Revert "When adding event listener, use fuzzy window for last event time."
This reverts commit 6db6d622ee87746c38116d5f53afede9226bdd30.
Reason for revert: issues such as b/131709052 where questionable frame pacing is observed. We could play with the ratios a bit but that would require a bit of tuning. Also, it looks like b/128918820 wasn't resolved by this change anyways so there's no evidence that this is a benefit.
Bug: 131709052
Test: systrace
Change-Id: I37656a8991a7040051cd5590c12b2a9a627e02a2
diff --git a/services/surfaceflinger/Scheduler/DispSync.cpp b/services/surfaceflinger/Scheduler/DispSync.cpp
index 871f556..abf7b71 100644
--- a/services/surfaceflinger/Scheduler/DispSync.cpp
+++ b/services/surfaceflinger/Scheduler/DispSync.cpp
@@ -210,17 +210,14 @@
const nsecs_t baseTime = now - mReferenceTime;
const nsecs_t numPeriodsSinceReference = baseTime / mPeriod;
const nsecs_t predictedReference = mReferenceTime + numPeriodsSinceReference * mPeriod;
- listener.mLastEventTime = predictedReference + mPhase + listener.mPhase;
- // If we're very close in time to the predicted last event time,
- // and we're not very close to the next predicted last event time
- // then we need to back up the last event time so that we can
- // attempt to fire an event immediately.
- //
- // Otherwise, keep the last event time that we predicted so that
- // we don't wake up early.
- if (isShorterThanPeriod(now - listener.mLastEventTime) &&
- !isShorterThanPeriod(listener.mLastEventTime + mPeriod - now)) {
- listener.mLastEventTime -= mPeriod;
+ const nsecs_t phaseCorrection = mPhase + listener.mPhase;
+ const nsecs_t predictedLastEventTime = predictedReference + phaseCorrection;
+ if (predictedLastEventTime >= now) {
+ // Make sure that the last event time does not exceed the current time.
+ // If it would, then back the last event time by a period.
+ listener.mLastEventTime = predictedLastEventTime - mPeriod;
+ } else {
+ listener.mLastEventTime = predictedLastEventTime;
}
} else {
listener.mLastEventTime = now + mPhase - mWakeupLatency;
@@ -316,7 +313,7 @@
// Sanity check that the duration is close enough in length to a period without
// falling into double-rate vsyncs.
- bool isShorterThanPeriod(nsecs_t duration) {
+ bool isCloseToPeriod(nsecs_t duration) {
// Ratio of 3/5 is arbitrary, but it must be greater than 1/2.
return duration < (3 * mPeriod) / 5;
}
@@ -332,7 +329,7 @@
nsecs_t t = computeListenerNextEventTimeLocked(eventListener, onePeriodAgo);
if (t < now) {
- if (isShorterThanPeriod(now - eventListener.mLastCallbackTime)) {
+ if (isCloseToPeriod(now - eventListener.mLastCallbackTime)) {
eventListener.mLastEventTime = t;
ALOGV("[%s] [%s] Skipping event due to model error", mName,
eventListener.mName);
@@ -392,7 +389,7 @@
// Check that it's been slightly more than half a period since the last
// event so that we don't accidentally fall into double-rate vsyncs
- if (isShorterThanPeriod(t - listener.mLastEventTime)) {
+ if (isCloseToPeriod(t - listener.mLastEventTime)) {
t += mPeriod;
ALOGV("[%s] Modifying t -> %" PRId64, mName, ns2us(t));
}