SF - plumbing game mode for metrics (Part 1)

This change adds a game mode in the Layer metadata that gets updated every
time a game app comes to the foreground. The gameMode is then set on the
Layer based on the metadata and reparenting.

The game mode will then be
updated in TimeStats as a dimension (Part 2, in a separate CL later).

Bug: 186025682
Test: libsurfaceflinger_unittest:GameModeTest

Change-Id: I09deffc01d1b318cc08d0475611289dec055c190

1 files changed, 14 insertions, 0 deletions

diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index a7c870483b..d78a8223c4 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -1651,12 +1651,25 @@ size_t Layer::getChildrenCount() const {
     return count;
 }
 
+void Layer::setGameModeForTree(int parentGameMode) {
+    int gameMode = parentGameMode;
+    auto& currentState = getCurrentState();
+    if (currentState.metadata.has(METADATA_GAME_MODE)) {
+        gameMode = currentState.metadata.getInt32(METADATA_GAME_MODE, 0);
+    }
+    setGameMode(gameMode);
+    for (const sp<Layer>& child : mCurrentChildren) {
+        child->setGameModeForTree(gameMode);
+    }
+}
+
 void Layer::addChild(const sp<Layer>& layer) {
     mChildrenChanged = true;
     setTransactionFlags(eTransactionNeeded);
 
     mCurrentChildren.add(layer);
     layer->setParent(this);
+    layer->setGameModeForTree(mGameMode);
     updateTreeHasFrameRateVote();
 }
 
@@ -1668,6 +1681,7 @@ ssize_t Layer::removeChild(const sp<Layer>& layer) {
     const auto removeResult = mCurrentChildren.remove(layer);
 
     updateTreeHasFrameRateVote();
+    layer->setGameModeForTree(0);
     layer->updateTreeHasFrameRateVote();
 
     return removeResult;