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 #   include <semaphore.h>
  49
  50 #endif
  51
  52 /*****************************************************************************
  53  * Constants
  54  *****************************************************************************/
  55
  56 /* Thread priorities */
  57 #ifdef __APPLE__
  58 #   define VLC_THREAD_PRIORITY_LOW      0
  59 #   define VLC_THREAD_PRIORITY_INPUT   22
  60 #   define VLC_THREAD_PRIORITY_AUDIO   22
  61 #   define VLC_THREAD_PRIORITY_VIDEO    0
  62 #   define VLC_THREAD_PRIORITY_OUTPUT  22
  63 #   define VLC_THREAD_PRIORITY_HIGHEST 22
  64
  65 #elif defined(LIBVLC_USE_PTHREAD)
  66 #   define VLC_THREAD_PRIORITY_LOW      0
  67 #   define VLC_THREAD_PRIORITY_INPUT   10
  68 #   define VLC_THREAD_PRIORITY_AUDIO    5
  69 #   define VLC_THREAD_PRIORITY_VIDEO    0
  70 #   define VLC_THREAD_PRIORITY_OUTPUT  15
  71 #   define VLC_THREAD_PRIORITY_HIGHEST 20
  72
  73 #elif defined(WIN32) || defined(UNDER_CE)
  74 /* Define different priorities for WinNT/2K/XP and Win9x/Me */
  75 #   define VLC_THREAD_PRIORITY_LOW 0
  76 #   define VLC_THREAD_PRIORITY_INPUT \
  77         THREAD_PRIORITY_ABOVE_NORMAL
  78 #   define VLC_THREAD_PRIORITY_AUDIO \
  79         THREAD_PRIORITY_HIGHEST
  80 #   define VLC_THREAD_PRIORITY_VIDEO 0
  81 #   define VLC_THREAD_PRIORITY_OUTPUT \
  82         THREAD_PRIORITY_ABOVE_NORMAL
  83 #   define VLC_THREAD_PRIORITY_HIGHEST \
  84         THREAD_PRIORITY_TIME_CRITICAL
  85
  86 #else
  87 #   define VLC_THREAD_PRIORITY_LOW 0
  88 #   define VLC_THREAD_PRIORITY_INPUT 0
  89 #   define VLC_THREAD_PRIORITY_AUDIO 0
  90 #   define VLC_THREAD_PRIORITY_VIDEO 0
  91 #   define VLC_THREAD_PRIORITY_OUTPUT 0
  92 #   define VLC_THREAD_PRIORITY_HIGHEST 0
  93
  94 #endif
  95
  96 /*****************************************************************************
  97  * Type definitions
  98  *****************************************************************************/
  99
 100 #if defined (LIBVLC_USE_PTHREAD)
 101 typedef pthread_t       vlc_thread_t;
 102 typedef pthread_mutex_t vlc_mutex_t;
 103 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
 104 typedef pthread_cond_t  vlc_cond_t;
 105 #define VLC_STATIC_COND  PTHREAD_COND_INITIALIZER
 106 typedef sem_t           vlc_sem_t;
 107 typedef pthread_rwlock_t vlc_rwlock_t;
 108 typedef pthread_key_t   vlc_threadvar_t;
 109 typedef struct vlc_timer *vlc_timer_t;
 110
 111 #elif defined( WIN32 )
 112 #if !defined( UNDER_CE )
 113 typedef HANDLE vlc_thread_t;
 114 #else
 115 typedef struct
 116 {
 117     HANDLE handle;
 118     HANDLE cancel_event;
 119 } *vlc_thread_t;
 120 #endif
 121
 122 typedef struct
 123 {
 124     bool dynamic;
 125     union
 126     {
 127         struct
 128         {
 129             bool locked;
 130             unsigned long contention;
 131         };
 132         CRITICAL_SECTION mutex;
 133     };
 134 } vlc_mutex_t;
 135 #define VLC_STATIC_MUTEX { false, { { false, 0 } } }
 136
 137 typedef struct
 138 {
 139     HANDLE   handle;
 140     unsigned clock;
 141 } vlc_cond_t;
 142
 143 typedef HANDLE  vlc_sem_t;
 144
 145 typedef struct
 146 {
 147     vlc_mutex_t   mutex;
 148     vlc_cond_t    read_wait;
 149     vlc_cond_t    write_wait;
 150     unsigned long readers;
 151     unsigned long writers;
 152     DWORD         writer;
 153 } vlc_rwlock_t;
 154
 155 typedef DWORD   vlc_threadvar_t;
 156 typedef struct vlc_timer *vlc_timer_t;
 157 #endif
 158
 159 #if defined( WIN32 ) && !defined ETIMEDOUT
 160 #  define ETIMEDOUT 10060 /* This is the value in winsock.h. */
 161 #endif
 162
 163 /*****************************************************************************
 164  * Function definitions
 165  *****************************************************************************/
 166 VLC_EXPORT( void, vlc_mutex_init,    ( vlc_mutex_t * ) );
 167 VLC_EXPORT( void, vlc_mutex_init_recursive, ( vlc_mutex_t * ) );
 168 VLC_EXPORT( void, vlc_mutex_destroy, ( vlc_mutex_t * ) );
 169 VLC_EXPORT( void, vlc_mutex_lock, ( vlc_mutex_t * ) );
 170 VLC_EXPORT( int,  vlc_mutex_trylock, ( vlc_mutex_t * ) LIBVLC_USED );
 171 VLC_EXPORT( void, vlc_mutex_unlock, ( vlc_mutex_t * ) );
 172 VLC_EXPORT( void, vlc_cond_init,     ( vlc_cond_t * ) );
 173 VLC_EXPORT( void, vlc_cond_init_daytime, ( vlc_cond_t * ) );
 174 VLC_EXPORT( void, vlc_cond_destroy,  ( vlc_cond_t * ) );
 175 VLC_EXPORT( void, vlc_cond_signal, (vlc_cond_t *) );
 176 VLC_EXPORT( void, vlc_cond_broadcast, (vlc_cond_t *) );
 177 VLC_EXPORT( void, vlc_cond_wait, (vlc_cond_t *, vlc_mutex_t *) );
 178 VLC_EXPORT( int,  vlc_cond_timedwait, (vlc_cond_t *, vlc_mutex_t *, mtime_t) );
 179 VLC_EXPORT( void, vlc_sem_init, (vlc_sem_t *, unsigned) );
 180 VLC_EXPORT( void, vlc_sem_destroy, (vlc_sem_t *) );
 181 VLC_EXPORT( int,  vlc_sem_post, (vlc_sem_t *) );
 182 VLC_EXPORT( void, vlc_sem_wait, (vlc_sem_t *) );
 183
 184 VLC_EXPORT( void, vlc_rwlock_init, (vlc_rwlock_t *) );
 185 VLC_EXPORT( void, vlc_rwlock_destroy, (vlc_rwlock_t *) );
 186 VLC_EXPORT( void, vlc_rwlock_rdlock, (vlc_rwlock_t *) );
 187 VLC_EXPORT( void, vlc_rwlock_wrlock, (vlc_rwlock_t *) );
 188 VLC_EXPORT( void, vlc_rwlock_unlock, (vlc_rwlock_t *) );
 189 VLC_EXPORT( int, vlc_threadvar_create, (vlc_threadvar_t * , void (*) (void *) ) );
 190 VLC_EXPORT( void, vlc_threadvar_delete, (vlc_threadvar_t *) );
 191 VLC_EXPORT( int, vlc_threadvar_set, (vlc_threadvar_t, void *) );
 192 VLC_EXPORT( void *, vlc_threadvar_get, (vlc_threadvar_t) );
 193 VLC_EXPORT( int,  vlc_thread_create, ( vlc_object_t *, const char *, int, const char *, void * ( * ) ( vlc_object_t * ), int ) LIBVLC_USED );
 194 VLC_EXPORT( int,  vlc_thread_set_priority, ( vlc_object_t *, const char *, int, int ) );
 195 VLC_EXPORT( void, vlc_thread_join,   ( vlc_object_t * ) );
 196
 197 VLC_EXPORT( int, vlc_clone, (vlc_thread_t *, void * (*) (void *), void *, int) LIBVLC_USED );
 198 VLC_EXPORT( void, vlc_cancel, (vlc_thread_t) );
 199 VLC_EXPORT( void, vlc_join, (vlc_thread_t, void **) );
 200 VLC_EXPORT (void, vlc_control_cancel, (int cmd, ...));
 201
 202 VLC_EXPORT( int, vlc_timer_create, (vlc_timer_t *, void (*) (void *), void *) LIBVLC_USED );
 203 VLC_EXPORT( void, vlc_timer_destroy, (vlc_timer_t) );
 204 VLC_EXPORT( void, vlc_timer_schedule, (vlc_timer_t, bool, mtime_t, mtime_t) );
 205 VLC_EXPORT( unsigned, vlc_timer_getoverrun, (vlc_timer_t) LIBVLC_USED );
 206
 207 #ifndef LIBVLC_USE_PTHREAD_CANCEL
 208 enum {
 209     VLC_CLEANUP_PUSH,
 210     VLC_CLEANUP_POP,
 211 };
 212 #endif
 213
 214 VLC_EXPORT( int, vlc_savecancel, (void) );
 215 VLC_EXPORT( void, vlc_restorecancel, (int state) );
 216 VLC_EXPORT( void, vlc_testcancel, (void) );
 217
 218 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
 219 /**
 220  * Registers a new procedure to run if the thread is cancelled (or otherwise
 221  * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
 222  * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
 223  * of the block between these two function calls is not allowed (read: it will
 224  * likely crash the whole process). If multiple procedures are registered,
 225  * they are handled in last-in first-out order.
 226  *
 227  * @param routine procedure to call if the thread ends
 228  * @param arg argument for the procedure
 229  */
 230 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
 231
 232 /**
 233  * Removes a cleanup procedure that was previously registered with
 234  * vlc_cleanup_push().
 235  */
 236 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
 237
 238 /**
 239  * Removes a cleanup procedure that was previously registered with
 240  * vlc_cleanup_push(), and executes it.
 241  */
 242 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
 243 #else
 244 typedef struct vlc_cleanup_t vlc_cleanup_t;
 245
 246 struct vlc_cleanup_t
 247 {
 248     vlc_cleanup_t *next;
 249     void         (*proc) (void *);
 250     void          *data;
 251 };
 252
 253 /* This macros opens a code block on purpose. This is needed for multiple
 254  * calls within a single function. This also prevent Win32 developers from
 255  * writing code that would break on POSIX (POSIX opens a block as well). */
 256 # define vlc_cleanup_push( routine, arg ) \
 257     do { \
 258         vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
 259         vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
 260
 261 # define vlc_cleanup_pop( ) \
 262         vlc_control_cancel (VLC_CLEANUP_POP); \
 263     } while (0)
 264
 265 # define vlc_cleanup_run( ) \
 266         vlc_control_cancel (VLC_CLEANUP_POP); \
 267         vlc_cleanup_data.proc (vlc_cleanup_data.data); \
 268     } while (0)
 269
 270 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
 271
 272 static inline void vlc_cleanup_lock (void *lock)
 273 {
 274     vlc_mutex_unlock ((vlc_mutex_t *)lock);
 275 }
 276 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
 277
 278 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
 279 typedef pthread_spinlock_t vlc_spinlock_t;
 280
 281 /**
 282  * Initializes a spinlock.
 283  */
 284 static inline void vlc_spin_init (vlc_spinlock_t *spin)
 285 {
 286     if (pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE))
 287         abort ();
 288 }
 289
 290 /**
 291  * Acquires a spinlock.
 292  */
 293 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
 294 {
 295     pthread_spin_lock (spin);
 296 }
 297
 298 /**
 299  * Releases a spinlock.
 300  */
 301 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
 302 {
 303     pthread_spin_unlock (spin);
 304 }
 305
 306 /**
 307  * Deinitializes a spinlock.
 308  */
 309 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
 310 {
 311     pthread_spin_destroy (spin);
 312 }
 313
 314 #elif defined (WIN32) && !defined (UNDER_CE)
 315
 316 typedef CRITICAL_SECTION vlc_spinlock_t;
 317
 318 /**
 319  * Initializes a spinlock.
 320  */
 321 static inline void vlc_spin_init (vlc_spinlock_t *spin)
 322 {
 323     if (!InitializeCriticalSectionAndSpinCount(spin, 4000))
 324         abort ();
 325 }
 326
 327 /**
 328  * Acquires a spinlock.
 329  */
 330 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
 331 {
 332     EnterCriticalSection(spin);
 333 }
 334
 335 /**
 336  * Releases a spinlock.
 337  */
 338 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
 339 {
 340     LeaveCriticalSection(spin);
 341 }
 342
 343 /**
 344  * Deinitializes a spinlock.
 345  */
 346 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
 347 {
 348     DeleteCriticalSection(spin);
 349 }
 350
 351 #else
 352
 353 /* Fallback to plain mutexes if spinlocks are not available */
 354 typedef vlc_mutex_t vlc_spinlock_t;
 355
 356 static inline void vlc_spin_init (vlc_spinlock_t *spin)
 357 {
 358     vlc_mutex_init (spin);
 359 }
 360
 361 # define vlc_spin_lock    vlc_mutex_lock
 362 # define vlc_spin_unlock  vlc_mutex_unlock
 363 # define vlc_spin_destroy vlc_mutex_destroy
 364 #endif
 365
 366 /**
 367  * Issues a full memory barrier.
 368  */
 369 #if defined (__APPLE__)
 370 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
 371 #endif
 372 static inline void barrier (void)
 373 {
 374 #if defined (__GNUC__) && !defined (__APPLE__) && \
 375             ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
 376     __sync_synchronize ();
 377 #elif defined(__APPLE__)
 378     OSMemoryBarrier ();
 379 #elif defined(__powerpc__)
 380     asm volatile ("sync":::"memory");
 381 #elif 0 // defined(__i386__) /*  Requires SSE2 support */
 382     asm volatile ("mfence":::"memory");
 383 #else
 384     vlc_spinlock_t spin;
 385     vlc_spin_init (&spin);
 386     vlc_spin_lock (&spin);
 387     vlc_spin_unlock (&spin);
 388     vlc_spin_destroy (&spin);
 389 #endif
 390 }
 391
 392 /*****************************************************************************
 393  * vlc_thread_create: create a thread
 394  *****************************************************************************/
 395 #define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY )         \
 396     vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, FUNC, PRIORITY )
 397
 398 /*****************************************************************************
 399  * vlc_thread_set_priority: set the priority of the calling thread
 400  *****************************************************************************/
 401 #define vlc_thread_set_priority( P_THIS, PRIORITY )                         \
 402     vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
 403
 404 /*****************************************************************************
 405  * vlc_thread_join: wait until a thread exits
 406  *****************************************************************************/
 407 #define vlc_thread_join( P_THIS )                                           \
 408     vlc_thread_join( VLC_OBJECT(P_THIS) )
 409
 410 #ifdef __cplusplus
 411 /**
 412  * Helper C++ class to lock a mutex.
 413  * The mutex is locked when the object is created, and unlocked when the object
 414  * is destroyed.
 415  */
 416 class vlc_mutex_locker
 417 {
 418     private:
 419         vlc_mutex_t *lock;
 420     public:
 421         vlc_mutex_locker (vlc_mutex_t *m) : lock (m)
 422         {
 423             vlc_mutex_lock (lock);
 424         }
 425
 426         ~vlc_mutex_locker (void)
 427         {
 428             vlc_mutex_unlock (lock);
 429         }
 430 };
 431 #endif
 432
 433 #endif /* !_VLC_THREADS_H */