SurfaceFlinger: calculate expected present once
Calculate the expected present time in the beginning of the frame
and use the same value across the frame composition.
Bug: 137873466
Test: App transitions
Change-Id: I0b41c62796f6150702e8d50ec7d28838d3a5aa87
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 0c9263b..56cccfb 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -1686,22 +1686,26 @@
return fence != Fence::NO_FENCE && (fence->getStatus() == Fence::Status::Unsignaled);
}
-nsecs_t SurfaceFlinger::getExpectedPresentTime() NO_THREAD_SAFETY_ANALYSIS {
+void SurfaceFlinger::populateExpectedPresentTime() NO_THREAD_SAFETY_ANALYSIS {
DisplayStatInfo stats;
mScheduler->getDisplayStatInfo(&stats);
const nsecs_t presentTime = mScheduler->getDispSyncExpectedPresentTime();
// Inflate the expected present time if we're targetting the next vsync.
- const nsecs_t correctedTime =
+ mExpectedPresentTime =
mVsyncModulator.getOffsets().sf < mPhaseOffsets->getOffsetThresholdForNextVsync()
? presentTime
: presentTime + stats.vsyncPeriod;
- return correctedTime;
}
void SurfaceFlinger::onMessageReceived(int32_t what) NO_THREAD_SAFETY_ANALYSIS {
ATRACE_CALL();
switch (what) {
case MessageQueue::INVALIDATE: {
+ // calculate the expected present time once and use the cached
+ // value throughout this frame to make sure all layers are
+ // seeing this same value.
+ populateExpectedPresentTime();
+
bool frameMissed = previousFrameMissed();
bool hwcFrameMissed = mHadDeviceComposition && frameMissed;
bool gpuFrameMissed = mHadClientComposition && frameMissed;
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 556a4b9..d836795 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -301,10 +301,11 @@
// TODO: this should be made accessible only to MessageQueue
void onMessageReceived(int32_t what);
- // Returns the expected present time for this frame.
+ // populates the expected present time for this frame.
// When we are in negative offsets, we perform a correction so that the
// predicted vsync for the *next* frame is used instead.
- nsecs_t getExpectedPresentTime();
+ void populateExpectedPresentTime();
+ nsecs_t getExpectedPresentTime() const { return mExpectedPresentTime; }
// for debugging only
// TODO: this should be made accessible only to HWComposer
@@ -1184,6 +1185,8 @@
// Flags to capture the state of Vsync in HWC
HWC2::Vsync mHWCVsyncState = HWC2::Vsync::Disable;
HWC2::Vsync mHWCVsyncPendingState = HWC2::Vsync::Disable;
+
+ nsecs_t mExpectedPresentTime;
};
} // namespace android