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 *);
118 #if defined( UNDER_CE )
125 CRITICAL_SECTION mutex;
128 #define VLC_STATIC_MUTEX { .initialized = 0, }
130 typedef HANDLE vlc_cond_t;
131 typedef DWORD vlc_threadvar_t;
135 #if defined( WIN32 ) && !defined ETIMEDOUT
136 # define ETIMEDOUT 10060 /* This is the value in winsock.h. */
139 /*****************************************************************************
140 * Function definitions
141 *****************************************************************************/
142 VLC_EXPORT( int, vlc_mutex_init, ( vlc_mutex_t * ) );
143 VLC_EXPORT( int, vlc_mutex_init_recursive, ( vlc_mutex_t * ) );
144 VLC_EXPORT( void, vlc_mutex_destroy, ( vlc_mutex_t * ) );
145 VLC_EXPORT( void, vlc_mutex_lock, ( vlc_mutex_t * ) );
146 VLC_EXPORT( void, vlc_mutex_unlock, ( vlc_mutex_t * ) );
147 VLC_EXPORT( int, vlc_cond_init, ( vlc_cond_t * ) );
148 VLC_EXPORT( void, vlc_cond_destroy, ( vlc_cond_t * ) );
149 VLC_EXPORT( void, vlc_cond_signal, (vlc_cond_t *) );
150 VLC_EXPORT( void, vlc_cond_broadcast, (vlc_cond_t *) );
151 VLC_EXPORT( void, vlc_cond_wait, (vlc_cond_t *, vlc_mutex_t *) );
152 VLC_EXPORT( int, vlc_cond_timedwait, (vlc_cond_t *, vlc_mutex_t *, mtime_t) );
153 VLC_EXPORT( int, vlc_threadvar_create, (vlc_threadvar_t * , void (*) (void *) ) );
154 VLC_EXPORT( void, vlc_threadvar_delete, (vlc_threadvar_t *) );
155 VLC_EXPORT( int, __vlc_thread_create, ( vlc_object_t *, const char *, int, const char *, void * ( * ) ( vlc_object_t * ), int, bool ) );
156 VLC_EXPORT( int, __vlc_thread_set_priority, ( vlc_object_t *, const char *, int, int ) );
157 VLC_EXPORT( void, __vlc_thread_join, ( vlc_object_t * ) );
159 VLC_EXPORT( int, vlc_clone, (vlc_thread_t *, void * (*) (void *), void *, int) );
160 VLC_EXPORT( void, vlc_cancel, (vlc_thread_t) );
161 VLC_EXPORT( void, vlc_join, (vlc_thread_t, void **) );
162 VLC_EXPORT (void, vlc_control_cancel, (int cmd, ...));
164 #ifndef LIBVLC_USE_PTHREAD_CANCEL
175 VLC_EXPORT(void, vlc_thread_ready, (vlc_object_t *obj));
176 #define vlc_thread_ready(o) vlc_thread_ready(VLC_OBJECT(o))
179 * Save the cancellation state and disable cancellation for the calling thread.
180 * This function must be called before entering a piece of code that is not
182 * @return Previous cancellation state (opaque value).
184 static inline int vlc_savecancel (void)
187 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
188 (void) pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
190 vlc_control_cancel (VLC_SAVE_CANCEL, &state);
196 * Restore the cancellation state for the calling thread.
197 * @param state previous state as returned by vlc_savecancel().
198 * @return Nothing, always succeeds.
200 static inline void vlc_restorecancel (int state)
202 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
203 (void) pthread_setcancelstate (state, NULL);
205 vlc_control_cancel (VLC_RESTORE_CANCEL, state);
210 * Issues an explicit deferred cancellation point.
211 * This has no effect if thread cancellation is disabled.
212 * This can be called when there is a rather slow non-sleeping operation.
214 static inline void vlc_testcancel (void)
216 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
217 pthread_testcancel ();
219 vlc_control_cancel (VLC_TEST_CANCEL);
223 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
225 * Registers a new procedure to run if the thread is cancelled (or otherwise
226 * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
227 * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
228 * of the block between these two function calls is not allowed (read: it will
229 * likely crash the whole process). If multiple procedures are registered,
230 * they are handled in last-in first-out order.
232 * @param routine procedure to call if the thread ends
233 * @param arg argument for the procedure
235 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
238 * Removes a cleanup procedure that was previously registered with
239 * vlc_cleanup_push().
241 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
244 * Removes a cleanup procedure that was previously registered with
245 * vlc_cleanup_push(), and executes it.
247 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
249 typedef struct vlc_cleanup_t vlc_cleanup_t;
254 void (*proc) (void *);
258 /* This macros opens a code block on purpose. This is needed for multiple
259 * calls within a single function. This also prevent Win32 developpers from
260 * writing code that would break on POSIX (POSIX opens a block as well). */
261 # define vlc_cleanup_push( routine, arg ) \
263 vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
264 vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
266 # define vlc_cleanup_pop( ) \
267 vlc_control_cancel (VLC_CLEANUP_POP); \
270 # define vlc_cleanup_run( ) \
271 vlc_control_cancel (VLC_CLEANUP_POP); \
272 vlc_cleanup_data.proc (vlc_cleanup_data.data); \
275 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
277 static inline void vlc_cleanup_lock (void *lock)
279 vlc_mutex_unlock ((vlc_mutex_t *)lock);
281 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
283 /*****************************************************************************
284 * vlc_threadvar_set: create: set the value of a thread-local variable
285 *****************************************************************************/
286 static inline int vlc_threadvar_set( vlc_threadvar_t * p_tls, void *p_value )
290 #if defined(LIBVLC_USE_PTHREAD)
291 i_ret = pthread_setspecific( *p_tls, p_value );
293 #elif defined( UNDER_CE ) || defined( WIN32 )
294 i_ret = TlsSetValue( *p_tls, p_value ) ? EINVAL : 0;
301 /*****************************************************************************
302 * vlc_threadvar_get: create: get the value of a thread-local variable
303 *****************************************************************************/
304 static inline void* vlc_threadvar_get( vlc_threadvar_t * p_tls )
308 #if defined(LIBVLC_USE_PTHREAD)
309 p_ret = pthread_getspecific( *p_tls );
311 #elif defined( UNDER_CE ) || defined( WIN32 )
312 p_ret = TlsGetValue( *p_tls );
319 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
320 typedef pthread_spinlock_t vlc_spinlock_t;
323 * Initializes a spinlock.
325 static inline int vlc_spin_init (vlc_spinlock_t *spin)
327 return pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE);
331 * Acquires a spinlock.
333 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
335 pthread_spin_lock (spin);
339 * Releases a spinlock.
341 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
343 pthread_spin_unlock (spin);
347 * Deinitializes a spinlock.
349 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
351 pthread_spin_destroy (spin);
354 #elif defined( WIN32 )
356 typedef CRITICAL_SECTION vlc_spinlock_t;
359 * Initializes a spinlock.
361 static inline int vlc_spin_init (vlc_spinlock_t *spin)
364 InitializeCriticalSection(spin);
367 return !InitializeCriticalSectionAndSpinCount(spin, 4000);
372 * Acquires a spinlock.
374 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
376 EnterCriticalSection(spin);
380 * Releases a spinlock.
382 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
384 LeaveCriticalSection(spin);
388 * Deinitializes a spinlock.
390 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
392 DeleteCriticalSection(spin);
397 /* Fallback to plain mutexes if spinlocks are not available */
398 typedef vlc_mutex_t vlc_spinlock_t;
400 static inline int vlc_spin_init (vlc_spinlock_t *spin)
402 return vlc_mutex_init (spin);
405 # define vlc_spin_lock vlc_mutex_lock
406 # define vlc_spin_unlock vlc_mutex_unlock
407 # define vlc_spin_destroy vlc_mutex_destroy
411 * Issues a full memory barrier.
413 #if defined (__APPLE__)
414 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
416 static inline void barrier (void)
418 #if defined (__GNUC__) && \
419 ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
420 __sync_synchronize ();
421 #elif defined(__APPLE__)
423 #elif defined(__powerpc__)
424 asm volatile ("sync":::"memory");
425 #elif 0 // defined(__i386__) /* Requires SSE2 support */
426 asm volatile ("mfence":::"memory");
429 vlc_spin_init (&spin);
430 vlc_spin_lock (&spin);
431 vlc_spin_unlock (&spin);
432 vlc_spin_destroy (&spin);
436 /*****************************************************************************
437 * vlc_thread_create: create a thread
438 *****************************************************************************/
439 #define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY, WAIT ) \
440 __vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, FUNC, PRIORITY, WAIT )
442 /*****************************************************************************
443 * vlc_thread_set_priority: set the priority of the calling thread
444 *****************************************************************************/
445 #define vlc_thread_set_priority( P_THIS, PRIORITY ) \
446 __vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
448 /*****************************************************************************
449 * vlc_thread_join: wait until a thread exits
450 *****************************************************************************/
451 #define vlc_thread_join( P_THIS ) \
452 __vlc_thread_join( VLC_OBJECT(P_THIS) )
456 * Helper C++ class to lock a mutex.
457 * The mutex is locked when the object is created, and unlocked when the object
460 class vlc_mutex_locker
465 vlc_mutex_locker (vlc_mutex_t *m) : lock (m)
467 vlc_mutex_lock (lock);
470 ~vlc_mutex_locker (void)
472 vlc_mutex_unlock (lock);
477 #endif /* !_VLC_THREADS_H */