From 6104af0e8c48ffc52819917215416740bfde9342 Mon Sep 17 00:00:00 2001
From: Chris Li <lihongyu@google.com>
Date: Tue, 17 Aug 2021 12:12:28 -0700
Subject: [PATCH] Fix race condition on size compat UI

Before, the leash might have been released while the update surface
position runnable was in queue. Now, we make sure the leash is valid
before update position.

Fix: 196942784
Test: manual
Change-Id: I2d052bf46b12a2441dbc0aa1aabf5dfe9be2fa45
---
 .../android/wm/shell/sizecompatui/SizeCompatUILayout.java  | 7 ++++++-
 .../wm/shell/sizecompatui/SizeCompatUIWindowManager.java   | 3 ++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/sizecompatui/SizeCompatUILayout.java b/libs/WindowManager/Shell/src/com/android/wm/shell/sizecompatui/SizeCompatUILayout.java
index a5e96d14dde61..20021ebea8346 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/sizecompatui/SizeCompatUILayout.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/sizecompatui/SizeCompatUILayout.java
@@ -28,6 +28,7 @@ import android.content.res.Configuration;
 import android.graphics.PixelFormat;
 import android.graphics.Rect;
 import android.os.Binder;
+import android.util.Log;
 import android.view.SurfaceControl;
 import android.view.View;
 import android.view.WindowManager;
@@ -45,7 +46,7 @@ import com.android.wm.shell.common.SyncTransactionQueue;
 class SizeCompatUILayout {
     private static final String TAG = "SizeCompatUILayout";
 
-    private final SyncTransactionQueue mSyncQueue;
+    final SyncTransactionQueue mSyncQueue;
     private final SizeCompatUIController.SizeCompatUICallback mCallback;
     private Context mContext;
     private Configuration mTaskConfig;
@@ -306,6 +307,10 @@ class SizeCompatUILayout {
 
     private void updateSurfacePosition(SurfaceControl leash, int positionX, int positionY) {
         mSyncQueue.runInSync(t -> {
+            if (!leash.isValid()) {
+                Log.w(TAG, "The leash has been released.");
+                return;
+            }
             t.setPosition(leash, positionX, positionY);
             // The size compat UI should be the topmost child of the Task in case there can be more
             // than one children.
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/sizecompatui/SizeCompatUIWindowManager.java b/libs/WindowManager/Shell/src/com/android/wm/shell/sizecompatui/SizeCompatUIWindowManager.java
index f634c4586e393..82f69c3e2985c 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/sizecompatui/SizeCompatUIWindowManager.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/sizecompatui/SizeCompatUIWindowManager.java
@@ -110,7 +110,8 @@ class SizeCompatUIWindowManager extends WindowlessWindowManager {
         }
 
         if (mLeash != null) {
-            new SurfaceControl.Transaction().remove(mLeash).apply();
+            final SurfaceControl leash = mLeash;
+            mLayout.mSyncQueue.runInSync(t -> t.remove(leash));
             mLeash = null;
         }
     }