2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2004 Wim Taymans <wim@fluendo.com>
5 * gstsystemclock.c: Default clock, uses the system clock
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Library General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
20 * Boston, MA 02110-1301, USA.
24 * SECTION:gstsystemclock
25 * @short_description: Default clock that uses the current system time
26 * @see_also: #GstClock
28 * The GStreamer core provides a GstSystemClock based on the system time.
29 * Asynchronous callbacks are scheduled from an internal thread.
31 * Clock implementors are encouraged to subclass this systemclock as it
32 * implements the async notification.
34 * Subclasses can however override all of the important methods for sync and
35 * async notifications to implement their own callback methods or blocking
39 #include "gst_private.h"
41 #include "gstsystemclock.h"
42 #include "gstenumtypes.h"
45 #include "glib-compat-private.h"
50 # define WIN32_LEAN_AND_MEAN /* prevents from including too many things */
51 # include <windows.h> /* QueryPerformance* stuff */
52 # undef WIN32_LEAN_AND_MEAN
54 # define EWOULDBLOCK EAGAIN /* This is just to placate gcc */
56 #endif /* G_OS_WIN32 */
59 #include <mach/mach_time.h>
62 #define GET_ENTRY_STATUS(e) ((GstClockReturn) g_atomic_int_get(&GST_CLOCK_ENTRY_STATUS(e)))
63 #define SET_ENTRY_STATUS(e,val) (g_atomic_int_set(&GST_CLOCK_ENTRY_STATUS(e),(val)))
64 #define CAS_ENTRY_STATUS(e,old,val) (g_atomic_int_compare_and_exchange(\
65 (&GST_CLOCK_ENTRY_STATUS(e)), (old), (val)))
67 /* Define this to get some extra debug about jitter from each clock_wait */
70 #define GST_SYSTEM_CLOCK_GET_COND(clock) (&GST_SYSTEM_CLOCK_CAST(clock)->priv->entries_changed)
71 #define GST_SYSTEM_CLOCK_WAIT(clock) g_cond_wait(GST_SYSTEM_CLOCK_GET_COND(clock),GST_OBJECT_GET_LOCK(clock))
72 #define GST_SYSTEM_CLOCK_TIMED_WAIT(clock,tv) g_cond_timed_wait(GST_SYSTEM_CLOCK_GET_COND(clock),GST_OBJECT_GET_LOCK(clock),tv)
73 #define GST_SYSTEM_CLOCK_BROADCAST(clock) g_cond_broadcast(GST_SYSTEM_CLOCK_GET_COND(clock))
75 struct _GstSystemClockPrivate
77 GThread *thread; /* thread for async notify */
81 GCond entries_changed;
83 GstClockType clock_type;
85 gint wakeup_count; /* the number of entries with a pending wakeup */
86 gboolean async_wakeup; /* if the wakeup was because of a async list change */
90 LARGE_INTEGER frequency;
91 #endif /* G_OS_WIN32 */
93 struct mach_timebase_info mach_timebase;
97 #define GST_SYSTEM_CLOCK_GET_PRIVATE(obj) \
98 (G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_SYSTEM_CLOCK, \
99 GstSystemClockPrivate))
101 #ifdef HAVE_POSIX_TIMERS
102 # ifdef HAVE_MONOTONIC_CLOCK
103 # define DEFAULT_CLOCK_TYPE GST_CLOCK_TYPE_MONOTONIC
105 # define DEFAULT_CLOCK_TYPE GST_CLOCK_TYPE_REALTIME
108 #define DEFAULT_CLOCK_TYPE GST_CLOCK_TYPE_REALTIME
118 /* the one instance of the systemclock */
119 static GstClock *_the_system_clock = NULL;
120 static gboolean _external_default_clock = FALSE;
122 static void gst_system_clock_dispose (GObject * object);
123 static void gst_system_clock_set_property (GObject * object, guint prop_id,
124 const GValue * value, GParamSpec * pspec);
125 static void gst_system_clock_get_property (GObject * object, guint prop_id,
126 GValue * value, GParamSpec * pspec);
128 static GstClockTime gst_system_clock_get_internal_time (GstClock * clock);
129 static guint64 gst_system_clock_get_resolution (GstClock * clock);
130 static GstClockReturn gst_system_clock_id_wait_jitter (GstClock * clock,
131 GstClockEntry * entry, GstClockTimeDiff * jitter);
132 static GstClockReturn gst_system_clock_id_wait_jitter_unlocked
133 (GstClock * clock, GstClockEntry * entry, GstClockTimeDiff * jitter,
135 static GstClockReturn gst_system_clock_id_wait_async (GstClock * clock,
136 GstClockEntry * entry);
137 static void gst_system_clock_id_unschedule (GstClock * clock,
138 GstClockEntry * entry);
139 static void gst_system_clock_async_thread (GstClock * clock);
140 static gboolean gst_system_clock_start_async (GstSystemClock * clock);
141 static void gst_system_clock_add_wakeup (GstSystemClock * sysclock);
143 static GMutex _gst_sysclock_mutex;
145 /* static guint gst_system_clock_signals[LAST_SIGNAL] = { 0 }; */
147 #define gst_system_clock_parent_class parent_class
148 G_DEFINE_TYPE (GstSystemClock, gst_system_clock, GST_TYPE_CLOCK);
151 gst_system_clock_class_init (GstSystemClockClass * klass)
153 GObjectClass *gobject_class;
154 GstClockClass *gstclock_class;
156 gobject_class = (GObjectClass *) klass;
157 gstclock_class = (GstClockClass *) klass;
159 g_type_class_add_private (klass, sizeof (GstSystemClockPrivate));
161 gobject_class->dispose = gst_system_clock_dispose;
162 gobject_class->set_property = gst_system_clock_set_property;
163 gobject_class->get_property = gst_system_clock_get_property;
165 g_object_class_install_property (gobject_class, PROP_CLOCK_TYPE,
166 g_param_spec_enum ("clock-type", "Clock type",
167 "The type of underlying clock implementation used",
168 GST_TYPE_CLOCK_TYPE, DEFAULT_CLOCK_TYPE,
169 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
171 gstclock_class->get_internal_time = gst_system_clock_get_internal_time;
172 gstclock_class->get_resolution = gst_system_clock_get_resolution;
173 gstclock_class->wait = gst_system_clock_id_wait_jitter;
174 gstclock_class->wait_async = gst_system_clock_id_wait_async;
175 gstclock_class->unschedule = gst_system_clock_id_unschedule;
179 gst_system_clock_init (GstSystemClock * clock)
181 GstSystemClockPrivate *priv;
183 GST_OBJECT_FLAG_SET (clock,
184 GST_CLOCK_FLAG_CAN_DO_SINGLE_SYNC |
185 GST_CLOCK_FLAG_CAN_DO_SINGLE_ASYNC |
186 GST_CLOCK_FLAG_CAN_DO_PERIODIC_SYNC |
187 GST_CLOCK_FLAG_CAN_DO_PERIODIC_ASYNC);
189 clock->priv = priv = GST_SYSTEM_CLOCK_GET_PRIVATE (clock);
191 priv->clock_type = DEFAULT_CLOCK_TYPE;
192 priv->timer = gst_poll_new_timer ();
194 priv->entries = NULL;
195 g_cond_init (&priv->entries_changed);
198 QueryPerformanceFrequency (&priv->frequency);
199 /* can be 0 if the hardware does not have hardware support */
200 if (priv->frequency.QuadPart != 0)
201 /* we take a base time so that time starts from 0 to ease debugging */
202 QueryPerformanceCounter (&priv->start);
203 #endif /* G_OS_WIN32 */
206 mach_timebase_info (&priv->mach_timebase);
210 /* Uncomment this to start the async clock thread straight away */
211 GST_OBJECT_LOCK (clock);
212 gst_system_clock_start_async (clock);
213 GST_OBJECT_UNLOCK (clock);
218 gst_system_clock_dispose (GObject * object)
220 GstClock *clock = (GstClock *) object;
221 GstSystemClock *sysclock = GST_SYSTEM_CLOCK_CAST (clock);
222 GstSystemClockPrivate *priv = sysclock->priv;
225 /* else we have to stop the thread */
226 GST_OBJECT_LOCK (clock);
227 priv->stopping = TRUE;
228 /* unschedule all entries */
229 for (entries = priv->entries; entries; entries = g_list_next (entries)) {
230 GstClockEntry *entry = (GstClockEntry *) entries->data;
232 GST_CAT_DEBUG (GST_CAT_CLOCK, "unscheduling entry %p", entry);
233 SET_ENTRY_STATUS (entry, GST_CLOCK_UNSCHEDULED);
235 GST_SYSTEM_CLOCK_BROADCAST (clock);
236 gst_system_clock_add_wakeup (sysclock);
237 GST_OBJECT_UNLOCK (clock);
240 g_thread_join (priv->thread);
242 GST_CAT_DEBUG (GST_CAT_CLOCK, "joined thread");
244 g_list_foreach (priv->entries, (GFunc) gst_clock_id_unref, NULL);
245 g_list_free (priv->entries);
246 priv->entries = NULL;
248 gst_poll_free (priv->timer);
249 g_cond_clear (&priv->entries_changed);
251 G_OBJECT_CLASS (parent_class)->dispose (object);
253 if (_the_system_clock == clock) {
254 _the_system_clock = NULL;
255 GST_CAT_DEBUG (GST_CAT_CLOCK, "disposed system clock");
260 gst_system_clock_set_property (GObject * object, guint prop_id,
261 const GValue * value, GParamSpec * pspec)
263 GstSystemClock *sysclock = GST_SYSTEM_CLOCK (object);
266 case PROP_CLOCK_TYPE:
267 sysclock->priv->clock_type = (GstClockType) g_value_get_enum (value);
268 GST_CAT_DEBUG (GST_CAT_CLOCK, "clock-type set to %d",
269 sysclock->priv->clock_type);
272 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
278 gst_system_clock_get_property (GObject * object, guint prop_id, GValue * value,
281 GstSystemClock *sysclock = GST_SYSTEM_CLOCK (object);
284 case PROP_CLOCK_TYPE:
285 g_value_set_enum (value, sysclock->priv->clock_type);
288 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
294 * gst_system_clock_set_default:
295 * @new_clock: a #GstClock
297 * Sets the default system clock that can be obtained with
298 * gst_system_clock_obtain().
300 * This is mostly used for testing and debugging purposes when you
301 * want to have control over the time reported by the default system
309 gst_system_clock_set_default (GstClock * new_clock)
313 g_mutex_lock (&_gst_sysclock_mutex);
314 clock = _the_system_clock;
317 g_object_unref (clock);
319 if (new_clock == NULL) {
320 GST_CAT_DEBUG (GST_CAT_CLOCK, "resetting default system clock");
321 _external_default_clock = FALSE;
323 GST_CAT_DEBUG (GST_CAT_CLOCK, "setting new default system clock to %p",
325 _external_default_clock = TRUE;
326 g_object_ref (new_clock);
328 _the_system_clock = new_clock;
329 g_mutex_unlock (&_gst_sysclock_mutex);
333 * gst_system_clock_obtain:
335 * Get a handle to the default system clock. The refcount of the
336 * clock will be increased so you need to unref the clock after
339 * Returns: (transfer full): the default clock.
344 gst_system_clock_obtain (void)
348 g_mutex_lock (&_gst_sysclock_mutex);
349 clock = _the_system_clock;
352 GST_CAT_DEBUG (GST_CAT_CLOCK, "creating new static system clock");
353 g_assert (!_external_default_clock);
354 clock = g_object_new (GST_TYPE_SYSTEM_CLOCK,
355 "name", "GstSystemClock", NULL);
357 g_assert (!g_object_is_floating (G_OBJECT (clock)));
359 _the_system_clock = clock;
360 g_mutex_unlock (&_gst_sysclock_mutex);
362 g_mutex_unlock (&_gst_sysclock_mutex);
363 GST_CAT_DEBUG (GST_CAT_CLOCK, "returning static system clock");
366 /* we ref it since we are a clock factory. */
367 gst_object_ref (clock);
372 gst_system_clock_remove_wakeup (GstSystemClock * sysclock)
374 g_return_if_fail (sysclock->priv->wakeup_count > 0);
376 sysclock->priv->wakeup_count--;
377 if (sysclock->priv->wakeup_count == 0) {
378 /* read the control socket byte when we removed the last wakeup count */
379 GST_CAT_DEBUG (GST_CAT_CLOCK, "reading control");
380 while (!gst_poll_read_control (sysclock->priv->timer)) {
381 g_warning ("gstsystemclock: read control failed, trying again\n");
383 GST_SYSTEM_CLOCK_BROADCAST (sysclock);
385 GST_CAT_DEBUG (GST_CAT_CLOCK, "wakeup count %d",
386 sysclock->priv->wakeup_count);
390 gst_system_clock_add_wakeup (GstSystemClock * sysclock)
392 /* only write the control socket for the first wakeup */
393 if (sysclock->priv->wakeup_count == 0) {
394 GST_CAT_DEBUG (GST_CAT_CLOCK, "writing control");
395 while (!gst_poll_write_control (sysclock->priv->timer)) {
396 if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR) {
398 ("gstsystemclock: write control failed in wakeup_async, trying again: %d:%s\n",
399 errno, g_strerror (errno));
402 ("gstsystemclock: write control failed in wakeup_async: %d:%s\n",
403 errno, g_strerror (errno));
408 sysclock->priv->wakeup_count++;
409 GST_CAT_DEBUG (GST_CAT_CLOCK, "wakeup count %d",
410 sysclock->priv->wakeup_count);
414 gst_system_clock_wait_wakeup (GstSystemClock * sysclock)
416 while (sysclock->priv->wakeup_count > 0) {
417 GST_SYSTEM_CLOCK_WAIT (sysclock);
421 /* this thread reads the sorted clock entries from the queue.
423 * It waits on each of them and fires the callback when the timeout occurs.
425 * When an entry in the queue was canceled before we wait for it, it is
428 * When waiting for an entry, it can become canceled, in that case we don't
429 * call the callback but move to the next item in the queue.
434 gst_system_clock_async_thread (GstClock * clock)
436 GstSystemClock *sysclock = GST_SYSTEM_CLOCK_CAST (clock);
437 GstSystemClockPrivate *priv = sysclock->priv;
439 GST_CAT_DEBUG (GST_CAT_CLOCK, "enter system clock thread");
440 GST_OBJECT_LOCK (clock);
442 GST_SYSTEM_CLOCK_BROADCAST (clock);
443 /* now enter our (almost) infinite loop */
444 while (!priv->stopping) {
445 GstClockEntry *entry;
446 GstClockTime requested;
449 /* check if something to be done */
450 while (priv->entries == NULL) {
451 GST_CAT_DEBUG (GST_CAT_CLOCK, "no clock entries, waiting..");
452 /* wait for work to do */
453 GST_SYSTEM_CLOCK_WAIT (clock);
454 GST_CAT_DEBUG (GST_CAT_CLOCK, "got signal");
455 /* clock was stopping, exit */
460 /* see if we have a pending wakeup because the order of the list
462 if (priv->async_wakeup) {
463 GST_CAT_DEBUG (GST_CAT_CLOCK, "clear async wakeup");
464 gst_system_clock_remove_wakeup (sysclock);
465 priv->async_wakeup = FALSE;
468 /* pick the next entry */
469 entry = priv->entries->data;
470 GST_OBJECT_UNLOCK (clock);
472 requested = entry->time;
474 /* now wait for the entry, we already hold the lock */
476 gst_system_clock_id_wait_jitter_unlocked (clock, (GstClockID) entry,
479 GST_OBJECT_LOCK (clock);
482 case GST_CLOCK_UNSCHEDULED:
483 /* entry was unscheduled, move to the next */
484 GST_CAT_DEBUG (GST_CAT_CLOCK, "async entry %p unscheduled", entry);
487 case GST_CLOCK_EARLY:
489 /* entry timed out normally, fire the callback and move to the next
491 GST_CAT_DEBUG (GST_CAT_CLOCK, "async entry %p timed out", entry);
493 /* unlock before firing the callback */
494 GST_OBJECT_UNLOCK (clock);
495 entry->func (clock, entry->time, (GstClockID) entry,
497 GST_OBJECT_LOCK (clock);
499 if (entry->type == GST_CLOCK_ENTRY_PERIODIC) {
500 GST_CAT_DEBUG (GST_CAT_CLOCK, "updating periodic entry %p", entry);
501 /* adjust time now */
502 entry->time = requested + entry->interval;
503 /* and resort the list now */
505 g_list_sort (priv->entries, gst_clock_id_compare_func);
509 GST_CAT_DEBUG (GST_CAT_CLOCK, "moving to next entry");
514 /* somebody unlocked the entry but is was not canceled, This means that
515 * either a new entry was added in front of the queue or some other entry
516 * was canceled. Whatever it is, pick the head entry of the list and
517 * continue waiting. */
518 GST_CAT_DEBUG (GST_CAT_CLOCK, "async entry %p needs restart", entry);
520 /* we set the entry back to the OK state. This is needed so that the
521 * _unschedule() code can see if an entry is currently being waited
522 * on (when its state is BUSY). */
523 SET_ENTRY_STATUS (entry, GST_CLOCK_OK);
526 GST_CAT_DEBUG (GST_CAT_CLOCK,
527 "strange result %d waiting for %p, skipping", res, entry);
528 g_warning ("%s: strange result %d waiting for %p, skipping",
529 GST_OBJECT_NAME (clock), res, entry);
533 /* we remove the current entry and unref it */
534 priv->entries = g_list_remove (priv->entries, entry);
535 gst_clock_id_unref ((GstClockID) entry);
539 GST_SYSTEM_CLOCK_BROADCAST (clock);
540 GST_OBJECT_UNLOCK (clock);
541 GST_CAT_DEBUG (GST_CAT_CLOCK, "exit system clock thread");
544 #ifdef HAVE_POSIX_TIMERS
545 static inline clockid_t
546 clock_type_to_posix_id (GstClockType clock_type)
548 #ifdef HAVE_MONOTONIC_CLOCK
549 if (clock_type == GST_CLOCK_TYPE_MONOTONIC)
550 return CLOCK_MONOTONIC;
553 return CLOCK_REALTIME;
559 gst_system_clock_get_internal_time (GstClock * clock)
561 #if defined __APPLE__
562 GstSystemClock *sysclock = GST_SYSTEM_CLOCK_CAST (clock);
563 uint64_t mach_t = mach_absolute_time ();
564 return gst_util_uint64_scale (mach_t, sysclock->priv->mach_timebase.numer,
565 sysclock->priv->mach_timebase.denom);
568 GstSystemClock *sysclock = GST_SYSTEM_CLOCK_CAST (clock);
570 if (sysclock->priv->frequency.QuadPart != 0) {
573 /* we prefer the highly accurate performance counters on windows */
574 QueryPerformanceCounter (&now);
576 return gst_util_uint64_scale (now.QuadPart - sysclock->priv->start.QuadPart,
577 GST_SECOND, sysclock->priv->frequency.QuadPart);
579 #endif /* G_OS_WIN32 */
580 #if !defined HAVE_POSIX_TIMERS || !defined HAVE_CLOCK_GETTIME
584 g_get_current_time (&timeval);
586 return GST_TIMEVAL_TO_TIME (timeval);
590 GstSystemClock *sysclock = GST_SYSTEM_CLOCK_CAST (clock);
594 ptype = clock_type_to_posix_id (sysclock->priv->clock_type);
596 if (G_UNLIKELY (clock_gettime (ptype, &ts)))
597 return GST_CLOCK_TIME_NONE;
599 return GST_TIMESPEC_TO_TIME (ts);
602 #endif /* __APPLE__ */
606 gst_system_clock_get_resolution (GstClock * clock)
608 #if defined __APPLE__
609 GstSystemClock *sysclock = GST_SYSTEM_CLOCK_CAST (clock);
610 return gst_util_uint64_scale (GST_NSECOND,
611 sysclock->priv->mach_timebase.numer, sysclock->priv->mach_timebase.denom);
614 GstSystemClock *sysclock = GST_SYSTEM_CLOCK_CAST (clock);
616 if (sysclock->priv->frequency.QuadPart != 0) {
617 return GST_SECOND / sysclock->priv->frequency.QuadPart;
619 #endif /* G_OS_WIN32 */
620 #if defined(HAVE_POSIX_TIMERS) && defined(HAVE_CLOCK_GETTIME)
622 GstSystemClock *sysclock = GST_SYSTEM_CLOCK_CAST (clock);
626 ptype = clock_type_to_posix_id (sysclock->priv->clock_type);
628 if (G_UNLIKELY (clock_getres (ptype, &ts)))
629 return GST_CLOCK_TIME_NONE;
631 return GST_TIMESPEC_TO_TIME (ts);
635 return 1 * GST_USECOND;
638 #endif /* __APPLE__ */
641 /* synchronously wait on the given GstClockEntry.
643 * We do this by blocking on the global GstPoll timer with
644 * the requested timeout. This allows us to unblock the
645 * entry by writing on the control fd.
647 * Note that writing the global GstPoll unlocks all waiting entries. So
648 * we need to check if an unlocked entry has changed when it unlocks.
650 * Entries that arrive too late are simply not waited on and a
651 * GST_CLOCK_EARLY result is returned.
655 static GstClockReturn
656 gst_system_clock_id_wait_jitter_unlocked (GstClock * clock,
657 GstClockEntry * entry, GstClockTimeDiff * jitter, gboolean restart)
659 GstSystemClock *sysclock = GST_SYSTEM_CLOCK_CAST (clock);
660 GstClockTime entryt, now;
661 GstClockTimeDiff diff;
662 GstClockReturn status;
664 status = GET_ENTRY_STATUS (entry);
665 if (G_UNLIKELY (status == GST_CLOCK_UNSCHEDULED))
666 return GST_CLOCK_UNSCHEDULED;
668 /* need to call the overridden method because we want to sync against the time
669 * of the clock, whatever the subclass uses as a clock. */
670 now = gst_clock_get_time (clock);
672 /* get the time of the entry */
673 entryt = GST_CLOCK_ENTRY_TIME (entry);
675 /* the diff of the entry with the clock is the amount of time we have to
677 diff = GST_CLOCK_DIFF (now, entryt);
678 if (G_LIKELY (jitter))
681 GST_CAT_DEBUG (GST_CAT_CLOCK, "entry %p"
682 " time %" GST_TIME_FORMAT
683 " now %" GST_TIME_FORMAT
684 " diff (time-now) %" G_GINT64_FORMAT,
685 entry, GST_TIME_ARGS (entryt), GST_TIME_ARGS (now), diff);
687 if (G_LIKELY (diff > 0)) {
688 #ifdef WAIT_DEBUGGING
696 status = GET_ENTRY_STATUS (entry);
698 /* stop when we are unscheduled */
699 if (G_UNLIKELY (status == GST_CLOCK_UNSCHEDULED))
702 /* mark the entry as busy but watch out for intermediate unscheduled
704 } while (G_UNLIKELY (!CAS_ENTRY_STATUS (entry, status, GST_CLOCK_BUSY)));
706 /* now wait on the entry, it either times out or the fd is written. The
707 * status of the entry is only BUSY around the poll. */
708 pollret = gst_poll_wait (sysclock->priv->timer, diff);
710 /* get the new status, mark as DONE. We do this so that the unschedule
711 * function knows when we left the poll and doesn't need to wakeup the
714 status = GET_ENTRY_STATUS (entry);
715 /* we were unscheduled, exit immediately */
716 if (G_UNLIKELY (status == GST_CLOCK_UNSCHEDULED))
718 } while (G_UNLIKELY (!CAS_ENTRY_STATUS (entry, status, GST_CLOCK_DONE)));
720 GST_CAT_DEBUG (GST_CAT_CLOCK, "entry %p unlocked, status %d, ret %d",
721 entry, status, pollret);
723 if (G_UNLIKELY (status == GST_CLOCK_UNSCHEDULED)) {
724 /* try to clean up The unschedule function managed to set the status to
725 * unscheduled. We now take the lock and mark the entry as unscheduled.
726 * This makes sure that the unschedule function doesn't perform a
727 * wakeup anymore. If the unschedule function has a change to perform
728 * the wakeup before us, we clean up here */
729 GST_OBJECT_LOCK (sysclock);
730 entry->unscheduled = TRUE;
731 if (entry->woken_up) {
732 gst_system_clock_remove_wakeup (sysclock);
734 GST_OBJECT_UNLOCK (sysclock);
737 if (G_UNLIKELY (pollret != 0)) {
738 /* some other id got unlocked */
740 /* this can happen if the entry got unlocked because of an async
741 * entry was added to the head of the async queue. */
742 GST_CAT_DEBUG (GST_CAT_CLOCK, "wakeup waiting for entry %p", entry);
746 /* wait till all the entries got woken up */
747 GST_OBJECT_LOCK (sysclock);
748 gst_system_clock_wait_wakeup (sysclock);
749 GST_OBJECT_UNLOCK (sysclock);
751 GST_CAT_DEBUG (GST_CAT_CLOCK, "entry %p needs to be restarted",
754 GST_CAT_DEBUG (GST_CAT_CLOCK, "entry %p unlocked after timeout",
758 /* reschedule if gst_poll_wait returned early or we have to reschedule after
760 now = gst_clock_get_time (clock);
761 diff = GST_CLOCK_DIFF (now, entryt);
764 /* timeout, this is fine, we can report success now */
765 if (G_UNLIKELY (!CAS_ENTRY_STATUS (entry, GST_CLOCK_DONE,
767 GST_CAT_DEBUG (GST_CAT_CLOCK, "unexpected status for entry %p",
769 status = GET_ENTRY_STATUS (entry);
772 status = GST_CLOCK_OK;
775 GST_CAT_DEBUG (GST_CAT_CLOCK,
776 "entry %p finished, diff %" G_GINT64_FORMAT, entry, diff);
778 #ifdef WAIT_DEBUGGING
779 final = gst_system_clock_get_internal_time (clock);
780 GST_CAT_DEBUG (GST_CAT_CLOCK, "Waited for %" G_GINT64_FORMAT
781 " got %" G_GINT64_FORMAT " diff %" G_GINT64_FORMAT
782 " %g target-offset %" G_GINT64_FORMAT " %g", entryt, now,
784 (double) (GstClockTimeDiff) (now - entryt) / GST_SECOND,
786 ((double) (GstClockTimeDiff) (final - target)) / GST_SECOND);
790 GST_CAT_DEBUG (GST_CAT_CLOCK,
791 "entry %p restart, diff %" G_GINT64_FORMAT, entry, diff);
796 /* we are right on time or too late */
797 if (G_UNLIKELY (diff == 0)) {
798 if (G_UNLIKELY (!CAS_ENTRY_STATUS (entry, status, GST_CLOCK_OK))) {
799 GST_CAT_DEBUG (GST_CAT_CLOCK, "unexpected status for entry %p", entry);
800 status = GET_ENTRY_STATUS (entry);
802 status = GST_CLOCK_OK;
805 if (G_UNLIKELY (!CAS_ENTRY_STATUS (entry, status, GST_CLOCK_EARLY))) {
806 GST_CAT_DEBUG (GST_CAT_CLOCK, "unexpected status for entry %p", entry);
807 status = GET_ENTRY_STATUS (entry);
809 status = GST_CLOCK_EARLY;
817 static GstClockReturn
818 gst_system_clock_id_wait_jitter (GstClock * clock, GstClockEntry * entry,
819 GstClockTimeDiff * jitter)
821 return gst_system_clock_id_wait_jitter_unlocked (clock, entry, jitter, TRUE);
824 /* Start the async clock thread. Must be called with the object lock
827 gst_system_clock_start_async (GstSystemClock * clock)
829 GError *error = NULL;
830 GstSystemClockPrivate *priv = clock->priv;
832 if (G_LIKELY (priv->thread != NULL))
833 return TRUE; /* Thread already running. Nothing to do */
835 priv->thread = g_thread_try_new ("GstSystemClock",
836 (GThreadFunc) gst_system_clock_async_thread, clock, &error);
838 if (G_UNLIKELY (error))
841 /* wait for it to spin up */
842 GST_SYSTEM_CLOCK_WAIT (clock);
849 g_warning ("could not create async clock thread: %s", error->message);
850 g_error_free (error);
855 /* Add an entry to the list of pending async waits. The entry is inserted
856 * in sorted order. If we inserted the entry at the head of the list, we
857 * need to signal the thread as it might either be waiting on it or waiting
862 static GstClockReturn
863 gst_system_clock_id_wait_async (GstClock * clock, GstClockEntry * entry)
865 GstSystemClock *sysclock;
866 GstSystemClockPrivate *priv;
869 sysclock = GST_SYSTEM_CLOCK_CAST (clock);
870 priv = sysclock->priv;
872 GST_CAT_DEBUG (GST_CAT_CLOCK, "adding async entry %p", entry);
874 GST_OBJECT_LOCK (clock);
875 /* Start the clock async thread if needed */
876 if (G_UNLIKELY (!gst_system_clock_start_async (sysclock)))
879 if (G_UNLIKELY (GET_ENTRY_STATUS (entry) == GST_CLOCK_UNSCHEDULED))
880 goto was_unscheduled;
883 head = priv->entries->data;
887 /* need to take a ref */
888 gst_clock_id_ref ((GstClockID) entry);
889 /* insert the entry in sorted order */
890 priv->entries = g_list_insert_sorted (priv->entries, entry,
891 gst_clock_id_compare_func);
893 /* only need to send the signal if the entry was added to the
894 * front, else the thread is just waiting for another entry and
895 * will get to this entry automatically. */
896 if (priv->entries->data == entry) {
897 GST_CAT_DEBUG (GST_CAT_CLOCK, "async entry added to head %p", head);
899 /* the list was empty before, signal the cond so that the async thread can
900 * start taking a look at the queue */
901 GST_CAT_DEBUG (GST_CAT_CLOCK, "first entry, sending signal");
902 GST_SYSTEM_CLOCK_BROADCAST (clock);
904 GstClockReturn status;
906 status = GET_ENTRY_STATUS (head);
907 GST_CAT_DEBUG (GST_CAT_CLOCK, "head entry %p status %d", head, status);
909 if (status == GST_CLOCK_BUSY) {
910 GST_CAT_DEBUG (GST_CAT_CLOCK, "head entry is busy");
911 /* the async thread was waiting for an entry, unlock the wait so that it
912 * looks at the new head entry instead, we only need to do this once */
913 if (!priv->async_wakeup) {
914 GST_CAT_DEBUG (GST_CAT_CLOCK, "wakeup async thread");
915 priv->async_wakeup = TRUE;
916 gst_system_clock_add_wakeup (sysclock);
921 GST_OBJECT_UNLOCK (clock);
928 /* Could not start the async clock thread */
929 GST_OBJECT_UNLOCK (clock);
930 return GST_CLOCK_ERROR;
934 GST_OBJECT_UNLOCK (clock);
935 return GST_CLOCK_UNSCHEDULED;
939 /* unschedule an entry. This will set the state of the entry to GST_CLOCK_UNSCHEDULED
940 * and will signal any thread waiting for entries to recheck their entry.
941 * We cannot really decide if the signal is needed or not because the entry
942 * could be waited on in async or sync mode.
947 gst_system_clock_id_unschedule (GstClock * clock, GstClockEntry * entry)
949 GstSystemClock *sysclock;
950 GstClockReturn status;
952 sysclock = GST_SYSTEM_CLOCK_CAST (clock);
954 GST_CAT_DEBUG (GST_CAT_CLOCK, "unscheduling entry %p", entry);
956 GST_OBJECT_LOCK (clock);
957 /* change the entry status to unscheduled */
959 status = GET_ENTRY_STATUS (entry);
960 } while (G_UNLIKELY (!CAS_ENTRY_STATUS (entry, status,
961 GST_CLOCK_UNSCHEDULED)));
963 if (G_LIKELY (status == GST_CLOCK_BUSY)) {
964 /* the entry was being busy, wake up all entries so that they recheck their
965 * status. We cannot wake up just one entry because allocating such a
966 * datastructure for each entry would be too heavy and unlocking an entry
967 * is usually done when shutting down or some other exceptional case. */
968 GST_CAT_DEBUG (GST_CAT_CLOCK, "entry was BUSY, doing wakeup");
969 if (!entry->unscheduled && !entry->woken_up) {
970 gst_system_clock_add_wakeup (sysclock);
971 entry->woken_up = TRUE;
974 GST_OBJECT_UNLOCK (clock);