SurfaceFlinger: keep LayerInfo history for inactive layers
Instead if clearing the history for past layers, keep a timestamp
that will be used to filter out the frames which are outdated. This
allows us to distinguish between frequent vs. infrequent layers when
we get a buffer after a long time of inactivity.
Test: adb shell /data/nativetest64/libsurfaceflinger_unittest/libsurfaceflinger_unittest
Bug: 147516364
Change-Id: Ieb64cf6fc17a306c2db04b734631334af6703e79
diff --git a/services/surfaceflinger/Scheduler/LayerInfoV2.cpp b/services/surfaceflinger/Scheduler/LayerInfoV2.cpp
index f309d4d..345b8f9 100644
--- a/services/surfaceflinger/Scheduler/LayerInfoV2.cpp
+++ b/services/surfaceflinger/Scheduler/LayerInfoV2.cpp
@@ -54,21 +54,40 @@
return mFrameTimes.back().queueTime >= getActiveLayerThreshold(now);
}
+bool LayerInfoV2::isFrameTimeValid(const FrameTimeData& frameTime) const {
+ return frameTime.queueTime >= std::chrono::duration_cast<std::chrono::nanoseconds>(
+ mFrameTimeValidSince.time_since_epoch())
+ .count();
+}
+
bool LayerInfoV2::isFrequent(nsecs_t now) const {
- // Assume layer is infrequent if too few present times have been recorded.
+ // If we know nothing about this layer we consider it as frequent as it might be the start
+ // of an animation.
if (mFrameTimes.size() < FREQUENT_LAYER_WINDOW_SIZE) {
- return false;
+ return true;
}
// Layer is frequent if the earliest value in the window of most recent present times is
// within threshold.
const auto it = mFrameTimes.end() - FREQUENT_LAYER_WINDOW_SIZE;
+ if (!isFrameTimeValid(*it)) {
+ return true;
+ }
+
const nsecs_t threshold = now - MAX_FREQUENT_LAYER_PERIOD_NS.count();
return it->queueTime >= threshold;
}
bool LayerInfoV2::hasEnoughDataForHeuristic() const {
// The layer had to publish at least HISTORY_SIZE or HISTORY_TIME of updates
+ if (mFrameTimes.size() < 2) {
+ return false;
+ }
+
+ if (!isFrameTimeValid(mFrameTimes.front())) {
+ return false;
+ }
+
if (mFrameTimes.size() < HISTORY_SIZE &&
mFrameTimes.back().queueTime - mFrameTimes.front().queueTime < HISTORY_TIME.count()) {
return false;
diff --git a/services/surfaceflinger/Scheduler/LayerInfoV2.h b/services/surfaceflinger/Scheduler/LayerInfoV2.h
index 564f05e..90f6310 100644
--- a/services/surfaceflinger/Scheduler/LayerInfoV2.h
+++ b/services/surfaceflinger/Scheduler/LayerInfoV2.h
@@ -82,12 +82,25 @@
// updated time, the updated time is the present time.
nsecs_t getLastUpdatedTime() const { return mLastUpdatedTime; }
- void clearHistory() { mFrameTimes.clear(); }
+ void clearHistory() {
+ // Mark mFrameTimeValidSince to now to ignore all previous frame times.
+ // We are not deleting the old frame to keep track of whether we should treat the first
+ // buffer as Max as we don't know anything about this layer or Min as this layer is
+ // posting infrequent updates.
+ mFrameTimeValidSince = std::chrono::steady_clock::now();
+ }
private:
+ // Used to store the layer timestamps
+ struct FrameTimeData {
+ nsecs_t presetTime; // desiredPresentTime, if provided
+ nsecs_t queueTime; // buffer queue time
+ };
+
bool isFrequent(nsecs_t now) const;
bool hasEnoughDataForHeuristic() const;
std::optional<float> calculateRefreshRateIfPossible();
+ bool isFrameTimeValid(const FrameTimeData&) const;
// Used for sanitizing the heuristic data
const nsecs_t mHighRefreshRatePeriod;
@@ -103,12 +116,9 @@
float fps;
} mLayerVote;
- // Used to store the layer timestamps
- struct FrameTimeData {
- nsecs_t presetTime; // desiredPresentTime, if provided
- nsecs_t queueTime; // buffer queue time
- };
std::deque<FrameTimeData> mFrameTimes;
+ std::chrono::time_point<std::chrono::steady_clock> mFrameTimeValidSince =
+ std::chrono::steady_clock::now();
static constexpr size_t HISTORY_SIZE = 90;
static constexpr std::chrono::nanoseconds HISTORY_TIME = 1s;
};