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 ) );
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
172 VLC_EXPORT( int, vlc_savecancel, (void) );
173 VLC_EXPORT( void, vlc_restorecancel, (int state) );
174 VLC_EXPORT( void, vlc_testcancel, (void) );
176 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
178 * Registers a new procedure to run if the thread is cancelled (or otherwise
179 * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
180 * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
181 * of the block between these two function calls is not allowed (read: it will
182 * likely crash the whole process). If multiple procedures are registered,
183 * they are handled in last-in first-out order.
185 * @param routine procedure to call if the thread ends
186 * @param arg argument for the procedure
188 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
191 * Removes a cleanup procedure that was previously registered with
192 * vlc_cleanup_push().
194 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
197 * Removes a cleanup procedure that was previously registered with
198 * vlc_cleanup_push(), and executes it.
200 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
202 typedef struct vlc_cleanup_t vlc_cleanup_t;
207 void (*proc) (void *);
211 /* This macros opens a code block on purpose. This is needed for multiple
212 * calls within a single function. This also prevent Win32 developpers from
213 * writing code that would break on POSIX (POSIX opens a block as well). */
214 # define vlc_cleanup_push( routine, arg ) \
216 vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
217 vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
219 # define vlc_cleanup_pop( ) \
220 vlc_control_cancel (VLC_CLEANUP_POP); \
223 # define vlc_cleanup_run( ) \
224 vlc_control_cancel (VLC_CLEANUP_POP); \
225 vlc_cleanup_data.proc (vlc_cleanup_data.data); \
228 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
230 static inline void vlc_cleanup_lock (void *lock)
232 vlc_mutex_unlock ((vlc_mutex_t *)lock);
234 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
236 /*****************************************************************************
237 * vlc_threadvar_set: create: set the value of a thread-local variable
238 *****************************************************************************/
239 static inline int vlc_threadvar_set( vlc_threadvar_t * p_tls, void *p_value )
243 #if defined(LIBVLC_USE_PTHREAD)
244 i_ret = pthread_setspecific( *p_tls, p_value );
246 #elif defined( UNDER_CE ) || defined( WIN32 )
247 i_ret = TlsSetValue( *p_tls, p_value ) ? EINVAL : 0;
254 /*****************************************************************************
255 * vlc_threadvar_get: create: get the value of a thread-local variable
256 *****************************************************************************/
257 static inline void* vlc_threadvar_get( vlc_threadvar_t * p_tls )
261 #if defined(LIBVLC_USE_PTHREAD)
262 p_ret = pthread_getspecific( *p_tls );
264 #elif defined( UNDER_CE ) || defined( WIN32 )
265 p_ret = TlsGetValue( *p_tls );
272 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
273 typedef pthread_spinlock_t vlc_spinlock_t;
276 * Initializes a spinlock.
278 static inline int vlc_spin_init (vlc_spinlock_t *spin)
280 return pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE);
284 * Acquires a spinlock.
286 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
288 pthread_spin_lock (spin);
292 * Releases a spinlock.
294 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
296 pthread_spin_unlock (spin);
300 * Deinitializes a spinlock.
302 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
304 pthread_spin_destroy (spin);
307 #elif defined( WIN32 )
309 typedef CRITICAL_SECTION vlc_spinlock_t;
312 * Initializes a spinlock.
314 static inline int vlc_spin_init (vlc_spinlock_t *spin)
317 InitializeCriticalSection(spin);
320 return !InitializeCriticalSectionAndSpinCount(spin, 4000);
325 * Acquires a spinlock.
327 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
329 EnterCriticalSection(spin);
333 * Releases a spinlock.
335 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
337 LeaveCriticalSection(spin);
341 * Deinitializes a spinlock.
343 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
345 DeleteCriticalSection(spin);
350 /* Fallback to plain mutexes if spinlocks are not available */
351 typedef vlc_mutex_t vlc_spinlock_t;
353 static inline int vlc_spin_init (vlc_spinlock_t *spin)
355 return vlc_mutex_init (spin);
358 # define vlc_spin_lock vlc_mutex_lock
359 # define vlc_spin_unlock vlc_mutex_unlock
360 # define vlc_spin_destroy vlc_mutex_destroy
364 * Issues a full memory barrier.
366 #if defined (__APPLE__)
367 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
369 static inline void barrier (void)
371 #if defined (__GNUC__) && \
372 ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
373 __sync_synchronize ();
374 #elif defined(__APPLE__)
376 #elif defined(__powerpc__)
377 asm volatile ("sync":::"memory");
378 #elif 0 // defined(__i386__) /* Requires SSE2 support */
379 asm volatile ("mfence":::"memory");
382 vlc_spin_init (&spin);
383 vlc_spin_lock (&spin);
384 vlc_spin_unlock (&spin);
385 vlc_spin_destroy (&spin);
389 /*****************************************************************************
390 * vlc_thread_create: create a thread
391 *****************************************************************************/
392 #define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY ) \
393 vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, FUNC, PRIORITY )
395 /*****************************************************************************
396 * vlc_thread_set_priority: set the priority of the calling thread
397 *****************************************************************************/
398 #define vlc_thread_set_priority( P_THIS, PRIORITY ) \
399 __vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
401 /*****************************************************************************
402 * vlc_thread_join: wait until a thread exits
403 *****************************************************************************/
404 #define vlc_thread_join( P_THIS ) \
405 __vlc_thread_join( VLC_OBJECT(P_THIS) )
409 * Helper C++ class to lock a mutex.
410 * The mutex is locked when the object is created, and unlocked when the object
413 class vlc_mutex_locker
418 vlc_mutex_locker (vlc_mutex_t *m) : lock (m)
420 vlc_mutex_lock (lock);
423 ~vlc_mutex_locker (void)
425 vlc_mutex_unlock (lock);
430 #endif /* !_VLC_THREADS_H */