Use new traversal function when order doesn't matter
The new traversal function just handles traversing children and ignores relative layers. It also doesn't care about the z order. We continue to use the traverseInZOrder functions
for cases when z order matters.
This optimization reduces total CPU time spent in SurfaceFlinger.
Total ~2% savings
The savings where measured sampling over a 20 second period while TouchLatency
bouncy ball app was running.
Baseline
https://pprof.corp.google.com/?id=2ec0b6ac8e24e1571a3173c763ecd7e1&focus=LayerVector%3A%3AtraverseInZOrder
Optimized
https://pprof.corp.google.com/?id=23596aeb3e9db163956dc621dd19d7a4&focus=LayerVector%3A%3Atraverse
Test: manual. checked that normal use on the phone did not have graphical corruptions.
Test: atest SurfaceFlinger_test libcompositionengine_test libsurfaceflinger_unittest
Test: go/wm-smoke
Port from ag/10112179
Change-Id: I60cc6b58efc0e95c5ccc204830a3d76d2e7633c7
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index f4d4329..4ac868e 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -1795,6 +1795,15 @@
}
}
+void Layer::traverse(LayerVector::StateSet state, const LayerVector::Visitor& visitor) {
+ visitor(this);
+ const LayerVector& children =
+ state == LayerVector::StateSet::Drawing ? mDrawingChildren : mCurrentChildren;
+ for (const sp<Layer>& child : children) {
+ child->traverse(state, visitor);
+ }
+}
+
LayerVector Layer::makeChildrenTraversalList(LayerVector::StateSet stateSet,
const std::vector<Layer*>& layersInTree) {
LOG_ALWAYS_FATAL_IF(stateSet == LayerVector::StateSet::Invalid,