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Commit dadac5a0 authored by Andrei Stanciu's avatar Andrei Stanciu
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Quick optimization for committing Layers 

Layer::commitChildList is a traversal by itself. Running it inside a
traversal results in an undesired n^2 traversal time.
commitChildList is swapping the common state with the drawing state and executes the assignment multiple times / Layer, which could become quite costly.


Change-Id: I15f670b7766a3c2a16abbd3ae20bb8a7c76ec852
Test: atest SurfaceFlinger_test - all tests pass.
parent 12d24c50

services/surfaceflinger/SurfaceFlinger.cpp

+13 −9
Original line number Diff line number Diff line
@@ -3027,15 +3027,19 @@ void SurfaceFlinger::commitTransactionLocked() { 
    // clear the "changed" flags in current state

    mCurrentState.colorMatrixChanged = false;



    for (const auto& rootLayer : mDrawingState.layersSortedByZ) {

        rootLayer->commitChildList();

    }

    // TODO(b/163019109): See if this traversal is needed at all...

    if (!mOffscreenLayers.empty()) {

        mDrawingState.traverse([&](Layer* layer) {

        layer->commitChildList();



            // If the layer can be reached when traversing mDrawingState, then the layer is no

            // longer offscreen. Remove the layer from the offscreenLayer set.

            if (mOffscreenLayers.count(layer)) {

                mOffscreenLayers.erase(layer);

            }

        });

    }



    commitOffscreenLayers();

    mDrawingState.traverse([&](Layer* layer) { layer->updateMirrorInfo(); });