From c9c7ebb464b4fdee664756880482956db512456a Mon Sep 17 00:00:00 2001
From: Ahan Wu <ahanwu@google.com>
Date: Mon, 17 Feb 2020 18:49:59 +0800
Subject: [PATCH] Fix potential NPE while releasing worker thread of
 ImageWallpaper

We nullify mWorker right in ImageWallpaper#destroy(),
we might get NPE if postRender is invoked later.
Thus, we add null check to avoid NPE.

Bug: 144039509
Bug: 146167292
Test: atest com.android.systemui
Test: atest CtsMultiUserHostTestCases
Change-Id: Idff558cbdbfa96df3154eb726a36645ee847c0bd
---
 .../src/com/android/systemui/ImageWallpaper.java       | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/packages/SystemUI/src/com/android/systemui/ImageWallpaper.java b/packages/SystemUI/src/com/android/systemui/ImageWallpaper.java
index 03bc738c8ab92..4473b010cbda1 100644
--- a/packages/SystemUI/src/com/android/systemui/ImageWallpaper.java
+++ b/packages/SystemUI/src/com/android/systemui/ImageWallpaper.java
@@ -168,12 +168,13 @@ public class ImageWallpaper extends WallpaperService {
         @Override
         public void onOffsetsChanged(float xOffset, float yOffset, float xOffsetStep,
                 float yOffsetStep, int xPixelOffset, int yPixelOffset) {
+            if (mWorker == null) return;
             mWorker.getThreadHandler().post(() -> mRenderer.updateOffsets(xOffset, yOffset));
         }
 
         @Override
         public void onAmbientModeChanged(boolean inAmbientMode, long animationDuration) {
-            if (!mNeedTransition) return;
+            if (mWorker == null || !mNeedTransition) return;
             final long duration = mShouldStopTransition ? 0 : animationDuration;
             if (DEBUG) {
                 Log.d(TAG, "onAmbientModeChanged: inAmbient=" + inAmbientMode
@@ -223,6 +224,7 @@ public class ImageWallpaper extends WallpaperService {
         @Override
         public void onSurfaceCreated(SurfaceHolder holder) {
             mShouldStopTransition = checkIfShouldStopTransition();
+            if (mWorker == null) return;
             mWorker.getThreadHandler().post(() -> {
                 mEglHelper.init(holder, needSupportWideColorGamut());
                 mRenderer.onSurfaceCreated();
@@ -231,6 +233,7 @@ public class ImageWallpaper extends WallpaperService {
 
         @Override
         public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) {
+            if (mWorker == null) return;
             mWorker.getThreadHandler().post(() -> {
                 mRenderer.onSurfaceChanged(width, height);
                 mNeedRedraw = true;
@@ -239,6 +242,7 @@ public class ImageWallpaper extends WallpaperService {
 
         @Override
         public void onSurfaceRedrawNeeded(SurfaceHolder holder) {
+            if (mWorker == null) return;
             if (DEBUG) {
                 Log.d(TAG, "onSurfaceRedrawNeeded: mNeedRedraw=" + mNeedRedraw);
             }
@@ -267,7 +271,7 @@ public class ImageWallpaper extends WallpaperService {
         @Override
         public void onStatePostChange() {
             // When back to home, we try to release EGL, which is preserved in lock screen or aod.
-            if (mController.getState() == StatusBarState.SHADE) {
+            if (mWorker != null && mController.getState() == StatusBarState.SHADE) {
                 mWorker.getThreadHandler().post(this::scheduleFinishRendering);
             }
         }
@@ -356,10 +360,12 @@ public class ImageWallpaper extends WallpaperService {
         }
 
         private void cancelFinishRenderingTask() {
+            if (mWorker == null) return;
             mWorker.getThreadHandler().removeCallbacks(mFinishRenderingTask);
         }
 
         private void scheduleFinishRendering() {
+            if (mWorker == null) return;
             cancelFinishRenderingTask();
             mWorker.getThreadHandler().postDelayed(mFinishRenderingTask, DELAY_FINISH_RENDERING);
         }