From 88f620534f9fe2c3a32765b2a34d3092ab889b1a Mon Sep 17 00:00:00 2001
From: Jorim Jaggi <jjaggi@google.com>
Date: Wed, 3 Jan 2018 17:05:00 +0100
Subject: [PATCH] Avoid setting size/position on Transaction if not needed

Passing the JNI layer is quite expensive. Avoid updating the
position/size if not needed by storing the last size.

Test: AppTransitionTests
Test: go/wm-smoke
Bug: 71510789
Change-Id: Ibb3660114fb0e573c9cd2144e5af11f57a96a9d6
---
 .../core/java/com/android/server/wm/TaskStack.java     | 10 +++++++++-
 .../java/com/android/server/wm/WindowContainer.java    |  6 ++++++
 .../core/java/com/android/server/wm/WindowState.java   |  4 +++-
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/services/core/java/com/android/server/wm/TaskStack.java b/services/core/java/com/android/server/wm/TaskStack.java
index 3ffc7fae5d0a1..eb8eae1a95d7d 100644
--- a/services/core/java/com/android/server/wm/TaskStack.java
+++ b/services/core/java/com/android/server/wm/TaskStack.java
@@ -44,6 +44,7 @@ import static com.android.server.wm.proto.StackProto.WINDOW_CONTAINER;
 
 import android.annotation.CallSuper;
 import android.content.res.Configuration;
+import android.graphics.Point;
 import android.graphics.Rect;
 import android.graphics.Region;
 import android.os.RemoteException;
@@ -145,6 +146,7 @@ public class TaskStack extends WindowContainer<Task> implements
      * For {@link #prepareSurfaces}.
      */
     final Rect mTmpDimBoundsRect = new Rect();
+    private final Point mLastSurfaceSize = new Point();
 
     TaskStack(WindowManagerService service, int stackId, StackWindowController controller) {
         super(service);
@@ -743,7 +745,13 @@ public class TaskStack extends WindowContainer<Task> implements
         }
 
         final Rect stackBounds = getBounds();
-        transaction.setSize(mSurfaceControl, stackBounds.width(), stackBounds.height());
+        final int width = stackBounds.width();
+        final int height = stackBounds.height();
+        if (width == mLastSurfaceSize.x && height == mLastSurfaceSize.y) {
+            return;
+        }
+        transaction.setSize(mSurfaceControl, width, height);
+        mLastSurfaceSize.set(width, height);
     }
 
     @Override
diff --git a/services/core/java/com/android/server/wm/WindowContainer.java b/services/core/java/com/android/server/wm/WindowContainer.java
index b251b53bc051e..114e1c369030f 100644
--- a/services/core/java/com/android/server/wm/WindowContainer.java
+++ b/services/core/java/com/android/server/wm/WindowContainer.java
@@ -95,6 +95,7 @@ class WindowContainer<E extends WindowContainer> extends ConfigurationContainer<
     protected final WindowManagerService mService;
 
     private final Point mTmpPos = new Point();
+    protected final Point mLastSurfacePosition = new Point();
 
     /** Total number of elements in this subtree, including our own hierarchy element. */
     private int mTreeWeight = 1;
@@ -1172,7 +1173,12 @@ class WindowContainer<E extends WindowContainer> extends ConfigurationContainer<
         }
 
         getRelativePosition(mTmpPos);
+        if (mTmpPos.equals(mLastSurfacePosition)) {
+            return;
+        }
+
         transaction.setPosition(mSurfaceControl, mTmpPos.x, mTmpPos.y);
+        mLastSurfacePosition.set(mTmpPos.x, mTmpPos.y);
 
         for (int i = mChildren.size() - 1; i >= 0; i--) {
             mChildren.get(i).updateSurfacePosition(transaction);
diff --git a/services/core/java/com/android/server/wm/WindowState.java b/services/core/java/com/android/server/wm/WindowState.java
index 863922f60aaed..0e025dc8a96db 100644
--- a/services/core/java/com/android/server/wm/WindowState.java
+++ b/services/core/java/com/android/server/wm/WindowState.java
@@ -4432,6 +4432,7 @@ class WindowState extends WindowContainer<WindowState> implements WindowManagerP
 
         // Leash is now responsible for position, so set our position to 0.
         t.setPosition(mSurfaceControl, 0, 0);
+        mLastSurfacePosition.set(0, 0);
     }
 
     @Override
@@ -4447,8 +4448,9 @@ class WindowState extends WindowContainer<WindowState> implements WindowManagerP
         }
 
         transformFrameToSurfacePosition(mFrame.left, mFrame.top, mSurfacePosition);
-        if (!mSurfaceAnimator.hasLeash()) {
+        if (!mSurfaceAnimator.hasLeash() && !mLastSurfacePosition.equals(mSurfacePosition)) {
             t.setPosition(mSurfaceControl, mSurfacePosition.x, mSurfacePosition.y);
+            mLastSurfacePosition.set(mSurfacePosition.x, mSurfacePosition.y);
         }
     }