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 VLC_API int vlc_thread_create( vlc_object_t *, void * ( * ) ( vlc_object_t * ), int ) VLC_USED VLC_DEPRECATED;
 198 VLC_API int vlc_thread_set_priority( vlc_object_t *, int ) VLC_DEPRECATED;
 199 VLC_API void vlc_thread_join( vlc_object_t * ) VLC_DEPRECATED;
 200
 201 VLC_API int vlc_clone(vlc_thread_t *, void * (*) (void *), void *, int) VLC_USED;
 202 VLC_API void vlc_cancel(vlc_thread_t);
 203 VLC_API void vlc_join(vlc_thread_t, void **);
 204 VLC_API void vlc_control_cancel (int cmd, ...);
 205
 206 VLC_API int vlc_timer_create(vlc_timer_t *, void (*) (void *), void *) VLC_USED;
 207 VLC_API void vlc_timer_destroy(vlc_timer_t);
 208 VLC_API void vlc_timer_schedule(vlc_timer_t, bool, mtime_t, mtime_t);
 209 VLC_API unsigned vlc_timer_getoverrun(vlc_timer_t) VLC_USED;
 210
 211 #ifndef LIBVLC_USE_PTHREAD_CANCEL
 212 enum {
 213     VLC_CLEANUP_PUSH,
 214     VLC_CLEANUP_POP,
 215 };
 216 #endif
 217
 218 VLC_API int vlc_savecancel(void);
 219 VLC_API void vlc_restorecancel(int state);
 220 VLC_API void vlc_testcancel(void);
 221
 222 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
 223 /**
 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.
 230  *
 231  * @param routine procedure to call if the thread ends
 232  * @param arg argument for the procedure
 233  */
 234 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
 235
 236 /**
 237  * Removes a cleanup procedure that was previously registered with
 238  * vlc_cleanup_push().
 239  */
 240 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
 241
 242 /**
 243  * Removes a cleanup procedure that was previously registered with
 244  * vlc_cleanup_push(), and executes it.
 245  */
 246 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
 247 #else
 248 typedef struct vlc_cleanup_t vlc_cleanup_t;
 249
 250 struct vlc_cleanup_t
 251 {
 252     vlc_cleanup_t *next;
 253     void         (*proc) (void *);
 254     void          *data;
 255 };
 256
 257 /* This macros opens a code block on purpose. This is needed for multiple
 258  * calls within a single function. This also prevent Win32 developers from
 259  * writing code that would break on POSIX (POSIX opens a block as well). */
 260 # define vlc_cleanup_push( routine, arg ) \
 261     do { \
 262         vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
 263         vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
 264
 265 # define vlc_cleanup_pop( ) \
 266         vlc_control_cancel (VLC_CLEANUP_POP); \
 267     } while (0)
 268
 269 # define vlc_cleanup_run( ) \
 270         vlc_control_cancel (VLC_CLEANUP_POP); \
 271         vlc_cleanup_data.proc (vlc_cleanup_data.data); \
 272     } while (0)
 273
 274 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
 275
 276 static inline void vlc_cleanup_lock (void *lock)
 277 {
 278     vlc_mutex_unlock ((vlc_mutex_t *)lock);
 279 }
 280 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
 281
 282 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
 283 typedef pthread_spinlock_t vlc_spinlock_t;
 284
 285 /**
 286  * Initializes a spinlock.
 287  */
 288 static inline void vlc_spin_init (vlc_spinlock_t *spin)
 289 {
 290     if (pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE))
 291         abort ();
 292 }
 293
 294 /**
 295  * Acquires a spinlock.
 296  */
 297 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
 298 {
 299     pthread_spin_lock (spin);
 300 }
 301
 302 /**
 303  * Releases a spinlock.
 304  */
 305 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
 306 {
 307     pthread_spin_unlock (spin);
 308 }
 309
 310 /**
 311  * Deinitializes a spinlock.
 312  */
 313 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
 314 {
 315     pthread_spin_destroy (spin);
 316 }
 317
 318 #elif defined (WIN32) && !defined (UNDER_CE)
 319
 320 typedef CRITICAL_SECTION vlc_spinlock_t;
 321
 322 /**
 323  * Initializes a spinlock.
 324  */
 325 static inline void vlc_spin_init (vlc_spinlock_t *spin)
 326 {
 327     if (!InitializeCriticalSectionAndSpinCount(spin, 4000))
 328         abort ();
 329 }
 330
 331 /**
 332  * Acquires a spinlock.
 333  */
 334 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
 335 {
 336     EnterCriticalSection(spin);
 337 }
 338
 339 /**
 340  * Releases a spinlock.
 341  */
 342 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
 343 {
 344     LeaveCriticalSection(spin);
 345 }
 346
 347 /**
 348  * Deinitializes a spinlock.
 349  */
 350 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
 351 {
 352     DeleteCriticalSection(spin);
 353 }
 354
 355 #else
 356
 357 /* Fallback to plain mutexes if spinlocks are not available */
 358 typedef vlc_mutex_t vlc_spinlock_t;
 359
 360 static inline void vlc_spin_init (vlc_spinlock_t *spin)
 361 {
 362     vlc_mutex_init (spin);
 363 }
 364
 365 # define vlc_spin_lock    vlc_mutex_lock
 366 # define vlc_spin_unlock  vlc_mutex_unlock
 367 # define vlc_spin_destroy vlc_mutex_destroy
 368 #endif
 369
 370 /**
 371  * Issues a full memory barrier.
 372  */
 373 #if defined (__APPLE__)
 374 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
 375 #endif
 376 static inline void barrier (void)
 377 {
 378 #if defined (__GNUC__) && !defined (__APPLE__) && \
 379             ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
 380     __sync_synchronize ();
 381 #elif defined(__APPLE__)
 382     OSMemoryBarrier ();
 383 #elif defined(__powerpc__)
 384     asm volatile ("sync":::"memory");
 385 #elif 0 // defined(__i386__) /*  Requires SSE2 support */
 386     asm volatile ("mfence":::"memory");
 387 #else
 388     vlc_spinlock_t spin;
 389     vlc_spin_init (&spin);
 390     vlc_spin_lock (&spin);
 391     vlc_spin_unlock (&spin);
 392     vlc_spin_destroy (&spin);
 393 #endif
 394 }
 395
 396 #define vlc_thread_create( P_THIS, FUNC, PRIORITY ) \
 397     vlc_thread_create( VLC_OBJECT(P_THIS), FUNC, PRIORITY )
 398
 399 #define vlc_thread_set_priority( P_THIS, PRIORITY )                         \
 400     vlc_thread_set_priority( VLC_OBJECT(P_THIS), PRIORITY )
 401
 402 #define vlc_thread_join( P_THIS )                                           \
 403     vlc_thread_join( VLC_OBJECT(P_THIS) )
 404
 405 #ifdef __cplusplus
 406 /**
 407  * Helper C++ class to lock a mutex.
 408  * The mutex is locked when the object is created, and unlocked when the object
 409  * is destroyed.
 410  */
 411 class vlc_mutex_locker
 412 {
 413     private:
 414         vlc_mutex_t *lock;
 415     public:
 416         vlc_mutex_locker (vlc_mutex_t *m) : lock (m)
 417         {
 418             vlc_mutex_lock (lock);
 419         }
 420
 421         ~vlc_mutex_locker (void)
 422         {
 423             vlc_mutex_unlock (lock);
 424         }
 425 };
 426 #endif
 427
 428 enum {
 429    VLC_AVCODEC_MUTEX = 0,
 430    VLC_GCRYPT_MUTEX,
 431    VLC_XLIB_MUTEX,
 432    /* Insert new entry HERE */
 433    VLC_MAX_MUTEX
 434 };
 435
 436 VLC_API void vlc_global_mutex( unsigned, bool );
 437 #define vlc_global_lock( n ) vlc_global_mutex( n, true )
 438 #define vlc_global_unlock( n ) vlc_global_mutex( n, false )
 439
 440 #endif /* !_VLC_THREADS_H */