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 # include <errno.h> /* WinCE API */
39 #elif defined( WIN32 )
40 # include <process.h> /* Win32 API */
43 #else /* pthreads (like Linux & BSD) */
44 # define LIBVLC_USE_PTHREAD 1
45 # define LIBVLC_USE_PTHREAD_CANCEL 1
46 # define _APPLE_C_SOURCE 1 /* Proper pthread semantics on OSX */
48 # include <stdlib.h> /* lldiv_t definition (only in C99) */
49 # include <unistd.h> /* _POSIX_SPIN_LOCKS */
51 # include <semaphore.h>
56 /*****************************************************************************
58 *****************************************************************************/
60 /* Thread priorities */
62 # define VLC_THREAD_PRIORITY_LOW 0
63 # define VLC_THREAD_PRIORITY_INPUT 22
64 # define VLC_THREAD_PRIORITY_AUDIO 22
65 # define VLC_THREAD_PRIORITY_VIDEO 0
66 # define VLC_THREAD_PRIORITY_OUTPUT 22
67 # define VLC_THREAD_PRIORITY_HIGHEST 22
69 #elif defined(LIBVLC_USE_PTHREAD)
70 # define VLC_THREAD_PRIORITY_LOW 0
71 # define VLC_THREAD_PRIORITY_INPUT 10
72 # define VLC_THREAD_PRIORITY_AUDIO 5
73 # define VLC_THREAD_PRIORITY_VIDEO 0
74 # define VLC_THREAD_PRIORITY_OUTPUT 15
75 # define VLC_THREAD_PRIORITY_HIGHEST 20
77 #elif defined(WIN32) || defined(UNDER_CE)
78 /* Define different priorities for WinNT/2K/XP and Win9x/Me */
79 # define VLC_THREAD_PRIORITY_LOW 0
80 # define VLC_THREAD_PRIORITY_INPUT \
81 THREAD_PRIORITY_ABOVE_NORMAL
82 # define VLC_THREAD_PRIORITY_AUDIO \
83 THREAD_PRIORITY_HIGHEST
84 # define VLC_THREAD_PRIORITY_VIDEO 0
85 # define VLC_THREAD_PRIORITY_OUTPUT \
86 THREAD_PRIORITY_ABOVE_NORMAL
87 # define VLC_THREAD_PRIORITY_HIGHEST \
88 THREAD_PRIORITY_TIME_CRITICAL
91 # define VLC_THREAD_PRIORITY_LOW 0
92 # define VLC_THREAD_PRIORITY_INPUT 0
93 # define VLC_THREAD_PRIORITY_AUDIO 0
94 # define VLC_THREAD_PRIORITY_VIDEO 0
95 # define VLC_THREAD_PRIORITY_OUTPUT 0
96 # define VLC_THREAD_PRIORITY_HIGHEST 0
100 /*****************************************************************************
102 *****************************************************************************/
104 #if defined (LIBVLC_USE_PTHREAD)
105 typedef pthread_t vlc_thread_t;
106 typedef pthread_mutex_t vlc_mutex_t;
107 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
108 typedef pthread_cond_t vlc_cond_t;
109 #define VLC_STATIC_COND PTHREAD_COND_INITIALIZER
110 typedef sem_t vlc_sem_t;
111 typedef pthread_rwlock_t vlc_rwlock_t;
112 typedef pthread_key_t vlc_threadvar_t;
113 typedef struct vlc_timer *vlc_timer_t;
115 #elif defined( WIN32 )
116 #if !defined( UNDER_CE )
117 typedef HANDLE vlc_thread_t;
134 unsigned long contention;
136 CRITICAL_SECTION mutex;
139 #define VLC_STATIC_MUTEX { false, { { false, 0 } } }
141 typedef HANDLE vlc_cond_t;
142 typedef HANDLE vlc_sem_t;
147 vlc_cond_t read_wait;
148 vlc_cond_t write_wait;
149 unsigned long readers;
150 unsigned long writers;
154 typedef DWORD vlc_threadvar_t;
155 typedef struct vlc_timer *vlc_timer_t;
158 #if defined( WIN32 ) && !defined ETIMEDOUT
159 # define ETIMEDOUT 10060 /* This is the value in winsock.h. */
162 /*****************************************************************************
163 * Function definitions
164 *****************************************************************************/
165 VLC_EXPORT( void, vlc_mutex_init, ( vlc_mutex_t * ) );
166 VLC_EXPORT( void, vlc_mutex_init_recursive, ( vlc_mutex_t * ) );
167 VLC_EXPORT( void, vlc_mutex_destroy, ( vlc_mutex_t * ) );
168 VLC_EXPORT( void, vlc_mutex_lock, ( vlc_mutex_t * ) );
169 VLC_EXPORT( int, vlc_mutex_trylock, ( vlc_mutex_t * ) LIBVLC_USED );
170 VLC_EXPORT( void, vlc_mutex_unlock, ( vlc_mutex_t * ) );
171 VLC_EXPORT( void, vlc_cond_init, ( vlc_cond_t * ) );
172 VLC_EXPORT( void, vlc_cond_destroy, ( vlc_cond_t * ) );
173 VLC_EXPORT( void, vlc_cond_signal, (vlc_cond_t *) );
174 VLC_EXPORT( void, vlc_cond_broadcast, (vlc_cond_t *) );
175 VLC_EXPORT( void, vlc_cond_wait, (vlc_cond_t *, vlc_mutex_t *) );
176 VLC_EXPORT( int, vlc_cond_timedwait, (vlc_cond_t *, vlc_mutex_t *, mtime_t) );
177 VLC_EXPORT( void, vlc_sem_init, (vlc_sem_t *, unsigned) );
178 VLC_EXPORT( void, vlc_sem_destroy, (vlc_sem_t *) );
179 VLC_EXPORT( int, vlc_sem_post, (vlc_sem_t *) );
180 VLC_EXPORT( void, vlc_sem_wait, (vlc_sem_t *) );
182 VLC_EXPORT( void, vlc_rwlock_init, (vlc_rwlock_t *) );
183 VLC_EXPORT( void, vlc_rwlock_destroy, (vlc_rwlock_t *) );
184 VLC_EXPORT( void, vlc_rwlock_rdlock, (vlc_rwlock_t *) );
185 VLC_EXPORT( void, vlc_rwlock_wrlock, (vlc_rwlock_t *) );
186 VLC_EXPORT( void, vlc_rwlock_unlock, (vlc_rwlock_t *) );
187 VLC_EXPORT( int, vlc_threadvar_create, (vlc_threadvar_t * , void (*) (void *) ) );
188 VLC_EXPORT( void, vlc_threadvar_delete, (vlc_threadvar_t *) );
189 VLC_EXPORT( int, vlc_threadvar_set, (vlc_threadvar_t, void *) );
190 VLC_EXPORT( void *, vlc_threadvar_get, (vlc_threadvar_t) );
191 VLC_EXPORT( int, vlc_thread_create, ( vlc_object_t *, const char *, int, const char *, void * ( * ) ( vlc_object_t * ), int ) LIBVLC_USED );
192 VLC_EXPORT( int, __vlc_thread_set_priority, ( vlc_object_t *, const char *, int, int ) );
193 VLC_EXPORT( void, __vlc_thread_join, ( vlc_object_t * ) );
195 VLC_EXPORT( int, vlc_clone, (vlc_thread_t *, void * (*) (void *), void *, int) LIBVLC_USED );
196 VLC_EXPORT( void, vlc_cancel, (vlc_thread_t) );
197 VLC_EXPORT( void, vlc_join, (vlc_thread_t, void **) );
198 VLC_EXPORT (void, vlc_control_cancel, (int cmd, ...));
200 VLC_EXPORT( int, vlc_timer_create, (vlc_timer_t *, void (*) (void *), void *) LIBVLC_USED );
201 VLC_EXPORT( void, vlc_timer_destroy, (vlc_timer_t) );
202 VLC_EXPORT( void, vlc_timer_schedule, (vlc_timer_t, bool, mtime_t, mtime_t) );
203 VLC_EXPORT( unsigned, vlc_timer_getoverrun, (vlc_timer_t) LIBVLC_USED );
205 #ifndef LIBVLC_USE_PTHREAD_CANCEL
213 VLC_EXPORT( int, vlc_savecancel, (void) );
214 VLC_EXPORT( void, vlc_restorecancel, (int state) );
215 VLC_EXPORT( void, vlc_testcancel, (void) );
217 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
219 * Registers a new procedure to run if the thread is cancelled (or otherwise
220 * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
221 * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
222 * of the block between these two function calls is not allowed (read: it will
223 * likely crash the whole process). If multiple procedures are registered,
224 * they are handled in last-in first-out order.
226 * @param routine procedure to call if the thread ends
227 * @param arg argument for the procedure
229 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
232 * Removes a cleanup procedure that was previously registered with
233 * vlc_cleanup_push().
235 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
238 * Removes a cleanup procedure that was previously registered with
239 * vlc_cleanup_push(), and executes it.
241 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
243 typedef struct vlc_cleanup_t vlc_cleanup_t;
248 void (*proc) (void *);
252 /* This macros opens a code block on purpose. This is needed for multiple
253 * calls within a single function. This also prevent Win32 developers from
254 * writing code that would break on POSIX (POSIX opens a block as well). */
255 # define vlc_cleanup_push( routine, arg ) \
257 vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
258 vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
260 # define vlc_cleanup_pop( ) \
261 vlc_control_cancel (VLC_CLEANUP_POP); \
264 # define vlc_cleanup_run( ) \
265 vlc_control_cancel (VLC_CLEANUP_POP); \
266 vlc_cleanup_data.proc (vlc_cleanup_data.data); \
269 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
271 static inline void vlc_cleanup_lock (void *lock)
273 vlc_mutex_unlock ((vlc_mutex_t *)lock);
275 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
277 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
278 typedef pthread_spinlock_t vlc_spinlock_t;
281 * Initializes a spinlock.
283 static inline void vlc_spin_init (vlc_spinlock_t *spin)
285 if (pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE))
290 * Acquires a spinlock.
292 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
294 pthread_spin_lock (spin);
298 * Releases a spinlock.
300 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
302 pthread_spin_unlock (spin);
306 * Deinitializes a spinlock.
308 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
310 pthread_spin_destroy (spin);
313 #elif defined (WIN32) && !defined (UNDER_CE)
315 typedef CRITICAL_SECTION vlc_spinlock_t;
318 * Initializes a spinlock.
320 static inline void vlc_spin_init (vlc_spinlock_t *spin)
322 if (!InitializeCriticalSectionAndSpinCount(spin, 4000))
327 * Acquires a spinlock.
329 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
331 EnterCriticalSection(spin);
335 * Releases a spinlock.
337 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
339 LeaveCriticalSection(spin);
343 * Deinitializes a spinlock.
345 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
347 DeleteCriticalSection(spin);
352 /* Fallback to plain mutexes if spinlocks are not available */
353 typedef vlc_mutex_t vlc_spinlock_t;
355 static inline void vlc_spin_init (vlc_spinlock_t *spin)
357 vlc_mutex_init (spin);
360 # define vlc_spin_lock vlc_mutex_lock
361 # define vlc_spin_unlock vlc_mutex_unlock
362 # define vlc_spin_destroy vlc_mutex_destroy
366 * Issues a full memory barrier.
368 #if defined (__APPLE__)
369 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
371 static inline void barrier (void)
373 #if defined (__GNUC__) && !defined (__APPLE__) && \
374 ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
375 __sync_synchronize ();
376 #elif defined(__APPLE__)
378 #elif defined(__powerpc__)
379 asm volatile ("sync":::"memory");
380 #elif 0 // defined(__i386__) /* Requires SSE2 support */
381 asm volatile ("mfence":::"memory");
384 vlc_spin_init (&spin);
385 vlc_spin_lock (&spin);
386 vlc_spin_unlock (&spin);
387 vlc_spin_destroy (&spin);
391 /*****************************************************************************
392 * vlc_thread_create: create a thread
393 *****************************************************************************/
394 #define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY ) \
395 vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, FUNC, PRIORITY )
397 /*****************************************************************************
398 * vlc_thread_set_priority: set the priority of the calling thread
399 *****************************************************************************/
400 #define vlc_thread_set_priority( P_THIS, PRIORITY ) \
401 __vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
403 /*****************************************************************************
404 * vlc_thread_join: wait until a thread exits
405 *****************************************************************************/
406 #define vlc_thread_join( P_THIS ) \
407 __vlc_thread_join( VLC_OBJECT(P_THIS) )
411 * Helper C++ class to lock a mutex.
412 * The mutex is locked when the object is created, and unlocked when the object
415 class vlc_mutex_locker
420 vlc_mutex_locker (vlc_mutex_t *m) : lock (m)
422 vlc_mutex_lock (lock);
425 ~vlc_mutex_locker (void)
427 vlc_mutex_unlock (lock);
432 #endif /* !_VLC_THREADS_H */