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 ) || defined( UNDER_CE )
116 void *(*entry) (void *);
120 typedef HANDLE vlc_mutex_t;
121 typedef HANDLE vlc_cond_t;
122 typedef DWORD vlc_threadvar_t;
126 #if defined( WIN32 ) && !defined ETIMEDOUT
127 # define ETIMEDOUT 10060 /* This is the value in winsock.h. */
130 /*****************************************************************************
131 * Function definitions
132 *****************************************************************************/
133 VLC_EXPORT( int, vlc_mutex_init, ( vlc_mutex_t * ) );
134 VLC_EXPORT( int, vlc_mutex_init_recursive, ( vlc_mutex_t * ) );
135 VLC_EXPORT( void, vlc_mutex_destroy, ( vlc_mutex_t * ) );
136 VLC_EXPORT( void, vlc_mutex_lock, ( vlc_mutex_t * ) );
137 VLC_EXPORT( void, vlc_mutex_unlock, ( vlc_mutex_t * ) );
138 VLC_EXPORT( int, vlc_cond_init, ( vlc_cond_t * ) );
139 VLC_EXPORT( void, vlc_cond_destroy, ( vlc_cond_t * ) );
140 VLC_EXPORT( void, vlc_cond_signal, (vlc_cond_t *) );
141 VLC_EXPORT( void, vlc_cond_broadcast, (vlc_cond_t *) );
142 VLC_EXPORT( void, vlc_cond_wait, (vlc_cond_t *, vlc_mutex_t *) );
143 VLC_EXPORT( int, vlc_cond_timedwait, (vlc_cond_t *, vlc_mutex_t *, mtime_t) );
144 VLC_EXPORT( int, vlc_threadvar_create, (vlc_threadvar_t * , void (*) (void *) ) );
145 VLC_EXPORT( void, vlc_threadvar_delete, (vlc_threadvar_t *) );
146 VLC_EXPORT( int, __vlc_thread_create, ( vlc_object_t *, const char *, int, const char *, void * ( * ) ( vlc_object_t * ), int, bool ) );
147 VLC_EXPORT( int, __vlc_thread_set_priority, ( vlc_object_t *, const char *, int, int ) );
148 VLC_EXPORT( void, __vlc_thread_join, ( vlc_object_t * ) );
150 VLC_EXPORT( int, vlc_clone, (vlc_thread_t *, void * (*) (void *), void *, int) );
151 VLC_EXPORT( void, vlc_cancel, (vlc_thread_t) );
152 VLC_EXPORT( void, vlc_join, (vlc_thread_t, void **) );
153 VLC_EXPORT (void, vlc_control_cancel, (int cmd, ...));
155 #ifndef LIBVLC_USE_PTHREAD_CANCEL
166 #define vlc_thread_ready vlc_object_signal
168 VLC_EXPORT(void, vlc_thread_fatal, (const char *action, int error, const char *function, const char *file, unsigned line));
170 #if defined(LIBVLC_USE_PTHREAD)
171 # define vlc_assert_locked( m ) \
172 assert (pthread_mutex_lock (m) == EDEADLK)
174 # define vlc_assert_locked( m ) (void)m
178 * Save the cancellation state and disable cancellation for the calling thread.
179 * This function must be called before entering a piece of code that is not
181 * @return Previous cancellation state (opaque value).
183 static inline int vlc_savecancel (void)
186 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
187 (void) pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
189 vlc_control_cancel (VLC_SAVE_CANCEL, &state);
195 * Restore the cancellation state for the calling thread.
196 * @param state previous state as returned by vlc_savecancel().
197 * @return Nothing, always succeeds.
199 static inline void vlc_restorecancel (int state)
201 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
202 (void) pthread_setcancelstate (state, NULL);
204 vlc_control_cancel (VLC_RESTORE_CANCEL, state);
209 * Issues an explicit deferred cancellation point.
210 * This has no effect if thread cancellation is disabled.
211 * This can be called when there is a rather slow non-sleeping operation.
213 static inline void vlc_testcancel (void)
215 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
216 pthread_testcancel ();
218 vlc_control_cancel (VLC_TEST_CANCEL);
222 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
224 * Registers a new procedure to run if the thread is cancelled (or otherwise
225 * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
226 * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
227 * of the block between these two function calls is not allowed (read: it will
228 * likely crash the whole process). If multiple procedures are registered,
229 * they are handled in last-in first-out order.
231 * @param routine procedure to call if the thread ends
232 * @param arg argument for the procedure
234 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
237 * Removes a cleanup procedure that was previously registered with
238 * vlc_cleanup_push().
240 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
243 * Removes a cleanup procedure that was previously registered with
244 * vlc_cleanup_push(), and executes it.
246 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
248 typedef struct vlc_cleanup_t vlc_cleanup_t;
253 void (*proc) (void *);
257 /* This macros opens a code block on purpose. This is needed for multiple
258 * calls within a single function. This also prevent Win32 developpers from
259 * writing code that would break on POSIX (POSIX opens a block as well). */
260 # define vlc_cleanup_push( routine, arg ) \
262 vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
263 vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
265 # define vlc_cleanup_pop( ) \
266 vlc_control_cancel (VLC_CLEANUP_POP); \
269 # define vlc_cleanup_run( ) \
270 vlc_control_cancel (VLC_CLEANUP_POP); \
271 vlc_cleanup_data.proc (vlc_cleanup_data.data); \
274 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
276 static inline void vlc_cleanup_lock (void *lock)
278 vlc_mutex_unlock ((vlc_mutex_t *)lock);
280 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
282 /*****************************************************************************
283 * vlc_threadvar_set: create: set the value of a thread-local variable
284 *****************************************************************************/
285 static inline int vlc_threadvar_set( vlc_threadvar_t * p_tls, void *p_value )
289 #if defined(LIBVLC_USE_PTHREAD)
290 i_ret = pthread_setspecific( *p_tls, p_value );
292 #elif defined( UNDER_CE ) || defined( WIN32 )
293 i_ret = TlsSetValue( *p_tls, p_value ) ? EINVAL : 0;
300 /*****************************************************************************
301 * vlc_threadvar_get: create: get the value of a thread-local variable
302 *****************************************************************************/
303 static inline void* vlc_threadvar_get( vlc_threadvar_t * p_tls )
307 #if defined(LIBVLC_USE_PTHREAD)
308 p_ret = pthread_getspecific( *p_tls );
310 #elif defined( UNDER_CE ) || defined( WIN32 )
311 p_ret = TlsGetValue( *p_tls );
318 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
319 typedef pthread_spinlock_t vlc_spinlock_t;
322 * Initializes a spinlock.
324 static inline int vlc_spin_init (vlc_spinlock_t *spin)
326 return pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE);
330 * Acquires a spinlock.
332 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
334 pthread_spin_lock (spin);
338 * Releases a spinlock.
340 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
342 pthread_spin_unlock (spin);
346 * Deinitializes a spinlock.
348 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
350 pthread_spin_destroy (spin);
353 #elif defined( WIN32 )
355 typedef CRITICAL_SECTION vlc_spinlock_t;
358 * Initializes a spinlock.
360 static inline int vlc_spin_init (vlc_spinlock_t *spin)
362 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__) && (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)
413 __sync_synchronize ();
414 #elif defined(__APPLE__)
416 #elif defined(__powerpc__)
417 asm volatile ("sync":::"memory");
418 #elif defined(__i386__)
419 asm volatile ("mfence":::"memory");
422 vlc_spin_init (&spin);
423 vlc_spin_lock (&spin);
424 vlc_spin_unlock (&spin);
425 vlc_spin_destroy (&spin);
429 /*****************************************************************************
430 * vlc_thread_create: create a thread
431 *****************************************************************************/
432 #define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY, WAIT ) \
433 __vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, FUNC, PRIORITY, WAIT )
435 /*****************************************************************************
436 * vlc_thread_set_priority: set the priority of the calling thread
437 *****************************************************************************/
438 #define vlc_thread_set_priority( P_THIS, PRIORITY ) \
439 __vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
441 /*****************************************************************************
442 * vlc_thread_join: wait until a thread exits
443 *****************************************************************************/
444 #define vlc_thread_join( P_THIS ) \
445 __vlc_thread_join( VLC_OBJECT(P_THIS) )
447 #endif /* !_VLC_THREADS_H */