX ) \
201 __vlc_mutex_lock( __FILE__, __LINE__, P_MUTEX )
203 VLC_EXPORT(void, vlc_pthread_fatal, (const char *action, int error, const char *file, unsigned line));
205 #if defined(LIBVLC_USE_PTHREAD)
206 # define VLC_THREAD_ASSERT( action ) \
208 vlc_pthread_fatal (action, val, psz_file, i_line)
210 # define VLC_THREAD_ASSERT ((void)(val))
213 static inline void __vlc_mutex_lock( const char * psz_file, int i_line,
214 vlc_mutex_t * p_mutex )
216 #if defined(LIBVLC_USE_PTHREAD)
217 # define vlc_assert_locked( m ) \
218 assert (pthread_mutex_lock (m) == EDEADLK)
219 int val = pthread_mutex_lock( p_mutex );
220 VLC_THREAD_ASSERT ("locking mutex");
222 #elif defined( UNDER_CE )
223 (void)psz_file; (void)i_line;
225 EnterCriticalSection( &p_mutex->csection );
227 #elif defined( WIN32 )
228 (void)psz_file; (void)i_line;
230 WaitForSingleObject( *p_mutex, INFINITE );
232 #elif defined( SYS_BEOS )
233 acquire_sem( p_mutex->lock );
238 #ifndef vlc_assert_locked
239 # define vlc_assert_locked( m ) (void)m
242 /*****************************************************************************
243 * vlc_mutex_unlock: unlock a mutex
244 *****************************************************************************/
245 #define vlc_mutex_unlock( P_MUTEX ) \
246 __vlc_mutex_unlock( __FILE__, __LINE__, P_MUTEX )
248 static inline void __vlc_mutex_unlock( const char * psz_file, int i_line,
249 vlc_mutex_t *p_mutex )
251 #if defined(LIBVLC_USE_PTHREAD)
252 int val = pthread_mutex_unlock( p_mutex );
253 VLC_THREAD_ASSERT ("unlocking mutex");
255 #elif defined( UNDER_CE )
256 (void)psz_file; (void)i_line;
258 LeaveCriticalSection( &p_mutex->csection );
260 #elif defined( WIN32 )
261 (void)psz_file; (void)i_line;
263 ReleaseMutex( *p_mutex );
265 #elif defined( SYS_BEOS )
266 release_sem( p_mutex->lock );
271 /*****************************************************************************
272 * vlc_mutex_destroy: destroy a mutex
273 *****************************************************************************/
274 #define vlc_mutex_destroy( P_MUTEX ) \
275 __vlc_mutex_destroy( __FILE__, __LINE__, P_MUTEX )
278 * Save the cancellation state and disable cancellation for the calling thread.
279 * This function must be called before entering a piece of code that is not
281 * @return Previous cancellation state (opaque value).
283 static inline int vlc_savecancel (void)
286 #if defined (LIBVLC_USE_PTHREAD)
287 (void) pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
289 vlc_control_cancel (VLC_SAVE_CANCEL, &state);
295 * Restore the cancellation state for the calling thread.
296 * @param state previous state as returned by vlc_savecancel().
297 * @return Nothing, always succeeds.
299 static inline void vlc_restorecancel (int state)
301 #if defined (LIBVLC_USE_PTHREAD)
302 (void) pthread_setcancelstate (state, NULL);
304 vlc_control_cancel (VLC_RESTORE_CANCEL, state);
309 * Issues an explicit deferred cancellation point.
310 * This has no effect if thread cancellation is disabled.
311 * This can be called when there is a rather slow non-sleeping operation.
313 static inline void vlc_testcancel (void)
315 #if defined (LIBVLC_USE_PTHREAD)
316 pthread_testcancel ();
318 vlc_control_cancel (VLC_TEST_CANCEL);
322 #if defined (LIBVLC_USE_PTHREAD)
324 * Registers a new procedure to run if the thread is cancelled (or otherwise
325 * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
326 * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
327 * of the block between these two function calls is not allowed (read: it will
328 * likely crash the whole process). If multiple procedures are registered,
329 * they are handled in last-in first-out order.
331 * @param routine procedure to call if the thread ends
332 * @param arg argument for the procedure
334 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
337 * Removes a cleanup procedure that was previously registered with
338 * vlc_cleanup_push().
340 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
343 * Removes a cleanup procedure that was previously registered with
344 * vlc_cleanup_push(), and executes it.
346 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
348 typedef struct vlc_cleanup_t vlc_cleanup_t;
353 void (*proc) (void *);
357 /* This macros opens a code block on purpose. This is needed for multiple
358 * calls within a single function. This also prevent Win32 developpers from
359 * writing code that would break on POSIX (POSIX opens a block as well). */
360 # define vlc_cleanup_push( routine, arg ) \
362 vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
363 vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
365 # define vlc_cleanup_pop( ) \
366 vlc_control_cancel (VLC_CLEANUP_POP); \
369 # define vlc_cleanup_run( ) \
370 vlc_control_cancel (VLC_CLEANUP_POP); \
371 vlc_cleanup_data.proc (vlc_cleanup_data.data); \
374 #endif /* LIBVLC_USE_PTHREAD */
376 static inline void vlc_cleanup_lock (void *lock)
378 vlc_mutex_unlock ((vlc_mutex_t *)lock);
380 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
382 /*****************************************************************************
383 * vlc_cond_init: initialize a condition
384 *****************************************************************************/
385 #define vlc_cond_init( P_THIS, P_COND ) \
386 __vlc_cond_init( P_COND )
388 /*****************************************************************************
389 * vlc_cond_signal: start a thread on condition completion
390 *****************************************************************************/
391 #define vlc_cond_signal( P_COND ) \
392 __vlc_cond_signal( __FILE__, __LINE__, P_COND )
394 static inline void __vlc_cond_signal( const char * psz_file, int i_line,
395 vlc_cond_t *p_condvar )
397 #if defined(LIBVLC_USE_PTHREAD)
398 int val = pthread_cond_signal( p_condvar );
399 VLC_THREAD_ASSERT ("signaling condition variable");
401 #elif defined( UNDER_CE ) || defined( WIN32 )
402 (void)psz_file; (void)i_line;
404 /* Release one waiting thread if one is available. */
405 /* For this trick to work properly, the vlc_cond_signal must be surrounded
406 * by a mutex. This will prevent another thread from stealing the signal */
407 /* PulseEvent() only works if none of the waiting threads is suspended.
408 * This is particularily problematic under a debug session.
409 * as documented in http://support.microsoft.com/kb/q173260/ */
410 PulseEvent( *p_condvar );
412 #elif defined( SYS_BEOS )
413 while( p_condvar->thread != -1 )
416 if( get_thread_info(p_condvar->thread, &info) == B_BAD_VALUE )
419 if( info.state != B_THREAD_SUSPENDED )
421 /* The waiting thread is not suspended so it could
422 * have been interrupted beetwen the unlock and the
423 * suspend_thread line. That is why we sleep a little
424 * before retesting p_condver->thread. */
429 /* Ok, we have to wake up that thread */
430 resume_thread( p_condvar->thread );
437 /*****************************************************************************
438 * vlc_cond_wait: wait until condition completion
439 *****************************************************************************/
440 #define vlc_cond_wait( P_COND, P_MUTEX ) \
441 __vlc_cond_wait( __FILE__, __LINE__, P_COND, P_MUTEX )
443 static inline void __vlc_cond_wait( const char * psz_file, int i_line,
444 vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex )
446 #if defined(LIBVLC_USE_PTHREAD)
447 int val = pthread_cond_wait( p_condvar, p_mutex );
448 VLC_THREAD_ASSERT ("waiting on condition");
450 #elif defined( UNDER_CE )
451 LeaveCriticalSection( &p_mutex->csection );
452 WaitForSingleObject( *p_condvar, INFINITE );
454 /* Reacquire the mutex before returning. */
455 vlc_mutex_lock( p_mutex );
457 #elif defined( WIN32 )
463 result = SignalObjectAndWait (*p_mutex, *p_condvar, INFINITE, TRUE);
465 /* Reacquire the mutex before returning. */
466 vlc_mutex_lock( p_mutex );
468 while (result == WAIT_IO_COMPLETION);
472 (void)psz_file; (void)i_line;
474 #elif defined( SYS_BEOS )
475 /* The p_condvar->thread var is initialized before the unlock because
476 * it enables to identify when the thread is interrupted beetwen the
477 * unlock line and the suspend_thread line */
478 p_condvar->thread = find_thread( NULL );
479 vlc_mutex_unlock( p_mutex );
480 suspend_thread( p_condvar->thread );
481 p_condvar->thread = -1;
483 vlc_mutex_lock( p_mutex );
489 /*****************************************************************************
490 * vlc_cond_timedwait: wait until condition completion or expiration
491 *****************************************************************************
492 * Returns 0 if object signaled, an error code in case of timeout or error.
493 *****************************************************************************/
494 #define vlc_cond_timedwait( P_COND, P_MUTEX, DEADLINE ) \
495 __vlc_cond_timedwait( __FILE__, __LINE__, P_COND, P_MUTEX, DEADLINE )
497 static inline int __vlc_cond_timedwait( const char * psz_file, int i_line,
498 vlc_cond_t *p_condvar,
499 vlc_mutex_t *p_mutex,
502 #if defined(LIBVLC_USE_PTHREAD)
503 lldiv_t d = lldiv( deadline, 1000000 );
504 struct timespec ts = { d.quot, d.rem * 1000 };
506 int val = pthread_cond_timedwait (p_condvar, p_mutex, &ts);
507 if (val != ETIMEDOUT)
508 VLC_THREAD_ASSERT ("timed-waiting on condition");
511 #elif defined( UNDER_CE )
512 mtime_t delay_ms = (deadline - mdate())/1000;
517 LeaveCriticalSection( &p_mutex->csection );
518 result = WaitForSingleObject( *p_condvar, delay_ms );
520 /* Reacquire the mutex before returning. */
521 vlc_mutex_lock( p_mutex );
523 (void)psz_file; (void)i_line;
525 return (result == WAIT_TIMEOUT) ? ETIMEDOUT : 0;
527 #elif defined( WIN32 )
529 DWORD result = WAIT_TIMEOUT;
531 (void)psz_file; (void)i_line;
534 while ((total = (deadline - mdate ()) > 0))
536 DWORD delay = (total > 0x7fffffff) ? 0x7fffffff : total;
537 result = SignalObjectAndWait( *p_mutex, *p_condvar,
540 /* Reacquire the mutex before return/cancel. */
541 vlc_mutex_lock (p_mutex);
542 if (result == WAIT_OBJECT_0)
543 return 0; /* Condition signaled! */
548 #elif defined( SYS_BEOS )
549 # error Unimplemented
554 /*****************************************************************************
555 * vlc_cond_destroy: destroy a condition
556 *****************************************************************************/
557 #define vlc_cond_destroy( P_COND ) \
558 __vlc_cond_destroy( __FILE__, __LINE__, P_COND )
560 /*****************************************************************************
561 * vlc_threadvar_set: create: set the value of a thread-local variable
562 *****************************************************************************/
563 static inline int vlc_threadvar_set( vlc_threadvar_t * p_tls, void *p_value )
567 #if defined(LIBVLC_USE_PTHREAD)
568 i_ret = pthread_setspecific( *p_tls, p_value );
570 #elif defined( SYS_BEOS )
573 #elif defined( UNDER_CE ) || defined( WIN32 )
574 i_ret = TlsSetValue( *p_tls, p_value ) ? EINVAL : 0;
581 /*****************************************************************************
582 * vlc_threadvar_get: create: get the value of a thread-local variable
583 *****************************************************************************/
584 static inline void* vlc_threadvar_get( vlc_threadvar_t * p_tls )
588 #if defined(LIBVLC_USE_PTHREAD)
589 p_ret = pthread_getspecific( *p_tls );
591 #elif defined( SYS_BEOS )
594 #elif defined( UNDER_CE ) || defined( WIN32 )
595 p_ret = TlsGetValue( *p_tls );
602 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
603 typedef pthread_spinlock_t vlc_spinlock_t;
606 * Initializes a spinlock.
608 static inline int vlc_spin_init (vlc_spinlock_t *spin)
610 return pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE);
614 * Acquires a spinlock.
616 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
618 pthread_spin_lock (spin);
622 * Releases a spinlock.
624 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
626 pthread_spin_unlock (spin);
630 * Deinitializes a spinlock.
632 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
634 pthread_spin_destroy (spin);
637 #elif defined( WIN32 )
639 typedef CRITICAL_SECTION vlc_spinlock_t;
642 * Initializes a spinlock.
644 static inline int vlc_spin_init (vlc_spinlock_t *spin)
646 return !InitializeCriticalSectionAndSpinCount(spin, 4000);
650 * Acquires a spinlock.
652 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
654 EnterCriticalSection(spin);
658 * Releases a spinlock.
660 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
662 LeaveCriticalSection(spin);
666 * Deinitializes a spinlock.
668 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
670 DeleteCriticalSection(spin);
675 /* Fallback to plain mutexes if spinlocks are not available */
676 typedef vlc_mutex_t vlc_spinlock_t;
678 static inline int vlc_spin_init (vlc_spinlock_t *spin)
680 return vlc_mutex_init (spin);
683 # define vlc_spin_lock vlc_mutex_lock
684 # define vlc_spin_unlock vlc_mutex_unlock
685 # define vlc_spin_destroy vlc_mutex_destroy
689 * Issues a full memory barrier.
691 #if defined (__APPLE__)
692 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
694 static inline void barrier (void)
696 #if defined (__GNUC__) && (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)
697 __sync_synchronize ();
698 #elif defined(__APPLE__)
700 #elif defined(__powerpc__)
701 asm volatile ("sync":::"memory");
702 #elif defined(__i386__)
703 asm volatile ("mfence":::"memory");
706 vlc_spin_init (&spin);
707 vlc_spin_lock (&spin);
708 vlc_spin_unlock (&spin);
709 vlc_spin_destroy (&spin);
713 /*****************************************************************************
714 * vlc_thread_create: create a thread
715 *****************************************************************************/
716 #define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY, WAIT ) \
717 __vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, FUNC, PRIORITY, WAIT )
719 /*****************************************************************************
720 * vlc_thread_set_priority: set the priority of the calling thread
721 *****************************************************************************/
722 #define vlc_thread_set_priority( P_THIS, PRIORITY ) \
723 __vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
725 /*****************************************************************************
726 * vlc_thread_join: wait until a thread exits
727 *****************************************************************************/
728 #define vlc_thread_join( P_THIS ) \
729 __vlc_thread_join( VLC_OBJECT(P_THIS), __FILE__, __LINE__ )
731 #endif /* !_VLC_THREADS_H */