TimeStats: bound the layer records and dump in SF dumpsys

Fixes: 131121064
Test: all SF tests
Change-Id: Ief641dfb4f69e5099a7fbf42dcdeecc5eb3d2bf9
diff --git a/services/surfaceflinger/TimeStats/TimeStats.cpp b/services/surfaceflinger/TimeStats/TimeStats.cpp
index 740099e..c97a19b 100644
--- a/services/surfaceflinger/TimeStats/TimeStats.cpp
+++ b/services/surfaceflinger/TimeStats/TimeStats.cpp
@@ -67,6 +67,16 @@
     }
 }
 
+std::string TimeStats::miniDump() {
+    ATRACE_CALL();
+
+    std::string result = "TimeStats miniDump:\n";
+    std::lock_guard<std::mutex> lock(mMutex);
+    android::base::StringAppendF(&result, "Number of tracked layers is %zu\n",
+                                 mTimeStatsTracker.size());
+    return result;
+}
+
 void TimeStats::incrementTotalFrames() {
     if (!mEnabled.load()) return;
 
@@ -252,7 +262,8 @@
           postTime);
 
     std::lock_guard<std::mutex> lock(mMutex);
-    if (!mTimeStatsTracker.count(layerID) && layerNameIsValid(layerName)) {
+    if (!mTimeStatsTracker.count(layerID) && mTimeStatsTracker.size() < MAX_NUM_LAYER_RECORDS &&
+        layerNameIsValid(layerName)) {
         mTimeStatsTracker[layerID].layerName = layerName;
     }
     if (!mTimeStatsTracker.count(layerID)) return;
diff --git a/services/surfaceflinger/TimeStats/TimeStats.h b/services/surfaceflinger/TimeStats/TimeStats.h
index d8c0786..4e040a3 100644
--- a/services/surfaceflinger/TimeStats/TimeStats.h
+++ b/services/surfaceflinger/TimeStats/TimeStats.h
@@ -41,6 +41,7 @@
 
     virtual void parseArgs(bool asProto, const Vector<String16>& args, std::string& result) = 0;
     virtual bool isEnabled() = 0;
+    virtual std::string miniDump();
 
     virtual void incrementTotalFrames() = 0;
     virtual void incrementMissedFrames() = 0;
@@ -112,6 +113,7 @@
 
     void parseArgs(bool asProto, const Vector<String16>& args, std::string& result) override;
     bool isEnabled() override;
+    std::string miniDump() override;
 
     void incrementTotalFrames() override;
     void incrementMissedFrames() override;
@@ -137,8 +139,6 @@
     void recordRefreshRate(uint32_t fps, nsecs_t duration) override;
     void setPresentFenceGlobal(const std::shared_ptr<FenceTime>& presentFence) override;
 
-    // TODO(zzyiwei): Bound the timeStatsTracker with weighted LRU
-    // static const size_t MAX_NUM_LAYER_RECORDS = 200;
     static const size_t MAX_NUM_TIME_RECORDS = 64;
 
 private:
@@ -159,6 +159,8 @@
     std::unordered_map<int32_t, LayerRecord> mTimeStatsTracker;
     PowerTime mPowerTime;
     GlobalRecord mGlobalRecord;
+
+    static const size_t MAX_NUM_LAYER_RECORDS = 200;
 };
 
 } // namespace impl