SF: Adding Layer History to SF.
Calculate average and median between the timestamp differences that come in for
individual layers, and store them to systrace.
See go/surface-flinger-scheduler for more details and systrace links.
Test: SF tests updated.
Bug: 113612090
Change-Id: I934bbe36ab57d16a5b219c7cb8e0580112238671
diff --git a/services/surfaceflinger/Scheduler/LayerHistory.cpp b/services/surfaceflinger/Scheduler/LayerHistory.cpp
index e944eb9..1f47949 100644
--- a/services/surfaceflinger/Scheduler/LayerHistory.cpp
+++ b/services/surfaceflinger/Scheduler/LayerHistory.cpp
@@ -39,11 +39,15 @@
void LayerHistory::incrementCounter() {
mCounter++;
mCounter = mCounter % ARRAY_SIZE;
+ // Clear all the previous data from the history. This is a ring buffer, so we are
+ // reusing memory.
mElements[mCounter].clear();
}
const std::unordered_map<std::string, nsecs_t>& LayerHistory::get(size_t index) const {
- return mElements.at(index);
+ // For the purposes of the layer history, the index = 0 always needs to start at the
+ // current counter, and then decrement to access the layers in correct historical order.
+ return mElements.at((ARRAY_SIZE + (mCounter - (index % ARRAY_SIZE))) % ARRAY_SIZE);
}
} // namespace android
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