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 #else /* pthreads (like Linux & BSD) */
44 # define LIBVLC_USE_PTHREAD 1
45 # define LIBVLC_USE_PTHREAD_CANCEL 1
46 # define _APPLE_C_SOURCE 1 /* Proper pthread semantics on OSX */
48 # include <stdlib.h> /* lldiv_t definition (only in C99) */
49 # include <unistd.h> /* _POSIX_SPIN_LOCKS */
51 /* Needed for pthread_cond_timedwait */
57 /*****************************************************************************
59 *****************************************************************************/
61 /* Thread priorities */
63 # define VLC_THREAD_PRIORITY_LOW 0
64 # define VLC_THREAD_PRIORITY_INPUT 22
65 # define VLC_THREAD_PRIORITY_AUDIO 22
66 # define VLC_THREAD_PRIORITY_VIDEO 0
67 # define VLC_THREAD_PRIORITY_OUTPUT 22
68 # define VLC_THREAD_PRIORITY_HIGHEST 22
70 #elif defined(LIBVLC_USE_PTHREAD)
71 # define VLC_THREAD_PRIORITY_LOW 0
72 # define VLC_THREAD_PRIORITY_INPUT 10
73 # define VLC_THREAD_PRIORITY_AUDIO 5
74 # define VLC_THREAD_PRIORITY_VIDEO 0
75 # define VLC_THREAD_PRIORITY_OUTPUT 15
76 # define VLC_THREAD_PRIORITY_HIGHEST 20
78 #elif defined(WIN32) || defined(UNDER_CE)
79 /* Define different priorities for WinNT/2K/XP and Win9x/Me */
80 # define VLC_THREAD_PRIORITY_LOW 0
81 # define VLC_THREAD_PRIORITY_INPUT \
82 (IS_WINNT ? THREAD_PRIORITY_ABOVE_NORMAL : 0)
83 # define VLC_THREAD_PRIORITY_AUDIO \
84 (IS_WINNT ? THREAD_PRIORITY_HIGHEST : 0)
85 # define VLC_THREAD_PRIORITY_VIDEO \
86 (IS_WINNT ? 0 : THREAD_PRIORITY_BELOW_NORMAL )
87 # define VLC_THREAD_PRIORITY_OUTPUT \
88 (IS_WINNT ? THREAD_PRIORITY_ABOVE_NORMAL : 0)
89 # define VLC_THREAD_PRIORITY_HIGHEST \
90 (IS_WINNT ? THREAD_PRIORITY_TIME_CRITICAL : 0)
93 # define VLC_THREAD_PRIORITY_LOW 0
94 # define VLC_THREAD_PRIORITY_INPUT 0
95 # define VLC_THREAD_PRIORITY_AUDIO 0
96 # define VLC_THREAD_PRIORITY_VIDEO 0
97 # define VLC_THREAD_PRIORITY_OUTPUT 0
98 # define VLC_THREAD_PRIORITY_HIGHEST 0
102 /*****************************************************************************
104 *****************************************************************************/
106 #if defined (LIBVLC_USE_PTHREAD)
107 typedef pthread_t vlc_thread_t;
108 typedef pthread_mutex_t vlc_mutex_t;
109 typedef pthread_cond_t vlc_cond_t;
110 typedef pthread_key_t vlc_threadvar_t;
112 #elif defined( WIN32 ) || defined( UNDER_CE )
116 void *(*entry) (void *);
120 typedef HANDLE vlc_mutex_t;
121 typedef HANDLE vlc_cond_t;
122 typedef DWORD vlc_threadvar_t;
126 #if defined( WIN32 ) && !defined ETIMEDOUT
127 # define ETIMEDOUT 10060 /* This is the value in winsock.h. */
130 /*****************************************************************************
131 * Function definitions
132 *****************************************************************************/
133 VLC_EXPORT( int, vlc_mutex_init, ( vlc_mutex_t * ) );
134 VLC_EXPORT( int, vlc_mutex_init_recursive, ( vlc_mutex_t * ) );
135 VLC_EXPORT( void, __vlc_mutex_destroy, ( const char *, int, vlc_mutex_t * ) );
136 VLC_EXPORT( int, vlc_cond_init, ( vlc_cond_t * ) );
137 VLC_EXPORT( void, __vlc_cond_destroy, ( const char *, int, vlc_cond_t * ) );
138 VLC_EXPORT( int, vlc_threadvar_create, (vlc_threadvar_t * , void (*) (void *) ) );
139 VLC_EXPORT( void, vlc_threadvar_delete, (vlc_threadvar_t *) );
140 VLC_EXPORT( int, __vlc_thread_create, ( vlc_object_t *, const char *, int, const char *, void * ( * ) ( vlc_object_t * ), int, bool ) );
141 VLC_EXPORT( int, __vlc_thread_set_priority, ( vlc_object_t *, const char *, int, int ) );
142 VLC_EXPORT( void, __vlc_thread_join, ( vlc_object_t * ) );
144 VLC_EXPORT( int, vlc_clone, (vlc_thread_t *, void * (*) (void *), void *, int) );
145 VLC_EXPORT( void, vlc_cancel, (vlc_thread_t) );
146 VLC_EXPORT( void, vlc_join, (vlc_thread_t, void **) );
147 VLC_EXPORT (void, vlc_control_cancel, (int cmd, ...));
149 #ifndef LIBVLC_USE_PTHREAD_CANCEL
160 #define vlc_thread_ready vlc_object_signal
162 /*****************************************************************************
163 * vlc_mutex_lock: lock a mutex
164 *****************************************************************************/
165 #define vlc_mutex_lock( P_MUTEX ) \
166 __vlc_mutex_lock( __FILE__, __LINE__, P_MUTEX )
168 VLC_EXPORT(void, vlc_thread_fatal, (const char *action, int error, const char *function, const char *file, unsigned line));
170 #if defined(LIBVLC_USE_PTHREAD)
171 # define VLC_THREAD_ASSERT( action ) \
173 vlc_thread_fatal (action, val, __func__, psz_file, i_line)
175 # define VLC_THREAD_ASSERT ((void)(val))
178 static inline void __vlc_mutex_lock( const char * psz_file, int i_line,
179 vlc_mutex_t * p_mutex )
181 #if defined(LIBVLC_USE_PTHREAD)
182 # define vlc_assert_locked( m ) \
183 assert (pthread_mutex_lock (m) == EDEADLK)
184 int val = pthread_mutex_lock( p_mutex );
185 VLC_THREAD_ASSERT ("locking mutex");
187 #elif defined( UNDER_CE )
188 (void)psz_file; (void)i_line;
190 EnterCriticalSection( &p_mutex->csection );
192 #elif defined( WIN32 )
193 (void)psz_file; (void)i_line;
195 WaitForSingleObject( *p_mutex, INFINITE );
200 #ifndef vlc_assert_locked
201 # define vlc_assert_locked( m ) (void)m
204 /*****************************************************************************
205 * vlc_mutex_unlock: unlock a mutex
206 *****************************************************************************/
207 #define vlc_mutex_unlock( P_MUTEX ) \
208 __vlc_mutex_unlock( __FILE__, __LINE__, P_MUTEX )
210 static inline void __vlc_mutex_unlock( const char * psz_file, int i_line,
211 vlc_mutex_t *p_mutex )
213 #if defined(LIBVLC_USE_PTHREAD)
214 int val = pthread_mutex_unlock( p_mutex );
215 VLC_THREAD_ASSERT ("unlocking mutex");
217 #elif defined( UNDER_CE )
218 (void)psz_file; (void)i_line;
220 LeaveCriticalSection( &p_mutex->csection );
222 #elif defined( WIN32 )
223 (void)psz_file; (void)i_line;
225 ReleaseMutex( *p_mutex );
230 /*****************************************************************************
231 * vlc_mutex_destroy: destroy a mutex
232 *****************************************************************************/
233 #define vlc_mutex_destroy( P_MUTEX ) \
234 __vlc_mutex_destroy( __FILE__, __LINE__, P_MUTEX )
237 * Save the cancellation state and disable cancellation for the calling thread.
238 * This function must be called before entering a piece of code that is not
240 * @return Previous cancellation state (opaque value).
242 static inline int vlc_savecancel (void)
245 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
246 (void) pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
248 vlc_control_cancel (VLC_SAVE_CANCEL, &state);
254 * Restore the cancellation state for the calling thread.
255 * @param state previous state as returned by vlc_savecancel().
256 * @return Nothing, always succeeds.
258 static inline void vlc_restorecancel (int state)
260 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
261 (void) pthread_setcancelstate (state, NULL);
263 vlc_control_cancel (VLC_RESTORE_CANCEL, state);
268 * Issues an explicit deferred cancellation point.
269 * This has no effect if thread cancellation is disabled.
270 * This can be called when there is a rather slow non-sleeping operation.
272 static inline void vlc_testcancel (void)
274 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
275 pthread_testcancel ();
277 vlc_control_cancel (VLC_TEST_CANCEL);
281 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
283 * Registers a new procedure to run if the thread is cancelled (or otherwise
284 * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
285 * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
286 * of the block between these two function calls is not allowed (read: it will
287 * likely crash the whole process). If multiple procedures are registered,
288 * they are handled in last-in first-out order.
290 * @param routine procedure to call if the thread ends
291 * @param arg argument for the procedure
293 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
296 * Removes a cleanup procedure that was previously registered with
297 * vlc_cleanup_push().
299 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
302 * Removes a cleanup procedure that was previously registered with
303 * vlc_cleanup_push(), and executes it.
305 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
307 typedef struct vlc_cleanup_t vlc_cleanup_t;
312 void (*proc) (void *);
316 /* This macros opens a code block on purpose. This is needed for multiple
317 * calls within a single function. This also prevent Win32 developpers from
318 * writing code that would break on POSIX (POSIX opens a block as well). */
319 # define vlc_cleanup_push( routine, arg ) \
321 vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
322 vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
324 # define vlc_cleanup_pop( ) \
325 vlc_control_cancel (VLC_CLEANUP_POP); \
328 # define vlc_cleanup_run( ) \
329 vlc_control_cancel (VLC_CLEANUP_POP); \
330 vlc_cleanup_data.proc (vlc_cleanup_data.data); \
333 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
335 static inline void vlc_cleanup_lock (void *lock)
337 vlc_mutex_unlock ((vlc_mutex_t *)lock);
339 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
341 /*****************************************************************************
342 * vlc_cond_signal: start a thread on condition completion
343 *****************************************************************************/
344 #define vlc_cond_signal( P_COND ) \
345 __vlc_cond_signal( __FILE__, __LINE__, P_COND )
347 static inline void __vlc_cond_signal( const char * psz_file, int i_line,
348 vlc_cond_t *p_condvar )
350 #if defined(LIBVLC_USE_PTHREAD)
351 int val = pthread_cond_signal( p_condvar );
352 VLC_THREAD_ASSERT ("signaling condition variable");
354 #elif defined( UNDER_CE ) || defined( WIN32 )
355 (void)psz_file; (void)i_line;
357 /* Release one waiting thread if one is available. */
358 /* For this trick to work properly, the vlc_cond_signal must be surrounded
359 * by a mutex. This will prevent another thread from stealing the signal */
360 /* PulseEvent() only works if none of the waiting threads is suspended.
361 * This is particularily problematic under a debug session.
362 * as documented in http://support.microsoft.com/kb/q173260/ */
363 PulseEvent( *p_condvar );
368 /*****************************************************************************
369 * vlc_cond_wait: wait until condition completion
370 *****************************************************************************/
371 #define vlc_cond_wait( P_COND, P_MUTEX ) \
372 __vlc_cond_wait( __FILE__, __LINE__, P_COND, P_MUTEX )
374 static inline void __vlc_cond_wait( const char * psz_file, int i_line,
375 vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex )
377 #if defined(LIBVLC_USE_PTHREAD)
378 int val = pthread_cond_wait( p_condvar, p_mutex );
379 VLC_THREAD_ASSERT ("waiting on condition");
381 #elif defined( UNDER_CE )
382 LeaveCriticalSection( &p_mutex->csection );
383 WaitForSingleObject( *p_condvar, INFINITE );
385 /* Reacquire the mutex before returning. */
386 vlc_mutex_lock( p_mutex );
388 #elif defined( WIN32 )
394 result = SignalObjectAndWait (*p_mutex, *p_condvar, INFINITE, TRUE);
396 /* Reacquire the mutex before returning. */
397 vlc_mutex_lock( p_mutex );
399 while (result == WAIT_IO_COMPLETION);
403 (void)psz_file; (void)i_line;
409 /*****************************************************************************
410 * vlc_cond_timedwait: wait until condition completion or expiration
411 *****************************************************************************
412 * Returns 0 if object signaled, an error code in case of timeout or error.
413 *****************************************************************************/
414 #define vlc_cond_timedwait( P_COND, P_MUTEX, DEADLINE ) \
415 __vlc_cond_timedwait( __FILE__, __LINE__, P_COND, P_MUTEX, DEADLINE )
417 static inline int __vlc_cond_timedwait( const char * psz_file, int i_line,
418 vlc_cond_t *p_condvar,
419 vlc_mutex_t *p_mutex,
422 #if defined(LIBVLC_USE_PTHREAD)
423 lldiv_t d = lldiv( deadline, CLOCK_FREQ );
424 struct timespec ts = { d.quot, d.rem * (1000000000 / CLOCK_FREQ) };
426 int val = pthread_cond_timedwait (p_condvar, p_mutex, &ts);
427 if (val != ETIMEDOUT)
428 VLC_THREAD_ASSERT ("timed-waiting on condition");
431 #elif defined( UNDER_CE )
432 mtime_t delay_ms = (deadline - mdate()) / (CLOCK_FREQ / 1000);
437 LeaveCriticalSection( &p_mutex->csection );
438 result = WaitForSingleObject( *p_condvar, delay_ms );
440 /* Reacquire the mutex before returning. */
441 vlc_mutex_lock( p_mutex );
443 (void)psz_file; (void)i_line;
445 return (result == WAIT_TIMEOUT) ? ETIMEDOUT : 0;
447 #elif defined( WIN32 )
449 DWORD result = WAIT_TIMEOUT;
451 (void)psz_file; (void)i_line;
454 while ((total = (deadline - mdate ()) > 0))
456 DWORD delay = (total > 0x7fffffff) ? 0x7fffffff : total;
457 result = SignalObjectAndWait( *p_mutex, *p_condvar,
460 /* Reacquire the mutex before return/cancel. */
461 vlc_mutex_lock (p_mutex);
462 if (result == WAIT_OBJECT_0)
463 return 0; /* Condition signaled! */
471 /*****************************************************************************
472 * vlc_cond_destroy: destroy a condition
473 *****************************************************************************/
474 #define vlc_cond_destroy( P_COND ) \
475 __vlc_cond_destroy( __FILE__, __LINE__, P_COND )
477 /*****************************************************************************
478 * vlc_threadvar_set: create: set the value of a thread-local variable
479 *****************************************************************************/
480 static inline int vlc_threadvar_set( vlc_threadvar_t * p_tls, void *p_value )
484 #if defined(LIBVLC_USE_PTHREAD)
485 i_ret = pthread_setspecific( *p_tls, p_value );
487 #elif defined( UNDER_CE ) || defined( WIN32 )
488 i_ret = TlsSetValue( *p_tls, p_value ) ? EINVAL : 0;
495 /*****************************************************************************
496 * vlc_threadvar_get: create: get the value of a thread-local variable
497 *****************************************************************************/
498 static inline void* vlc_threadvar_get( vlc_threadvar_t * p_tls )
502 #if defined(LIBVLC_USE_PTHREAD)
503 p_ret = pthread_getspecific( *p_tls );
505 #elif defined( UNDER_CE ) || defined( WIN32 )
506 p_ret = TlsGetValue( *p_tls );
513 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
514 typedef pthread_spinlock_t vlc_spinlock_t;
517 * Initializes a spinlock.
519 static inline int vlc_spin_init (vlc_spinlock_t *spin)
521 return pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE);
525 * Acquires a spinlock.
527 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
529 pthread_spin_lock (spin);
533 * Releases a spinlock.
535 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
537 pthread_spin_unlock (spin);
541 * Deinitializes a spinlock.
543 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
545 pthread_spin_destroy (spin);
548 #elif defined( WIN32 )
550 typedef CRITICAL_SECTION vlc_spinlock_t;
553 * Initializes a spinlock.
555 static inline int vlc_spin_init (vlc_spinlock_t *spin)
557 return !InitializeCriticalSectionAndSpinCount(spin, 4000);
561 * Acquires a spinlock.
563 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
565 EnterCriticalSection(spin);
569 * Releases a spinlock.
571 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
573 LeaveCriticalSection(spin);
577 * Deinitializes a spinlock.
579 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
581 DeleteCriticalSection(spin);
586 /* Fallback to plain mutexes if spinlocks are not available */
587 typedef vlc_mutex_t vlc_spinlock_t;
589 static inline int vlc_spin_init (vlc_spinlock_t *spin)
591 return vlc_mutex_init (spin);
594 # define vlc_spin_lock vlc_mutex_lock
595 # define vlc_spin_unlock vlc_mutex_unlock
596 # define vlc_spin_destroy vlc_mutex_destroy
600 * Issues a full memory barrier.
602 #if defined (__APPLE__)
603 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
605 static inline void barrier (void)
607 #if defined (__GNUC__) && (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)
608 __sync_synchronize ();
609 #elif defined(__APPLE__)
611 #elif defined(__powerpc__)
612 asm volatile ("sync":::"memory");
613 #elif defined(__i386__)
614 asm volatile ("mfence":::"memory");
617 vlc_spin_init (&spin);
618 vlc_spin_lock (&spin);
619 vlc_spin_unlock (&spin);
620 vlc_spin_destroy (&spin);
624 /*****************************************************************************
625 * vlc_thread_create: create a thread
626 *****************************************************************************/
627 #define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY, WAIT ) \
628 __vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, FUNC, PRIORITY, WAIT )
630 /*****************************************************************************
631 * vlc_thread_set_priority: set the priority of the calling thread
632 *****************************************************************************/
633 #define vlc_thread_set_priority( P_THIS, PRIORITY ) \
634 __vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
636 /*****************************************************************************
637 * vlc_thread_join: wait until a thread exits
638 *****************************************************************************/
639 #define vlc_thread_join( P_THIS ) \
640 __vlc_thread_join( VLC_OBJECT(P_THIS) )
642 #endif /* !_VLC_THREADS_H */