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
40 # define ETIMEDOUT 10060 /* This is the value in winsock.h. */
43 typedef struct vlc_thread *vlc_thread_t;
52 unsigned long contention;
54 CRITICAL_SECTION mutex;
57 #define VLC_STATIC_MUTEX { false, { { false, 0 } } }
63 #define VLC_STATIC_COND { 0, 0 }
64 typedef HANDLE vlc_sem_t;
65 #define LIBVLC_NEED_RWLOCK
66 typedef struct vlc_threadvar *vlc_threadvar_t;
67 typedef struct vlc_timer *vlc_timer_t;
69 # define VLC_THREAD_PRIORITY_LOW 0
70 # define VLC_THREAD_PRIORITY_INPUT THREAD_PRIORITY_ABOVE_NORMAL
71 # define VLC_THREAD_PRIORITY_AUDIO THREAD_PRIORITY_HIGHEST
72 # define VLC_THREAD_PRIORITY_VIDEO 0
73 # define VLC_THREAD_PRIORITY_OUTPUT THREAD_PRIORITY_ABOVE_NORMAL
74 # define VLC_THREAD_PRIORITY_HIGHEST THREAD_PRIORITY_TIME_CRITICAL
76 #elif defined (__OS2__)
79 typedef struct vlc_thread *vlc_thread_t;
88 unsigned long contention;
93 #define VLC_STATIC_MUTEX { false, { { false, 0 } } }
99 #define VLC_STATIC_COND { 0, 0 }
100 #define LIBVLC_NEED_SEMAPHORE
101 #define LIBVLC_NEED_RWLOCK
102 typedef struct vlc_threadvar *vlc_threadvar_t;
103 typedef struct vlc_timer *vlc_timer_t;
105 # define VLC_THREAD_PRIORITY_LOW 0
106 # define VLC_THREAD_PRIORITY_INPUT \
107 MAKESHORT(PRTYD_MAXIMUM / 2, PRTYC_REGULAR)
108 # define VLC_THREAD_PRIORITY_AUDIO MAKESHORT(PRTYD_MAXIMUM, PRTYC_REGULAR)
109 # define VLC_THREAD_PRIORITY_VIDEO 0
110 # define VLC_THREAD_PRIORITY_OUTPUT \
111 MAKESHORT(PRTYD_MAXIMUM / 2, PRTYC_REGULAR)
112 # define VLC_THREAD_PRIORITY_HIGHEST MAKESHORT(0, PRTYC_TIMECRITICAL)
114 # define pthread_sigmask sigprocmask
116 #elif defined (__ANDROID__) /* pthreads subset without pthread_cancel() */
118 # include <pthread.h>
120 # define LIBVLC_USE_PTHREAD_CLEANUP 1
121 # define LIBVLC_NEED_SEMAPHORE
122 # define LIBVLC_NEED_RWLOCK
124 typedef struct vlc_thread *vlc_thread_t;
125 typedef pthread_mutex_t vlc_mutex_t;
126 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
127 typedef pthread_cond_t vlc_cond_t;
128 #define VLC_STATIC_COND PTHREAD_COND_INITIALIZER
130 typedef pthread_key_t vlc_threadvar_t;
131 typedef struct vlc_timer *vlc_timer_t;
133 # define VLC_THREAD_PRIORITY_LOW 0
134 # define VLC_THREAD_PRIORITY_INPUT 0
135 # define VLC_THREAD_PRIORITY_AUDIO 0
136 # define VLC_THREAD_PRIORITY_VIDEO 0
137 # define VLC_THREAD_PRIORITY_OUTPUT 0
138 # define VLC_THREAD_PRIORITY_HIGHEST 0
140 #elif defined (__APPLE__)
141 # define _APPLE_C_SOURCE 1 /* Proper pthread semantics on OSX */
143 # include <pthread.h>
144 /* Unnamed POSIX semaphores not supported on Mac OS X */
145 # include <mach/semaphore.h>
146 # include <mach/task.h>
147 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
148 # define LIBVLC_USE_PTHREAD 1
149 # define LIBVLC_USE_PTHREAD_CLEANUP 1
150 # define LIBVLC_USE_PTHREAD_CANCEL 1
152 typedef pthread_t vlc_thread_t;
153 typedef pthread_mutex_t vlc_mutex_t;
154 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
155 typedef pthread_cond_t vlc_cond_t;
156 #define VLC_STATIC_COND PTHREAD_COND_INITIALIZER
157 typedef semaphore_t vlc_sem_t;
158 typedef pthread_rwlock_t vlc_rwlock_t;
159 #define VLC_STATIC_RWLOCK PTHREAD_RWLOCK_INITIALIZER
160 typedef pthread_key_t vlc_threadvar_t;
161 typedef struct vlc_timer *vlc_timer_t;
163 # define VLC_THREAD_PRIORITY_LOW 0
164 # define VLC_THREAD_PRIORITY_INPUT 22
165 # define VLC_THREAD_PRIORITY_AUDIO 22
166 # define VLC_THREAD_PRIORITY_VIDEO 0
167 # define VLC_THREAD_PRIORITY_OUTPUT 22
168 # define VLC_THREAD_PRIORITY_HIGHEST 22
170 #else /* POSIX threads */
171 # include <unistd.h> /* _POSIX_SPIN_LOCKS */
172 # include <pthread.h>
173 # include <semaphore.h>
174 # define LIBVLC_USE_PTHREAD 1
175 # define LIBVLC_USE_PTHREAD_CLEANUP 1
176 # define LIBVLC_USE_PTHREAD_CANCEL 1
178 typedef pthread_t vlc_thread_t;
179 typedef pthread_mutex_t vlc_mutex_t;
180 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
181 typedef pthread_cond_t vlc_cond_t;
182 #define VLC_STATIC_COND PTHREAD_COND_INITIALIZER
183 typedef sem_t vlc_sem_t;
184 typedef pthread_rwlock_t vlc_rwlock_t;
185 #define VLC_STATIC_RWLOCK PTHREAD_RWLOCK_INITIALIZER
186 typedef pthread_key_t vlc_threadvar_t;
187 typedef struct vlc_timer *vlc_timer_t;
189 # define VLC_THREAD_PRIORITY_LOW 0
190 # define VLC_THREAD_PRIORITY_INPUT 10
191 # define VLC_THREAD_PRIORITY_AUDIO 5
192 # define VLC_THREAD_PRIORITY_VIDEO 0
193 # define VLC_THREAD_PRIORITY_OUTPUT 15
194 # define VLC_THREAD_PRIORITY_HIGHEST 20
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 /*****************************************************************************
218 * Function definitions
219 *****************************************************************************/
220 VLC_API void vlc_mutex_init( vlc_mutex_t * );
221 VLC_API void vlc_mutex_init_recursive( vlc_mutex_t * );
222 VLC_API void vlc_mutex_destroy( vlc_mutex_t * );
223 VLC_API void vlc_mutex_lock( vlc_mutex_t * );
224 VLC_API int vlc_mutex_trylock( vlc_mutex_t * ) VLC_USED;
225 VLC_API void vlc_mutex_unlock( vlc_mutex_t * );
226 VLC_API void vlc_cond_init( vlc_cond_t * );
227 VLC_API void vlc_cond_init_daytime( vlc_cond_t * );
228 VLC_API void vlc_cond_destroy( vlc_cond_t * );
229 VLC_API void vlc_cond_signal(vlc_cond_t *);
230 VLC_API void vlc_cond_broadcast(vlc_cond_t *);
231 VLC_API void vlc_cond_wait(vlc_cond_t *, vlc_mutex_t *);
232 VLC_API int vlc_cond_timedwait(vlc_cond_t *, vlc_mutex_t *, mtime_t);
233 VLC_API void vlc_sem_init(vlc_sem_t *, unsigned);
234 VLC_API void vlc_sem_destroy(vlc_sem_t *);
235 VLC_API int vlc_sem_post(vlc_sem_t *);
236 VLC_API void vlc_sem_wait(vlc_sem_t *);
238 VLC_API void vlc_rwlock_init(vlc_rwlock_t *);
239 VLC_API void vlc_rwlock_destroy(vlc_rwlock_t *);
240 VLC_API void vlc_rwlock_rdlock(vlc_rwlock_t *);
241 VLC_API void vlc_rwlock_wrlock(vlc_rwlock_t *);
242 VLC_API void vlc_rwlock_unlock(vlc_rwlock_t *);
243 VLC_API int vlc_threadvar_create(vlc_threadvar_t * , void (*) (void *) );
244 VLC_API void vlc_threadvar_delete(vlc_threadvar_t *);
245 VLC_API int vlc_threadvar_set(vlc_threadvar_t, void *);
246 VLC_API void * vlc_threadvar_get(vlc_threadvar_t);
248 VLC_API int vlc_clone(vlc_thread_t *, void * (*) (void *), void *, int) VLC_USED;
249 VLC_API void vlc_cancel(vlc_thread_t);
250 VLC_API void vlc_join(vlc_thread_t, void **);
251 VLC_API void vlc_control_cancel (int cmd, ...);
253 VLC_API mtime_t mdate(void);
254 VLC_API void mwait(mtime_t deadline);
255 VLC_API void msleep(mtime_t delay);
257 #define VLC_HARD_MIN_SLEEP 10000 /* 10 milliseconds = 1 tick at 100Hz */
258 #define VLC_SOFT_MIN_SLEEP 9000000 /* 9 seconds */
260 #if VLC_GCC_VERSION(4,3)
261 /* Linux has 100, 250, 300 or 1000Hz
263 * HZ=100 by default on FreeBSD, but some architectures use a 1000Hz timer
267 __attribute__((unused))
268 __attribute__((noinline))
269 __attribute__((error("sorry, cannot sleep for such short a time")))
270 mtime_t impossible_delay( mtime_t delay )
273 return VLC_HARD_MIN_SLEEP;
277 __attribute__((unused))
278 __attribute__((noinline))
279 __attribute__((warning("use proper event handling instead of short delay")))
280 mtime_t harmful_delay( mtime_t delay )
285 # define check_delay( d ) \
286 ((__builtin_constant_p(d < VLC_HARD_MIN_SLEEP) \
287 && (d < VLC_HARD_MIN_SLEEP)) \
288 ? impossible_delay(d) \
289 : ((__builtin_constant_p(d < VLC_SOFT_MIN_SLEEP) \
290 && (d < VLC_SOFT_MIN_SLEEP)) \
295 __attribute__((unused))
296 __attribute__((noinline))
297 __attribute__((error("deadlines can not be constant")))
298 mtime_t impossible_deadline( mtime_t deadline )
303 # define check_deadline( d ) \
304 (__builtin_constant_p(d) ? impossible_deadline(d) : d)
306 # define check_delay(d) (d)
307 # define check_deadline(d) (d)
310 #define msleep(d) msleep(check_delay(d))
311 #define mwait(d) mwait(check_deadline(d))
313 VLC_API int vlc_timer_create(vlc_timer_t *, void (*) (void *), void *) VLC_USED;
314 VLC_API void vlc_timer_destroy(vlc_timer_t);
315 VLC_API void vlc_timer_schedule(vlc_timer_t, bool, mtime_t, mtime_t);
316 VLC_API unsigned vlc_timer_getoverrun(vlc_timer_t) VLC_USED;
318 VLC_API unsigned vlc_GetCPUCount(void);
320 VLC_API int vlc_savecancel(void);
321 VLC_API void vlc_restorecancel(int state);
322 VLC_API void vlc_testcancel(void);
324 #if defined (LIBVLC_USE_PTHREAD_CLEANUP)
326 * Registers a new procedure to run if the thread is cancelled (or otherwise
327 * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
328 * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
329 * of the block between these two function calls is not allowed (read: it will
330 * likely crash the whole process). If multiple procedures are registered,
331 * they are handled in last-in first-out order.
333 * @param routine procedure to call if the thread ends
334 * @param arg argument for the procedure
336 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
339 * Removes a cleanup procedure that was previously registered with
340 * vlc_cleanup_push().
342 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
345 * Removes a cleanup procedure that was previously registered with
346 * vlc_cleanup_push(), and executes it.
348 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
356 typedef struct vlc_cleanup_t vlc_cleanup_t;
361 void (*proc) (void *);
365 /* This macros opens a code block on purpose. This is needed for multiple
366 * calls within a single function. This also prevent Win32 developers from
367 * writing code that would break on POSIX (POSIX opens a block as well). */
368 # define vlc_cleanup_push( routine, arg ) \
370 vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
371 vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
373 # define vlc_cleanup_pop( ) \
374 vlc_control_cancel (VLC_CLEANUP_POP); \
377 # define vlc_cleanup_run( ) \
378 vlc_control_cancel (VLC_CLEANUP_POP); \
379 vlc_cleanup_data.proc (vlc_cleanup_data.data); \
382 #endif /* !LIBVLC_USE_PTHREAD_CLEANUO */
384 #ifndef LIBVLC_USE_PTHREAD_CANCEL
385 /* poll() with cancellation */
386 static inline int vlc_poll (struct pollfd *fds, unsigned nfds, int timeout)
392 int val = poll (fds, nfds, timeout);
399 return poll (fds, nfds, timeout);
401 # define poll(u,n,t) vlc_poll(u, n, t)
403 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
405 static inline void vlc_cleanup_lock (void *lock)
407 vlc_mutex_unlock ((vlc_mutex_t *)lock);
409 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
411 #if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
412 typedef pthread_spinlock_t vlc_spinlock_t;
415 * Initializes a spinlock.
417 static inline void vlc_spin_init (vlc_spinlock_t *spin)
419 if (pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE))
424 * Acquires a spinlock.
426 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
428 pthread_spin_lock (spin);
432 * Releases a spinlock.
434 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
436 pthread_spin_unlock (spin);
440 * Deinitializes a spinlock.
442 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
444 pthread_spin_destroy (spin);
447 #elif defined (WIN32)
448 typedef CRITICAL_SECTION vlc_spinlock_t;
450 static inline void vlc_spin_init (vlc_spinlock_t *spin)
452 if (!InitializeCriticalSectionAndSpinCount(spin, 4000))
456 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
458 EnterCriticalSection(spin);
461 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
463 LeaveCriticalSection(spin);
466 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
468 DeleteCriticalSection(spin);
472 /* Fallback to plain mutexes if spinlocks are not available */
473 typedef vlc_mutex_t vlc_spinlock_t;
475 static inline void vlc_spin_init (vlc_spinlock_t *spin)
477 vlc_mutex_init (spin);
480 # define vlc_spin_lock vlc_mutex_lock
481 # define vlc_spin_unlock vlc_mutex_unlock
482 # define vlc_spin_destroy vlc_mutex_destroy
486 * Issues a full memory barrier.
488 static inline void barrier (void)
490 #if defined (__GNUC__) && !defined (__APPLE__) && \
491 ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
492 __sync_synchronize ();
493 #elif defined(__APPLE__)
495 #elif defined(__powerpc__)
496 asm volatile ("sync":::"memory");
497 #elif 0 // defined(__i386__) /* Requires SSE2 support */
498 asm volatile ("mfence":::"memory");
501 vlc_spin_init (&spin);
502 vlc_spin_lock (&spin);
503 vlc_spin_unlock (&spin);
504 vlc_spin_destroy (&spin);
510 * Helper C++ class to lock a mutex.
511 * The mutex is locked when the object is created, and unlocked when the object
514 class vlc_mutex_locker
519 vlc_mutex_locker (vlc_mutex_t *m) : lock (m)
521 vlc_mutex_lock (lock);
524 ~vlc_mutex_locker (void)
526 vlc_mutex_unlock (lock);
533 VLC_AVCODEC_MUTEX = 0,
539 /* Insert new entry HERE */
543 VLC_API void vlc_global_mutex( unsigned, bool );
544 #define vlc_global_lock( n ) vlc_global_mutex( n, true )
545 #define vlc_global_unlock( n ) vlc_global_mutex( n, false )
547 #endif /* !_VLC_THREADS_H */