From 64660bedad0dad36fa9ca9c1544701383c1f5f32 Mon Sep 17 00:00:00 2001
From: Robert Carr <racarr@google.com>
Date: Mon, 26 Aug 2019 16:20:55 -0700
Subject: [PATCH] Avoid global transaction in magnifier

It's not good to use the global transaction from the render thread
like this as the UI thread could also be using it from SurfaceView. Transaction
objects require external synchronization so we could be corrupting them.

Bug: 140070297
Test: Builds
Change-Id: I17b4c1417d45cc825fca380350c326ed6b3edcf6
---
 core/java/android/widget/Magnifier.java | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/core/java/android/widget/Magnifier.java b/core/java/android/widget/Magnifier.java
index d3c69725b45b6..f58b6d192fde9 100644
--- a/core/java/android/widget/Magnifier.java
+++ b/core/java/android/widget/Magnifier.java
@@ -800,6 +800,7 @@ public final class Magnifier {
         // The surface we allocate for the magnifier content + shadow.
         private final SurfaceSession mSurfaceSession;
         private final SurfaceControl mSurfaceControl;
+        private final SurfaceControl.Transaction mTransaction = new SurfaceControl.Transaction();
         private final Surface mSurface;
         // The renderer used for the allocated surface.
         private final ThreadedRenderer.SimpleRenderer mRenderer;
@@ -1081,16 +1082,16 @@ public final class Magnifier {
                             return;
                         }
                         // Show or move the window at the content draw frame.
-                        SurfaceControl.openTransaction();
-                        mSurfaceControl.deferTransactionUntil(mSurface, frame);
+                        mTransaction.deferTransactionUntilSurface(mSurfaceControl, mSurface, frame);
                         if (updateWindowPosition) {
-                            mSurfaceControl.setPosition(pendingX, pendingY);
+                            mTransaction.setPosition(mSurfaceControl, pendingX, pendingY);
                         }
                         if (firstDraw) {
-                            mSurfaceControl.setLayer(SURFACE_Z);
-                            mSurfaceControl.show();
+                            mTransaction.setLayer(mSurfaceControl, SURFACE_Z)
+                                .show(mSurfaceControl);
+
                         }
-                        SurfaceControl.closeTransaction();
+                        mTransaction.apply();
                     };
                     mRenderer.setLightCenter(mDisplay, pendingX, pendingY);
                 } else {