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 typedef struct vlc_rwlock vlc_rwlock_t;
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 }
199 typedef struct vlc_rwlock vlc_rwlock_t;
200 typedef struct vlc_threadvar *vlc_threadvar_t;
201 typedef struct vlc_timer *vlc_timer_t;
205 #ifndef VLC_STATIC_RWLOCK
212 # define VLC_STATIC_RWLOCK { VLC_STATIC_MUTEX, VLC_STATIC_COND, 0 }
215 #if defined( WIN32 ) && !defined ETIMEDOUT
216 # define ETIMEDOUT 10060 /* This is the value in winsock.h. */
219 /*****************************************************************************
220 * Function definitions
221 *****************************************************************************/
222 VLC_API void vlc_mutex_init( vlc_mutex_t * );
223 VLC_API void vlc_mutex_init_recursive( vlc_mutex_t * );
224 VLC_API void vlc_mutex_destroy( vlc_mutex_t * );
225 VLC_API void vlc_mutex_lock( vlc_mutex_t * );
226 VLC_API int vlc_mutex_trylock( vlc_mutex_t * ) VLC_USED;
227 VLC_API void vlc_mutex_unlock( vlc_mutex_t * );
228 VLC_API void vlc_cond_init( vlc_cond_t * );
229 VLC_API void vlc_cond_init_daytime( vlc_cond_t * );
230 VLC_API void vlc_cond_destroy( vlc_cond_t * );
231 VLC_API void vlc_cond_signal(vlc_cond_t *);
232 VLC_API void vlc_cond_broadcast(vlc_cond_t *);
233 VLC_API void vlc_cond_wait(vlc_cond_t *, vlc_mutex_t *);
234 VLC_API int vlc_cond_timedwait(vlc_cond_t *, vlc_mutex_t *, mtime_t);
235 VLC_API void vlc_sem_init(vlc_sem_t *, unsigned);
236 VLC_API void vlc_sem_destroy(vlc_sem_t *);
237 VLC_API int vlc_sem_post(vlc_sem_t *);
238 VLC_API void vlc_sem_wait(vlc_sem_t *);
240 VLC_API void vlc_rwlock_init(vlc_rwlock_t *);
241 VLC_API void vlc_rwlock_destroy(vlc_rwlock_t *);
242 VLC_API void vlc_rwlock_rdlock(vlc_rwlock_t *);
243 VLC_API void vlc_rwlock_wrlock(vlc_rwlock_t *);
244 VLC_API void vlc_rwlock_unlock(vlc_rwlock_t *);
245 VLC_API int vlc_threadvar_create(vlc_threadvar_t * , void (*) (void *) );
246 VLC_API void vlc_threadvar_delete(vlc_threadvar_t *);
247 VLC_API int vlc_threadvar_set(vlc_threadvar_t, void *);
248 VLC_API void * vlc_threadvar_get(vlc_threadvar_t);
250 VLC_API int vlc_clone(vlc_thread_t *, void * (*) (void *), void *, int) VLC_USED;
251 VLC_API void vlc_cancel(vlc_thread_t);
252 VLC_API void vlc_join(vlc_thread_t, void **);
253 VLC_API void vlc_control_cancel (int cmd, ...);
255 VLC_API mtime_t mdate(void);
256 VLC_API void mwait(mtime_t deadline);
257 VLC_API void msleep(mtime_t delay);
259 #define VLC_HARD_MIN_SLEEP 10000 /* 10 milliseconds = 1 tick at 100Hz */
260 #define VLC_SOFT_MIN_SLEEP 9000000 /* 9 seconds */
262 #if VLC_GCC_VERSION(4,3)
263 /* Linux has 100, 250, 300 or 1000Hz
265 * HZ=100 by default on FreeBSD, but some architectures use a 1000Hz timer
269 __attribute__((unused))
270 __attribute__((noinline))
271 __attribute__((error("sorry, cannot sleep for such short a time")))
272 mtime_t impossible_delay( mtime_t delay )
275 return VLC_HARD_MIN_SLEEP;
279 __attribute__((unused))
280 __attribute__((noinline))
281 __attribute__((warning("use proper event handling instead of short delay")))
282 mtime_t harmful_delay( mtime_t delay )
287 # define check_delay( d ) \
288 ((__builtin_constant_p(d < VLC_HARD_MIN_SLEEP) \
289 && (d < VLC_HARD_MIN_SLEEP)) \
290 ? impossible_delay(d) \
291 : ((__builtin_constant_p(d < VLC_SOFT_MIN_SLEEP) \
292 && (d < VLC_SOFT_MIN_SLEEP)) \
297 __attribute__((unused))
298 __attribute__((noinline))
299 __attribute__((error("deadlines can not be constant")))
300 mtime_t impossible_deadline( mtime_t deadline )
305 # define check_deadline( d ) \
306 (__builtin_constant_p(d) ? impossible_deadline(d) : d)
308 # define check_delay(d) (d)
309 # define check_deadline(d) (d)
312 #define msleep(d) msleep(check_delay(d))
313 #define mwait(d) mwait(check_deadline(d))
315 VLC_API int vlc_timer_create(vlc_timer_t *, void (*) (void *), void *) VLC_USED;
316 VLC_API void vlc_timer_destroy(vlc_timer_t);
317 VLC_API void vlc_timer_schedule(vlc_timer_t, bool, mtime_t, mtime_t);
318 VLC_API unsigned vlc_timer_getoverrun(vlc_timer_t) VLC_USED;
320 VLC_API unsigned vlc_GetCPUCount(void);
322 #ifndef LIBVLC_USE_PTHREAD_CANCEL
329 VLC_API int vlc_savecancel(void);
330 VLC_API void vlc_restorecancel(int state);
331 VLC_API void vlc_testcancel(void);
333 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
335 * Registers a new procedure to run if the thread is cancelled (or otherwise
336 * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
337 * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
338 * of the block between these two function calls is not allowed (read: it will
339 * likely crash the whole process). If multiple procedures are registered,
340 * they are handled in last-in first-out order.
342 * @param routine procedure to call if the thread ends
343 * @param arg argument for the procedure
345 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
348 * Removes a cleanup procedure that was previously registered with
349 * vlc_cleanup_push().
351 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
354 * Removes a cleanup procedure that was previously registered with
355 * vlc_cleanup_push(), and executes it.
357 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
359 typedef struct vlc_cleanup_t vlc_cleanup_t;
364 void (*proc) (void *);
368 /* This macros opens a code block on purpose. This is needed for multiple
369 * calls within a single function. This also prevent Win32 developers from
370 * writing code that would break on POSIX (POSIX opens a block as well). */
371 # define vlc_cleanup_push( routine, arg ) \
373 vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
374 vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
376 # define vlc_cleanup_pop( ) \
377 vlc_control_cancel (VLC_CLEANUP_POP); \
380 # define vlc_cleanup_run( ) \
381 vlc_control_cancel (VLC_CLEANUP_POP); \
382 vlc_cleanup_data.proc (vlc_cleanup_data.data); \
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)
449 typedef CRITICAL_SECTION vlc_spinlock_t;
452 * Initializes a spinlock.
454 static inline void vlc_spin_init (vlc_spinlock_t *spin)
456 if (!InitializeCriticalSectionAndSpinCount(spin, 4000))
461 * Acquires a spinlock.
463 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
465 EnterCriticalSection(spin);
469 * Releases a spinlock.
471 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
473 LeaveCriticalSection(spin);
477 * Deinitializes a spinlock.
479 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
481 DeleteCriticalSection(spin);
486 /* Fallback to plain mutexes if spinlocks are not available */
487 typedef vlc_mutex_t vlc_spinlock_t;
489 static inline void vlc_spin_init (vlc_spinlock_t *spin)
491 vlc_mutex_init (spin);
494 # define vlc_spin_lock vlc_mutex_lock
495 # define vlc_spin_unlock vlc_mutex_unlock
496 # define vlc_spin_destroy vlc_mutex_destroy
500 * Issues a full memory barrier.
502 #if defined (__APPLE__)
503 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
505 static inline void barrier (void)
507 #if defined (__GNUC__) && !defined (__APPLE__) && \
508 ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
509 __sync_synchronize ();
510 #elif defined(__APPLE__)
512 #elif defined(__powerpc__)
513 asm volatile ("sync":::"memory");
514 #elif 0 // defined(__i386__) /* Requires SSE2 support */
515 asm volatile ("mfence":::"memory");
518 vlc_spin_init (&spin);
519 vlc_spin_lock (&spin);
520 vlc_spin_unlock (&spin);
521 vlc_spin_destroy (&spin);
527 * Helper C++ class to lock a mutex.
528 * The mutex is locked when the object is created, and unlocked when the object
531 class vlc_mutex_locker
536 vlc_mutex_locker (vlc_mutex_t *m) : lock (m)
538 vlc_mutex_lock (lock);
541 ~vlc_mutex_locker (void)
543 vlc_mutex_unlock (lock);
549 VLC_AVCODEC_MUTEX = 0,
555 /* Insert new entry HERE */
559 VLC_API void vlc_global_mutex( unsigned, bool );
560 #define vlc_global_lock( n ) vlc_global_mutex( n, true )
561 #define vlc_global_unlock( n ) vlc_global_mutex( n, false )
563 #endif /* !_VLC_THREADS_H */