From 884e68eefba7316360e0e771466627a090d6dfe9 Mon Sep 17 00:00:00 2001
From: Adrian Roos <roosa@google.com>
Date: Tue, 14 Mar 2023 11:03:47 +0000
Subject: [PATCH] WindowProcessController: Fix potential memory leak

Fixes an issue where the WindowProcessController may leak after process
death due to still having listeners registered.

Now unregisters all listeners when the process record gets removed.

Fixes: 273149525
Test: atest WindowProcessControllerTests WindowProcessControllerMapTests
Change-Id: I44323f280ed7aa641ab41c4e62a354a4525a4268
---
 .../android/server/wm/WindowProcessController.java   |  7 +++++++
 .../server/wm/WindowProcessControllerMap.java        |  3 ++-
 .../server/wm/WindowProcessControllerMapTests.java   | 12 ++++++++++++
 .../server/wm/WindowProcessControllerTests.java      | 11 +++++++++++
 4 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/services/core/java/com/android/server/wm/WindowProcessController.java b/services/core/java/com/android/server/wm/WindowProcessController.java
index 2b15a790c7e13..6ef29e7679a9e 100644
--- a/services/core/java/com/android/server/wm/WindowProcessController.java
+++ b/services/core/java/com/android/server/wm/WindowProcessController.java
@@ -1340,6 +1340,13 @@ public class WindowProcessController extends ConfigurationContainer<Configuratio
         unregisterDisplayAreaConfigurationListener();
     }
 
+    /**
+     * Destroys the WindwoProcessController, after the process has been removed.
+     */
+    void destroy() {
+        unregisterConfigurationListeners();
+    }
+
     /**
      * Check if activity configuration override for the activity process needs an update and perform
      * if needed. By default we try to override the process configuration to match the top activity
diff --git a/services/core/java/com/android/server/wm/WindowProcessControllerMap.java b/services/core/java/com/android/server/wm/WindowProcessControllerMap.java
index 2767972f7ea01..424b0436a008b 100644
--- a/services/core/java/com/android/server/wm/WindowProcessControllerMap.java
+++ b/services/core/java/com/android/server/wm/WindowProcessControllerMap.java
@@ -19,8 +19,8 @@ package com.android.server.wm;
 import android.util.ArraySet;
 import android.util.SparseArray;
 
-import java.util.Map;
 import java.util.HashMap;
+import java.util.Map;
 
 final class WindowProcessControllerMap {
 
@@ -67,6 +67,7 @@ final class WindowProcessControllerMap {
             mPidMap.remove(pid);
             // remove process from mUidMap
             removeProcessFromUidMap(proc);
+            proc.destroy();
         }
     }
 
diff --git a/services/tests/wmtests/src/com/android/server/wm/WindowProcessControllerMapTests.java b/services/tests/wmtests/src/com/android/server/wm/WindowProcessControllerMapTests.java
index c2ee0798fd070..2a3c9bca0cc69 100644
--- a/services/tests/wmtests/src/com/android/server/wm/WindowProcessControllerMapTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/WindowProcessControllerMapTests.java
@@ -22,6 +22,8 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
 
 import android.os.UserHandle;
 import android.platform.test.annotations.Presubmit;
@@ -129,4 +131,14 @@ public class WindowProcessControllerMapTests extends WindowTestsBase {
         assertEquals(uid2processes.size(), 1);
         assertEquals(mProcessMap.getProcess(FAKE_PID1), pid1uid2);
     }
+
+    @Test
+    public void testRemove_callsDestroy() {
+        var proc = spy(pid1uid1);
+        mProcessMap.put(FAKE_PID1, proc);
+
+        mProcessMap.remove(FAKE_PID1);
+
+        verify(proc).destroy();
+    }
 }
diff --git a/services/tests/wmtests/src/com/android/server/wm/WindowProcessControllerTests.java b/services/tests/wmtests/src/com/android/server/wm/WindowProcessControllerTests.java
index 3abf7ce665ae7..3945f38b5842e 100644
--- a/services/tests/wmtests/src/com/android/server/wm/WindowProcessControllerTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/WindowProcessControllerTests.java
@@ -157,6 +157,17 @@ public class WindowProcessControllerTests extends WindowTestsBase {
         assertEquals(displayBounds, mWpc.getConfiguration().windowConfiguration.getBounds());
     }
 
+    @Test
+    public void testDestroy_unregistersDisplayAreaListener() {
+        final TestDisplayContent testDisplayContent1 = createTestDisplayContentInContainer();
+        final DisplayArea imeContainer1 = testDisplayContent1.getImeContainer();
+        mWpc.registerDisplayAreaConfigurationListener(imeContainer1);
+
+        mWpc.destroy();
+
+        assertNull(mWpc.getDisplayArea());
+    }
+
     @Test
     public void testSetRunningRecentsAnimation() {
         mWpc.setRunningRecentsAnimation(true);