From 69515b2261335be4bd8510ed5a40a6bed3d7b48f Mon Sep 17 00:00:00 2001
From: Erik Wolsheimer <ewol@google.com>
Date: Wed, 17 May 2017 11:20:43 -0700
Subject: [PATCH] Fix race condition triggered by quick stop/start of Dream

Bug: 28455483
Change-Id: I20de24c68e468e61bb8fc704bacf73dc6df63b0a
---
 .../android/server/dreams/DreamManagerService.java   | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/services/core/java/com/android/server/dreams/DreamManagerService.java b/services/core/java/com/android/server/dreams/DreamManagerService.java
index 79a4deebc3da9..cbc1039f82cb7 100644
--- a/services/core/java/com/android/server/dreams/DreamManagerService.java
+++ b/services/core/java/com/android/server/dreams/DreamManagerService.java
@@ -86,6 +86,7 @@ public final class DreamManagerService extends SystemService {
     private boolean mCurrentDreamCanDoze;
     private boolean mCurrentDreamIsDozing;
     private boolean mCurrentDreamIsWaking;
+    private Runnable mStopDreamRunnable;
     private int mCurrentDreamDozeScreenState = Display.STATE_UNKNOWN;
     private int mCurrentDreamDozeScreenBrightness = PowerManager.BRIGHTNESS_DEFAULT;
 
@@ -349,6 +350,11 @@ public final class DreamManagerService extends SystemService {
 
     private void startDreamLocked(final ComponentName name,
             final boolean isTest, final boolean canDoze, final int userId) {
+        if (mStopDreamRunnable != null) {
+            mHandler.removeCallbacks(mStopDreamRunnable);
+            mStopDreamRunnable = null;
+        }
+
         if (Objects.equal(mCurrentDreamName, name)
                 && mCurrentDreamIsTest == isTest
                 && mCurrentDreamCanDoze == canDoze
@@ -386,13 +392,15 @@ public final class DreamManagerService extends SystemService {
                 mCurrentDreamIsWaking = true;
             }
 
-            mHandler.post(new Runnable() {
+            mStopDreamRunnable = new Runnable() {
                 @Override
                 public void run() {
                     Slog.i(TAG, "Performing gentle wake from dream.");
                     mController.stopDream(immediate);
+                    mStopDreamRunnable = null;
                 }
-            });
+            };
+            mHandler.post(mStopDreamRunnable);
         }
     }