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
;
112 #elif defined( WIN32 )
116 void *(*entry
) (void *);
122 CRITICAL_SECTION mutex
;
125 #define VLC_STATIC_MUTEX { .initialized = 0, }
127 typedef HANDLE vlc_cond_t
;
128 typedef DWORD vlc_threadvar_t
;
132 #if defined( WIN32 ) && !defined ETIMEDOUT
133 # define ETIMEDOUT 10060 /* This is the value in winsock.h. */
136 /*****************************************************************************
137 * Function definitions
138 *****************************************************************************/
139 VLC_EXPORT( int, vlc_mutex_init
, ( vlc_mutex_t
* ) );
140 VLC_EXPORT( int, vlc_mutex_init_recursive
, ( vlc_mutex_t
* ) );
141 VLC_EXPORT( void, vlc_mutex_destroy
, ( vlc_mutex_t
* ) );
142 VLC_EXPORT( void, vlc_mutex_lock
, ( vlc_mutex_t
* ) );
143 VLC_EXPORT( void, vlc_mutex_unlock
, ( vlc_mutex_t
* ) );
144 VLC_EXPORT( int, vlc_cond_init
, ( vlc_cond_t
* ) );
145 VLC_EXPORT( void, vlc_cond_destroy
, ( vlc_cond_t
* ) );
146 VLC_EXPORT( void, vlc_cond_signal
, (vlc_cond_t
*) );
147 VLC_EXPORT( void, vlc_cond_broadcast
, (vlc_cond_t
*) );
148 VLC_EXPORT( void, vlc_cond_wait
, (vlc_cond_t
*, vlc_mutex_t
*) );
149 VLC_EXPORT( int, vlc_cond_timedwait
, (vlc_cond_t
*, vlc_mutex_t
*, mtime_t
) );
150 VLC_EXPORT( int, vlc_threadvar_create
, (vlc_threadvar_t
* , void (*) (void *) ) );
151 VLC_EXPORT( void, vlc_threadvar_delete
, (vlc_threadvar_t
*) );
152 VLC_EXPORT( int, __vlc_thread_create
, ( vlc_object_t
*, const char *, int, const char *, void * ( * ) ( vlc_object_t
* ), int, bool ) );
153 VLC_EXPORT( int, __vlc_thread_set_priority
, ( vlc_object_t
*, const char *, int, int ) );
154 VLC_EXPORT( void, __vlc_thread_join
, ( vlc_object_t
* ) );
156 VLC_EXPORT( int, vlc_clone
, (vlc_thread_t
*, void * (*) (void *), void *, int) );
157 VLC_EXPORT( void, vlc_cancel
, (vlc_thread_t
) );
158 VLC_EXPORT( void, vlc_join
, (vlc_thread_t
, void **) );
159 VLC_EXPORT (void, vlc_control_cancel
, (int cmd
, ...));
161 #ifndef LIBVLC_USE_PTHREAD_CANCEL
172 VLC_EXPORT(void, vlc_thread_ready
, (vlc_object_t
*obj
));
173 #define vlc_thread_ready(o) vlc_thread_ready(VLC_OBJECT(o))
176 * Save the cancellation state and disable cancellation for the calling thread.
177 * This function must be called before entering a piece of code that is not
179 * @return Previous cancellation state (opaque value).
181 static inline int vlc_savecancel (void)
184 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
185 (void) pthread_setcancelstate (PTHREAD_CANCEL_DISABLE
, &state
);
187 vlc_control_cancel (VLC_SAVE_CANCEL
, &state
);
193 * Restore the cancellation state for the calling thread.
194 * @param state previous state as returned by vlc_savecancel().
195 * @return Nothing, always succeeds.
197 static inline void vlc_restorecancel (int state
)
199 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
200 (void) pthread_setcancelstate (state
, NULL
);
202 vlc_control_cancel (VLC_RESTORE_CANCEL
, state
);
207 * Issues an explicit deferred cancellation point.
208 * This has no effect if thread cancellation is disabled.
209 * This can be called when there is a rather slow non-sleeping operation.
211 static inline void vlc_testcancel (void)
213 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
214 pthread_testcancel ();
216 vlc_control_cancel (VLC_TEST_CANCEL
);
220 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
222 * Registers a new procedure to run if the thread is cancelled (or otherwise
223 * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
224 * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
225 * of the block between these two function calls is not allowed (read: it will
226 * likely crash the whole process). If multiple procedures are registered,
227 * they are handled in last-in first-out order.
229 * @param routine procedure to call if the thread ends
230 * @param arg argument for the procedure
232 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
235 * Removes a cleanup procedure that was previously registered with
236 * vlc_cleanup_push().
238 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
241 * Removes a cleanup procedure that was previously registered with
242 * vlc_cleanup_push(), and executes it.
244 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
246 typedef struct vlc_cleanup_t vlc_cleanup_t
;
251 void (*proc
) (void *);
255 /* This macros opens a code block on purpose. This is needed for multiple
256 * calls within a single function. This also prevent Win32 developpers from
257 * writing code that would break on POSIX (POSIX opens a block as well). */
258 # define vlc_cleanup_push( routine, arg ) \
260 vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
261 vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
263 # define vlc_cleanup_pop( ) \
264 vlc_control_cancel (VLC_CLEANUP_POP); \
267 # define vlc_cleanup_run( ) \
268 vlc_control_cancel (VLC_CLEANUP_POP); \
269 vlc_cleanup_data.proc (vlc_cleanup_data.data); \
272 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
274 static inline void vlc_cleanup_lock (void *lock
)
276 vlc_mutex_unlock ((vlc_mutex_t
*)lock
);
278 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
280 /*****************************************************************************
281 * vlc_threadvar_set: create: set the value of a thread-local variable
282 *****************************************************************************/
283 static inline int vlc_threadvar_set( vlc_threadvar_t
* p_tls
, void *p_value
)
287 #if defined(LIBVLC_USE_PTHREAD)
288 i_ret
= pthread_setspecific( *p_tls
, p_value
);
290 #elif defined( UNDER_CE ) || defined( WIN32 )
291 i_ret
= TlsSetValue( *p_tls
, p_value
) ? EINVAL
: 0;
298 /*****************************************************************************
299 * vlc_threadvar_get: create: get the value of a thread-local variable
300 *****************************************************************************/
301 static inline void* vlc_threadvar_get( vlc_threadvar_t
* p_tls
)
305 #if defined(LIBVLC_USE_PTHREAD)
306 p_ret
= pthread_getspecific( *p_tls
);
308 #elif defined( UNDER_CE ) || defined( WIN32 )
309 p_ret
= TlsGetValue( *p_tls
);
316 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
317 typedef pthread_spinlock_t vlc_spinlock_t
;
320 * Initializes a spinlock.
322 static inline int vlc_spin_init (vlc_spinlock_t
*spin
)
324 return pthread_spin_init (spin
, PTHREAD_PROCESS_PRIVATE
);
328 * Acquires a spinlock.
330 static inline void vlc_spin_lock (vlc_spinlock_t
*spin
)
332 pthread_spin_lock (spin
);
336 * Releases a spinlock.
338 static inline void vlc_spin_unlock (vlc_spinlock_t
*spin
)
340 pthread_spin_unlock (spin
);
344 * Deinitializes a spinlock.
346 static inline void vlc_spin_destroy (vlc_spinlock_t
*spin
)
348 pthread_spin_destroy (spin
);
351 #elif defined( WIN32 )
353 typedef CRITICAL_SECTION vlc_spinlock_t
;
356 * Initializes a spinlock.
358 static inline int vlc_spin_init (vlc_spinlock_t
*spin
)
361 InitializeCriticalSection(spin
);
364 return !InitializeCriticalSectionAndSpinCount(spin
, 4000);
369 * Acquires a spinlock.
371 static inline void vlc_spin_lock (vlc_spinlock_t
*spin
)
373 EnterCriticalSection(spin
);
377 * Releases a spinlock.
379 static inline void vlc_spin_unlock (vlc_spinlock_t
*spin
)
381 LeaveCriticalSection(spin
);
385 * Deinitializes a spinlock.
387 static inline void vlc_spin_destroy (vlc_spinlock_t
*spin
)
389 DeleteCriticalSection(spin
);
394 /* Fallback to plain mutexes if spinlocks are not available */
395 typedef vlc_mutex_t vlc_spinlock_t
;
397 static inline int vlc_spin_init (vlc_spinlock_t
*spin
)
399 return vlc_mutex_init (spin
);
402 # define vlc_spin_lock vlc_mutex_lock
403 # define vlc_spin_unlock vlc_mutex_unlock
404 # define vlc_spin_destroy vlc_mutex_destroy
408 * Issues a full memory barrier.
410 #if defined (__APPLE__)
411 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
413 static inline void barrier (void)
415 #if defined (__GNUC__) && \
416 ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
417 __sync_synchronize ();
418 #elif defined(__APPLE__)
420 #elif defined(__powerpc__)
421 asm volatile ("sync":::"memory");
422 #elif 0 // defined(__i386__) /* Requires SSE2 support */
423 asm volatile ("mfence":::"memory");
426 vlc_spin_init (&spin
);
427 vlc_spin_lock (&spin
);
428 vlc_spin_unlock (&spin
);
429 vlc_spin_destroy (&spin
);
433 /*****************************************************************************
434 * vlc_thread_create: create a thread
435 *****************************************************************************/
436 #define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY, WAIT ) \
437 __vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, FUNC, PRIORITY, WAIT )
439 /*****************************************************************************
440 * vlc_thread_set_priority: set the priority of the calling thread
441 *****************************************************************************/
442 #define vlc_thread_set_priority( P_THIS, PRIORITY ) \
443 __vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
445 /*****************************************************************************
446 * vlc_thread_join: wait until a thread exits
447 *****************************************************************************/
448 #define vlc_thread_join( P_THIS ) \
449 __vlc_thread_join( VLC_OBJECT(P_THIS) )
451 #endif /* !_VLC_THREADS_H */