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 VLC authors and VideoLAN
   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 it
  14  * under the terms of the GNU Lesser General Public License as published by
  15  * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU Lesser General Public License
  24  * along with this program; if not, write to the Free Software Foundation,
  25  * 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 #elif defined( __OS2__ )                                        /* OS/2 API  */
  42 #   include <errno.h>
  43
  44 #   define pthread_sigmask  sigprocmask
  45
  46 #else                                         /* pthreads (like Linux & BSD) */
  47 #   define LIBVLC_USE_PTHREAD 1
  48 #   define LIBVLC_USE_PTHREAD_CANCEL 1
  49 #   define _APPLE_C_SOURCE    1 /* Proper pthread semantics on OSX */
  50
  51 #   include <unistd.h> /* _POSIX_SPIN_LOCKS */
  52 #   include <pthread.h>
  53
  54 /* Unnamed POSIX semaphores not supported on Mac OS X, use Mach semaphores instead */
  55 #   if defined (__APPLE__)
  56 #      include <mach/semaphore.h>
  57 #      include <mach/task.h>
  58 #   else
  59 #      include <semaphore.h>
  60 #   endif
  61
  62 #endif
  63
  64 /*****************************************************************************
  65  * Constants
  66  *****************************************************************************/
  67
  68 /* Thread priorities */
  69 #ifdef __APPLE__
  70 #   define VLC_THREAD_PRIORITY_LOW      0
  71 #   define VLC_THREAD_PRIORITY_INPUT   22
  72 #   define VLC_THREAD_PRIORITY_AUDIO   22
  73 #   define VLC_THREAD_PRIORITY_VIDEO    0
  74 #   define VLC_THREAD_PRIORITY_OUTPUT  22
  75 #   define VLC_THREAD_PRIORITY_HIGHEST 22
  76
  77 #elif defined(LIBVLC_USE_PTHREAD)
  78 #   define VLC_THREAD_PRIORITY_LOW      0
  79 #   define VLC_THREAD_PRIORITY_INPUT   10
  80 #   define VLC_THREAD_PRIORITY_AUDIO    5
  81 #   define VLC_THREAD_PRIORITY_VIDEO    0
  82 #   define VLC_THREAD_PRIORITY_OUTPUT  15
  83 #   define VLC_THREAD_PRIORITY_HIGHEST 20
  84
  85 #elif defined(WIN32) || defined(UNDER_CE)
  86 /* Define different priorities for WinNT/2K/XP and Win9x/Me */
  87 #   define VLC_THREAD_PRIORITY_LOW 0
  88 #   define VLC_THREAD_PRIORITY_INPUT \
  89         THREAD_PRIORITY_ABOVE_NORMAL
  90 #   define VLC_THREAD_PRIORITY_AUDIO \
  91         THREAD_PRIORITY_HIGHEST
  92 #   define VLC_THREAD_PRIORITY_VIDEO 0
  93 #   define VLC_THREAD_PRIORITY_OUTPUT \
  94         THREAD_PRIORITY_ABOVE_NORMAL
  95 #   define VLC_THREAD_PRIORITY_HIGHEST \
  96         THREAD_PRIORITY_TIME_CRITICAL
  97
  98 #elif defined(__OS2__)
  99 #   define VLC_THREAD_PRIORITY_LOW      0
 100 #   define VLC_THREAD_PRIORITY_INPUT    MAKESHORT( PRTYD_MAXIMUM / 2, PRTYC_REGULAR )
 101 #   define VLC_THREAD_PRIORITY_AUDIO    MAKESHORT( PRTYD_MAXIMUM, PRTYC_REGULAR )
 102 #   define VLC_THREAD_PRIORITY_VIDEO    0
 103 #   define VLC_THREAD_PRIORITY_OUTPUT   MAKESHORT( PRTYD_MAXIMUM / 2, PRTYC_REGULAR )
 104 #   define VLC_THREAD_PRIORITY_HIGHEST  MAKESHORT( 0, PRTYC_TIMECRITICAL )
 105
 106 #else
 107 #   define VLC_THREAD_PRIORITY_LOW 0
 108 #   define VLC_THREAD_PRIORITY_INPUT 0
 109 #   define VLC_THREAD_PRIORITY_AUDIO 0
 110 #   define VLC_THREAD_PRIORITY_VIDEO 0
 111 #   define VLC_THREAD_PRIORITY_OUTPUT 0
 112 #   define VLC_THREAD_PRIORITY_HIGHEST 0
 113
 114 #endif
 115
 116 /*****************************************************************************
 117  * Type definitions
 118  *****************************************************************************/
 119
 120 #if defined (LIBVLC_USE_PTHREAD)
 121 typedef pthread_t       vlc_thread_t;
 122 typedef pthread_mutex_t vlc_mutex_t;
 123 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
 124 typedef pthread_cond_t  vlc_cond_t;
 125 #define VLC_STATIC_COND  PTHREAD_COND_INITIALIZER
 126 typedef pthread_rwlock_t vlc_rwlock_t;
 127 #define VLC_STATIC_RWLOCK PTHREAD_RWLOCK_INITIALIZER
 128 typedef pthread_key_t   vlc_threadvar_t;
 129 typedef struct vlc_timer *vlc_timer_t;
 130
 131 #if defined (__APPLE__)
 132 typedef semaphore_t     vlc_sem_t;
 133 #else
 134 typedef sem_t           vlc_sem_t;
 135 #endif
 136
 137 #elif defined( WIN32 )
 138 typedef struct vlc_thread *vlc_thread_t;
 139
 140 typedef struct
 141 {
 142     bool dynamic;
 143     union
 144     {
 145         struct
 146         {
 147             bool locked;
 148             unsigned long contention;
 149         };
 150         CRITICAL_SECTION mutex;
 151     };
 152 } vlc_mutex_t;
 153 #define VLC_STATIC_MUTEX { false, { { false, 0 } } }
 154
 155 typedef struct
 156 {
 157     HANDLE   handle;
 158     unsigned clock;
 159 } vlc_cond_t;
 160 #define VLC_STATIC_COND { 0, 0 }
 161
 162 typedef HANDLE  vlc_sem_t;
 163
 164 typedef struct
 165 {
 166     vlc_mutex_t   mutex;
 167     vlc_cond_t    wait;
 168     unsigned long readers;
 169     unsigned long writers;
 170     DWORD         writer;
 171 } vlc_rwlock_t;
 172 #define VLC_STATIC_RWLOCK \
 173     { VLC_STATIC_MUTEX, VLC_STATIC_COND, 0, 0, 0 }
 174
 175 typedef struct vlc_threadvar *vlc_threadvar_t;
 176 typedef struct vlc_timer *vlc_timer_t;
 177
 178 #elif defined( __OS2__ )
 179 typedef struct vlc_thread *vlc_thread_t;
 180
 181 typedef struct
 182 {
 183     bool dynamic;
 184     union
 185     {
 186         struct
 187         {
 188             bool locked;
 189             unsigned long contention;
 190         };
 191         HMTX hmtx;
 192     };
 193 } vlc_mutex_t;
 194
 195 #define VLC_STATIC_MUTEX { false, { { false, 0 } } }
 196
 197 typedef struct
 198 {
 199     HEV      hev;
 200     unsigned clock;
 201 } vlc_cond_t;
 202
 203 #define VLC_STATIC_COND { 0, 0 }
 204
 205 typedef struct
 206 {
 207     HEV  hev;
 208     HMTX wait_mutex;
 209     HMTX count_mutex;
 210     int  count;
 211 } vlc_sem_t;
 212
 213 typedef struct
 214 {
 215     vlc_mutex_t   mutex;
 216     vlc_cond_t    wait;
 217     unsigned long readers;
 218     unsigned long writers;
 219     int           writer;
 220 } vlc_rwlock_t;
 221 #define VLC_STATIC_RWLOCK \
 222     { VLC_STATIC_MUTEX, VLC_STATIC_COND, 0, 0, 0 }
 223
 224 typedef struct vlc_threadvar *vlc_threadvar_t;
 225 typedef struct vlc_timer *vlc_timer_t;
 226
 227 #endif
 228
 229 #if defined( WIN32 ) && !defined ETIMEDOUT
 230 #  define ETIMEDOUT 10060 /* This is the value in winsock.h. */
 231 #endif
 232
 233 /*****************************************************************************
 234  * Function definitions
 235  *****************************************************************************/
 236 VLC_API void vlc_mutex_init( vlc_mutex_t * );
 237 VLC_API void vlc_mutex_init_recursive( vlc_mutex_t * );
 238 VLC_API void vlc_mutex_destroy( vlc_mutex_t * );
 239 VLC_API void vlc_mutex_lock( vlc_mutex_t * );
 240 VLC_API int vlc_mutex_trylock( vlc_mutex_t * ) VLC_USED;
 241 VLC_API void vlc_mutex_unlock( vlc_mutex_t * );
 242 VLC_API void vlc_cond_init( vlc_cond_t * );
 243 VLC_API void vlc_cond_init_daytime( vlc_cond_t * );
 244 VLC_API void vlc_cond_destroy( vlc_cond_t * );
 245 VLC_API void vlc_cond_signal(vlc_cond_t *);
 246 VLC_API void vlc_cond_broadcast(vlc_cond_t *);
 247 VLC_API void vlc_cond_wait(vlc_cond_t *, vlc_mutex_t *);
 248 VLC_API int vlc_cond_timedwait(vlc_cond_t *, vlc_mutex_t *, mtime_t);
 249 VLC_API void vlc_sem_init(vlc_sem_t *, unsigned);
 250 VLC_API void vlc_sem_destroy(vlc_sem_t *);
 251 VLC_API int vlc_sem_post(vlc_sem_t *);
 252 VLC_API void vlc_sem_wait(vlc_sem_t *);
 253
 254 VLC_API void vlc_rwlock_init(vlc_rwlock_t *);
 255 VLC_API void vlc_rwlock_destroy(vlc_rwlock_t *);
 256 VLC_API void vlc_rwlock_rdlock(vlc_rwlock_t *);
 257 VLC_API void vlc_rwlock_wrlock(vlc_rwlock_t *);
 258 VLC_API void vlc_rwlock_unlock(vlc_rwlock_t *);
 259 VLC_API int vlc_threadvar_create(vlc_threadvar_t * , void (*) (void *) );
 260 VLC_API void vlc_threadvar_delete(vlc_threadvar_t *);
 261 VLC_API int vlc_threadvar_set(vlc_threadvar_t, void *);
 262 VLC_API void * vlc_threadvar_get(vlc_threadvar_t);
 263
 264 VLC_API int vlc_clone(vlc_thread_t *, void * (*) (void *), void *, int) VLC_USED;
 265 VLC_API void vlc_cancel(vlc_thread_t);
 266 VLC_API void vlc_join(vlc_thread_t, void **);
 267 VLC_API void vlc_control_cancel (int cmd, ...);
 268
 269 VLC_API mtime_t mdate(void);
 270 VLC_API void mwait(mtime_t deadline);
 271 VLC_API void msleep(mtime_t delay);
 272
 273 #define VLC_HARD_MIN_SLEEP   10000 /* 10 milliseconds = 1 tick at 100Hz */
 274 #define VLC_SOFT_MIN_SLEEP 9000000 /* 9 seconds */
 275
 276 #if VLC_GCC_VERSION(4,3)
 277 /* Linux has 100, 250, 300 or 1000Hz
 278  *
 279  * HZ=100 by default on FreeBSD, but some architectures use a 1000Hz timer
 280  */
 281
 282 static
 283 __attribute__((unused))
 284 __attribute__((noinline))
 285 __attribute__((error("sorry, cannot sleep for such short a time")))
 286 mtime_t impossible_delay( mtime_t delay )
 287 {
 288     (void) delay;
 289     return VLC_HARD_MIN_SLEEP;
 290 }
 291
 292 static
 293 __attribute__((unused))
 294 __attribute__((noinline))
 295 __attribute__((warning("use proper event handling instead of short delay")))
 296 mtime_t harmful_delay( mtime_t delay )
 297 {
 298     return delay;
 299 }
 300
 301 # define check_delay( d ) \
 302     ((__builtin_constant_p(d < VLC_HARD_MIN_SLEEP) \
 303    && (d < VLC_HARD_MIN_SLEEP)) \
 304        ? impossible_delay(d) \
 305        : ((__builtin_constant_p(d < VLC_SOFT_MIN_SLEEP) \
 306        && (d < VLC_SOFT_MIN_SLEEP)) \
 307            ? harmful_delay(d) \
 308            : d))
 309
 310 static
 311 __attribute__((unused))
 312 __attribute__((noinline))
 313 __attribute__((error("deadlines can not be constant")))
 314 mtime_t impossible_deadline( mtime_t deadline )
 315 {
 316     return deadline;
 317 }
 318
 319 # define check_deadline( d ) \
 320     (__builtin_constant_p(d) ? impossible_deadline(d) : d)
 321 #else
 322 # define check_delay(d) (d)
 323 # define check_deadline(d) (d)
 324 #endif
 325
 326 #define msleep(d) msleep(check_delay(d))
 327 #define mwait(d) mwait(check_deadline(d))
 328
 329 VLC_API int vlc_timer_create(vlc_timer_t *, void (*) (void *), void *) VLC_USED;
 330 VLC_API void vlc_timer_destroy(vlc_timer_t);
 331 VLC_API void vlc_timer_schedule(vlc_timer_t, bool, mtime_t, mtime_t);
 332 VLC_API unsigned vlc_timer_getoverrun(vlc_timer_t) VLC_USED;
 333
 334 VLC_API unsigned vlc_GetCPUCount(void);
 335
 336 #ifndef LIBVLC_USE_PTHREAD_CANCEL
 337 enum {
 338     VLC_CLEANUP_PUSH,
 339     VLC_CLEANUP_POP,
 340 };
 341 #endif
 342
 343 VLC_API int vlc_savecancel(void);
 344 VLC_API void vlc_restorecancel(int state);
 345 VLC_API void vlc_testcancel(void);
 346
 347 #if defined (LIBVLC_USE_PTHREAD_CANCEL)
 348 /**
 349  * Registers a new procedure to run if the thread is cancelled (or otherwise
 350  * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
 351  * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
 352  * of the block between these two function calls is not allowed (read: it will
 353  * likely crash the whole process). If multiple procedures are registered,
 354  * they are handled in last-in first-out order.
 355  *
 356  * @param routine procedure to call if the thread ends
 357  * @param arg argument for the procedure
 358  */
 359 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
 360
 361 /**
 362  * Removes a cleanup procedure that was previously registered with
 363  * vlc_cleanup_push().
 364  */
 365 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
 366
 367 /**
 368  * Removes a cleanup procedure that was previously registered with
 369  * vlc_cleanup_push(), and executes it.
 370  */
 371 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
 372 #else
 373 typedef struct vlc_cleanup_t vlc_cleanup_t;
 374
 375 struct vlc_cleanup_t
 376 {
 377     vlc_cleanup_t *next;
 378     void         (*proc) (void *);
 379     void          *data;
 380 };
 381
 382 /* This macros opens a code block on purpose. This is needed for multiple
 383  * calls within a single function. This also prevent Win32 developers from
 384  * writing code that would break on POSIX (POSIX opens a block as well). */
 385 # define vlc_cleanup_push( routine, arg ) \
 386     do { \
 387         vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
 388         vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
 389
 390 # define vlc_cleanup_pop( ) \
 391         vlc_control_cancel (VLC_CLEANUP_POP); \
 392     } while (0)
 393
 394 # define vlc_cleanup_run( ) \
 395         vlc_control_cancel (VLC_CLEANUP_POP); \
 396         vlc_cleanup_data.proc (vlc_cleanup_data.data); \
 397     } while (0)
 398
 399 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
 400
 401 static inline void vlc_cleanup_lock (void *lock)
 402 {
 403     vlc_mutex_unlock ((vlc_mutex_t *)lock);
 404 }
 405 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
 406
 407 # if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
 408 typedef pthread_spinlock_t vlc_spinlock_t;
 409
 410 /**
 411  * Initializes a spinlock.
 412  */
 413 static inline void vlc_spin_init (vlc_spinlock_t *spin)
 414 {
 415     if (pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE))
 416         abort ();
 417 }
 418
 419 /**
 420  * Acquires a spinlock.
 421  */
 422 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
 423 {
 424     pthread_spin_lock (spin);
 425 }
 426
 427 /**
 428  * Releases a spinlock.
 429  */
 430 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
 431 {
 432     pthread_spin_unlock (spin);
 433 }
 434
 435 /**
 436  * Deinitializes a spinlock.
 437  */
 438 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
 439 {
 440     pthread_spin_destroy (spin);
 441 }
 442
 443 #elif defined (WIN32) && !defined (UNDER_CE)
 444
 445 typedef CRITICAL_SECTION vlc_spinlock_t;
 446
 447 /**
 448  * Initializes a spinlock.
 449  */
 450 static inline void vlc_spin_init (vlc_spinlock_t *spin)
 451 {
 452     if (!InitializeCriticalSectionAndSpinCount(spin, 4000))
 453         abort ();
 454 }
 455
 456 /**
 457  * Acquires a spinlock.
 458  */
 459 static inline void vlc_spin_lock (vlc_spinlock_t *spin)
 460 {
 461     EnterCriticalSection(spin);
 462 }
 463
 464 /**
 465  * Releases a spinlock.
 466  */
 467 static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
 468 {
 469     LeaveCriticalSection(spin);
 470 }
 471
 472 /**
 473  * Deinitializes a spinlock.
 474  */
 475 static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
 476 {
 477     DeleteCriticalSection(spin);
 478 }
 479
 480 #else
 481
 482 /* Fallback to plain mutexes if spinlocks are not available */
 483 typedef vlc_mutex_t vlc_spinlock_t;
 484
 485 static inline void vlc_spin_init (vlc_spinlock_t *spin)
 486 {
 487     vlc_mutex_init (spin);
 488 }
 489
 490 # define vlc_spin_lock    vlc_mutex_lock
 491 # define vlc_spin_unlock  vlc_mutex_unlock
 492 # define vlc_spin_destroy vlc_mutex_destroy
 493 #endif
 494
 495 /**
 496  * Issues a full memory barrier.
 497  */
 498 #if defined (__APPLE__)
 499 # include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
 500 #endif
 501 static inline void barrier (void)
 502 {
 503 #if defined (__GNUC__) && !defined (__APPLE__) && \
 504             ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1))
 505     __sync_synchronize ();
 506 #elif defined(__APPLE__)
 507     OSMemoryBarrier ();
 508 #elif defined(__powerpc__)
 509     asm volatile ("sync":::"memory");
 510 #elif 0 // defined(__i386__) /*  Requires SSE2 support */
 511     asm volatile ("mfence":::"memory");
 512 #else
 513     vlc_spinlock_t spin;
 514     vlc_spin_init (&spin);
 515     vlc_spin_lock (&spin);
 516     vlc_spin_unlock (&spin);
 517     vlc_spin_destroy (&spin);
 518 #endif
 519 }
 520
 521 #ifdef __cplusplus
 522 /**
 523  * Helper C++ class to lock a mutex.
 524  * The mutex is locked when the object is created, and unlocked when the object
 525  * is destroyed.
 526  */
 527 class vlc_mutex_locker
 528 {
 529     private:
 530         vlc_mutex_t *lock;
 531     public:
 532         vlc_mutex_locker (vlc_mutex_t *m) : lock (m)
 533         {
 534             vlc_mutex_lock (lock);
 535         }
 536
 537         ~vlc_mutex_locker (void)
 538         {
 539             vlc_mutex_unlock (lock);
 540         }
 541 };
 542 #endif
 543
 544 enum {
 545    VLC_AVCODEC_MUTEX = 0,
 546    VLC_GCRYPT_MUTEX,
 547    VLC_XLIB_MUTEX,
 548    VLC_MOSAIC_MUTEX,
 549    VLC_HIGHLIGHT_MUTEX,
 550    /* Insert new entry HERE */
 551    VLC_MAX_MUTEX
 552 };
 553
 554 VLC_API void vlc_global_mutex( unsigned, bool );
 555 #define vlc_global_lock( n ) vlc_global_mutex( n, true )
 556 #define vlc_global_unlock( n ) vlc_global_mutex( n, false )
 557
 558 #endif /* !_VLC_THREADS_H */