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 )
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 (IS_WINNT ? THREAD_PRIORITY_ABOVE_NORMAL : 0)
83 # define VLC_THREAD_PRIORITY_AUDIO \
84 (IS_WINNT ? THREAD_PRIORITY_HIGHEST : 0)
85 # define VLC_THREAD_PRIORITY_VIDEO \
86 (IS_WINNT ? 0 : THREAD_PRIORITY_BELOW_NORMAL )
87 # define VLC_THREAD_PRIORITY_OUTPUT \
88 (IS_WINNT ? THREAD_PRIORITY_ABOVE_NORMAL : 0)
89 # define VLC_THREAD_PRIORITY_HIGHEST \
90 (IS_WINNT ? THREAD_PRIORITY_TIME_CRITICAL : 0)
93 # define VLC_THREAD_PRIORITY_LOW 0
94 # define VLC_THREAD_PRIORITY_INPUT 0
95 # define VLC_THREAD_PRIORITY_AUDIO 0
96 # define VLC_THREAD_PRIORITY_VIDEO 0
97 # define VLC_THREAD_PRIORITY_OUTPUT 0
98 # define VLC_THREAD_PRIORITY_HIGHEST 0
102 /*****************************************************************************
104 *****************************************************************************/
106 #if defined (LIBVLC_USE_PTHREAD)
107 typedef pthread_t vlc_thread_t;
108 typedef pthread_mutex_t vlc_mutex_t;
109 typedef pthread_cond_t vlc_cond_t;
110 typedef pthread_key_t vlc_threadvar_t;
112 #elif defined( WIN32 )
116 void *(*entry) (void *);
122 CRITICAL_SECTION mutex;
128 typedef HANDLE vlc_cond_t;
129 typedef DWORD vlc_threadvar_t;
133 #if defined( WIN32 ) && !defined ETIMEDOUT
134 # define ETIMEDOUT 10060 /* This is the value in winsock.h. */
137 /*****************************************************************************
138 * Function definitions
139 *****************************************************************************/
140 VLC_EXPORT( int, vlc_mutex_init, ( vlc_mutex_t * ) );
141 VLC_EXPORT( int, vlc_mutex_init_recursive, ( vlc_mutex_t * ) );
142 VLC_EXPORT( void, vlc_mutex_destroy, ( vlc_mutex_t * ) );
143 VLC_EXPORT( void, vlc_mutex_lock, ( vlc_mutex_t * ) );
144 VLC_EXPORT( void, vlc_mutex_unlock, ( vlc_mutex_t * ) );
145 VLC_EXPORT( int, vlc_cond_init, ( vlc_cond_t * ) );
146 VLC_EXPORT( void, vlc_cond_destroy, ( vlc_cond_t * ) );
147 VLC_EXPORT( void, vlc_cond_signal, (vlc_cond_t *) );
148 VLC_EXPORT( void, vlc_cond_broadcast, (vlc_cond_t *) );
149 VLC_EXPORT( void, vlc_cond_wait, (vlc_cond_t *, vlc_mutex_t *) );
150 VLC_EXPORT( int, vlc_cond_timedwait, (vlc_cond_t *, vlc_mutex_t *, mtime_t) );
151 VLC_EXPORT( int, vlc_threadvar_create, (vlc_threadvar_t * , void (*) (void *) ) );
152 VLC_EXPORT( void, vlc_threadvar_delete, (vlc_threadvar_t *) );
153 VLC_EXPORT( int, __vlc_thread_create, ( vlc_object_t *, const char *, int, const char *, void * ( * ) ( vlc_object_t * ), int, bool ) );
154 VLC_EXPORT( int, __vlc_thread_set_priority, ( vlc_object_t *, const char *, int, int ) );
155 VLC_EXPORT( void, __vlc_thread_join, ( vlc_object_t * ) );
157 VLC_EXPORT( int, vlc_clone, (vlc_thread_t *, void * (*) (void *), void *, int) );
158 VLC_EXPORT( void, vlc_cancel, (vlc_thread_t) );
159 VLC_EXPORT( void, vlc_join, (vlc_thread_t, void **) );
160 VLC_EXPORT (void, vlc_control_cancel, (int cmd, ...));
162 #ifndef LIBVLC_USE_PTHREAD_CANCEL
173 #define vlc_thread_ready vlc_object_signal
175 #if defined(LIBVLC_USE_PTHREAD)
176 # define vlc_assert_locked( m ) \
177 assert (pthread_mutex_lock (m) == EDEADLK)
179 # define vlc_assert_locked( m ) (void)m
183 * Save the cancellation state and disable cancellation for the calling thread.
184 * This function must be called before entering a piece of code that is not
186 * @return Previous cancellation state (opaque value).
188 static inline int vlc_savecancel (void)
191 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
192 (void) pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
194 vlc_control_cancel (VLC_SAVE_CANCEL, &state);
200 * Restore the cancellation state for the calling thread.
201 * @param state previous state as returned by vlc_savecancel().
202 * @return Nothing, always succeeds.
204 static inline void vlc_restorecancel (int state)
206 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
207 (void) pthread_setcancelstate (state, NULL);
209 vlc_control_cancel (VLC_RESTORE_CANCEL, state);
214 * Issues an explicit deferred cancellation point.
215 * This has no effect if thread cancellation is disabled.
216 * This can be called when there is a rather slow non-sleeping operation.
218 static inline void vlc_testcancel (void)
220 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
221 pthread_testcancel ();
223 vlc_control_cancel (VLC_TEST_CANCEL);
227 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
229 * Registers a new procedure to run if the thread is cancelled (or otherwise
230 * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
231 * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
232 * of the block between these two function calls is not allowed (read: it will
233 * likely crash the whole process). If multiple procedures are registered,
234 * they are handled in last-in first-out order.
236 * @param routine procedure to call if the thread ends
237 * @param arg argument for the procedure
239 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
242 * Removes a cleanup procedure that was previously registered with
243 * vlc_cleanup_push().
245 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
248 * Removes a cleanup procedure that was previously registered with
249 * vlc_cleanup_push(), and executes it.
251 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
253 typedef struct vlc_cleanup_t vlc_cleanup_t;
258 void (*proc) (void *);
262 /* This macros opens a code block on purpose. This is needed for multiple
263 * calls within a single function. This also prevent Win32 developpers from
264 * writing code that would break on POSIX (POSIX opens a block as well). */
265 # define vlc_cleanup_push( routine, arg ) \
267 vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
268 vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
270 # define vlc_cleanup_pop( ) \
271 vlc_control_cancel (VLC_CLEANUP_POP); \
274 # define vlc_cleanup_run( ) \
275 vlc_control_cancel (VLC_CLEANUP_POP); \
276 vlc_cleanup_data.proc (vlc_cleanup_data.data); \
279 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
281 static inline void vlc_cleanup_lock (void *lock)
283 vlc_mutex_unlock ((vlc_mutex_t *)lock);
285 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
287 /*****************************************************************************
288 * vlc_threadvar_set: create: set the value of a thread-local variable
289 *****************************************************************************/
290 static inline int vlc_threadvar_set( vlc_threadvar_t * p_tls, void *p_value )
294 #if defined(LIBVLC_USE_PTHREAD)
295 i_ret = pthread_setspecific( *p_tls, p_value );
297 #elif defined( UNDER_CE ) || defined( WIN32 )
298 i_ret = TlsSetValue( *p_tls, p_value ) ? EINVAL : 0;
305 /*****************************************************************************
306 * vlc_threadvar_get: create: get the value of a thread-local variable
307 *****************************************************************************/
308 static inline void* vlc_threadvar_get( vlc_threadvar_t * p_tls )
312 #if defined(LIBVLC_USE_PTHREAD)
313 p_ret = pthread_getspecific( *p_tls );
315 #elif defined( UNDER_CE ) || defined( WIN32 )
316 p_ret = TlsGetValue( *p_tls );
323 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
324 typedef pthread_spinlock_t vlc_spinlock_t;
327 * Initializes a spinlock.
329 static inline int vlc_spin_init (vlc_spinlock_t *spin)
331 return pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE);
335 * Acquires a spinlock.
337 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
339 pthread_spin_lock (spin);
343 * Releases a spinlock.
345 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
347 pthread_spin_unlock (spin);
351 * Deinitializes a spinlock.
353 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
355 pthread_spin_destroy (spin);
358 #elif defined( WIN32 )
360 typedef CRITICAL_SECTION vlc_spinlock_t;
363 * Initializes a spinlock.
365 static inline int vlc_spin_init (vlc_spinlock_t *spin)
367 return !InitializeCriticalSectionAndSpinCount(spin, 4000);
371 * Acquires a spinlock.
373 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
375 EnterCriticalSection(spin);
379 * Releases a spinlock.
381 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
383 LeaveCriticalSection(spin);
387 * Deinitializes a spinlock.
389 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
391 DeleteCriticalSection(spin);
396 /* Fallback to plain mutexes if spinlocks are not available */
397 typedef vlc_mutex_t vlc_spinlock_t;
399 static inline int vlc_spin_init (vlc_spinlock_t *spin)
401 return vlc_mutex_init (spin);
404 # define vlc_spin_lock vlc_mutex_lock
405 # define vlc_spin_unlock vlc_mutex_unlock
406 # define vlc_spin_destroy vlc_mutex_destroy
410 * Issues a full memory barrier.
412 #if defined (__APPLE__)
413 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
415 static inline void barrier (void)
417 #if defined (__GNUC__) && (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)
418 __sync_synchronize ();
419 #elif defined(__APPLE__)
421 #elif defined(__powerpc__)
422 asm volatile ("sync":::"memory");
423 #elif defined(__i386__)
424 asm volatile ("mfence":::"memory");
427 vlc_spin_init (&spin);
428 vlc_spin_lock (&spin);
429 vlc_spin_unlock (&spin);
430 vlc_spin_destroy (&spin);
434 /*****************************************************************************
435 * vlc_thread_create: create a thread
436 *****************************************************************************/
437 #define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY, WAIT ) \
438 __vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, FUNC, PRIORITY, WAIT )
440 /*****************************************************************************
441 * vlc_thread_set_priority: set the priority of the calling thread
442 *****************************************************************************/
443 #define vlc_thread_set_priority( P_THIS, PRIORITY ) \
444 __vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
446 /*****************************************************************************
447 * vlc_thread_join: wait until a thread exits
448 *****************************************************************************/
449 #define vlc_thread_join( P_THIS ) \
450 __vlc_thread_join( VLC_OBJECT(P_THIS) )
452 #endif /* !_VLC_THREADS_H */