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 )
38 #elif defined( WIN32 )
39 # include <process.h> /* Win32 API */
41 #else /* pthreads (like Linux & BSD) */
42 # define LIBVLC_USE_PTHREAD 1
43 # define LIBVLC_USE_PTHREAD_CANCEL 1
44 # define _APPLE_C_SOURCE 1 /* Proper pthread semantics on OSX */
46 # include <unistd.h> /* _POSIX_SPIN_LOCKS */
49 /* Unnamed POSIX semaphores not supported on Mac OS X, use Mach semaphores instead */
50 # if defined (__APPLE__)
51 # include <mach/semaphore.h>
52 # include <mach/task.h>
54 # include <semaphore.h>
59 /*****************************************************************************
61 *****************************************************************************/
63 /* Thread priorities */
65 # define VLC_THREAD_PRIORITY_LOW 0
66 # define VLC_THREAD_PRIORITY_INPUT 22
67 # define VLC_THREAD_PRIORITY_AUDIO 22
68 # define VLC_THREAD_PRIORITY_VIDEO 0
69 # define VLC_THREAD_PRIORITY_OUTPUT 22
70 # define VLC_THREAD_PRIORITY_HIGHEST 22
72 #elif defined(LIBVLC_USE_PTHREAD)
73 # define VLC_THREAD_PRIORITY_LOW 0
74 # define VLC_THREAD_PRIORITY_INPUT 10
75 # define VLC_THREAD_PRIORITY_AUDIO 5
76 # define VLC_THREAD_PRIORITY_VIDEO 0
77 # define VLC_THREAD_PRIORITY_OUTPUT 15
78 # define VLC_THREAD_PRIORITY_HIGHEST 20
80 #elif defined(WIN32) || defined(UNDER_CE)
81 /* Define different priorities for WinNT/2K/XP and Win9x/Me */
82 # define VLC_THREAD_PRIORITY_LOW 0
83 # define VLC_THREAD_PRIORITY_INPUT \
84 THREAD_PRIORITY_ABOVE_NORMAL
85 # define VLC_THREAD_PRIORITY_AUDIO \
86 THREAD_PRIORITY_HIGHEST
87 # define VLC_THREAD_PRIORITY_VIDEO 0
88 # define VLC_THREAD_PRIORITY_OUTPUT \
89 THREAD_PRIORITY_ABOVE_NORMAL
90 # define VLC_THREAD_PRIORITY_HIGHEST \
91 THREAD_PRIORITY_TIME_CRITICAL
94 # define VLC_THREAD_PRIORITY_LOW 0
95 # define VLC_THREAD_PRIORITY_INPUT 0
96 # define VLC_THREAD_PRIORITY_AUDIO 0
97 # define VLC_THREAD_PRIORITY_VIDEO 0
98 # define VLC_THREAD_PRIORITY_OUTPUT 0
99 # define VLC_THREAD_PRIORITY_HIGHEST 0
103 /*****************************************************************************
105 *****************************************************************************/
107 #if defined (LIBVLC_USE_PTHREAD)
108 typedef pthread_t vlc_thread_t
;
109 typedef pthread_mutex_t vlc_mutex_t
;
110 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
111 typedef pthread_cond_t vlc_cond_t
;
112 #define VLC_STATIC_COND PTHREAD_COND_INITIALIZER
113 typedef pthread_rwlock_t vlc_rwlock_t
;
114 #define VLC_STATIC_RWLOCK PTHREAD_RWLOCK_INITIALIZER
115 typedef pthread_key_t vlc_threadvar_t
;
116 typedef struct vlc_timer
*vlc_timer_t
;
118 #if defined (__APPLE__)
119 typedef semaphore_t vlc_sem_t
;
121 typedef sem_t vlc_sem_t
;
124 #elif defined( WIN32 )
125 typedef struct vlc_thread
*vlc_thread_t
;
135 unsigned long contention
;
137 CRITICAL_SECTION mutex
;
140 #define VLC_STATIC_MUTEX { false, { { false, 0 } } }
147 #define VLC_STATIC_COND { 0, 0 }
149 typedef HANDLE vlc_sem_t
;
155 unsigned long readers
;
156 unsigned long writers
;
159 #define VLC_STATIC_RWLOCK \
160 { VLC_STATIC_MUTEX, VLC_STATIC_COND, 0, 0, 0 }
162 typedef struct vlc_threadvar
*vlc_threadvar_t
;
163 typedef struct vlc_timer
*vlc_timer_t
;
166 #if defined( WIN32 ) && !defined ETIMEDOUT
167 # define ETIMEDOUT 10060 /* This is the value in winsock.h. */
170 /*****************************************************************************
171 * Function definitions
172 *****************************************************************************/
173 VLC_API
void vlc_mutex_init( vlc_mutex_t
* );
174 VLC_API
void vlc_mutex_init_recursive( vlc_mutex_t
* );
175 VLC_API
void vlc_mutex_destroy( vlc_mutex_t
* );
176 VLC_API
void vlc_mutex_lock( vlc_mutex_t
* );
177 VLC_API
int vlc_mutex_trylock( vlc_mutex_t
* ) VLC_USED
;
178 VLC_API
void vlc_mutex_unlock( vlc_mutex_t
* );
179 VLC_API
void vlc_cond_init( vlc_cond_t
* );
180 VLC_API
void vlc_cond_init_daytime( vlc_cond_t
* );
181 VLC_API
void vlc_cond_destroy( vlc_cond_t
* );
182 VLC_API
void vlc_cond_signal(vlc_cond_t
*);
183 VLC_API
void vlc_cond_broadcast(vlc_cond_t
*);
184 VLC_API
void vlc_cond_wait(vlc_cond_t
*, vlc_mutex_t
*);
185 VLC_API
int vlc_cond_timedwait(vlc_cond_t
*, vlc_mutex_t
*, mtime_t
);
186 VLC_API
void vlc_sem_init(vlc_sem_t
*, unsigned);
187 VLC_API
void vlc_sem_destroy(vlc_sem_t
*);
188 VLC_API
int vlc_sem_post(vlc_sem_t
*);
189 VLC_API
void vlc_sem_wait(vlc_sem_t
*);
191 VLC_API
void vlc_rwlock_init(vlc_rwlock_t
*);
192 VLC_API
void vlc_rwlock_destroy(vlc_rwlock_t
*);
193 VLC_API
void vlc_rwlock_rdlock(vlc_rwlock_t
*);
194 VLC_API
void vlc_rwlock_wrlock(vlc_rwlock_t
*);
195 VLC_API
void vlc_rwlock_unlock(vlc_rwlock_t
*);
196 VLC_API
int vlc_threadvar_create(vlc_threadvar_t
* , void (*) (void *) );
197 VLC_API
void vlc_threadvar_delete(vlc_threadvar_t
*);
198 VLC_API
int vlc_threadvar_set(vlc_threadvar_t
, void *);
199 VLC_API
void * vlc_threadvar_get(vlc_threadvar_t
);
201 VLC_API
int vlc_clone(vlc_thread_t
*, void * (*) (void *), void *, int) VLC_USED
;
202 VLC_API
void vlc_cancel(vlc_thread_t
);
203 VLC_API
void vlc_join(vlc_thread_t
, void **);
204 VLC_API
void vlc_control_cancel (int cmd
, ...);
206 VLC_API mtime_t
mdate(void);
207 VLC_API
void mwait(mtime_t deadline
);
208 VLC_API
void msleep(mtime_t delay
);
210 #define VLC_HARD_MIN_SLEEP 10000 /* 10 milliseconds = 1 tick at 100Hz */
211 #define VLC_SOFT_MIN_SLEEP 9000000 /* 9 seconds */
213 #if VLC_GCC_VERSION(4,3)
214 /* Linux has 100, 250, 300 or 1000Hz
216 * HZ=100 by default on FreeBSD, but some architectures use a 1000Hz timer
220 __attribute__((unused
))
221 __attribute__((noinline
))
222 __attribute__((error("sorry, cannot sleep for such short a time")))
223 mtime_t
impossible_delay( mtime_t delay
)
226 return VLC_HARD_MIN_SLEEP
;
230 __attribute__((unused
))
231 __attribute__((noinline
))
232 __attribute__((warning("use proper event handling instead of short delay")))
233 mtime_t
harmful_delay( mtime_t delay
)
238 # define check_delay( d ) \
239 ((__builtin_constant_p(d < VLC_HARD_MIN_SLEEP) \
240 && (d < VLC_HARD_MIN_SLEEP)) \
241 ? impossible_delay(d) \
242 : ((__builtin_constant_p(d < VLC_SOFT_MIN_SLEEP) \
243 && (d < VLC_SOFT_MIN_SLEEP)) \
248 __attribute__((unused
))
249 __attribute__((noinline
))
250 __attribute__((error("deadlines can not be constant")))
251 mtime_t
impossible_deadline( mtime_t deadline
)
256 # define check_deadline( d ) \
257 (__builtin_constant_p(d) ? impossible_deadline(d) : d)
259 # define check_delay(d) (d)
260 # define check_deadline(d) (d)
263 #define msleep(d) msleep(check_delay(d))
264 #define mwait(d) mwait(check_deadline(d))
266 VLC_API
int vlc_timer_create(vlc_timer_t
*, void (*) (void *), void *) VLC_USED
;
267 VLC_API
void vlc_timer_destroy(vlc_timer_t
);
268 VLC_API
void vlc_timer_schedule(vlc_timer_t
, bool, mtime_t
, mtime_t
);
269 VLC_API
unsigned vlc_timer_getoverrun(vlc_timer_t
) VLC_USED
;
271 VLC_API
unsigned vlc_GetCPUCount(void);
273 #ifndef LIBVLC_USE_PTHREAD_CANCEL
280 VLC_API
int vlc_savecancel(void);
281 VLC_API
void vlc_restorecancel(int state
);
282 VLC_API
void vlc_testcancel(void);
284 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
286 * Registers a new procedure to run if the thread is cancelled (or otherwise
287 * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
288 * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
289 * of the block between these two function calls is not allowed (read: it will
290 * likely crash the whole process). If multiple procedures are registered,
291 * they are handled in last-in first-out order.
293 * @param routine procedure to call if the thread ends
294 * @param arg argument for the procedure
296 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
299 * Removes a cleanup procedure that was previously registered with
300 * vlc_cleanup_push().
302 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
305 * Removes a cleanup procedure that was previously registered with
306 * vlc_cleanup_push(), and executes it.
308 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
310 typedef struct vlc_cleanup_t vlc_cleanup_t
;
315 void (*proc
) (void *);
319 /* This macros opens a code block on purpose. This is needed for multiple
320 * calls within a single function. This also prevent Win32 developers from
321 * writing code that would break on POSIX (POSIX opens a block as well). */
322 # define vlc_cleanup_push( routine, arg ) \
324 vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
325 vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
327 # define vlc_cleanup_pop( ) \
328 vlc_control_cancel (VLC_CLEANUP_POP); \
331 # define vlc_cleanup_run( ) \
332 vlc_control_cancel (VLC_CLEANUP_POP); \
333 vlc_cleanup_data.proc (vlc_cleanup_data.data); \
336 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
338 static inline void vlc_cleanup_lock (void *lock
)
340 vlc_mutex_unlock ((vlc_mutex_t
*)lock
);
342 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
344 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
345 typedef pthread_spinlock_t vlc_spinlock_t
;
348 * Initializes a spinlock.
350 static inline void vlc_spin_init (vlc_spinlock_t
*spin
)
352 if (pthread_spin_init (spin
, PTHREAD_PROCESS_PRIVATE
))
357 * Acquires a spinlock.
359 static inline void vlc_spin_lock (vlc_spinlock_t
*spin
)
361 pthread_spin_lock (spin
);
365 * Releases a spinlock.
367 static inline void vlc_spin_unlock (vlc_spinlock_t
*spin
)
369 pthread_spin_unlock (spin
);
373 * Deinitializes a spinlock.
375 static inline void vlc_spin_destroy (vlc_spinlock_t
*spin
)
377 pthread_spin_destroy (spin
);
380 #elif defined (WIN32) && !defined (UNDER_CE)
382 typedef CRITICAL_SECTION vlc_spinlock_t
;
385 * Initializes a spinlock.
387 static inline void vlc_spin_init (vlc_spinlock_t
*spin
)
389 if (!InitializeCriticalSectionAndSpinCount(spin
, 4000))
394 * Acquires a spinlock.
396 static inline void vlc_spin_lock (vlc_spinlock_t
*spin
)
398 EnterCriticalSection(spin
);
402 * Releases a spinlock.
404 static inline void vlc_spin_unlock (vlc_spinlock_t
*spin
)
406 LeaveCriticalSection(spin
);
410 * Deinitializes a spinlock.
412 static inline void vlc_spin_destroy (vlc_spinlock_t
*spin
)
414 DeleteCriticalSection(spin
);
419 /* Fallback to plain mutexes if spinlocks are not available */
420 typedef vlc_mutex_t vlc_spinlock_t
;
422 static inline void vlc_spin_init (vlc_spinlock_t
*spin
)
424 vlc_mutex_init (spin
);
427 # define vlc_spin_lock vlc_mutex_lock
428 # define vlc_spin_unlock vlc_mutex_unlock
429 # define vlc_spin_destroy vlc_mutex_destroy
433 * Issues a full memory barrier.
435 #if defined (__APPLE__)
436 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
438 static inline void barrier (void)
440 #if defined (__GNUC__) && !defined (__APPLE__) && \
441 ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
442 __sync_synchronize ();
443 #elif defined(__APPLE__)
445 #elif defined(__powerpc__)
446 asm volatile ("sync":::"memory");
447 #elif 0 // defined(__i386__) /* Requires SSE2 support */
448 asm volatile ("mfence":::"memory");
451 vlc_spin_init (&spin
);
452 vlc_spin_lock (&spin
);
453 vlc_spin_unlock (&spin
);
454 vlc_spin_destroy (&spin
);
460 * Helper C++ class to lock a mutex.
461 * The mutex is locked when the object is created, and unlocked when the object
464 class vlc_mutex_locker
469 vlc_mutex_locker (vlc_mutex_t
*m
) : lock (m
)
471 vlc_mutex_lock (lock
);
474 ~vlc_mutex_locker (void)
476 vlc_mutex_unlock (lock
);
482 VLC_AVCODEC_MUTEX
= 0,
487 /* Insert new entry HERE */
491 VLC_API
void vlc_global_mutex( unsigned, bool );
492 #define vlc_global_lock( n ) vlc_global_mutex( n, true )
493 #define vlc_global_unlock( n ) vlc_global_mutex( n, false )
495 #endif /* !_VLC_THREADS_H */