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
132 #define VLC_STATIC_COND { PTHREAD_COND_INITIALIZER, CLOCK_REALTIME }
134 typedef pthread_key_t vlc_threadvar_t;
135 typedef struct vlc_timer *vlc_timer_t;
137 # define VLC_THREAD_PRIORITY_LOW 0
138 # define VLC_THREAD_PRIORITY_INPUT 0
139 # define VLC_THREAD_PRIORITY_AUDIO 0
140 # define VLC_THREAD_PRIORITY_VIDEO 0
141 # define VLC_THREAD_PRIORITY_OUTPUT 0
142 # define VLC_THREAD_PRIORITY_HIGHEST 0
144 #elif defined (__APPLE__)
145 # define _APPLE_C_SOURCE 1 /* Proper pthread semantics on OSX */
147 # include <pthread.h>
148 /* Unnamed POSIX semaphores not supported on Mac OS X */
149 # include <mach/semaphore.h>
150 # include <mach/task.h>
151 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
152 # define LIBVLC_USE_PTHREAD 1
153 # define LIBVLC_USE_PTHREAD_CLEANUP 1
154 # define LIBVLC_USE_PTHREAD_CANCEL 1
156 typedef pthread_t vlc_thread_t;
157 typedef pthread_mutex_t vlc_mutex_t;
158 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
159 typedef pthread_cond_t vlc_cond_t;
160 #define VLC_STATIC_COND PTHREAD_COND_INITIALIZER
161 typedef semaphore_t vlc_sem_t;
162 typedef pthread_rwlock_t vlc_rwlock_t;
163 #define VLC_STATIC_RWLOCK PTHREAD_RWLOCK_INITIALIZER
164 typedef pthread_key_t vlc_threadvar_t;
165 typedef struct vlc_timer *vlc_timer_t;
167 # define VLC_THREAD_PRIORITY_LOW 0
168 # define VLC_THREAD_PRIORITY_INPUT 22
169 # define VLC_THREAD_PRIORITY_AUDIO 22
170 # define VLC_THREAD_PRIORITY_VIDEO 0
171 # define VLC_THREAD_PRIORITY_OUTPUT 22
172 # define VLC_THREAD_PRIORITY_HIGHEST 22
174 #else /* POSIX threads */
175 # include <unistd.h> /* _POSIX_SPIN_LOCKS */
176 # include <pthread.h>
177 # include <semaphore.h>
178 # define LIBVLC_USE_PTHREAD 1
179 # define LIBVLC_USE_PTHREAD_CLEANUP 1
180 # define LIBVLC_USE_PTHREAD_CANCEL 1
182 typedef pthread_t vlc_thread_t;
183 typedef pthread_mutex_t vlc_mutex_t;
184 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
185 typedef pthread_cond_t vlc_cond_t;
186 #define VLC_STATIC_COND PTHREAD_COND_INITIALIZER
187 typedef sem_t vlc_sem_t;
188 typedef pthread_rwlock_t vlc_rwlock_t;
189 #define VLC_STATIC_RWLOCK PTHREAD_RWLOCK_INITIALIZER
190 typedef pthread_key_t vlc_threadvar_t;
191 typedef struct vlc_timer *vlc_timer_t;
193 # define VLC_THREAD_PRIORITY_LOW 0
194 # define VLC_THREAD_PRIORITY_INPUT 10
195 # define VLC_THREAD_PRIORITY_AUDIO 5
196 # define VLC_THREAD_PRIORITY_VIDEO 0
197 # define VLC_THREAD_PRIORITY_OUTPUT 15
198 # define VLC_THREAD_PRIORITY_HIGHEST 20
202 #ifdef LIBVLC_NEED_SEMAPHORE
203 typedef struct vlc_sem
211 #ifdef LIBVLC_NEED_RWLOCK
212 typedef struct vlc_rwlock
218 # define VLC_STATIC_RWLOCK { VLC_STATIC_MUTEX, VLC_STATIC_COND, 0 }
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 VLC_API int vlc_savecancel(void);
325 VLC_API void vlc_restorecancel(int state);
326 VLC_API void vlc_testcancel(void);
328 #if defined (LIBVLC_USE_PTHREAD_CLEANUP)
330 * Registers a new procedure to run if the thread is cancelled (or otherwise
331 * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
332 * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
333 * of the block between these two function calls is not allowed (read: it will
334 * likely crash the whole process). If multiple procedures are registered,
335 * they are handled in last-in first-out order.
337 * @param routine procedure to call if the thread ends
338 * @param arg argument for the procedure
340 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
343 * Removes a cleanup procedure that was previously registered with
344 * vlc_cleanup_push().
346 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
349 * Removes a cleanup procedure that was previously registered with
350 * vlc_cleanup_push(), and executes it.
352 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
360 typedef struct vlc_cleanup_t vlc_cleanup_t;
365 void (*proc) (void *);
369 /* This macros opens a code block on purpose. This is needed for multiple
370 * calls within a single function. This also prevent Win32 developers from
371 * writing code that would break on POSIX (POSIX opens a block as well). */
372 # define vlc_cleanup_push( routine, arg ) \
374 vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
375 vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
377 # define vlc_cleanup_pop( ) \
378 vlc_control_cancel (VLC_CLEANUP_POP); \
381 # define vlc_cleanup_run( ) \
382 vlc_control_cancel (VLC_CLEANUP_POP); \
383 vlc_cleanup_data.proc (vlc_cleanup_data.data); \
386 #endif /* !LIBVLC_USE_PTHREAD_CLEANUO */
388 #ifndef LIBVLC_USE_PTHREAD_CANCEL
389 /* poll() with cancellation */
390 static inline int vlc_poll (struct pollfd *fds, unsigned nfds, int timeout)
396 int val = poll (fds, nfds, timeout);
403 return poll (fds, nfds, timeout);
405 # define poll(u,n,t) vlc_poll(u, n, t)
407 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
409 static inline void vlc_cleanup_lock (void *lock)
411 vlc_mutex_unlock ((vlc_mutex_t *)lock);
413 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
415 #if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
416 typedef pthread_spinlock_t vlc_spinlock_t;
419 * Initializes a spinlock.
421 static inline void vlc_spin_init (vlc_spinlock_t *spin)
423 if (pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE))
428 * Acquires a spinlock.
430 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
432 pthread_spin_lock (spin);
436 * Releases a spinlock.
438 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
440 pthread_spin_unlock (spin);
444 * Deinitializes a spinlock.
446 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
448 pthread_spin_destroy (spin);
451 #elif defined (WIN32)
452 typedef CRITICAL_SECTION vlc_spinlock_t;
454 static inline void vlc_spin_init (vlc_spinlock_t *spin)
456 if (!InitializeCriticalSectionAndSpinCount(spin, 4000))
460 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
462 EnterCriticalSection(spin);
465 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
467 LeaveCriticalSection(spin);
470 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
472 DeleteCriticalSection(spin);
476 /* Fallback to plain mutexes if spinlocks are not available */
477 typedef vlc_mutex_t vlc_spinlock_t;
479 static inline void vlc_spin_init (vlc_spinlock_t *spin)
481 vlc_mutex_init (spin);
484 # define vlc_spin_lock vlc_mutex_lock
485 # define vlc_spin_unlock vlc_mutex_unlock
486 # define vlc_spin_destroy vlc_mutex_destroy
490 * Issues a full memory barrier.
492 static inline void barrier (void)
494 #if defined (__GNUC__) && !defined (__APPLE__) && \
495 ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
496 __sync_synchronize ();
497 #elif defined(__APPLE__)
499 #elif defined(__powerpc__)
500 asm volatile ("sync":::"memory");
501 #elif 0 // defined(__i386__) /* Requires SSE2 support */
502 asm volatile ("mfence":::"memory");
505 vlc_spin_init (&spin);
506 vlc_spin_lock (&spin);
507 vlc_spin_unlock (&spin);
508 vlc_spin_destroy (&spin);
514 * Helper C++ class to lock a mutex.
515 * The mutex is locked when the object is created, and unlocked when the object
518 class vlc_mutex_locker
523 vlc_mutex_locker (vlc_mutex_t *m) : lock (m)
525 vlc_mutex_lock (lock);
528 ~vlc_mutex_locker (void)
530 vlc_mutex_unlock (lock);
537 VLC_AVCODEC_MUTEX = 0,
543 /* Insert new entry HERE */
547 VLC_API void vlc_global_mutex( unsigned, bool );
548 #define vlc_global_lock( n ) vlc_global_mutex( n, true )
549 #define vlc_global_unlock( n ) vlc_global_mutex( n, false )
551 #endif /* !_VLC_THREADS_H */