1 /*****************************************************************************
2 * w32thread.c : Win32 back-end for LibVLC
3 *****************************************************************************
4 * Copyright (C) 1999-2009 the VideoLAN team
7 * Authors: Jean-Marc Dressler <polux@via.ecp.fr>
8 * Samuel Hocevar <sam@zoy.org>
9 * Gildas Bazin <gbazin@netcourrier.com>
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software
26 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
27 *****************************************************************************/
33 #include <vlc_common.h>
40 # include <mmsystem.h>
43 static vlc_threadvar_t cancel_key;
46 * Per-thread cancellation data
48 typedef struct vlc_cancel_t
50 vlc_cleanup_t *cleaners;
59 # define VLC_CANCEL_INIT { NULL, true, false }
61 # define VLC_CANCEL_INIT { NULL, NULL, true, false }
65 static void CALLBACK vlc_cancel_self (ULONG_PTR dummy);
67 static DWORD vlc_cancelable_wait (DWORD count, const HANDLE *handles,
70 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
73 /* Main thread - cannot be cancelled anyway */
74 return WaitForMultipleObjects (count, handles, FALSE, delay);
76 HANDLE new_handles[count + 1];
77 memcpy(new_handles, handles, count * sizeof(HANDLE));
78 new_handles[count] = nfo->cancel_event;
79 DWORD result = WaitForMultipleObjects (count + 1, new_handles, FALSE,
81 if (result == WAIT_OBJECT_0 + count)
83 vlc_cancel_self (NULL);
84 return WAIT_IO_COMPLETION;
92 DWORD SleepEx (DWORD dwMilliseconds, BOOL bAlertable)
96 DWORD result = vlc_cancelable_wait (0, NULL, dwMilliseconds);
97 return (result == WAIT_TIMEOUT) ? 0 : WAIT_IO_COMPLETION;
101 Sleep(dwMilliseconds);
106 DWORD WaitForSingleObjectEx (HANDLE hHandle, DWORD dwMilliseconds,
111 /* The MSDN documentation specifies different return codes,
112 * but in practice they are the same. We just check that it
114 #if WAIT_ABANDONED != WAIT_ABANDONED_0
115 # error Windows headers changed, code needs to be rewritten!
117 return vlc_cancelable_wait (1, &hHandle, dwMilliseconds);
121 return WaitForSingleObject (hHandle, dwMilliseconds);
125 DWORD WaitForMultipleObjectsEx (DWORD nCount, const HANDLE *lpHandles,
126 BOOL bWaitAll, DWORD dwMilliseconds,
131 /* We do not support the bWaitAll case */
133 return vlc_cancelable_wait (nCount, lpHandles, dwMilliseconds);
137 return WaitForMultipleObjects (nCount, lpHandles, bWaitAll,
143 static vlc_mutex_t super_mutex;
145 BOOL WINAPI DllMain (HINSTANCE hinstDll, DWORD fdwReason, LPVOID lpvReserved)
152 case DLL_PROCESS_ATTACH:
153 vlc_mutex_init (&super_mutex);
154 vlc_threadvar_create (&cancel_key, free);
157 case DLL_PROCESS_DETACH:
158 vlc_threadvar_delete( &cancel_key );
159 vlc_mutex_destroy (&super_mutex);
166 void vlc_mutex_init( vlc_mutex_t *p_mutex )
168 /* This creates a recursive mutex. This is OK as fast mutexes have
169 * no defined behavior in case of recursive locking. */
170 InitializeCriticalSection (&p_mutex->mutex);
171 p_mutex->initialized = 1;
174 void vlc_mutex_init_recursive( vlc_mutex_t *p_mutex )
176 InitializeCriticalSection( &p_mutex->mutex );
177 p_mutex->initialized = 1;
181 void vlc_mutex_destroy (vlc_mutex_t *p_mutex)
183 assert (InterlockedExchange (&p_mutex->initialized, -1) == 1);
184 DeleteCriticalSection (&p_mutex->mutex);
187 void vlc_mutex_lock (vlc_mutex_t *p_mutex)
189 if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
190 { /* ^^ We could also lock super_mutex all the time... sluggish */
191 assert (p_mutex != &super_mutex); /* this one cannot be static */
193 vlc_mutex_lock (&super_mutex);
194 if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
195 vlc_mutex_init (p_mutex);
196 /* FIXME: destroy the mutex some time... */
197 vlc_mutex_unlock (&super_mutex);
199 assert (InterlockedExchange (&p_mutex->initialized, 1) == 1);
200 EnterCriticalSection (&p_mutex->mutex);
203 int vlc_mutex_trylock (vlc_mutex_t *p_mutex)
205 if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
206 { /* ^^ We could also lock super_mutex all the time... sluggish */
207 assert (p_mutex != &super_mutex); /* this one cannot be static */
209 vlc_mutex_lock (&super_mutex);
210 if (InterlockedCompareExchange (&p_mutex->initialized, 0, 0) == 0)
211 vlc_mutex_init (p_mutex);
212 /* FIXME: destroy the mutex some time... */
213 vlc_mutex_unlock (&super_mutex);
215 assert (InterlockedExchange (&p_mutex->initialized, 1) == 1);
216 return TryEnterCriticalSection (&p_mutex->mutex) ? 0 : EBUSY;
219 void vlc_mutex_unlock (vlc_mutex_t *p_mutex)
221 assert (InterlockedExchange (&p_mutex->initialized, 1) == 1);
222 LeaveCriticalSection (&p_mutex->mutex);
225 /*** Condition variables ***/
226 void vlc_cond_init( vlc_cond_t *p_condvar )
228 /* Create a manual-reset event (manual reset is needed for broadcast). */
229 *p_condvar = CreateEvent (NULL, TRUE, FALSE, NULL);
234 void vlc_cond_destroy (vlc_cond_t *p_condvar)
236 CloseHandle (*p_condvar);
239 void vlc_cond_signal (vlc_cond_t *p_condvar)
241 /* NOTE: This will cause a broadcast, that is wrong.
242 * This will also wake up the next waiting thread if no threads are yet
243 * waiting, which is also wrong. However both of these issues are allowed
244 * by the provision for spurious wakeups. Better have too many wakeups
245 * than too few (= deadlocks). */
246 SetEvent (*p_condvar);
249 void vlc_cond_broadcast (vlc_cond_t *p_condvar)
251 SetEvent (*p_condvar);
254 void vlc_cond_wait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex)
261 LeaveCriticalSection (&p_mutex->mutex);
262 result = WaitForSingleObjectEx (*p_condvar, INFINITE, TRUE);
263 EnterCriticalSection (&p_mutex->mutex);
265 while (result == WAIT_IO_COMPLETION);
267 assert (result != WAIT_ABANDONED); /* another thread failed to cleanup! */
268 assert (result != WAIT_FAILED);
269 ResetEvent (*p_condvar);
272 int vlc_cond_timedwait (vlc_cond_t *p_condvar, vlc_mutex_t *p_mutex,
281 mtime_t total = (deadline - mdate ())/1000;
285 DWORD delay = (total > 0x7fffffff) ? 0x7fffffff : total;
286 LeaveCriticalSection (&p_mutex->mutex);
287 result = WaitForSingleObjectEx (*p_condvar, delay, TRUE);
288 EnterCriticalSection (&p_mutex->mutex);
290 while (result == WAIT_IO_COMPLETION);
292 assert (result != WAIT_ABANDONED);
293 assert (result != WAIT_FAILED);
294 ResetEvent (*p_condvar);
296 return (result == WAIT_OBJECT_0) ? 0 : ETIMEDOUT;
300 void vlc_sem_init (vlc_sem_t *sem, unsigned value)
302 *sem = CreateSemaphore (NULL, value, 0x7fffffff, NULL);
307 void vlc_sem_destroy (vlc_sem_t *sem)
312 int vlc_sem_post (vlc_sem_t *sem)
314 ReleaseSemaphore (*sem, 1, NULL);
315 return 0; /* FIXME */
318 void vlc_sem_wait (vlc_sem_t *sem)
325 result = WaitForSingleObjectEx (*sem, INFINITE, TRUE);
327 while (result == WAIT_IO_COMPLETION);
330 /*** Read/write locks */
331 /* SRW (Slim Read Write) locks are available in Vista+ only */
332 void vlc_rwlock_init (vlc_rwlock_t *lock)
334 vlc_mutex_init (&lock->mutex);
335 vlc_cond_init (&lock->read_wait);
336 vlc_cond_init (&lock->write_wait);
337 lock->readers = 0; /* active readers */
338 lock->writers = 0; /* waiting or active writers */
339 lock->writer = 0; /* ID of active writer */
343 * Destroys an initialized unused read/write lock.
345 void vlc_rwlock_destroy (vlc_rwlock_t *lock)
347 vlc_cond_destroy (&lock->read_wait);
348 vlc_cond_destroy (&lock->write_wait);
349 vlc_mutex_destroy (&lock->mutex);
353 * Acquires a read/write lock for reading. Recursion is allowed.
355 void vlc_rwlock_rdlock (vlc_rwlock_t *lock)
357 vlc_mutex_lock (&lock->mutex);
358 while (lock->writer != 0)
359 vlc_cond_wait (&lock->read_wait, &lock->mutex);
360 if (lock->readers == ULONG_MAX)
363 vlc_mutex_unlock (&lock->mutex);
367 * Acquires a read/write lock for writing. Recursion is not allowed.
369 void vlc_rwlock_wrlock (vlc_rwlock_t *lock)
371 vlc_mutex_lock (&lock->mutex);
372 if (lock->writers == ULONG_MAX)
375 while ((lock->readers > 0) || (lock->writer != 0))
376 vlc_cond_wait (&lock->write_wait, &lock->mutex);
378 lock->writer = GetCurrentThreadId ();
379 vlc_mutex_unlock (&lock->mutex);
383 * Releases a read/write lock.
385 void vlc_rwlock_unlock (vlc_rwlock_t *lock)
387 vlc_mutex_lock (&lock->mutex);
388 if (lock->readers > 0)
389 lock->readers--; /* Read unlock */
391 lock->writer = 0; /* Write unlock */
393 if (lock->writers > 0)
395 if (lock->readers == 0)
396 vlc_cond_signal (&lock->write_wait);
399 vlc_cond_broadcast (&lock->read_wait);
400 vlc_mutex_unlock (&lock->mutex);
403 /*** Thread-specific variables (TLS) ***/
404 int vlc_threadvar_create (vlc_threadvar_t *p_tls, void (*destr) (void *))
406 #warning FIXME: use destr() callback and stop leaking!
410 return (*p_tls == TLS_OUT_OF_INDEXES) ? EAGAIN : 0;
413 void vlc_threadvar_delete (vlc_threadvar_t *p_tls)
419 * Sets a thread-local variable.
420 * @param key thread-local variable key (created with vlc_threadvar_create())
421 * @param value new value for the variable for the calling thread
422 * @return 0 on success, a system error code otherwise.
424 int vlc_threadvar_set (vlc_threadvar_t key, void *value)
426 return TlsSetValue (key, value) ? ENOMEM : 0;
430 * Gets the value of a thread-local variable for the calling thread.
431 * This function cannot fail.
432 * @return the value associated with the given variable for the calling
433 * or NULL if there is no value.
435 void *vlc_threadvar_get (vlc_threadvar_t key)
437 return TlsGetValue (key);
442 void vlc_threads_setup (libvlc_int_t *p_libvlc)
447 struct vlc_entry_data
449 void * (*func) (void *);
456 static unsigned __stdcall vlc_entry (void *p)
458 vlc_cancel_t cancel_data = VLC_CANCEL_INIT;
459 struct vlc_entry_data data;
461 memcpy (&data, p, sizeof (data));
465 cancel_data.cancel_event = data.cancel_event;
468 vlc_threadvar_set (cancel_key, &cancel_data);
469 data.func (data.data);
473 int vlc_clone (vlc_thread_t *p_handle, void * (*entry) (void *), void *data,
479 struct vlc_entry_data *entry_data = malloc (sizeof (*entry_data));
480 if (entry_data == NULL)
482 entry_data->func = entry;
483 entry_data->data = data;
486 /* When using the MSVCRT C library you have to use the _beginthreadex
487 * function instead of CreateThread, otherwise you'll end up with
488 * memory leaks and the signal functions not working (see Microsoft
489 * Knowledge Base, article 104641) */
490 hThread = (HANDLE)(uintptr_t)
491 _beginthreadex (NULL, 0, vlc_entry, entry_data, CREATE_SUSPENDED, NULL);
498 /* Thread closes the handle when exiting, duplicate it here
499 * to be on the safe side when joining. */
500 if (!DuplicateHandle (GetCurrentProcess (), hThread,
501 GetCurrentProcess (), p_handle, 0, FALSE,
502 DUPLICATE_SAME_ACCESS))
504 CloseHandle (hThread);
509 vlc_thread_t th = malloc (sizeof (*th));
512 th->cancel_event = CreateEvent (NULL, FALSE, FALSE, NULL);
513 if (th->cancel_event == NULL)
518 entry_data->cancel_event = th->cancel_event;
520 /* Not sure if CREATE_SUSPENDED + ResumeThread() is any useful on WinCE.
521 * Thread handles act up, too. */
522 th->handle = CreateThread (NULL, 128*1024, vlc_entry, entry_data,
523 CREATE_SUSPENDED, NULL);
524 if (th->handle == NULL)
526 CloseHandle (th->cancel_event);
532 hThread = th->handle;
536 ResumeThread (hThread);
538 SetThreadPriority (hThread, priority);
547 void vlc_join (vlc_thread_t handle, void **result)
550 # define handle handle->handle
554 while (WaitForSingleObjectEx (handle, INFINITE, TRUE)
555 == WAIT_IO_COMPLETION);
557 CloseHandle (handle);
558 assert (result == NULL); /* <- FIXME if ever needed */
561 CloseHandle (handle->cancel_event);
566 void vlc_detach (vlc_thread_t handle)
569 CloseHandle (handle);
571 /* FIXME: handle->cancel_event leak */
572 CloseHandle (handle->handle);
577 /*** Thread cancellation ***/
579 /* APC procedure for thread cancellation */
580 static void CALLBACK vlc_cancel_self (ULONG_PTR dummy)
583 vlc_control_cancel (VLC_DO_CANCEL);
586 void vlc_cancel (vlc_thread_t thread_id)
589 QueueUserAPC (vlc_cancel_self, thread_id, 0);
591 SetEvent (thread_id->cancel_event);
595 int vlc_savecancel (void)
599 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
601 return false; /* Main thread - cannot be cancelled anyway */
603 state = nfo->killable;
604 nfo->killable = false;
608 void vlc_restorecancel (int state)
610 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
611 assert (state == false || state == true);
614 return; /* Main thread - cannot be cancelled anyway */
616 assert (!nfo->killable);
617 nfo->killable = state != 0;
620 void vlc_testcancel (void)
622 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
624 return; /* Main thread - cannot be cancelled anyway */
626 if (nfo->killable && nfo->killed)
628 for (vlc_cleanup_t *p = nfo->cleaners; p != NULL; p = p->next)
638 void vlc_control_cancel (int cmd, ...)
640 /* NOTE: This function only modifies thread-specific data, so there is no
641 * need to lock anything. */
644 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
646 return; /* Main thread - cannot be cancelled anyway */
655 case VLC_CLEANUP_PUSH:
657 /* cleaner is a pointer to the caller stack, no need to allocate
658 * and copy anything. As a nice side effect, this cannot fail. */
659 vlc_cleanup_t *cleaner = va_arg (ap, vlc_cleanup_t *);
660 cleaner->next = nfo->cleaners;
661 nfo->cleaners = cleaner;
665 case VLC_CLEANUP_POP:
667 nfo->cleaners = nfo->cleaners->next;
684 void (*func) (void *);
689 static void CALLBACK vlc_timer_do (void *val, BOOLEAN timeout)
691 struct vlc_timer *timer = val;
694 timer->func (timer->data);
697 static void CALLBACK vlc_timer_do (unsigned timer_id, unsigned msg,
698 DWORD_PTR user, DWORD_PTR unused1,
701 struct vlc_timer *timer = (struct vlc_timer *) user;
702 assert (timer_id == timer->id);
707 timer->func (timer->data);
711 mtime_t interval = timer->interval * 1000;
712 vlc_timer_schedule (timer, false, interval, interval);
717 int vlc_timer_create (vlc_timer_t *id, void (*func) (void *), void *data)
719 struct vlc_timer *timer = malloc (sizeof (*timer));
726 timer->handle = INVALID_HANDLE_VALUE;
735 void vlc_timer_destroy (vlc_timer_t timer)
738 if (timer->handle != INVALID_HANDLE_VALUE)
739 DeleteTimerQueueTimer (NULL, timer->handle, INVALID_HANDLE_VALUE);
742 timeKillEvent (timer->id);
743 /* FIXME: timers that have not yet completed will trigger use-after-free */
748 void vlc_timer_schedule (vlc_timer_t timer, bool absolute,
749 mtime_t value, mtime_t interval)
752 if (timer->handle != INVALID_HANDLE_VALUE)
754 DeleteTimerQueueTimer (NULL, timer->handle, NULL);
755 timer->handle = INVALID_HANDLE_VALUE;
760 timeKillEvent (timer->id);
770 value = (value + 999) / 1000;
771 interval = (interval + 999) / 1000;
774 if (!CreateTimerQueueTimer (&timer->handle, NULL, vlc_timer_do, timer,
775 value, interval, WT_EXECUTEDEFAULT))
778 timeGetDevCaps (&caps, sizeof(caps));
780 unsigned delay = value;
781 delay = __MAX(delay, caps.wPeriodMin);
782 delay = __MIN(delay, caps.wPeriodMax);
784 unsigned event = TIME_ONESHOT;
786 if (interval == delay)
787 event = TIME_PERIODIC;
789 timer->interval = interval;
791 timer->id = timeSetEvent (delay, delay / 20, vlc_timer_do, (DWORD) timer,
798 unsigned vlc_timer_getoverrun (vlc_timer_t timer)