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 /* Needed for pthread_cond_timedwait */
57 /*****************************************************************************
59 *****************************************************************************/
61 /* Thread priorities */
63 # define VLC_THREAD_PRIORITY_LOW 0
64 # define VLC_THREAD_PRIORITY_INPUT 22
65 # define VLC_THREAD_PRIORITY_AUDIO 22
66 # define VLC_THREAD_PRIORITY_VIDEO 0
67 # define VLC_THREAD_PRIORITY_OUTPUT 22
68 # define VLC_THREAD_PRIORITY_HIGHEST 22
70 #elif defined(LIBVLC_USE_PTHREAD)
71 # define VLC_THREAD_PRIORITY_LOW 0
72 # define VLC_THREAD_PRIORITY_INPUT 10
73 # define VLC_THREAD_PRIORITY_AUDIO 5
74 # define VLC_THREAD_PRIORITY_VIDEO 0
75 # define VLC_THREAD_PRIORITY_OUTPUT 15
76 # define VLC_THREAD_PRIORITY_HIGHEST 20
78 #elif defined(WIN32) || defined(UNDER_CE)
79 /* Define different priorities for WinNT/2K/XP and Win9x/Me */
80 # define VLC_THREAD_PRIORITY_LOW 0
81 # define VLC_THREAD_PRIORITY_INPUT \
82 THREAD_PRIORITY_ABOVE_NORMAL
83 # define VLC_THREAD_PRIORITY_AUDIO \
84 THREAD_PRIORITY_HIGHEST
85 # define VLC_THREAD_PRIORITY_VIDEO 0
86 # define VLC_THREAD_PRIORITY_OUTPUT \
87 THREAD_PRIORITY_ABOVE_NORMAL
88 # define VLC_THREAD_PRIORITY_HIGHEST \
89 THREAD_PRIORITY_TIME_CRITICAL
92 # define VLC_THREAD_PRIORITY_LOW 0
93 # define VLC_THREAD_PRIORITY_INPUT 0
94 # define VLC_THREAD_PRIORITY_AUDIO 0
95 # define VLC_THREAD_PRIORITY_VIDEO 0
96 # define VLC_THREAD_PRIORITY_OUTPUT 0
97 # define VLC_THREAD_PRIORITY_HIGHEST 0
101 /*****************************************************************************
103 *****************************************************************************/
105 #if defined (LIBVLC_USE_PTHREAD)
106 typedef pthread_t vlc_thread_t;
107 typedef pthread_mutex_t vlc_mutex_t;
108 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
109 typedef pthread_cond_t vlc_cond_t;
110 typedef pthread_key_t vlc_threadvar_t;
111 typedef struct vlc_timer_t vlc_timer_t;
115 void (*func) (vlc_timer_t *, void *);
119 #elif defined( WIN32 )
123 void *(*entry) (void *);
125 #if defined( UNDER_CE )
133 CRITICAL_SECTION mutex;
135 #define VLC_STATIC_MUTEX { 0, }
137 typedef HANDLE vlc_cond_t;
138 typedef DWORD vlc_threadvar_t;
139 typedef struct vlc_timer_t vlc_timer_t;
143 void (*func) (vlc_timer_t *, void *);
146 CRITICAL_SECTION serializer;
147 LONG volatile counter;
152 #if defined( WIN32 ) && !defined ETIMEDOUT
153 # define ETIMEDOUT 10060 /* This is the value in winsock.h. */
156 /*****************************************************************************
157 * Function definitions
158 *****************************************************************************/
159 VLC_EXPORT( void, vlc_mutex_init, ( vlc_mutex_t * ) );
160 VLC_EXPORT( void, vlc_mutex_init_recursive, ( vlc_mutex_t * ) );
161 VLC_EXPORT( void, vlc_mutex_destroy, ( vlc_mutex_t * ) );
162 VLC_EXPORT( void, vlc_mutex_lock, ( vlc_mutex_t * ) );
163 VLC_EXPORT( int, vlc_mutex_trylock, ( vlc_mutex_t * ) LIBVLC_USED );
164 VLC_EXPORT( void, vlc_mutex_unlock, ( vlc_mutex_t * ) );
165 VLC_EXPORT( void, vlc_cond_init, ( vlc_cond_t * ) );
166 VLC_EXPORT( void, vlc_cond_destroy, ( vlc_cond_t * ) );
167 VLC_EXPORT( void, vlc_cond_signal, (vlc_cond_t *) );
168 VLC_EXPORT( void, vlc_cond_broadcast, (vlc_cond_t *) );
169 VLC_EXPORT( void, vlc_cond_wait, (vlc_cond_t *, vlc_mutex_t *) );
170 VLC_EXPORT( int, vlc_cond_timedwait, (vlc_cond_t *, vlc_mutex_t *, mtime_t) );
171 VLC_EXPORT( int, vlc_threadvar_create, (vlc_threadvar_t * , void (*) (void *) ) );
172 VLC_EXPORT( void, vlc_threadvar_delete, (vlc_threadvar_t *) );
173 VLC_EXPORT( int, vlc_threadvar_set, (vlc_threadvar_t, void *) );
174 VLC_EXPORT( void *, vlc_threadvar_get, (vlc_threadvar_t) );
175 VLC_EXPORT( int, vlc_thread_create, ( vlc_object_t *, const char *, int, const char *, void * ( * ) ( vlc_object_t * ), int ) LIBVLC_USED );
176 VLC_EXPORT( int, __vlc_thread_set_priority, ( vlc_object_t *, const char *, int, int ) );
177 VLC_EXPORT( void, __vlc_thread_join, ( vlc_object_t * ) );
179 VLC_EXPORT( int, vlc_clone, (vlc_thread_t *, void * (*) (void *), void *, int) LIBVLC_USED );
180 VLC_EXPORT( void, vlc_cancel, (vlc_thread_t) );
181 VLC_EXPORT( void, vlc_join, (vlc_thread_t, void **) );
182 VLC_EXPORT (void, vlc_control_cancel, (int cmd, ...));
184 VLC_EXPORT( int, vlc_timer_create, (vlc_timer_t *, void (*) (vlc_timer_t *, void *), void *) LIBVLC_USED );
185 VLC_EXPORT( void, vlc_timer_destroy, (vlc_timer_t *) );
186 VLC_EXPORT( void, vlc_timer_schedule, (vlc_timer_t *, bool, mtime_t, mtime_t) );
187 VLC_EXPORT( unsigned, vlc_timer_getoverrun, (const vlc_timer_t *) LIBVLC_USED );
189 #ifndef LIBVLC_USE_PTHREAD_CANCEL
197 VLC_EXPORT( int, vlc_savecancel, (void) );
198 VLC_EXPORT( void, vlc_restorecancel, (int state) );
199 VLC_EXPORT( void, vlc_testcancel, (void) );
201 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
203 * Registers a new procedure to run if the thread is cancelled (or otherwise
204 * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
205 * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
206 * of the block between these two function calls is not allowed (read: it will
207 * likely crash the whole process). If multiple procedures are registered,
208 * they are handled in last-in first-out order.
210 * @param routine procedure to call if the thread ends
211 * @param arg argument for the procedure
213 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
216 * Removes a cleanup procedure that was previously registered with
217 * vlc_cleanup_push().
219 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
222 * Removes a cleanup procedure that was previously registered with
223 * vlc_cleanup_push(), and executes it.
225 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
227 typedef struct vlc_cleanup_t vlc_cleanup_t;
232 void (*proc) (void *);
236 /* This macros opens a code block on purpose. This is needed for multiple
237 * calls within a single function. This also prevent Win32 developpers from
238 * writing code that would break on POSIX (POSIX opens a block as well). */
239 # define vlc_cleanup_push( routine, arg ) \
241 vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
242 vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
244 # define vlc_cleanup_pop( ) \
245 vlc_control_cancel (VLC_CLEANUP_POP); \
248 # define vlc_cleanup_run( ) \
249 vlc_control_cancel (VLC_CLEANUP_POP); \
250 vlc_cleanup_data.proc (vlc_cleanup_data.data); \
253 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
255 static inline void vlc_cleanup_lock (void *lock)
257 vlc_mutex_unlock ((vlc_mutex_t *)lock);
259 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
261 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
262 typedef pthread_spinlock_t vlc_spinlock_t;
265 * Initializes a spinlock.
267 static inline void vlc_spin_init (vlc_spinlock_t *spin)
269 if (pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE))
274 * Acquires a spinlock.
276 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
278 pthread_spin_lock (spin);
282 * Releases a spinlock.
284 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
286 pthread_spin_unlock (spin);
290 * Deinitializes a spinlock.
292 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
294 pthread_spin_destroy (spin);
297 #elif defined (WIN32) && !defined (UNDER_CE)
299 typedef CRITICAL_SECTION vlc_spinlock_t;
302 * Initializes a spinlock.
304 static inline void vlc_spin_init (vlc_spinlock_t *spin)
306 if (!InitializeCriticalSectionAndSpinCount(spin, 4000))
311 * Acquires a spinlock.
313 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
315 EnterCriticalSection(spin);
319 * Releases a spinlock.
321 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
323 LeaveCriticalSection(spin);
327 * Deinitializes a spinlock.
329 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
331 DeleteCriticalSection(spin);
336 /* Fallback to plain mutexes if spinlocks are not available */
337 typedef vlc_mutex_t vlc_spinlock_t;
339 static inline void vlc_spin_init (vlc_spinlock_t *spin)
341 vlc_mutex_init (spin);
344 # define vlc_spin_lock vlc_mutex_lock
345 # define vlc_spin_unlock vlc_mutex_unlock
346 # define vlc_spin_destroy vlc_mutex_destroy
350 * Issues a full memory barrier.
352 #if defined (__APPLE__)
353 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
355 static inline void barrier (void)
357 #if defined (__GNUC__) && !defined (__APPLE__) && \
358 ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
359 __sync_synchronize ();
360 #elif defined(__APPLE__)
362 #elif defined(__powerpc__)
363 asm volatile ("sync":::"memory");
364 #elif 0 // defined(__i386__) /* Requires SSE2 support */
365 asm volatile ("mfence":::"memory");
368 vlc_spin_init (&spin);
369 vlc_spin_lock (&spin);
370 vlc_spin_unlock (&spin);
371 vlc_spin_destroy (&spin);
375 /*****************************************************************************
376 * vlc_thread_create: create a thread
377 *****************************************************************************/
378 #define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY ) \
379 vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, FUNC, PRIORITY )
381 /*****************************************************************************
382 * vlc_thread_set_priority: set the priority of the calling thread
383 *****************************************************************************/
384 #define vlc_thread_set_priority( P_THIS, PRIORITY ) \
385 __vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
387 /*****************************************************************************
388 * vlc_thread_join: wait until a thread exits
389 *****************************************************************************/
390 #define vlc_thread_join( P_THIS ) \
391 __vlc_thread_join( VLC_OBJECT(P_THIS) )
395 * Helper C++ class to lock a mutex.
396 * The mutex is locked when the object is created, and unlocked when the object
399 class vlc_mutex_locker
404 vlc_mutex_locker (vlc_mutex_t *m) : lock (m)
406 vlc_mutex_lock (lock);
409 ~vlc_mutex_locker (void)
411 vlc_mutex_unlock (lock);
416 #endif /* !_VLC_THREADS_H */