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 VLC authors and VideoLAN
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 it
14 * under the terms of the GNU Lesser General Public License as published by
15 * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
23 * You should have received a copy of the GNU Lesser General Public License
24 * along with this program; if not, write to the Free Software Foundation,
25 * 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
38 # include <process.h> /* Win32 API */
40 #elif defined( __OS2__ ) /* OS/2 API */
43 # define pthread_sigmask sigprocmask
45 #else /* pthreads (like Linux & BSD) */
46 # define LIBVLC_USE_PTHREAD 1
47 # define LIBVLC_USE_PTHREAD_CANCEL 1
48 # define _APPLE_C_SOURCE 1 /* Proper pthread semantics on OSX */
50 # include <unistd.h> /* _POSIX_SPIN_LOCKS */
53 /* Unnamed POSIX semaphores not supported on Mac OS X, use Mach semaphores instead */
54 # if defined (__APPLE__)
55 # include <mach/semaphore.h>
56 # include <mach/task.h>
58 # include <semaphore.h>
63 /*****************************************************************************
65 *****************************************************************************/
67 /* Thread priorities */
69 # define VLC_THREAD_PRIORITY_LOW 0
70 # define VLC_THREAD_PRIORITY_INPUT 22
71 # define VLC_THREAD_PRIORITY_AUDIO 22
72 # define VLC_THREAD_PRIORITY_VIDEO 0
73 # define VLC_THREAD_PRIORITY_OUTPUT 22
74 # define VLC_THREAD_PRIORITY_HIGHEST 22
76 #elif defined(LIBVLC_USE_PTHREAD)
77 # define VLC_THREAD_PRIORITY_LOW 0
78 # define VLC_THREAD_PRIORITY_INPUT 10
79 # define VLC_THREAD_PRIORITY_AUDIO 5
80 # define VLC_THREAD_PRIORITY_VIDEO 0
81 # define VLC_THREAD_PRIORITY_OUTPUT 15
82 # define VLC_THREAD_PRIORITY_HIGHEST 20
85 /* Define different priorities for WinNT/2K/XP and Win9x/Me */
86 # define VLC_THREAD_PRIORITY_LOW 0
87 # define VLC_THREAD_PRIORITY_INPUT \
88 THREAD_PRIORITY_ABOVE_NORMAL
89 # define VLC_THREAD_PRIORITY_AUDIO \
90 THREAD_PRIORITY_HIGHEST
91 # define VLC_THREAD_PRIORITY_VIDEO 0
92 # define VLC_THREAD_PRIORITY_OUTPUT \
93 THREAD_PRIORITY_ABOVE_NORMAL
94 # define VLC_THREAD_PRIORITY_HIGHEST \
95 THREAD_PRIORITY_TIME_CRITICAL
97 #elif defined(__OS2__)
98 # define VLC_THREAD_PRIORITY_LOW 0
99 # define VLC_THREAD_PRIORITY_INPUT MAKESHORT( PRTYD_MAXIMUM / 2, PRTYC_REGULAR )
100 # define VLC_THREAD_PRIORITY_AUDIO MAKESHORT( PRTYD_MAXIMUM, PRTYC_REGULAR )
101 # define VLC_THREAD_PRIORITY_VIDEO 0
102 # define VLC_THREAD_PRIORITY_OUTPUT MAKESHORT( PRTYD_MAXIMUM / 2, PRTYC_REGULAR )
103 # define VLC_THREAD_PRIORITY_HIGHEST MAKESHORT( 0, PRTYC_TIMECRITICAL )
106 # define VLC_THREAD_PRIORITY_LOW 0
107 # define VLC_THREAD_PRIORITY_INPUT 0
108 # define VLC_THREAD_PRIORITY_AUDIO 0
109 # define VLC_THREAD_PRIORITY_VIDEO 0
110 # define VLC_THREAD_PRIORITY_OUTPUT 0
111 # define VLC_THREAD_PRIORITY_HIGHEST 0
115 /*****************************************************************************
117 *****************************************************************************/
119 #if defined (LIBVLC_USE_PTHREAD)
120 typedef pthread_t vlc_thread_t;
121 typedef pthread_mutex_t vlc_mutex_t;
122 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
123 typedef pthread_cond_t vlc_cond_t;
124 #define VLC_STATIC_COND PTHREAD_COND_INITIALIZER
125 typedef pthread_rwlock_t vlc_rwlock_t;
126 #define VLC_STATIC_RWLOCK PTHREAD_RWLOCK_INITIALIZER
127 typedef pthread_key_t vlc_threadvar_t;
128 typedef struct vlc_timer *vlc_timer_t;
130 #if defined (__APPLE__)
131 typedef semaphore_t vlc_sem_t;
133 typedef sem_t vlc_sem_t;
136 #elif defined( WIN32 )
137 typedef struct vlc_thread *vlc_thread_t;
147 unsigned long contention;
149 CRITICAL_SECTION mutex;
152 #define VLC_STATIC_MUTEX { false, { { false, 0 } } }
159 #define VLC_STATIC_COND { 0, 0 }
161 typedef HANDLE vlc_sem_t;
162 #define LIBVLC_NEED_RWLOCK
163 typedef struct vlc_threadvar *vlc_threadvar_t;
164 typedef struct vlc_timer *vlc_timer_t;
166 #elif defined( __OS2__ )
167 typedef struct vlc_thread *vlc_thread_t;
177 unsigned long contention;
182 #define VLC_STATIC_MUTEX { false, { { false, 0 } } }
189 #define VLC_STATIC_COND { 0, 0 }
191 #define LIBVLC_NEED_SEMAPHORE
192 #define LIBVLC_NEED_RWLOCK
193 typedef struct vlc_threadvar *vlc_threadvar_t;
194 typedef struct vlc_timer *vlc_timer_t;
198 #ifdef LIBVLC_NEED_SEMAPHORE
199 typedef struct vlc_sem
207 #ifdef LIBVLC_NEED_RWLOCK
208 typedef struct vlc_rwlock
214 # define VLC_STATIC_RWLOCK { VLC_STATIC_MUTEX, VLC_STATIC_COND, 0 }
217 #if defined( WIN32 ) && !defined ETIMEDOUT
218 # define ETIMEDOUT 10060 /* This is the value in winsock.h. */
221 /*****************************************************************************
222 * Function definitions
223 *****************************************************************************/
224 VLC_API void vlc_mutex_init( vlc_mutex_t * );
225 VLC_API void vlc_mutex_init_recursive( vlc_mutex_t * );
226 VLC_API void vlc_mutex_destroy( vlc_mutex_t * );
227 VLC_API void vlc_mutex_lock( vlc_mutex_t * );
228 VLC_API int vlc_mutex_trylock( vlc_mutex_t * ) VLC_USED;
229 VLC_API void vlc_mutex_unlock( vlc_mutex_t * );
230 VLC_API void vlc_cond_init( vlc_cond_t * );
231 VLC_API void vlc_cond_init_daytime( vlc_cond_t * );
232 VLC_API void vlc_cond_destroy( vlc_cond_t * );
233 VLC_API void vlc_cond_signal(vlc_cond_t *);
234 VLC_API void vlc_cond_broadcast(vlc_cond_t *);
235 VLC_API void vlc_cond_wait(vlc_cond_t *, vlc_mutex_t *);
236 VLC_API int vlc_cond_timedwait(vlc_cond_t *, vlc_mutex_t *, mtime_t);
237 VLC_API void vlc_sem_init(vlc_sem_t *, unsigned);
238 VLC_API void vlc_sem_destroy(vlc_sem_t *);
239 VLC_API int vlc_sem_post(vlc_sem_t *);
240 VLC_API void vlc_sem_wait(vlc_sem_t *);
242 VLC_API void vlc_rwlock_init(vlc_rwlock_t *);
243 VLC_API void vlc_rwlock_destroy(vlc_rwlock_t *);
244 VLC_API void vlc_rwlock_rdlock(vlc_rwlock_t *);
245 VLC_API void vlc_rwlock_wrlock(vlc_rwlock_t *);
246 VLC_API void vlc_rwlock_unlock(vlc_rwlock_t *);
247 VLC_API int vlc_threadvar_create(vlc_threadvar_t * , void (*) (void *) );
248 VLC_API void vlc_threadvar_delete(vlc_threadvar_t *);
249 VLC_API int vlc_threadvar_set(vlc_threadvar_t, void *);
250 VLC_API void * vlc_threadvar_get(vlc_threadvar_t);
252 VLC_API int vlc_clone(vlc_thread_t *, void * (*) (void *), void *, int) VLC_USED;
253 VLC_API void vlc_cancel(vlc_thread_t);
254 VLC_API void vlc_join(vlc_thread_t, void **);
255 VLC_API void vlc_control_cancel (int cmd, ...);
257 VLC_API mtime_t mdate(void);
258 VLC_API void mwait(mtime_t deadline);
259 VLC_API void msleep(mtime_t delay);
261 #define VLC_HARD_MIN_SLEEP 10000 /* 10 milliseconds = 1 tick at 100Hz */
262 #define VLC_SOFT_MIN_SLEEP 9000000 /* 9 seconds */
264 #if VLC_GCC_VERSION(4,3)
265 /* Linux has 100, 250, 300 or 1000Hz
267 * HZ=100 by default on FreeBSD, but some architectures use a 1000Hz timer
271 __attribute__((unused))
272 __attribute__((noinline))
273 __attribute__((error("sorry, cannot sleep for such short a time")))
274 mtime_t impossible_delay( mtime_t delay )
277 return VLC_HARD_MIN_SLEEP;
281 __attribute__((unused))
282 __attribute__((noinline))
283 __attribute__((warning("use proper event handling instead of short delay")))
284 mtime_t harmful_delay( mtime_t delay )
289 # define check_delay( d ) \
290 ((__builtin_constant_p(d < VLC_HARD_MIN_SLEEP) \
291 && (d < VLC_HARD_MIN_SLEEP)) \
292 ? impossible_delay(d) \
293 : ((__builtin_constant_p(d < VLC_SOFT_MIN_SLEEP) \
294 && (d < VLC_SOFT_MIN_SLEEP)) \
299 __attribute__((unused))
300 __attribute__((noinline))
301 __attribute__((error("deadlines can not be constant")))
302 mtime_t impossible_deadline( mtime_t deadline )
307 # define check_deadline( d ) \
308 (__builtin_constant_p(d) ? impossible_deadline(d) : d)
310 # define check_delay(d) (d)
311 # define check_deadline(d) (d)
314 #define msleep(d) msleep(check_delay(d))
315 #define mwait(d) mwait(check_deadline(d))
317 VLC_API int vlc_timer_create(vlc_timer_t *, void (*) (void *), void *) VLC_USED;
318 VLC_API void vlc_timer_destroy(vlc_timer_t);
319 VLC_API void vlc_timer_schedule(vlc_timer_t, bool, mtime_t, mtime_t);
320 VLC_API unsigned vlc_timer_getoverrun(vlc_timer_t) VLC_USED;
322 VLC_API unsigned vlc_GetCPUCount(void);
324 #ifndef LIBVLC_USE_PTHREAD_CANCEL
331 VLC_API int vlc_savecancel(void);
332 VLC_API void vlc_restorecancel(int state);
333 VLC_API void vlc_testcancel(void);
335 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
337 * Registers a new procedure to run if the thread is cancelled (or otherwise
338 * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
339 * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
340 * of the block between these two function calls is not allowed (read: it will
341 * likely crash the whole process). If multiple procedures are registered,
342 * they are handled in last-in first-out order.
344 * @param routine procedure to call if the thread ends
345 * @param arg argument for the procedure
347 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
350 * Removes a cleanup procedure that was previously registered with
351 * vlc_cleanup_push().
353 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
356 * Removes a cleanup procedure that was previously registered with
357 * vlc_cleanup_push(), and executes it.
359 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
361 typedef struct vlc_cleanup_t vlc_cleanup_t;
366 void (*proc) (void *);
370 /* This macros opens a code block on purpose. This is needed for multiple
371 * calls within a single function. This also prevent Win32 developers from
372 * writing code that would break on POSIX (POSIX opens a block as well). */
373 # define vlc_cleanup_push( routine, arg ) \
375 vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
376 vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
378 # define vlc_cleanup_pop( ) \
379 vlc_control_cancel (VLC_CLEANUP_POP); \
382 # define vlc_cleanup_run( ) \
383 vlc_control_cancel (VLC_CLEANUP_POP); \
384 vlc_cleanup_data.proc (vlc_cleanup_data.data); \
387 /* poll() with cancellation */
388 static inline int vlc_poll (struct pollfd *fds, unsigned nfds, int timeout)
394 int val = poll (fds, nfds, timeout);
401 return poll (fds, nfds, timeout);
403 # define poll(u,n,t) vlc_poll(u, n, t)
405 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
407 static inline void vlc_cleanup_lock (void *lock)
409 vlc_mutex_unlock ((vlc_mutex_t *)lock);
411 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
413 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
414 typedef pthread_spinlock_t vlc_spinlock_t;
417 * Initializes a spinlock.
419 static inline void vlc_spin_init (vlc_spinlock_t *spin)
421 if (pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE))
426 * Acquires a spinlock.
428 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
430 pthread_spin_lock (spin);
434 * Releases a spinlock.
436 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
438 pthread_spin_unlock (spin);
442 * Deinitializes a spinlock.
444 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
446 pthread_spin_destroy (spin);
449 #elif defined (WIN32)
451 typedef CRITICAL_SECTION vlc_spinlock_t;
454 * Initializes a spinlock.
456 static inline void vlc_spin_init (vlc_spinlock_t *spin)
458 if (!InitializeCriticalSectionAndSpinCount(spin, 4000))
463 * Acquires a spinlock.
465 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
467 EnterCriticalSection(spin);
471 * Releases a spinlock.
473 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
475 LeaveCriticalSection(spin);
479 * Deinitializes a spinlock.
481 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
483 DeleteCriticalSection(spin);
488 /* Fallback to plain mutexes if spinlocks are not available */
489 typedef vlc_mutex_t vlc_spinlock_t;
491 static inline void vlc_spin_init (vlc_spinlock_t *spin)
493 vlc_mutex_init (spin);
496 # define vlc_spin_lock vlc_mutex_lock
497 # define vlc_spin_unlock vlc_mutex_unlock
498 # define vlc_spin_destroy vlc_mutex_destroy
502 * Issues a full memory barrier.
504 #if defined (__APPLE__)
505 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
507 static inline void barrier (void)
509 #if defined (__GNUC__) && !defined (__APPLE__) && \
510 ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
511 __sync_synchronize ();
512 #elif defined(__APPLE__)
514 #elif defined(__powerpc__)
515 asm volatile ("sync":::"memory");
516 #elif 0 // defined(__i386__) /* Requires SSE2 support */
517 asm volatile ("mfence":::"memory");
520 vlc_spin_init (&spin);
521 vlc_spin_lock (&spin);
522 vlc_spin_unlock (&spin);
523 vlc_spin_destroy (&spin);
529 * Helper C++ class to lock a mutex.
530 * The mutex is locked when the object is created, and unlocked when the object
533 class vlc_mutex_locker
538 vlc_mutex_locker (vlc_mutex_t *m) : lock (m)
540 vlc_mutex_lock (lock);
543 ~vlc_mutex_locker (void)
545 vlc_mutex_unlock (lock);
551 VLC_AVCODEC_MUTEX = 0,
557 /* Insert new entry HERE */
561 VLC_API void vlc_global_mutex( unsigned, bool );
562 #define vlc_global_lock( n ) vlc_global_mutex( n, true )
563 #define vlc_global_unlock( n ) vlc_global_mutex( n, false )
565 #endif /* !_VLC_THREADS_H */