Enlarge mLast4FrameMetricsInfos from 4 to 6 entries

As a result of tuning SurfaceFlinger durations
(debug.sf.late.sf.duration etc.), the ring buffer of the frame metrics
infos is sometimes too small, and already popped the frame's info when
its GPU complete is triggered and doing onSurfaceStatsAvailable(), so
finishFrame() is not called for this frame, which causes incorrect
jank judgement on the next frame.

Increase the ring buffer size from 4 to 6 can avoid the issue.

Bug: 354618175
Test: no skipped frame in onSurfaceStatsAvailable
Flag: EXEMPT bugfix
Change-Id: I2865365213e16cfebe63b949aae332cea32d8927

2 files changed, 17 insertions, 17 deletions

diff --git a/libs/hwui/renderthread/CanvasContext.cpp b/libs/hwui/renderthread/CanvasContext.cpp
index 8bb11badb607..dfda25d013ed 100644
--- a/libs/hwui/renderthread/CanvasContext.cpp
+++ b/libs/hwui/renderthread/CanvasContext.cpp
@@ -761,8 +761,8 @@ void CanvasContext::draw(bool solelyTextureViewUpdates) {
         if (mExpectSurfaceStats) {
             reportMetricsWithPresentTime();
             {  // acquire lock
-                std::lock_guard lock(mLast4FrameMetricsInfosMutex);
-                FrameMetricsInfo& next = mLast4FrameMetricsInfos.next();
+                std::lock_guard lock(mLastFrameMetricsInfosMutex);
+                FrameMetricsInfo& next = mLastFrameMetricsInfos.next();
                 next.frameInfo = mCurrentFrameInfo;
                 next.frameNumber = frameCompleteNr;
                 next.surfaceId = mSurfaceControlGenerationId;
@@ -816,12 +816,12 @@ void CanvasContext::reportMetricsWithPresentTime() {
     int32_t surfaceControlId;
 
     {  // acquire lock
-        std::scoped_lock lock(mLast4FrameMetricsInfosMutex);
-        if (mLast4FrameMetricsInfos.size() != mLast4FrameMetricsInfos.capacity()) {
+        std::scoped_lock lock(mLastFrameMetricsInfosMutex);
+        if (mLastFrameMetricsInfos.size() != mLastFrameMetricsInfos.capacity()) {
             // Not enough frames yet
             return;
         }
-        auto frameMetricsInfo = mLast4FrameMetricsInfos.front();
+        auto frameMetricsInfo = mLastFrameMetricsInfos.front();
         forthBehind = frameMetricsInfo.frameInfo;
         frameNumber = frameMetricsInfo.frameNumber;
         surfaceControlId = frameMetricsInfo.surfaceId;
@@ -869,12 +869,12 @@ void CanvasContext::removeFrameMetricsObserver(FrameMetricsObserver* observer) {
     }
 }
 
-FrameInfo* CanvasContext::getFrameInfoFromLast4(uint64_t frameNumber, uint32_t surfaceControlId) {
-    std::scoped_lock lock(mLast4FrameMetricsInfosMutex);
-    for (size_t i = 0; i < mLast4FrameMetricsInfos.size(); i++) {
-        if (mLast4FrameMetricsInfos[i].frameNumber == frameNumber &&
-            mLast4FrameMetricsInfos[i].surfaceId == surfaceControlId) {
-            return mLast4FrameMetricsInfos[i].frameInfo;
+FrameInfo* CanvasContext::getFrameInfoFromLastFew(uint64_t frameNumber, uint32_t surfaceControlId) {
+    std::scoped_lock lock(mLastFrameMetricsInfosMutex);
+    for (size_t i = 0; i < mLastFrameMetricsInfos.size(); i++) {
+        if (mLastFrameMetricsInfos[i].frameNumber == frameNumber &&
+            mLastFrameMetricsInfos[i].surfaceId == surfaceControlId) {
+            return mLastFrameMetricsInfos[i].frameInfo;
         }
     }
 
@@ -894,7 +894,7 @@ void CanvasContext::onSurfaceStatsAvailable(void* context, int32_t surfaceContro
     }
     uint64_t frameNumber = functions.getFrameNumberFunc(stats);
 
-    FrameInfo* frameInfo = instance->getFrameInfoFromLast4(frameNumber, surfaceControlId);
+    FrameInfo* frameInfo = instance->getFrameInfoFromLastFew(frameNumber, surfaceControlId);
 
     if (frameInfo != nullptr) {
         std::scoped_lock lock(instance->mFrameInfoMutex);
diff --git a/libs/hwui/renderthread/CanvasContext.h b/libs/hwui/renderthread/CanvasContext.h
index e2e3fa35b9b0..cb3753822035 100644
--- a/libs/hwui/renderthread/CanvasContext.h
+++ b/libs/hwui/renderthread/CanvasContext.h
@@ -260,7 +260,7 @@ private:
     void finishFrame(FrameInfo* frameInfo);
 
     /**
-     * Invoke 'reportFrameMetrics' on the last frame stored in 'mLast4FrameInfos'.
+     * Invoke 'reportFrameMetrics' on the last frame stored in 'mLastFrameInfos'.
      * Populate the 'presentTime' field before calling.
      */
     void reportMetricsWithPresentTime();
@@ -271,7 +271,7 @@ private:
         int32_t surfaceId;
     };
 
-    FrameInfo* getFrameInfoFromLast4(uint64_t frameNumber, uint32_t surfaceControlId);
+    FrameInfo* getFrameInfoFromLastFew(uint64_t frameNumber, uint32_t surfaceControlId);
 
     Frame getFrame();
 
@@ -336,9 +336,9 @@ private:
 
     // List of data of frames that are awaiting GPU completion reporting. Used to compute frame
     // metrics and determine whether or not to report the metrics.
-    RingBuffer<FrameMetricsInfo, 4> mLast4FrameMetricsInfos
-            GUARDED_BY(mLast4FrameMetricsInfosMutex);
-    std::mutex mLast4FrameMetricsInfosMutex;
+    RingBuffer<FrameMetricsInfo, 6> mLastFrameMetricsInfos
+            GUARDED_BY(mLastFrameMetricsInfosMutex);
+    std::mutex mLastFrameMetricsInfosMutex;
 
     std::string mName;
     JankTracker mJankTracker;