# undef WIN32_LEAN_AND_MEAN
#endif /* G_OS_WIN32 */
+#define GET_ENTRY_STATUS(e) (g_atomic_int_get(&GST_CLOCK_ENTRY_STATUS(e)))
+#define SET_ENTRY_STATUS(e,val) (g_atomic_int_set(&GST_CLOCK_ENTRY_STATUS(e),(val)))
+#define CAS_ENTRY_STATUS(e,old,val) (g_atomic_int_compare_and_exchange(\
+ ((volatile gint *)&GST_CLOCK_ENTRY_STATUS(e)), (old), (val)))
+
/* Define this to get some extra debug about jitter from each clock_wait */
#undef WAIT_DEBUGGING
GstClockEntry *entry = (GstClockEntry *) entries->data;
GST_CAT_DEBUG (GST_CAT_CLOCK, "unscheduling entry %p", entry);
- entry->status = GST_CLOCK_UNSCHEDULED;
+ SET_ENTRY_STATUS (entry, GST_CLOCK_UNSCHEDULED);
}
GST_CLOCK_BROADCAST (clock);
gst_system_clock_add_wakeup (sysclock);
/* pick the next entry */
entry = clock->entries->data;
- /* if it was unscheduled, just move on to the next entry */
- if (entry->status == GST_CLOCK_UNSCHEDULED) {
- GST_CAT_DEBUG (GST_CAT_CLOCK, "entry %p was unscheduled", entry);
- goto next_entry;
- }
+ GST_OBJECT_UNLOCK (clock);
requested = entry->time;
gst_system_clock_id_wait_jitter_unlocked (clock, (GstClockID) entry,
NULL, FALSE);
+ GST_OBJECT_LOCK (clock);
+
switch (res) {
case GST_CLOCK_UNSCHEDULED:
/* entry was unscheduled, move to the next */
/* we set the entry back to the OK state. This is needed so that the
* _unschedule() code can see if an entry is currently being waited
* on (when its state is BUSY). */
- entry->status = GST_CLOCK_OK;
+ SET_ENTRY_STATUS (entry, GST_CLOCK_OK);
continue;
default:
GST_CAT_DEBUG (GST_CAT_CLOCK,
/* synchronously wait on the given GstClockEntry.
*
- * We do this by blocking on the global clock GCond variable with
- * the requested time as a timeout. This allows us to unblock the
- * entry by signaling the GCond variable.
+ * We do this by blocking on the global GstPoll timer with
+ * the requested timeout. This allows us to unblock the
+ * entry by writing on the control fd.
*
- * Note that signaling the global GCond unlocks all waiting entries. So
+ * Note that writing the global GstPoll unlocks all waiting entries. So
* we need to check if an unlocked entry has changed when it unlocks.
*
* Entries that arrive too late are simply not waited on and a
* GST_CLOCK_EARLY result is returned.
*
- * should be called with LOCK held.
- *
* MT safe.
*/
static GstClockReturn
GstClockEntry * entry, GstClockTimeDiff * jitter, gboolean restart)
{
GstSystemClock *sysclock = GST_SYSTEM_CLOCK_CAST (clock);
- GstClockTime entryt, real, now;
+ GstClockTime entryt, now;
GstClockTimeDiff diff;
+ GstClockReturn status;
+
+ if (G_UNLIKELY (GET_ENTRY_STATUS (entry) == GST_CLOCK_UNSCHEDULED))
+ return GST_CLOCK_UNSCHEDULED;
/* need to call the overridden method because we want to sync against the time
* of the clock, whatever the subclass uses as a clock. */
- real = GST_CLOCK_GET_CLASS (clock)->get_internal_time (clock);
- now = gst_clock_adjust_unlocked (clock, real);
+ now = gst_clock_get_time (clock);
/* get the time of the entry */
entryt = GST_CLOCK_ENTRY_TIME (entry);
- if (jitter) {
- *jitter = GST_CLOCK_DIFF (entryt, now);
- }
/* the diff of the entry with the clock is the amount of time we have to
* wait */
- diff = entryt - now;
+ diff = GST_CLOCK_DIFF (now, entryt);
+ if (G_LIKELY (jitter))
+ *jitter = -diff;
GST_CAT_DEBUG (GST_CAT_CLOCK, "entry %p"
" time %" GST_TIME_FORMAT
" now %" GST_TIME_FORMAT
- " real %" GST_TIME_FORMAT
" diff (time-now) %" G_GINT64_FORMAT,
- entry,
- GST_TIME_ARGS (entryt), GST_TIME_ARGS (now), GST_TIME_ARGS (real), diff);
+ entry, GST_TIME_ARGS (entryt), GST_TIME_ARGS (now), diff);
- if (diff > 0) {
+ if (G_LIKELY (diff > 0)) {
#ifdef WAIT_DEBUGGING
GstClockTime final;
#endif
- while (entry->status != GST_CLOCK_UNSCHEDULED) {
+ while (TRUE) {
gint pollret;
- /* mark the entry as busy */
- entry->status = GST_CLOCK_BUSY;
- GST_OBJECT_UNLOCK (clock);
+ do {
+ status = GET_ENTRY_STATUS (entry);
+
+ /* stop when we are unscheduled */
+ if (G_UNLIKELY (status == GST_CLOCK_UNSCHEDULED))
+ goto done;
- /* now wait on the entry, it either times out or the fd is written. */
+ /* mark the entry as busy but watch out for intermediate unscheduled
+ * statuses */
+ } while (G_UNLIKELY (!CAS_ENTRY_STATUS (entry, status, GST_CLOCK_BUSY)));
+
+ /* now wait on the entry, it either times out or the fd is written. The
+ * status of the entry is only BUSY around the poll. */
pollret = gst_poll_wait (sysclock->priv->timer, diff);
- /* another thread can read the fd before we get the lock */
- GST_OBJECT_LOCK (clock);
- if (entry->status == GST_CLOCK_UNSCHEDULED) {
- GST_CAT_DEBUG (GST_CAT_CLOCK, "entry %p unlocked", entry);
- gst_system_clock_remove_wakeup (sysclock);
+ /* get the new status, mark as DONE. We do this so that the unschedule
+ * function knows when we left the poll and doesn't need to wakeup the
+ * poll anymore. */
+ do {
+ status = GET_ENTRY_STATUS (entry);
+ /* we were unscheduled, exit immediately */
+ if (G_UNLIKELY (status == GST_CLOCK_UNSCHEDULED))
+ break;
+ } while (G_UNLIKELY (!CAS_ENTRY_STATUS (entry, status, GST_CLOCK_DONE)));
+
+ GST_CAT_DEBUG (GST_CAT_CLOCK, "entry %p unlocked, status %d, ret %d",
+ entry, status, pollret);
+
+ if (G_UNLIKELY (status == GST_CLOCK_UNSCHEDULED)) {
+ /* try to clean up The unschedule function managed to set the status to
+ * unscheduled. We now take the lock and mark the entry as unscheduled.
+ * This makes sure that the unschedule function doesn't perform a
+ * wakeup anymore. If the unschedule function has a change to perform
+ * the wakeup before us, we clean up here */
+ GST_OBJECT_LOCK (sysclock);
+ entry->unscheduled = TRUE;
+ if (entry->woken_up) {
+ gst_system_clock_remove_wakeup (sysclock);
+ }
+ GST_OBJECT_UNLOCK (sysclock);
+ goto done;
} else {
- if (pollret != 0) {
+ if (G_UNLIKELY (pollret != 0)) {
/* some other id got unlocked */
if (!restart) {
/* this can happen if the entry got unlocked because of an async
* entry was added to the head of the async queue. */
GST_CAT_DEBUG (GST_CAT_CLOCK, "wakeup waiting for entry %p", entry);
- break;
+ goto done;
}
- /* mark ourselves as EARLY, we release the lock and we could be
- * unscheduled ourselves but we don't want the unscheduling thread
- * to write on the control socket (it does that when an entry has a
- * BUSY status). */
- entry->status = GST_CLOCK_EARLY;
-
/* wait till all the entries got woken up */
+ GST_OBJECT_LOCK (sysclock);
gst_system_clock_wait_wakeup (sysclock);
-
- /* we released the lock in the wait, recheck our status, we don't need
- * to remove the wakeup count because we marked the entry as EARLY
- * before releasing the object lock. */
- if (entry->status == GST_CLOCK_UNSCHEDULED) {
- GST_CAT_DEBUG (GST_CAT_CLOCK, "entry %p got unscheduled", entry);
- break;
- }
+ GST_OBJECT_UNLOCK (sysclock);
GST_CAT_DEBUG (GST_CAT_CLOCK, "entry %p needs to be restarted",
entry);
/* reschedule if gst_poll_wait returned early or we have to reschedule after
* an unlock*/
- real = GST_CLOCK_GET_CLASS (clock)->get_internal_time (clock);
- now = gst_clock_adjust_unlocked (clock, real);
- diff = entryt - now;
+ now = gst_clock_get_time (clock);
+ diff = GST_CLOCK_DIFF (now, entryt);
if (diff <= 0) {
/* timeout, this is fine, we can report success now */
- entry->status = GST_CLOCK_OK;
+ status = GST_CLOCK_OK;
+ SET_ENTRY_STATUS (entry, status);
GST_CAT_DEBUG (GST_CAT_CLOCK,
"entry %p finished, diff %" G_GINT64_FORMAT, entry, diff);
(final - target),
((double) (GstClockTimeDiff) (final - target)) / GST_SECOND);
#endif
- break;
+ goto done;
} else {
GST_CAT_DEBUG (GST_CAT_CLOCK,
"entry %p restart, diff %" G_GINT64_FORMAT, entry, diff);
}
}
}
- } else if (diff == 0) {
- entry->status = GST_CLOCK_OK;
} else {
- entry->status = GST_CLOCK_EARLY;
+ /* we are right on time or too late */
+ if (G_UNLIKELY (diff == 0))
+ status = GST_CLOCK_OK;
+ else
+ status = GST_CLOCK_EARLY;
+
+ SET_ENTRY_STATUS (entry, status);
}
- return entry->status;
+done:
+ return status;
}
static GstClockReturn
gst_system_clock_id_wait_jitter (GstClock * clock, GstClockEntry * entry,
GstClockTimeDiff * jitter)
{
- GstClockReturn ret;
-
- GST_OBJECT_LOCK (clock);
- if (G_UNLIKELY (entry->status == GST_CLOCK_UNSCHEDULED))
- goto was_unscheduled;
-
- ret = gst_system_clock_id_wait_jitter_unlocked (clock, entry, jitter, TRUE);
- GST_OBJECT_UNLOCK (clock);
-
- return ret;
-
- /* ERRORS */
-was_unscheduled:
- {
- GST_OBJECT_UNLOCK (clock);
- return GST_CLOCK_UNSCHEDULED;
- }
+ return gst_system_clock_id_wait_jitter_unlocked (clock, entry, jitter, TRUE);
}
/* Start the async clock thread. Must be called with the object lock
if (G_UNLIKELY (!gst_system_clock_start_async (sysclock)))
goto thread_error;
- if (G_UNLIKELY (entry->status == GST_CLOCK_UNSCHEDULED))
+ if (G_UNLIKELY (GET_ENTRY_STATUS (entry) == GST_CLOCK_UNSCHEDULED))
goto was_unscheduled;
if (clock->entries)
* front, else the thread is just waiting for another entry and
* will get to this entry automatically. */
if (clock->entries->data == entry) {
- GST_CAT_DEBUG (GST_CAT_CLOCK, "async entry added to head");
+ GST_CAT_DEBUG (GST_CAT_CLOCK, "async entry added to head %p", head);
if (head == NULL) {
/* the list was empty before, signal the cond so that the async thread can
* start taking a look at the queue */
GST_CAT_DEBUG (GST_CAT_CLOCK, "first entry, sending signal");
GST_CLOCK_BROADCAST (clock);
} else {
- if (head->status == GST_CLOCK_BUSY) {
+ GstClockReturn status;
+
+ status = GET_ENTRY_STATUS (head);
+ GST_CAT_DEBUG (GST_CAT_CLOCK, "head entry %p status %d", head, status);
+
+ if (status == GST_CLOCK_BUSY) {
+ GST_CAT_DEBUG (GST_CAT_CLOCK, "head entry is busy");
/* the async thread was waiting for an entry, unlock the wait so that it
* looks at the new head entry instead, we only need to do this once */
if (!sysclock->priv->async_wakeup) {
gst_system_clock_id_unschedule (GstClock * clock, GstClockEntry * entry)
{
GstSystemClock *sysclock;
+ GstClockReturn status;
sysclock = GST_SYSTEM_CLOCK_CAST (clock);
GST_CAT_DEBUG (GST_CAT_CLOCK, "unscheduling entry %p", entry);
GST_OBJECT_LOCK (clock);
- if (entry->status == GST_CLOCK_BUSY) {
+ /* change the entry status to unscheduled */
+ do {
+ status = GET_ENTRY_STATUS (entry);
+ } while (G_UNLIKELY (!CAS_ENTRY_STATUS (entry, status,
+ GST_CLOCK_UNSCHEDULED)));
+
+ if (G_LIKELY (status == GST_CLOCK_BUSY)) {
/* the entry was being busy, wake up all entries so that they recheck their
* status. We cannot wake up just one entry because allocating such a
* datastructure for each entry would be too heavy and unlocking an entry
* is usually done when shutting down or some other exceptional case. */
GST_CAT_DEBUG (GST_CAT_CLOCK, "entry was BUSY, doing wakeup");
- gst_system_clock_add_wakeup (sysclock);
+ if (!entry->unscheduled && !entry->woken_up) {
+ gst_system_clock_add_wakeup (sysclock);
+ entry->woken_up = TRUE;
+ }
}
- /* when it leaves the poll, it'll detect the unscheduled */
- entry->status = GST_CLOCK_UNSCHEDULED;
GST_OBJECT_UNLOCK (clock);
}
projects / platform / upstream / gstreamer.git / commitdiff