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 (_WIN32)
  38 # include <process.h>
  39 # ifndef ETIMEDOUT
  40 #  define ETIMEDOUT 10060 /* This is the value in winsock.h. */
  41 # endif
  42
  43 typedef struct vlc_thread *vlc_thread_t;
  44 typedef struct
  45 {
  46     bool dynamic;
  47     union
  48     {
  49         struct
  50         {
  51             bool locked;
  52             unsigned long contention;
  53         };
  54         CRITICAL_SECTION mutex;
  55     };
  56 } vlc_mutex_t;
  57 #define VLC_STATIC_MUTEX { false, { { false, 0 } } }
  58 typedef struct
  59 {
  60     HANDLE   handle;
  61     unsigned clock;
  62 } vlc_cond_t;
  63 #define VLC_STATIC_COND { 0, 0 }
  64 typedef HANDLE vlc_sem_t;
  65 #define LIBVLC_NEED_RWLOCK
  66 typedef struct vlc_threadvar *vlc_threadvar_t;
  67 typedef struct vlc_timer *vlc_timer_t;
  68
  69 # define VLC_THREAD_PRIORITY_LOW      0
  70 # define VLC_THREAD_PRIORITY_INPUT    THREAD_PRIORITY_ABOVE_NORMAL
  71 # define VLC_THREAD_PRIORITY_AUDIO    THREAD_PRIORITY_HIGHEST
  72 # define VLC_THREAD_PRIORITY_VIDEO    0
  73 # define VLC_THREAD_PRIORITY_OUTPUT   THREAD_PRIORITY_ABOVE_NORMAL
  74 # define VLC_THREAD_PRIORITY_HIGHEST  THREAD_PRIORITY_TIME_CRITICAL
  75
  76 #elif defined (__OS2__)
  77 # include <errno.h>
  78
  79 typedef struct vlc_thread *vlc_thread_t;
  80 typedef struct
  81 {
  82     bool dynamic;
  83     union
  84     {
  85         struct
  86         {
  87             bool locked;
  88             unsigned long contention;
  89         };
  90         HMTX hmtx;
  91     };
  92 } vlc_mutex_t;
  93 #define VLC_STATIC_MUTEX { false, { { false, 0 } } }
  94 typedef struct
  95 {
  96     HEV      hev;
  97     unsigned clock;
  98 } vlc_cond_t;
  99 #define VLC_STATIC_COND { 0, 0 }
 100 #define LIBVLC_NEED_SEMAPHORE
 101 #define LIBVLC_NEED_RWLOCK
 102 typedef struct vlc_threadvar *vlc_threadvar_t;
 103 typedef struct vlc_timer *vlc_timer_t;
 104
 105 # define VLC_THREAD_PRIORITY_LOW      0
 106 # define VLC_THREAD_PRIORITY_INPUT \
 107                                     MAKESHORT(PRTYD_MAXIMUM / 2, PRTYC_REGULAR)
 108 # define VLC_THREAD_PRIORITY_AUDIO    MAKESHORT(PRTYD_MAXIMUM, PRTYC_REGULAR)
 109 # define VLC_THREAD_PRIORITY_VIDEO    0
 110 # define VLC_THREAD_PRIORITY_OUTPUT \
 111                                     MAKESHORT(PRTYD_MAXIMUM / 2, PRTYC_REGULAR)
 112 # define VLC_THREAD_PRIORITY_HIGHEST  MAKESHORT(0, PRTYC_TIMECRITICAL)
 113
 114 # define pthread_sigmask  sigprocmask
 115
 116 #elif defined (__ANDROID__)      /* pthreads subset without pthread_cancel() */
 117 # include <unistd.h>
 118 # include <pthread.h>
 119 # include <poll.h>
 120 # define LIBVLC_USE_PTHREAD_CLEANUP   1
 121 # define LIBVLC_NEED_SEMAPHORE
 122 # define LIBVLC_NEED_RWLOCK
 123
 124 typedef struct vlc_thread *vlc_thread_t;
 125 typedef pthread_mutex_t vlc_mutex_t;
 126 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
 127 typedef struct
 128 {
 129     pthread_cond_t cond;
 130     unsigned clock;
 131 } vlc_cond_t;
 132 #define VLC_STATIC_COND  { PTHREAD_COND_INITIALIZER, CLOCK_REALTIME }
 133
 134 typedef pthread_key_t   vlc_threadvar_t;
 135 typedef struct vlc_timer *vlc_timer_t;
 136
 137 # define VLC_THREAD_PRIORITY_LOW      0
 138 # define VLC_THREAD_PRIORITY_INPUT    0
 139 # define VLC_THREAD_PRIORITY_AUDIO    0
 140 # define VLC_THREAD_PRIORITY_VIDEO    0
 141 # define VLC_THREAD_PRIORITY_OUTPUT   0
 142 # define VLC_THREAD_PRIORITY_HIGHEST  0
 143
 144 #elif defined (__APPLE__)
 145 # define _APPLE_C_SOURCE    1 /* Proper pthread semantics on OSX */
 146 # include <unistd.h>
 147 # include <pthread.h>
 148 /* Unnamed POSIX semaphores not supported on Mac OS X */
 149 # include <mach/semaphore.h>
 150 # include <mach/task.h>
 151 # define LIBVLC_USE_PTHREAD           1
 152 # define LIBVLC_USE_PTHREAD_CLEANUP   1
 153 # define LIBVLC_USE_PTHREAD_CANCEL    1
 154
 155 typedef pthread_t       vlc_thread_t;
 156 typedef pthread_mutex_t vlc_mutex_t;
 157 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
 158 typedef struct
 159 {
 160     pthread_cond_t cond;
 161     unsigned clock;
 162 } vlc_cond_t;
 163 #define VLC_STATIC_COND  { PTHREAD_COND_INITIALIZER, 0 }
 164 typedef semaphore_t     vlc_sem_t;
 165 typedef pthread_rwlock_t vlc_rwlock_t;
 166 #define VLC_STATIC_RWLOCK PTHREAD_RWLOCK_INITIALIZER
 167 typedef pthread_key_t   vlc_threadvar_t;
 168 typedef struct vlc_timer *vlc_timer_t;
 169
 170 # define VLC_THREAD_PRIORITY_LOW      0
 171 # define VLC_THREAD_PRIORITY_INPUT   22
 172 # define VLC_THREAD_PRIORITY_AUDIO   22
 173 # define VLC_THREAD_PRIORITY_VIDEO    0
 174 # define VLC_THREAD_PRIORITY_OUTPUT  22
 175 # define VLC_THREAD_PRIORITY_HIGHEST 22
 176
 177 #else /* POSIX threads */
 178 # include <unistd.h> /* _POSIX_SPIN_LOCKS */
 179 # include <pthread.h>
 180 # include <semaphore.h>
 181 # define LIBVLC_USE_PTHREAD           1
 182 # define LIBVLC_USE_PTHREAD_CLEANUP   1
 183 # define LIBVLC_USE_PTHREAD_CANCEL    1
 184
 185 typedef pthread_t       vlc_thread_t;
 186 typedef pthread_mutex_t vlc_mutex_t;
 187 #define VLC_STATIC_MUTEX PTHREAD_MUTEX_INITIALIZER
 188 typedef pthread_cond_t  vlc_cond_t;
 189 #define VLC_STATIC_COND  PTHREAD_COND_INITIALIZER
 190 typedef sem_t           vlc_sem_t;
 191 typedef pthread_rwlock_t vlc_rwlock_t;
 192 #define VLC_STATIC_RWLOCK PTHREAD_RWLOCK_INITIALIZER
 193 typedef pthread_key_t   vlc_threadvar_t;
 194 typedef struct vlc_timer *vlc_timer_t;
 195
 196 # define VLC_THREAD_PRIORITY_LOW      0
 197 # define VLC_THREAD_PRIORITY_INPUT   10
 198 # define VLC_THREAD_PRIORITY_AUDIO    5
 199 # define VLC_THREAD_PRIORITY_VIDEO    0
 200 # define VLC_THREAD_PRIORITY_OUTPUT  15
 201 # define VLC_THREAD_PRIORITY_HIGHEST 20
 202
 203 #endif
 204
 205 #ifdef LIBVLC_NEED_SEMAPHORE
 206 typedef struct vlc_sem
 207 {
 208     vlc_mutex_t lock;
 209     vlc_cond_t  wait;
 210     unsigned    value;
 211 } vlc_sem_t;
 212 #endif
 213
 214 #ifdef LIBVLC_NEED_RWLOCK
 215 typedef struct vlc_rwlock
 216 {
 217     vlc_mutex_t   mutex;
 218     vlc_cond_t    wait;
 219     long          state;
 220 } vlc_rwlock_t;
 221 # define VLC_STATIC_RWLOCK { VLC_STATIC_MUTEX, VLC_STATIC_COND, 0 }
 222 #endif
 223
 224 /*****************************************************************************
 225  * Function definitions
 226  *****************************************************************************/
 227 VLC_API void vlc_mutex_init( vlc_mutex_t * );
 228 VLC_API void vlc_mutex_init_recursive( vlc_mutex_t * );
 229 VLC_API void vlc_mutex_destroy( vlc_mutex_t * );
 230 VLC_API void vlc_mutex_lock( vlc_mutex_t * );
 231 VLC_API int vlc_mutex_trylock( vlc_mutex_t * ) VLC_USED;
 232 VLC_API void vlc_mutex_unlock( vlc_mutex_t * );
 233 VLC_API void vlc_cond_init( vlc_cond_t * );
 234 VLC_API void vlc_cond_init_daytime( vlc_cond_t * );
 235 VLC_API void vlc_cond_destroy( vlc_cond_t * );
 236 VLC_API void vlc_cond_signal(vlc_cond_t *);
 237 VLC_API void vlc_cond_broadcast(vlc_cond_t *);
 238 VLC_API void vlc_cond_wait(vlc_cond_t *, vlc_mutex_t *);
 239 VLC_API int vlc_cond_timedwait(vlc_cond_t *, vlc_mutex_t *, mtime_t);
 240 VLC_API void vlc_sem_init(vlc_sem_t *, unsigned);
 241 VLC_API void vlc_sem_destroy(vlc_sem_t *);
 242 VLC_API int vlc_sem_post(vlc_sem_t *);
 243 VLC_API void vlc_sem_wait(vlc_sem_t *);
 244
 245 VLC_API void vlc_rwlock_init(vlc_rwlock_t *);
 246 VLC_API void vlc_rwlock_destroy(vlc_rwlock_t *);
 247 VLC_API void vlc_rwlock_rdlock(vlc_rwlock_t *);
 248 VLC_API void vlc_rwlock_wrlock(vlc_rwlock_t *);
 249 VLC_API void vlc_rwlock_unlock(vlc_rwlock_t *);
 250 VLC_API int vlc_threadvar_create(vlc_threadvar_t * , void (*) (void *) );
 251 VLC_API void vlc_threadvar_delete(vlc_threadvar_t *);
 252 VLC_API int vlc_threadvar_set(vlc_threadvar_t, void *);
 253 VLC_API void * vlc_threadvar_get(vlc_threadvar_t);
 254
 255 VLC_API int vlc_clone(vlc_thread_t *, void * (*) (void *), void *, int) VLC_USED;
 256 VLC_API void vlc_cancel(vlc_thread_t);
 257 VLC_API void vlc_join(vlc_thread_t, void **);
 258 VLC_API void vlc_control_cancel (int cmd, ...);
 259
 260 VLC_API mtime_t mdate(void);
 261 VLC_API void mwait(mtime_t deadline);
 262 VLC_API void msleep(mtime_t delay);
 263
 264 #define VLC_HARD_MIN_SLEEP   10000 /* 10 milliseconds = 1 tick at 100Hz */
 265 #define VLC_SOFT_MIN_SLEEP 9000000 /* 9 seconds */
 266
 267 #if VLC_GCC_VERSION(4,3)
 268 /* Linux has 100, 250, 300 or 1000Hz
 269  *
 270  * HZ=100 by default on FreeBSD, but some architectures use a 1000Hz timer
 271  */
 272
 273 static
 274 __attribute__((unused))
 275 __attribute__((noinline))
 276 __attribute__((error("sorry, cannot sleep for such short a time")))
 277 mtime_t impossible_delay( mtime_t delay )
 278 {
 279     (void) delay;
 280     return VLC_HARD_MIN_SLEEP;
 281 }
 282
 283 static
 284 __attribute__((unused))
 285 __attribute__((noinline))
 286 __attribute__((warning("use proper event handling instead of short delay")))
 287 mtime_t harmful_delay( mtime_t delay )
 288 {
 289     return delay;
 290 }
 291
 292 # define check_delay( d ) \
 293     ((__builtin_constant_p(d < VLC_HARD_MIN_SLEEP) \
 294    && (d < VLC_HARD_MIN_SLEEP)) \
 295        ? impossible_delay(d) \
 296        : ((__builtin_constant_p(d < VLC_SOFT_MIN_SLEEP) \
 297        && (d < VLC_SOFT_MIN_SLEEP)) \
 298            ? harmful_delay(d) \
 299            : d))
 300
 301 static
 302 __attribute__((unused))
 303 __attribute__((noinline))
 304 __attribute__((error("deadlines can not be constant")))
 305 mtime_t impossible_deadline( mtime_t deadline )
 306 {
 307     return deadline;
 308 }
 309
 310 # define check_deadline( d ) \
 311     (__builtin_constant_p(d) ? impossible_deadline(d) : d)
 312 #else
 313 # define check_delay(d) (d)
 314 # define check_deadline(d) (d)
 315 #endif
 316
 317 #define msleep(d) msleep(check_delay(d))
 318 #define mwait(d) mwait(check_deadline(d))
 319
 320 VLC_API int vlc_timer_create(vlc_timer_t *, void (*) (void *), void *) VLC_USED;
 321 VLC_API void vlc_timer_destroy(vlc_timer_t);
 322 VLC_API void vlc_timer_schedule(vlc_timer_t, bool, mtime_t, mtime_t);
 323 VLC_API unsigned vlc_timer_getoverrun(vlc_timer_t) VLC_USED;
 324
 325 VLC_API unsigned vlc_GetCPUCount(void);
 326
 327 VLC_API int vlc_savecancel(void);
 328 VLC_API void vlc_restorecancel(int state);
 329 VLC_API void vlc_testcancel(void);
 330
 331 #if defined (LIBVLC_USE_PTHREAD_CLEANUP)
 332 /**
 333  * Registers a new procedure to run if the thread is cancelled (or otherwise
 334  * exits prematurely). Any call to vlc_cleanup_push() <b>must</b> paired with a
 335  * call to either vlc_cleanup_pop() or vlc_cleanup_run(). Branching into or out
 336  * of the block between these two function calls is not allowed (read: it will
 337  * likely crash the whole process). If multiple procedures are registered,
 338  * they are handled in last-in first-out order.
 339  *
 340  * @param routine procedure to call if the thread ends
 341  * @param arg argument for the procedure
 342  */
 343 # define vlc_cleanup_push( routine, arg ) pthread_cleanup_push (routine, arg)
 344
 345 /**
 346  * Removes a cleanup procedure that was previously registered with
 347  * vlc_cleanup_push().
 348  */
 349 # define vlc_cleanup_pop( ) pthread_cleanup_pop (0)
 350
 351 /**
 352  * Removes a cleanup procedure that was previously registered with
 353  * vlc_cleanup_push(), and executes it.
 354  */
 355 # define vlc_cleanup_run( ) pthread_cleanup_pop (1)
 356
 357 #else
 358 enum
 359 {
 360     VLC_CLEANUP_PUSH,
 361     VLC_CLEANUP_POP,
 362 };
 363 typedef struct vlc_cleanup_t vlc_cleanup_t;
 364
 365 struct vlc_cleanup_t
 366 {
 367     vlc_cleanup_t *next;
 368     void         (*proc) (void *);
 369     void          *data;
 370 };
 371
 372 /* This macros opens a code block on purpose. This is needed for multiple
 373  * calls within a single function. This also prevent Win32 developers from
 374  * writing code that would break on POSIX (POSIX opens a block as well). */
 375 # define vlc_cleanup_push( routine, arg ) \
 376     do { \
 377         vlc_cleanup_t vlc_cleanup_data = { NULL, routine, arg, }; \
 378         vlc_control_cancel (VLC_CLEANUP_PUSH, &vlc_cleanup_data)
 379
 380 # define vlc_cleanup_pop( ) \
 381         vlc_control_cancel (VLC_CLEANUP_POP); \
 382     } while (0)
 383
 384 # define vlc_cleanup_run( ) \
 385         vlc_control_cancel (VLC_CLEANUP_POP); \
 386         vlc_cleanup_data.proc (vlc_cleanup_data.data); \
 387     } while (0)
 388
 389 #endif /* !LIBVLC_USE_PTHREAD_CLEANUP */
 390
 391 #ifndef LIBVLC_USE_PTHREAD_CANCEL
 392 /* poll() with cancellation */
 393 # ifdef __OS2__
 394 int vlc_poll (struct pollfd *fds, unsigned nfds, int timeout);
 395 # else
 396 static inline int vlc_poll (struct pollfd *fds, unsigned nfds, int timeout)
 397 {
 398     int val;
 399
 400     do
 401     {
 402         int ugly_timeout = ((unsigned)timeout >= 50) ? 50 : timeout;
 403         if (timeout >= 0)
 404             timeout -= ugly_timeout;
 405
 406         vlc_testcancel ();
 407         val = poll (fds, nfds, ugly_timeout);
 408     }
 409     while (val == 0 && timeout != 0);
 410
 411     return val;
 412 }
 413 # endif
 414
 415 # define poll(u,n,t) vlc_poll(u, n, t)
 416
 417 #endif /* LIBVLC_USE_PTHREAD_CANCEL */
 418
 419 static inline void vlc_cleanup_lock (void *lock)
 420 {
 421     vlc_mutex_unlock ((vlc_mutex_t *)lock);
 422 }
 423 #define mutex_cleanup_push( lock ) vlc_cleanup_push (vlc_cleanup_lock, lock)
 424
 425 #ifdef __cplusplus
 426 /**
 427  * Helper C++ class to lock a mutex.
 428  * The mutex is locked when the object is created, and unlocked when the object
 429  * is destroyed.
 430  */
 431 class vlc_mutex_locker
 432 {
 433     private:
 434         vlc_mutex_t *lock;
 435     public:
 436         vlc_mutex_locker (vlc_mutex_t *m) : lock (m)
 437         {
 438             vlc_mutex_lock (lock);
 439         }
 440
 441         ~vlc_mutex_locker (void)
 442         {
 443             vlc_mutex_unlock (lock);
 444         }
 445 };
 446 #endif
 447
 448 enum
 449 {
 450    VLC_AVCODEC_MUTEX = 0,
 451    VLC_GCRYPT_MUTEX,
 452    VLC_XLIB_MUTEX,
 453    VLC_MOSAIC_MUTEX,
 454    VLC_HIGHLIGHT_MUTEX,
 455    VLC_ATOMIC_MUTEX,
 456    /* Insert new entry HERE */
 457    VLC_MAX_MUTEX
 458 };
 459
 460 VLC_API void vlc_global_mutex( unsigned, bool );
 461 #define vlc_global_lock( n ) vlc_global_mutex( n, true )
 462 #define vlc_global_unlock( n ) vlc_global_mutex( n, false )
 463
 464 #endif /* !_VLC_THREADS_H */