commit 548f4497df58f43f85f5e0c4e9e0a41bd6b8bae7
author ramindani <ramindani@google.com> Thu Jun 13 10:29:04 2024 -0700
committer ramindani <ramindani@google.com> Mon Jun 17 18:58:01 2024 -0700
tree 16b8bb38b287f744ef55b69b86cac1d40670d4a2
parent 33f4e0e65995426645be48e8a96a6e71784ed865

SF: Update vsync timeline validUntil to be exact vsync time.

Introduce Timeline::isWithin function that puts sourced vsync time
source into Unique, Shared and Outside categories.

BUG: 343603085
Test: atest VSyncPredictorTest
Flag: com.android.graphics.surfaceflinger.flags.vrr_bugfix_24q4
Change-Id: I99094e64c8403455158a6e794bd4d2ce32429f93

services/surfaceflinger/Scheduler/VSyncPredictor.cpp

diff --git a/services/surfaceflinger/Scheduler/VSyncPredictor.cpp b/services/surfaceflinger/Scheduler/VSyncPredictor.cpp
index dd3c4b0..0644aca 100644
--- a/services/surfaceflinger/Scheduler/VSyncPredictor.cpp
+++ b/services/surfaceflinger/Scheduler/VSyncPredictor.cpp
@@ -360,7 +360,11 @@
     purgeTimelines(now);
 
     for (auto& timeline : mTimelines) {
-        if (timeline.validUntil() && timeline.validUntil()->ns() > vsync) {
+        const bool isVsyncValid = FlagManager::getInstance().vrr_bugfix_24q4()
+                ? timeline.isWithin(TimePoint::fromNs(vsync)) ==
+                        VsyncTimeline::VsyncOnTimeline::Unique
+                : timeline.validUntil() && timeline.validUntil()->ns() > vsync;
+        if (isVsyncValid) {
             return timeline.isVSyncInPhase(model, vsync, frameRate);
         }
     }
@@ -395,8 +399,14 @@
         mLastCommittedVsync = TimePoint::fromNs(0);
 
     } else {
-        mTimelines.back().freeze(
-                TimePoint::fromNs(mLastCommittedVsync.ns() + mIdealPeriod.ns() / 2));
+        if (FlagManager::getInstance().vrr_bugfix_24q4()) {
+            // We need to freeze the timeline at the committed vsync so that we don't
+            // overshoot the deadline.
+            mTimelines.back().freeze(mLastCommittedVsync);
+        } else {
+            mTimelines.back().freeze(
+                    TimePoint::fromNs(mLastCommittedVsync.ns() + mIdealPeriod.ns() / 2));
+        }
     }
     mTimelines.emplace_back(mLastCommittedVsync, mIdealPeriod, renderRate);
     purgeTimelines(TimePoint::fromNs(mClock->now()));
@@ -611,7 +621,10 @@
 
     while (mTimelines.size() > 1) {
         const auto validUntilOpt = mTimelines.front().validUntil();
-        if (validUntilOpt && *validUntilOpt < now) {
+        const bool isTimelineOutDated = FlagManager::getInstance().vrr_bugfix_24q4()
+                ? mTimelines.front().isWithin(now) == VsyncTimeline::VsyncOnTimeline::Outside
+                : validUntilOpt && *validUntilOpt < now;
+        if (isTimelineOutDated) {
             mTimelines.pop_front();
         } else {
             break;
@@ -660,9 +673,12 @@
             vsyncTime += missedVsync.fixup.ns();
             ATRACE_FORMAT_INSTANT("lastFrameMissed");
         } else if (mightBackpressure && lastVsyncOpt) {
-            // lastVsyncOpt is based on the old timeline before we shifted it. we should correct it
-            // first before trying to use it.
-            lastVsyncOpt = snapToVsyncAlignedWithRenderRate(model, *lastVsyncOpt);
+            if (!FlagManager::getInstance().vrr_bugfix_24q4()) {
+                // lastVsyncOpt does not need to be corrected with the new rate, and
+                // it should be used as is to avoid skipping a frame when changing rates are
+                // aligned at vsync time.
+                lastVsyncOpt = snapToVsyncAlignedWithRenderRate(model, *lastVsyncOpt);
+            }
             const auto vsyncDiff = vsyncTime - *lastVsyncOpt;
             if (vsyncDiff <= minFramePeriodOpt->ns() - threshold) {
                 // avoid a duplicate vsync
@@ -681,7 +697,10 @@
     }
 
     ATRACE_FORMAT_INSTANT("vsync in %.2fms", float(vsyncTime - TimePoint::now().ns()) / 1e6f);
-    if (mValidUntil && vsyncTime > mValidUntil->ns()) {
+    const bool isVsyncInvalid = FlagManager::getInstance().vrr_bugfix_24q4()
+            ? isWithin(TimePoint::fromNs(vsyncTime)) == VsyncOnTimeline::Outside
+            : mValidUntil && vsyncTime > mValidUntil->ns();
+    if (isVsyncInvalid) {
         ATRACE_FORMAT_INSTANT("no longer valid for vsync in %.2f",
                               static_cast<float>(vsyncTime - TimePoint::now().ns()) / 1e6f);
         return std::nullopt;