From c3eaf662257919343210b96f5d5aef161df0723e Mon Sep 17 00:00:00 2001
From: Riddle Hsu <riddlehsu@google.com>
Date: Tue, 18 Jan 2022 15:40:25 +0800
Subject: [PATCH] Fix leakage of DisplayContent referenced from
 TransitionController

Unlike AppTransition which is associated DisplayContent, the
TransitionController is a global instance. So it needs to unregister
the listener when the display is removed.

Bug: 214991741
Test: Start/stop screen recording multiple times (create virtual
      display). The heap dump of system server should not contain
      many DisplayContent instances.
Change-Id: I44e2a794981fc114ada0ce98cd2471adf623d856
(cherry picked from commit 491914c17c869a174f91d0414181d1be11e040a3)
Merged-In:I44e2a794981fc114ada0ce98cd2471adf623d856
---
 services/core/java/com/android/server/wm/DisplayContent.java  | 2 --
 services/core/java/com/android/server/wm/DisplayPolicy.java   | 1 +
 .../core/java/com/android/server/wm/TransitionController.java | 4 ++++
 .../java/com/android/server/wm/WindowOrganizerController.java | 1 +
 4 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index 40549548da625..1e31fdab30d08 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -1067,8 +1067,6 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
 
         mAppTransition = new AppTransition(mWmService.mContext, mWmService, this);
         mAppTransition.registerListenerLocked(mWmService.mActivityManagerAppTransitionNotifier);
-        mTransitionController.registerLegacyListener(
-                mWmService.mActivityManagerAppTransitionNotifier);
         mAppTransition.registerListenerLocked(mFixedRotationTransitionListener);
         mAppTransitionController = new AppTransitionController(mWmService, this);
         mUnknownAppVisibilityController = new UnknownAppVisibilityController(mWmService, this);
diff --git a/services/core/java/com/android/server/wm/DisplayPolicy.java b/services/core/java/com/android/server/wm/DisplayPolicy.java
index ef3c5a3df84e5..1ff2ebeb8c14f 100644
--- a/services/core/java/com/android/server/wm/DisplayPolicy.java
+++ b/services/core/java/com/android/server/wm/DisplayPolicy.java
@@ -3311,6 +3311,7 @@ public class DisplayPolicy {
     }
 
     void release() {
+        mDisplayContent.mTransitionController.unregisterLegacyListener(mAppTransitionListener);
         mHandler.post(mGestureNavigationSettingsObserver::unregister);
     }
 
diff --git a/services/core/java/com/android/server/wm/TransitionController.java b/services/core/java/com/android/server/wm/TransitionController.java
index e05457010df8e..929ec3b929b24 100644
--- a/services/core/java/com/android/server/wm/TransitionController.java
+++ b/services/core/java/com/android/server/wm/TransitionController.java
@@ -430,6 +430,10 @@ class TransitionController {
         mLegacyListeners.add(listener);
     }
 
+    void unregisterLegacyListener(WindowManagerInternal.AppTransitionListener listener) {
+        mLegacyListeners.remove(listener);
+    }
+
     void dispatchLegacyAppTransitionPending() {
         for (int i = 0; i < mLegacyListeners.size(); ++i) {
             mLegacyListeners.get(i).onAppTransitionPendingLocked();
diff --git a/services/core/java/com/android/server/wm/WindowOrganizerController.java b/services/core/java/com/android/server/wm/WindowOrganizerController.java
index 42766bdb07320..6970c7942a505 100644
--- a/services/core/java/com/android/server/wm/WindowOrganizerController.java
+++ b/services/core/java/com/android/server/wm/WindowOrganizerController.java
@@ -137,6 +137,7 @@ class WindowOrganizerController extends IWindowOrganizerController.Stub
 
     void setWindowManager(WindowManagerService wms) {
         mTransitionController = new TransitionController(mService, wms.mTaskSnapshotController);
+        mTransitionController.registerLegacyListener(wms.mActivityManagerAppTransitionNotifier);
     }
 
     TransitionController getTransitionController() {