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 #if !defined( UNDER_CE )
 125 typedef HANDLE vlc_thread_t;
 126 #else
 127 typedef struct
 128 {
 129     HANDLE handle;
 130     HANDLE cancel_event;
 131 } *vlc_thread_t;
 132 #endif
 133
 134 typedef struct
 135 {
 136     bool dynamic;
 137     union
 138     {
 139         struct
 140         {
 141             bool locked;
 142             unsigned long contention;
 143         };
 144         CRITICAL_SECTION mutex;
 145     };
 146 } vlc_mutex_t;
 147 #define VLC_STATIC_MUTEX { false, { { false, 0 } } }
 148
 149 typedef struct
 150 {
 151     HANDLE   handle;
 152     unsigned clock;
 153 } vlc_cond_t;
 154
 155 typedef HANDLE  vlc_sem_t;
 156
 157 typedef struct
 158 {
 159     vlc_mutex_t   mutex;
 160     vlc_cond_t    read_wait;
 161     vlc_cond_t    write_wait;
 162     unsigned long readers;
 163     unsigned long writers;
 164     DWORD         writer;
 165 } vlc_rwlock_t;
 166
 167 typedef DWORD   vlc_threadvar_t;
 168 typedef struct vlc_timer *vlc_timer_t;
 169 #endif
 170
 171 #if defined( WIN32 ) && !defined ETIMEDOUT
 172 #  define ETIMEDOUT 10060 /* This is the value in winsock.h. */
 173 #endif
 174
 175 /*****************************************************************************
 176  * Function definitions
 177  *****************************************************************************/
 178 VLC_EXPORT( void, vlc_mutex_init,    ( vlc_mutex_t * ) );
 179 VLC_EXPORT( void, vlc_mutex_init_recursive, ( vlc_mutex_t * ) );
 180 VLC_EXPORT( void, vlc_mutex_destroy, ( vlc_mutex_t * ) );
 181 VLC_EXPORT( void, vlc_mutex_lock, ( vlc_mutex_t * ) );
 182 VLC_EXPORT( int,  vlc_mutex_trylock, ( vlc_mutex_t * ) LIBVLC_USED );
 183 VLC_EXPORT( void, vlc_mutex_unlock, ( vlc_mutex_t * ) );
 184 VLC_EXPORT( void, vlc_cond_init,     ( vlc_cond_t * ) );
 185 VLC_EXPORT( void, vlc_cond_init_daytime, ( vlc_cond_t * ) );
 186 VLC_EXPORT( void, vlc_cond_destroy,  ( vlc_cond_t * ) );
 187 VLC_EXPORT( void, vlc_cond_signal, (vlc_cond_t *) );
 188 VLC_EXPORT( void, vlc_cond_broadcast, (vlc_cond_t *) );
 189 VLC_EXPORT( void, vlc_cond_wait, (vlc_cond_t *, vlc_mutex_t *) );
 190 VLC_EXPORT( int,  vlc_cond_timedwait, (vlc_cond_t *, vlc_mutex_t *, mtime_t) );
 191 VLC_EXPORT( void, vlc_sem_init, (vlc_sem_t *, unsigned) );
 192 VLC_EXPORT( void, vlc_sem_destroy, (vlc_sem_t *) );
 193 VLC_EXPORT( int,  vlc_sem_post, (vlc_sem_t *) );
 194 VLC_EXPORT( void, vlc_sem_wait, (vlc_sem_t *) );
 195
 196 VLC_EXPORT( void, vlc_rwlock_init, (vlc_rwlock_t *) );
 197 VLC_EXPORT( void, vlc_rwlock_destroy, (vlc_rwlock_t *) );
 198 VLC_EXPORT( void, vlc_rwlock_rdlock, (vlc_rwlock_t *) );
 199 VLC_EXPORT( void, vlc_rwlock_wrlock, (vlc_rwlock_t *) );
 200 VLC_EXPORT( void, vlc_rwlock_unlock, (vlc_rwlock_t *) );
 201 VLC_EXPORT( int, vlc_threadvar_create, (vlc_threadvar_t * , void (*) (void *) ) );
 202 VLC_EXPORT( void, vlc_threadvar_delete, (vlc_threadvar_t *) );
 203 VLC_EXPORT( int, vlc_threadvar_set, (vlc_threadvar_t, void *) );
 204 VLC_EXPORT( void *, vlc_threadvar_get, (vlc_threadvar_t) );
 205 VLC_EXPORT( int,  vlc_thread_create, ( vlc_object_t *, const char *, int, const char *, void * ( * ) ( vlc_object_t * ), int ) LIBVLC_USED );
 206 VLC_EXPORT( int,  vlc_thread_set_priority, ( vlc_object_t *, const char *, int, int ) );
 207 VLC_EXPORT( void, vlc_thread_join,   ( vlc_object_t * ) );
 208
 209 VLC_EXPORT( int, vlc_clone, (vlc_thread_t *, void * (*) (void *), void *, int) LIBVLC_USED );
 210 VLC_EXPORT( void, vlc_cancel, (vlc_thread_t) );
 211 VLC_EXPORT( void, vlc_join, (vlc_thread_t, void **) );
 212 VLC_EXPORT (void, vlc_control_cancel, (int cmd, ...));
 213
 214 VLC_EXPORT( int, vlc_timer_create, (vlc_timer_t *, void (*) (void *), void *) LIBVLC_USED );
 215 VLC_EXPORT( void, vlc_timer_destroy, (vlc_timer_t) );
 216 VLC_EXPORT( void, vlc_timer_schedule, (vlc_timer_t, bool, mtime_t, mtime_t) );
 217 VLC_EXPORT( unsigned, vlc_timer_getoverrun, (vlc_timer_t) LIBVLC_USED );
 218
 219 #ifndef LIBVLC_USE_PTHREAD_CANCEL
 220 enum {
 221     VLC_CLEANUP_PUSH,
 222     VLC_CLEANUP_POP,
 223 };
 224 #endif
 225
 226 VLC_EXPORT( int, vlc_savecancel, (void) );
 227 VLC_EXPORT( void, vlc_restorecancel, (int state) );
 228 VLC_EXPORT( void, vlc_testcancel, (void) );
 229
 230 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
 231 /**
 232  * Registers a new procedure to run if the thread is cancelled (or otherwise
 233  * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
 234  * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
 235  * of the block between these two function calls is not allowed (read: it will
 236  * likely crash the whole process). If multiple procedures are registered,
 237  * they are handled in last-in first-out order.
 238  *
 239  * @param routine procedure to call if the thread ends
 240  * @param arg argument for the procedure
 241  */
 242 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
 243
 244 /**
 245  * Removes a cleanup procedure that was previously registered with
 246  * vlc_cleanup_push().
 247  */
 248 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
 249
 250 /**
 251  * Removes a cleanup procedure that was previously registered with
 252  * vlc_cleanup_push(), and executes it.
 253  */
 254 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
 255 #else
 256 typedef struct vlc_cleanup_t vlc_cleanup_t;
 257
 258 struct vlc_cleanup_t
 259 {
 260     vlc_cleanup_t *next;
 261     void         (*proc) (void *);
 262     void          *data;
 263 };
 264
 265 /* This macros opens a code block on purpose. This is needed for multiple
 266  * calls within a single function. This also prevent Win32 developers from
 267  * writing code that would break on POSIX (POSIX opens a block as well). */
 268 # define vlc_cleanup_push( routine, arg ) \
 269     do { \
 270         vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
 271         vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
 272
 273 # define vlc_cleanup_pop( ) \
 274         vlc_control_cancel (VLC_CLEANUP_POP); \
 275     } while (0)
 276
 277 # define vlc_cleanup_run( ) \
 278         vlc_control_cancel (VLC_CLEANUP_POP); \
 279         vlc_cleanup_data.proc (vlc_cleanup_data.data); \
 280     } while (0)
 281
 282 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
 283
 284 static inline void vlc_cleanup_lock (void *lock)
 285 {
 286     vlc_mutex_unlock ((vlc_mutex_t *)lock);
 287 }
 288 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
 289
 290 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
 291 typedef pthread_spinlock_t vlc_spinlock_t;
 292
 293 /**
 294  * Initializes a spinlock.
 295  */
 296 static inline void vlc_spin_init (vlc_spinlock_t *spin)
 297 {
 298     if (pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE))
 299         abort ();
 300 }
 301
 302 /**
 303  * Acquires a spinlock.
 304  */
 305 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
 306 {
 307     pthread_spin_lock (spin);
 308 }
 309
 310 /**
 311  * Releases a spinlock.
 312  */
 313 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
 314 {
 315     pthread_spin_unlock (spin);
 316 }
 317
 318 /**
 319  * Deinitializes a spinlock.
 320  */
 321 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
 322 {
 323     pthread_spin_destroy (spin);
 324 }
 325
 326 #elif defined (WIN32) && !defined (UNDER_CE)
 327
 328 typedef CRITICAL_SECTION vlc_spinlock_t;
 329
 330 /**
 331  * Initializes a spinlock.
 332  */
 333 static inline void vlc_spin_init (vlc_spinlock_t *spin)
 334 {
 335     if (!InitializeCriticalSectionAndSpinCount(spin, 4000))
 336         abort ();
 337 }
 338
 339 /**
 340  * Acquires a spinlock.
 341  */
 342 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
 343 {
 344     EnterCriticalSection(spin);
 345 }
 346
 347 /**
 348  * Releases a spinlock.
 349  */
 350 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
 351 {
 352     LeaveCriticalSection(spin);
 353 }
 354
 355 /**
 356  * Deinitializes a spinlock.
 357  */
 358 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
 359 {
 360     DeleteCriticalSection(spin);
 361 }
 362
 363 #else
 364
 365 /* Fallback to plain mutexes if spinlocks are not available */
 366 typedef vlc_mutex_t vlc_spinlock_t;
 367
 368 static inline void vlc_spin_init (vlc_spinlock_t *spin)
 369 {
 370     vlc_mutex_init (spin);
 371 }
 372
 373 # define vlc_spin_lock    vlc_mutex_lock
 374 # define vlc_spin_unlock  vlc_mutex_unlock
 375 # define vlc_spin_destroy vlc_mutex_destroy
 376 #endif
 377
 378 /**
 379  * Issues a full memory barrier.
 380  */
 381 #if defined (__APPLE__)
 382 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
 383 #endif
 384 static inline void barrier (void)
 385 {
 386 #if defined (__GNUC__) && !defined (__APPLE__) && \
 387             ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
 388     __sync_synchronize ();
 389 #elif defined(__APPLE__)
 390     OSMemoryBarrier ();
 391 #elif defined(__powerpc__)
 392     asm volatile ("sync":::"memory");
 393 #elif 0 // defined(__i386__) /*  Requires SSE2 support */
 394     asm volatile ("mfence":::"memory");
 395 #else
 396     vlc_spinlock_t spin;
 397     vlc_spin_init (&spin);
 398     vlc_spin_lock (&spin);
 399     vlc_spin_unlock (&spin);
 400     vlc_spin_destroy (&spin);
 401 #endif
 402 }
 403
 404 /*****************************************************************************
 405  * vlc_thread_create: create a thread
 406  *****************************************************************************/
 407 #define vlc_thread_create( P_THIS, PSZ_NAME, FUNC, PRIORITY )         \
 408     vlc_thread_create( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PSZ_NAME, FUNC, PRIORITY )
 409
 410 /*****************************************************************************
 411  * vlc_thread_set_priority: set the priority of the calling thread
 412  *****************************************************************************/
 413 #define vlc_thread_set_priority( P_THIS, PRIORITY )                         \
 414     vlc_thread_set_priority( VLC_OBJECT(P_THIS), __FILE__, __LINE__, PRIORITY )
 415
 416 /*****************************************************************************
 417  * vlc_thread_join: wait until a thread exits
 418  *****************************************************************************/
 419 #define vlc_thread_join( P_THIS )                                           \
 420     vlc_thread_join( VLC_OBJECT(P_THIS) )
 421
 422 #ifdef __cplusplus
 423 /**
 424  * Helper C++ class to lock a mutex.
 425  * The mutex is locked when the object is created, and unlocked when the object
 426  * is destroyed.
 427  */
 428 class vlc_mutex_locker
 429 {
 430     private:
 431         vlc_mutex_t *lock;
 432     public:
 433         vlc_mutex_locker (vlc_mutex_t *m) : lock (m)
 434         {
 435             vlc_mutex_lock (lock);
 436         }
 437
 438         ~vlc_mutex_locker (void)
 439         {
 440             vlc_mutex_unlock (lock);
 441         }
 442 };
 443 #endif
 444
 445 enum {
 446    VLC_AVCODEC_MUTEX = 0,
 447    VLC_GCRYPT_MUTEX,
 448    VLC_XLIB_MUTEX,
 449    /* Insert new entry HERE */
 450    VLC_MAX_MUTEX
 451 };
 452
 453 VLC_EXPORT( void, vlc_global_mutex, ( unsigned, bool ) );
 454 #define vlc_global_lock( n ) vlc_global_mutex( n, true )
 455 #define vlc_global_unlock( n ) vlc_global_mutex( n, false )
 456
 457 #endif /* !_VLC_THREADS_H */