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 typedef pthread_cond_t vlc_cond_t;
109 typedef pthread_key_t vlc_threadvar_t;
111 #elif defined( WIN32 )
115 void *(*entry) (void *);
121 CRITICAL_SECTION mutex;
124 typedef HANDLE vlc_cond_t;
125 typedef DWORD vlc_threadvar_t;
129 #if defined( WIN32 ) && !defined ETIMEDOUT
130 # define ETIMEDOUT 10060 /* This is the value in winsock.h. */
133 /*****************************************************************************
134 * Function definitions
135 *****************************************************************************/
136 VLC_EXPORT( int, vlc_mutex_init, ( vlc_mutex_t * ) );
137 VLC_EXPORT( int, vlc_mutex_init_recursive, ( vlc_mutex_t * ) );
138 VLC_EXPORT( void, vlc_mutex_destroy, ( vlc_mutex_t * ) );
139 VLC_EXPORT( void, vlc_mutex_lock, ( vlc_mutex_t * ) );
140 VLC_EXPORT( void, vlc_mutex_unlock, ( vlc_mutex_t * ) );
141 VLC_EXPORT( int, vlc_cond_init, ( vlc_cond_t * ) );
142 VLC_EXPORT( void, vlc_cond_destroy, ( vlc_cond_t * ) );
143 VLC_EXPORT( void, vlc_cond_signal, (vlc_cond_t *) );
144 VLC_EXPORT( void, vlc_cond_broadcast, (vlc_cond_t *) );
145 VLC_EXPORT( void, vlc_cond_wait, (vlc_cond_t *, vlc_mutex_t *) );
146 VLC_EXPORT( int, vlc_cond_timedwait, (vlc_cond_t *, vlc_mutex_t *, mtime_t) );
147 VLC_EXPORT( int, vlc_threadvar_create, (vlc_threadvar_t * , void (*) (void *) ) );
148 VLC_EXPORT( void, vlc_threadvar_delete, (vlc_threadvar_t *) );
149 VLC_EXPORT( int, __vlc_thread_create, ( vlc_object_t *, const char *, int, const char *, void * ( * ) ( vlc_object_t * ), int, bool ) );
150 VLC_EXPORT( int, __vlc_thread_set_priority, ( vlc_object_t *, const char *, int, int ) );
151 VLC_EXPORT( void, __vlc_thread_join, ( vlc_object_t * ) );
153 VLC_EXPORT( int, vlc_clone, (vlc_thread_t *, void * (*) (void *), void *, int) );
154 VLC_EXPORT( void, vlc_cancel, (vlc_thread_t) );
155 VLC_EXPORT( void, vlc_join, (vlc_thread_t, void **) );
156 VLC_EXPORT (void, vlc_control_cancel, (int cmd, ...));
158 #ifndef LIBVLC_USE_PTHREAD_CANCEL
169 VLC_EXPORT(void, vlc_thread_ready, (vlc_object_t *obj));
170 #define vlc_thread_ready(o) vlc_thread_ready(VLC_OBJECT(o))
173 * Save the cancellation state and disable cancellation for the calling thread.
174 * This function must be called before entering a piece of code that is not
176 * @return Previous cancellation state (opaque value).
178 static inline int vlc_savecancel (void)
181 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
182 (void) pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
184 vlc_control_cancel (VLC_SAVE_CANCEL, &state);
190 * Restore the cancellation state for the calling thread.
191 * @param state previous state as returned by vlc_savecancel().
192 * @return Nothing, always succeeds.
194 static inline void vlc_restorecancel (int state)
196 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
197 (void) pthread_setcancelstate (state, NULL);
199 vlc_control_cancel (VLC_RESTORE_CANCEL, state);
204 * Issues an explicit deferred cancellation point.
205 * This has no effect if thread cancellation is disabled.
206 * This can be called when there is a rather slow non-sleeping operation.
208 static inline void vlc_testcancel (void)
210 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
211 pthread_testcancel ();
213 vlc_control_cancel (VLC_TEST_CANCEL);
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 developpers 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 /*****************************************************************************
278 * vlc_threadvar_set: create: set the value of a thread-local variable
279 *****************************************************************************/
280 static inline int vlc_threadvar_set( vlc_threadvar_t * p_tls, void *p_value )
284 #if defined(LIBVLC_USE_PTHREAD)
285 i_ret = pthread_setspecific( *p_tls, p_value );
287 #elif defined( UNDER_CE ) || defined( WIN32 )
288 i_ret = TlsSetValue( *p_tls, p_value ) ? EINVAL : 0;
295 /*****************************************************************************
296 * vlc_threadvar_get: create: get the value of a thread-local variable
297 *****************************************************************************/
298 static inline void* vlc_threadvar_get( vlc_threadvar_t * p_tls )
302 #if defined(LIBVLC_USE_PTHREAD)
303 p_ret = pthread_getspecific( *p_tls );
305 #elif defined( UNDER_CE ) || defined( WIN32 )
306 p_ret = TlsGetValue( *p_tls );
313 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
314 typedef pthread_spinlock_t vlc_spinlock_t;
317 * Initializes a spinlock.
319 static inline int vlc_spin_init (vlc_spinlock_t *spin)
321 return pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE);
325 * Acquires a spinlock.
327 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
329 pthread_spin_lock (spin);
333 * Releases a spinlock.
335 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
337 pthread_spin_unlock (spin);
341 * Deinitializes a spinlock.
343 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
345 pthread_spin_destroy (spin);
348 #elif defined( WIN32 )
350 typedef CRITICAL_SECTION vlc_spinlock_t;
353 * Initializes a spinlock.
355 static inline int vlc_spin_init (vlc_spinlock_t *spin)
358 InitializeCriticalSection(spin);
361 return !InitializeCriticalSectionAndSpinCount(spin, 4000);
366 * Acquires a spinlock.
368 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
370 EnterCriticalSection(spin);
374 * Releases a spinlock.
376 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
378 LeaveCriticalSection(spin);
382 * Deinitializes a spinlock.
384 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
386 DeleteCriticalSection(spin);
391 /* Fallback to plain mutexes if spinlocks are not available */
392 typedef vlc_mutex_t vlc_spinlock_t;
394 static inline int vlc_spin_init (vlc_spinlock_t *spin)
396 return vlc_mutex_init (spin);
399 # define vlc_spin_lock vlc_mutex_lock
400 # define vlc_spin_unlock vlc_mutex_unlock
401 # define vlc_spin_destroy vlc_mutex_destroy
405 * Issues a full memory barrier.
407 #if defined (__APPLE__)
408 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
410 static inline void barrier (void)
412 #if defined (__GNUC__) && \
413 ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
414 __sync_synchronize ();
415 #elif defined(__APPLE__)
417 #elif defined(__powerpc__)
418 asm volatile ("sync":::"memory");
419 #elif 0 // defined(__i386__) /* Requires SSE2 support */
420 asm volatile ("mfence":::"memory");
423 vlc_spin_init (&spin);
424 vlc_spin_lock (&spin);
425 vlc_spin_unlock (&spin);
426 vlc_spin_destroy (&spin);
430 /*****************************************************************************
431 * vlc_thread_create: create a thread
432 *****************************************************************************/
433 #define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY, WAIT ) \
434 __vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, FUNC, PRIORITY, WAIT )
436 /*****************************************************************************
437 * vlc_thread_set_priority: set the priority of the calling thread
438 *****************************************************************************/
439 #define vlc_thread_set_priority( P_THIS, PRIORITY ) \
440 __vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
442 /*****************************************************************************
443 * vlc_thread_join: wait until a thread exits
444 *****************************************************************************/
445 #define vlc_thread_join( P_THIS ) \
446 __vlc_thread_join( VLC_OBJECT(P_THIS) )
448 #endif /* !_VLC_THREADS_H */