include/vlc_threads.h

   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
   7  *
   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>
  12  *
  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.
  17  *
  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.
  22  *
  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  *****************************************************************************/
  27
  28 #ifndef VLC_THREADS_H_
  29 #define VLC_THREADS_H_
  30
  31 /**
  32  * \file
  33  * This file defines structures and functions for handling threads in vlc
  34  *
  35  */
  36
  37 #if defined( UNDER_CE )
  38 #elif defined( WIN32 )
  39 #   include <process.h>                                         /* Win32 API */
  40
  41 #else                                         /* pthreads (like Linux & BSD) */
  42 #   define LIBVLC_USE_PTHREAD 1
  43 #   define LIBVLC_USE_PTHREAD_CANCEL 1
  44 #   define _APPLE_C_SOURCE    1 /* Proper pthread semantics on OSX */
  45
  46 #   include <unistd.h> /* _POSIX_SPIN_LOCKS */
  47 #   include <pthread.h>
  48
  49 /* Unnamed POSIX semaphores not supported on Mac OS X, use Mach semaphores instead */
  50 #   if defined (__APPLE__)
  51 #      include <mach/semaphore.h>
  52 #      include <mach/task.h>
  53 #   else
  54 #      include <semaphore.h>
  55 #   endif
  56
  57 #endif
  58
  59 /*****************************************************************************
  60  * Constants
  61  *****************************************************************************/
  62
  63 /* Thread priorities */
  64 #ifdef __APPLE__
  65 #   define VLC_THREAD_PRIORITY_LOW      0
  66 #   define VLC_THREAD_PRIORITY_INPUT   22
  67 #   define VLC_THREAD_PRIORITY_AUDIO   22
  68 #   define VLC_THREAD_PRIORITY_VIDEO    0
  69 #   define VLC_THREAD_PRIORITY_OUTPUT  22
  70 #   define VLC_THREAD_PRIORITY_HIGHEST 22
  71
  72 #elif defined(LIBVLC_USE_PTHREAD)
  73 #   define VLC_THREAD_PRIORITY_LOW      0
  74 #   define VLC_THREAD_PRIORITY_INPUT   10
  75 #   define VLC_THREAD_PRIORITY_AUDIO    5
  76 #   define VLC_THREAD_PRIORITY_VIDEO    0
  77 #   define VLC_THREAD_PRIORITY_OUTPUT  15
  78 #   define VLC_THREAD_PRIORITY_HIGHEST 20
  79
  80 #elif defined(WIN32) || defined(UNDER_CE)
  81 /* Define different priorities for WinNT/2K/XP and Win9x/Me */
  82 #   define VLC_THREAD_PRIORITY_LOW 0
  83 #   define VLC_THREAD_PRIORITY_INPUT \
  84         THREAD_PRIORITY_ABOVE_NORMAL
  85 #   define VLC_THREAD_PRIORITY_AUDIO \
  86         THREAD_PRIORITY_HIGHEST
  87 #   define VLC_THREAD_PRIORITY_VIDEO 0
  88 #   define VLC_THREAD_PRIORITY_OUTPUT \
  89         THREAD_PRIORITY_ABOVE_NORMAL
  90 #   define VLC_THREAD_PRIORITY_HIGHEST \
  91         THREAD_PRIORITY_TIME_CRITICAL
  92
  93 #else
  94 #   define VLC_THREAD_PRIORITY_LOW 0
  95 #   define VLC_THREAD_PRIORITY_INPUT 0
  96 #   define VLC_THREAD_PRIORITY_AUDIO 0
  97 #   define VLC_THREAD_PRIORITY_VIDEO 0
  98 #   define VLC_THREAD_PRIORITY_OUTPUT 0
  99 #   define VLC_THREAD_PRIORITY_HIGHEST 0
 100
 101 #endif
 102
 103 /*****************************************************************************
 104  * Type definitions
 105  *****************************************************************************/
 106
 107 #if defined (LIBVLC_USE_PTHREAD)
 108 typedef pthread_t       vlc_thread_t;
 109 typedef pthread_mutex_t vlc_mutex_t;
 110 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
 111 typedef pthread_cond_t  vlc_cond_t;
 112 #define VLC_STATIC_COND  PTHREAD_COND_INITIALIZER
 113 typedef pthread_rwlock_t vlc_rwlock_t;
 114 typedef pthread_key_t   vlc_threadvar_t;
 115 typedef struct vlc_timer *vlc_timer_t;
 116
 117 #if defined (__APPLE__)
 118 typedef semaphore_t     vlc_sem_t;
 119 #else
 120 typedef sem_t           vlc_sem_t;
 121 #endif
 122
 123 #elif defined( WIN32 )
 124 typedef struct vlc_thread *vlc_thread_t;
 125
 126 typedef struct
 127 {
 128     bool dynamic;
 129     union
 130     {
 131         struct
 132         {
 133             bool locked;
 134             unsigned long contention;
 135         };
 136         CRITICAL_SECTION mutex;
 137     };
 138 } vlc_mutex_t;
 139 #define VLC_STATIC_MUTEX { false, { { false, 0 } } }
 140
 141 typedef struct
 142 {
 143     HANDLE   handle;
 144     unsigned clock;
 145 } vlc_cond_t;
 146
 147 typedef HANDLE  vlc_sem_t;
 148
 149 typedef struct
 150 {
 151     vlc_mutex_t   mutex;
 152     vlc_cond_t    read_wait;
 153     vlc_cond_t    write_wait;
 154     unsigned long readers;
 155     unsigned long writers;
 156     DWORD         writer;
 157 } vlc_rwlock_t;
 158
 159 typedef struct vlc_threadvar *vlc_threadvar_t;
 160 typedef struct vlc_timer *vlc_timer_t;
 161 #endif
 162
 163 #if defined( WIN32 ) && !defined ETIMEDOUT
 164 #  define ETIMEDOUT 10060 /* This is the value in winsock.h. */
 165 #endif
 166
 167 /*****************************************************************************
 168  * Function definitions
 169  *****************************************************************************/
 170 VLC_API void vlc_mutex_init( vlc_mutex_t * );
 171 VLC_API void vlc_mutex_init_recursive( vlc_mutex_t * );
 172 VLC_API void vlc_mutex_destroy( vlc_mutex_t * );
 173 VLC_API void vlc_mutex_lock( vlc_mutex_t * );
 174 VLC_API int vlc_mutex_trylock( vlc_mutex_t * ) VLC_USED;
 175 VLC_API void vlc_mutex_unlock( vlc_mutex_t * );
 176 VLC_API void vlc_cond_init( vlc_cond_t * );
 177 VLC_API void vlc_cond_init_daytime( vlc_cond_t * );
 178 VLC_API void vlc_cond_destroy( vlc_cond_t * );
 179 VLC_API void vlc_cond_signal(vlc_cond_t *);
 180 VLC_API void vlc_cond_broadcast(vlc_cond_t *);
 181 VLC_API void vlc_cond_wait(vlc_cond_t *, vlc_mutex_t *);
 182 VLC_API int vlc_cond_timedwait(vlc_cond_t *, vlc_mutex_t *, mtime_t);
 183 VLC_API void vlc_sem_init(vlc_sem_t *, unsigned);
 184 VLC_API void vlc_sem_destroy(vlc_sem_t *);
 185 VLC_API int vlc_sem_post(vlc_sem_t *);
 186 VLC_API void vlc_sem_wait(vlc_sem_t *);
 187
 188 VLC_API void vlc_rwlock_init(vlc_rwlock_t *);
 189 VLC_API void vlc_rwlock_destroy(vlc_rwlock_t *);
 190 VLC_API void vlc_rwlock_rdlock(vlc_rwlock_t *);
 191 VLC_API void vlc_rwlock_wrlock(vlc_rwlock_t *);
 192 VLC_API void vlc_rwlock_unlock(vlc_rwlock_t *);
 193 VLC_API int vlc_threadvar_create(vlc_threadvar_t * , void (*) (void *) );
 194 VLC_API void vlc_threadvar_delete(vlc_threadvar_t *);
 195 VLC_API int vlc_threadvar_set(vlc_threadvar_t, void *);
 196 VLC_API void * vlc_threadvar_get(vlc_threadvar_t);
 197
 198 VLC_API int vlc_clone(vlc_thread_t *, void * (*) (void *), void *, int) VLC_USED;
 199 VLC_API void vlc_cancel(vlc_thread_t);
 200 VLC_API void vlc_join(vlc_thread_t, void **);
 201 VLC_API void vlc_control_cancel (int cmd, ...);
 202
 203 VLC_API int vlc_timer_create(vlc_timer_t *, void (*) (void *), void *) VLC_USED;
 204 VLC_API void vlc_timer_destroy(vlc_timer_t);
 205 VLC_API void vlc_timer_schedule(vlc_timer_t, bool, mtime_t, mtime_t);
 206 VLC_API unsigned vlc_timer_getoverrun(vlc_timer_t) VLC_USED;
 207
 208 #ifndef LIBVLC_USE_PTHREAD_CANCEL
 209 enum {
 210     VLC_CLEANUP_PUSH,
 211     VLC_CLEANUP_POP,
 212 };
 213 #endif
 214
 215 VLC_API int vlc_savecancel(void);
 216 VLC_API void vlc_restorecancel(int state);
 217 VLC_API void vlc_testcancel(void);
 218
 219 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
 220 /**
 221  * Registers a new procedure to run if the thread is cancelled (or otherwise
 222  * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
 223  * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
 224  * of the block between these two function calls is not allowed (read: it will
 225  * likely crash the whole process). If multiple procedures are registered,
 226  * they are handled in last-in first-out order.
 227  *
 228  * @param routine procedure to call if the thread ends
 229  * @param arg argument for the procedure
 230  */
 231 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
 232
 233 /**
 234  * Removes a cleanup procedure that was previously registered with
 235  * vlc_cleanup_push().
 236  */
 237 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
 238
 239 /**
 240  * Removes a cleanup procedure that was previously registered with
 241  * vlc_cleanup_push(), and executes it.
 242  */
 243 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
 244 #else
 245 typedef struct vlc_cleanup_t vlc_cleanup_t;
 246
 247 struct vlc_cleanup_t
 248 {
 249     vlc_cleanup_t *next;
 250     void         (*proc) (void *);
 251     void          *data;
 252 };
 253
 254 /* This macros opens a code block on purpose. This is needed for multiple
 255  * calls within a single function. This also prevent Win32 developers from
 256  * writing code that would break on POSIX (POSIX opens a block as well). */
 257 # define vlc_cleanup_push( routine, arg ) \
 258     do { \
 259         vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
 260         vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
 261
 262 # define vlc_cleanup_pop( ) \
 263         vlc_control_cancel (VLC_CLEANUP_POP); \
 264     } while (0)
 265
 266 # define vlc_cleanup_run( ) \
 267         vlc_control_cancel (VLC_CLEANUP_POP); \
 268         vlc_cleanup_data.proc (vlc_cleanup_data.data); \
 269     } while (0)
 270
 271 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
 272
 273 static inline void vlc_cleanup_lock (void *lock)
 274 {
 275     vlc_mutex_unlock ((vlc_mutex_t *)lock);
 276 }
 277 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
 278
 279 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
 280 typedef pthread_spinlock_t vlc_spinlock_t;
 281
 282 /**
 283  * Initializes a spinlock.
 284  */
 285 static inline void vlc_spin_init (vlc_spinlock_t *spin)
 286 {
 287     if (pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE))
 288         abort ();
 289 }
 290
 291 /**
 292  * Acquires a spinlock.
 293  */
 294 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
 295 {
 296     pthread_spin_lock (spin);
 297 }
 298
 299 /**
 300  * Releases a spinlock.
 301  */
 302 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
 303 {
 304     pthread_spin_unlock (spin);
 305 }
 306
 307 /**
 308  * Deinitializes a spinlock.
 309  */
 310 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
 311 {
 312     pthread_spin_destroy (spin);
 313 }
 314
 315 #elif defined (WIN32) && !defined (UNDER_CE)
 316
 317 typedef CRITICAL_SECTION vlc_spinlock_t;
 318
 319 /**
 320  * Initializes a spinlock.
 321  */
 322 static inline void vlc_spin_init (vlc_spinlock_t *spin)
 323 {
 324     if (!InitializeCriticalSectionAndSpinCount(spin, 4000))
 325         abort ();
 326 }
 327
 328 /**
 329  * Acquires a spinlock.
 330  */
 331 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
 332 {
 333     EnterCriticalSection(spin);
 334 }
 335
 336 /**
 337  * Releases a spinlock.
 338  */
 339 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
 340 {
 341     LeaveCriticalSection(spin);
 342 }
 343
 344 /**
 345  * Deinitializes a spinlock.
 346  */
 347 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
 348 {
 349     DeleteCriticalSection(spin);
 350 }
 351
 352 #else
 353
 354 /* Fallback to plain mutexes if spinlocks are not available */
 355 typedef vlc_mutex_t vlc_spinlock_t;
 356
 357 static inline void vlc_spin_init (vlc_spinlock_t *spin)
 358 {
 359     vlc_mutex_init (spin);
 360 }
 361
 362 # define vlc_spin_lock    vlc_mutex_lock
 363 # define vlc_spin_unlock  vlc_mutex_unlock
 364 # define vlc_spin_destroy vlc_mutex_destroy
 365 #endif
 366
 367 /**
 368  * Issues a full memory barrier.
 369  */
 370 #if defined (__APPLE__)
 371 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
 372 #endif
 373 static inline void barrier (void)
 374 {
 375 #if defined (__GNUC__) && !defined (__APPLE__) && \
 376             ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
 377     __sync_synchronize ();
 378 #elif defined(__APPLE__)
 379     OSMemoryBarrier ();
 380 #elif defined(__powerpc__)
 381     asm volatile ("sync":::"memory");
 382 #elif 0 // defined(__i386__) /*  Requires SSE2 support */
 383     asm volatile ("mfence":::"memory");
 384 #else
 385     vlc_spinlock_t spin;
 386     vlc_spin_init (&spin);
 387     vlc_spin_lock (&spin);
 388     vlc_spin_unlock (&spin);
 389     vlc_spin_destroy (&spin);
 390 #endif
 391 }
 392
 393 #ifdef __cplusplus
 394 /**
 395  * Helper C++ class to lock a mutex.
 396  * The mutex is locked when the object is created, and unlocked when the object
 397  * is destroyed.
 398  */
 399 class vlc_mutex_locker
 400 {
 401     private:
 402         vlc_mutex_t *lock;
 403     public:
 404         vlc_mutex_locker (vlc_mutex_t *m) : lock (m)
 405         {
 406             vlc_mutex_lock (lock);
 407         }
 408
 409         ~vlc_mutex_locker (void)
 410         {
 411             vlc_mutex_unlock (lock);
 412         }
 413 };
 414 #endif
 415
 416 enum {
 417    VLC_AVCODEC_MUTEX = 0,
 418    VLC_GCRYPT_MUTEX,
 419    VLC_XLIB_MUTEX,
 420    /* Insert new entry HERE */
 421    VLC_MAX_MUTEX
 422 };
 423
 424 VLC_API void vlc_global_mutex( unsigned, bool );
 425 #define vlc_global_lock( n ) vlc_global_mutex( n, true )
 426 #define vlc_global_unlock( n ) vlc_global_mutex( n, false )
 427
 428 #endif /* !_VLC_THREADS_H */