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;
299 /*** Read/write locks */
300 /* SRW (Slim Read Write) locks are available in Vista+ only */
301 void vlc_rwlock_init (vlc_rwlock_t *lock)
303 vlc_mutex_init (&lock->mutex);
304 vlc_cond_init (&lock->read_wait);
305 vlc_cond_init (&lock->write_wait);
306 lock->readers = 0; /* active readers */
307 lock->writers = 0; /* waiting or active writers */
308 lock->writer = 0; /* ID of active writer */
312 * Destroys an initialized unused read/write lock.
314 void vlc_rwlock_destroy (vlc_rwlock_t *lock)
316 vlc_cond_destroy (&lock->read_wait);
317 vlc_cond_destroy (&lock->write_wait);
318 vlc_mutex_destroy (&lock->mutex);
322 * Acquires a read/write lock for reading. Recursion is allowed.
324 void vlc_rwlock_rdlock (vlc_rwlock_t *lock)
326 vlc_mutex_lock (&lock->mutex);
327 while (lock->writer != 0)
328 vlc_cond_wait (&lock->read_wait, &lock->mutex);
329 if (lock->readers == ULONG_MAX)
332 vlc_mutex_unlock (&lock->mutex);
336 * Acquires a read/write lock for writing. Recursion is not allowed.
338 void vlc_rwlock_wrlock (vlc_rwlock_t *lock)
340 vlc_mutex_lock (&lock->mutex);
341 if (lock->writers == ULONG_MAX)
344 while ((lock->readers > 0) || (lock->writer != 0))
345 vlc_cond_wait (&lock->write_wait, &lock->mutex);
347 lock->writer = GetCurrentThreadId ();
348 vlc_mutex_unlock (&lock->mutex);
352 * Releases a read/write lock.
354 void vlc_rwlock_unlock (vlc_rwlock_t *lock)
356 vlc_mutex_lock (&lock->mutex);
357 if (lock->readers > 0)
358 lock->readers--; /* Read unlock */
360 lock->writer = 0; /* Write unlock */
362 if (lock->writers > 0)
364 if (lock->readers == 0)
365 vlc_cond_signal (&lock->write_wait);
368 vlc_cond_broadcast (&lock->read_wait);
369 vlc_mutex_unlock (&lock->mutex);
372 /*** Thread-specific variables (TLS) ***/
373 int vlc_threadvar_create (vlc_threadvar_t *p_tls, void (*destr) (void *))
375 #warning FIXME: use destr() callback and stop leaking!
378 return (*p_tls == TLS_OUT_OF_INDEXES) ? EAGAIN : 0;
381 void vlc_threadvar_delete (vlc_threadvar_t *p_tls)
387 * Sets a thread-local variable.
388 * @param key thread-local variable key (created with vlc_threadvar_create())
389 * @param value new value for the variable for the calling thread
390 * @return 0 on success, a system error code otherwise.
392 int vlc_threadvar_set (vlc_threadvar_t key, void *value)
394 return TlsSetValue (key, value) ? ENOMEM : 0;
398 * Gets the value of a thread-local variable for the calling thread.
399 * This function cannot fail.
400 * @return the value associated with the given variable for the calling
401 * or NULL if there is no value.
403 void *vlc_threadvar_get (vlc_threadvar_t key)
405 return TlsGetValue (key);
410 void vlc_threads_setup (libvlc_int_t *p_libvlc)
415 struct vlc_entry_data
417 void * (*func) (void *);
424 static unsigned __stdcall vlc_entry (void *p)
426 vlc_cancel_t cancel_data = VLC_CANCEL_INIT;
427 struct vlc_entry_data data;
429 memcpy (&data, p, sizeof (data));
433 cancel_data.cancel_event = data.cancel_event;
436 vlc_threadvar_set (cancel_key, &cancel_data);
437 data.func (data.data);
441 int vlc_clone (vlc_thread_t *p_handle, void * (*entry) (void *), void *data,
447 struct vlc_entry_data *entry_data = malloc (sizeof (*entry_data));
448 if (entry_data == NULL)
450 entry_data->func = entry;
451 entry_data->data = data;
454 /* When using the MSVCRT C library you have to use the _beginthreadex
455 * function instead of CreateThread, otherwise you'll end up with
456 * memory leaks and the signal functions not working (see Microsoft
457 * Knowledge Base, article 104641) */
458 hThread = (HANDLE)(uintptr_t)
459 _beginthreadex (NULL, 0, vlc_entry, entry_data, CREATE_SUSPENDED, NULL);
466 /* Thread closes the handle when exiting, duplicate it here
467 * to be on the safe side when joining. */
468 if (!DuplicateHandle (GetCurrentProcess (), hThread,
469 GetCurrentProcess (), p_handle, 0, FALSE,
470 DUPLICATE_SAME_ACCESS))
472 CloseHandle (hThread);
477 vlc_thread_t th = malloc (sizeof (*th));
480 th->cancel_event = CreateEvent (NULL, FALSE, FALSE, NULL);
481 if (th->cancel_event == NULL)
486 entry_data->cancel_event = th->cancel_event;
488 /* Not sure if CREATE_SUSPENDED + ResumeThread() is any useful on WinCE.
489 * Thread handles act up, too. */
490 th->handle = CreateThread (NULL, 128*1024, vlc_entry, entry_data,
491 CREATE_SUSPENDED, NULL);
492 if (th->handle == NULL)
494 CloseHandle (th->cancel_event);
500 hThread = th->handle;
504 ResumeThread (hThread);
506 SetThreadPriority (hThread, priority);
515 void vlc_join (vlc_thread_t handle, void **result)
518 # define handle handle->handle
522 while (WaitForSingleObjectEx (handle, INFINITE, TRUE)
523 == WAIT_IO_COMPLETION);
525 CloseHandle (handle);
526 assert (result == NULL); /* <- FIXME if ever needed */
529 CloseHandle (handle->cancel_event);
534 void vlc_detach (vlc_thread_t handle)
537 CloseHandle (handle);
539 /* FIXME: handle->cancel_event leak */
540 CloseHandle (handle->handle);
545 /*** Thread cancellation ***/
547 /* APC procedure for thread cancellation */
548 static void CALLBACK vlc_cancel_self (ULONG_PTR dummy)
551 vlc_control_cancel (VLC_DO_CANCEL);
554 void vlc_cancel (vlc_thread_t thread_id)
557 QueueUserAPC (vlc_cancel_self, thread_id, 0);
559 SetEvent (thread_id->cancel_event);
563 int vlc_savecancel (void)
567 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
569 return false; /* Main thread - cannot be cancelled anyway */
571 state = nfo->killable;
572 nfo->killable = false;
576 void vlc_restorecancel (int state)
578 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
579 assert (state == false || state == true);
582 return; /* Main thread - cannot be cancelled anyway */
584 assert (!nfo->killable);
585 nfo->killable = state != 0;
588 void vlc_testcancel (void)
590 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
592 return; /* Main thread - cannot be cancelled anyway */
594 if (nfo->killable && nfo->killed)
596 for (vlc_cleanup_t *p = nfo->cleaners; p != NULL; p = p->next)
606 void vlc_control_cancel (int cmd, ...)
608 /* NOTE: This function only modifies thread-specific data, so there is no
609 * need to lock anything. */
612 vlc_cancel_t *nfo = vlc_threadvar_get (cancel_key);
614 return; /* Main thread - cannot be cancelled anyway */
623 case VLC_CLEANUP_PUSH:
625 /* cleaner is a pointer to the caller stack, no need to allocate
626 * and copy anything. As a nice side effect, this cannot fail. */
627 vlc_cleanup_t *cleaner = va_arg (ap, vlc_cleanup_t *);
628 cleaner->next = nfo->cleaners;
629 nfo->cleaners = cleaner;
633 case VLC_CLEANUP_POP:
635 nfo->cleaners = nfo->cleaners->next;
652 void (*func) (void *);
657 static void CALLBACK vlc_timer_do (void *val, BOOLEAN timeout)
659 struct vlc_timer *timer = val;
662 timer->func (timer->data);
665 static void CALLBACK vlc_timer_do (unsigned timer_id, unsigned msg,
666 DWORD_PTR user, DWORD_PTR unused1,
669 struct vlc_timer *timer = (struct vlc_timer *) user;
670 assert (timer_id == timer->id);
675 timer->func (timer->data);
679 mtime_t interval = timer->interval * 1000;
680 vlc_timer_schedule (timer, false, interval, interval);
685 int vlc_timer_create (vlc_timer_t *id, void (*func) (void *), void *data)
687 struct vlc_timer *timer = malloc (sizeof (*timer));
694 timer->handle = INVALID_HANDLE_VALUE;
703 void vlc_timer_destroy (vlc_timer_t timer)
706 if (timer->handle != INVALID_HANDLE_VALUE)
707 DeleteTimerQueueTimer (NULL, timer->handle, INVALID_HANDLE_VALUE);
710 timeKillEvent (timer->id);
711 /* FIXME: timers that have not yet completed will trigger use-after-free */
716 void vlc_timer_schedule (vlc_timer_t timer, bool absolute,
717 mtime_t value, mtime_t interval)
720 if (timer->handle != INVALID_HANDLE_VALUE)
722 DeleteTimerQueueTimer (NULL, timer->handle, NULL);
723 timer->handle = INVALID_HANDLE_VALUE;
728 timeKillEvent (timer->id);
738 value = (value + 999) / 1000;
739 interval = (interval + 999) / 1000;
742 if (!CreateTimerQueueTimer (&timer->handle, NULL, vlc_timer_do, timer,
743 value, interval, WT_EXECUTEDEFAULT))
746 timeGetDevCaps (&caps, sizeof(caps));
748 unsigned delay = value;
749 delay = __MAX(delay, caps.wPeriodMin);
750 delay = __MIN(delay, caps.wPeriodMax);
752 unsigned event = TIME_ONESHOT;
754 if (interval == delay)
755 event = TIME_PERIODIC;
757 timer->interval = interval;
759 timer->id = timeSetEvent (delay, delay / 20, vlc_timer_do, (DWORD) timer,
766 unsigned vlc_timer_getoverrun (vlc_timer_t timer)