From 2ac3cdfb2217470d316ac64bc9c2f010b059eb39 Mon Sep 17 00:00:00 2001
From: Jacky Wang <jiannan@google.com>
Date: Thu, 9 Jan 2025 18:22:19 +0800
Subject: [PATCH] Fix memory leak on Accessibility screen

The root cause is that androidx.preference.Preference does not implement
equals and hashCode methods, but it is used as Map key (see bug comment2
for more details). Given that Preference.getParent() can find the
category, we can simplify the data structure from Map to List.

Bug: 388696327
Flag: EXEMPT bugfix
Test: Resume/Pause Accessibility screen 100 times
Change-Id: Ib70acbf2147048730f8a4e8fd66731f9efdadecf
---
 .../accessibility/AccessibilitySettings.java      | 15 +++++----------
 .../accessibility/AccessibilitySettingsTest.java  |  5 ++---
 2 files changed, 7 insertions(+), 13 deletions(-)

diff --git a/src/com/android/settings/accessibility/AccessibilitySettings.java b/src/com/android/settings/accessibility/AccessibilitySettings.java
index 6f0ef9e70cb..c0341cc5949 100644
--- a/src/com/android/settings/accessibility/AccessibilitySettings.java
+++ b/src/com/android/settings/accessibility/AccessibilitySettings.java
@@ -148,9 +148,7 @@ public class AccessibilitySettings extends DashboardFragment implements
 
     private final Map<String, PreferenceCategory> mCategoryToPrefCategoryMap =
             new ArrayMap<>();
-    @VisibleForTesting
-    final Map<Preference, PreferenceCategory> mServicePreferenceToPreferenceCategoryMap =
-            new ArrayMap<>();
+    private final List<Preference> mServicePreferences = new ArrayList<>();
     private final Map<ComponentName, PreferenceCategory> mPreBundledServiceComponentToCategoryMap =
             new ArrayMap<>();
 
@@ -372,13 +370,10 @@ public class AccessibilitySettings extends DashboardFragment implements
         // Since services category is auto generated we have to do a pass
         // to generate it since services can come and go and then based on
         // the global accessibility state to decided whether it is enabled.
-        final ArrayList<Preference> servicePreferences =
-                new ArrayList<>(mServicePreferenceToPreferenceCategoryMap.keySet());
-        for (int i = 0; i < servicePreferences.size(); i++) {
-            Preference service = servicePreferences.get(i);
-            PreferenceCategory category = mServicePreferenceToPreferenceCategoryMap.get(service);
-            category.removePreference(service);
+        for (Preference service : mServicePreferences) {
+            service.getParent().removePreference(service);
         }
+        mServicePreferences.clear();
 
         initializePreBundledServicesMapFromArray(CATEGORY_SCREEN_READER,
                 R.array.config_preinstalled_screen_reader_services);
@@ -423,7 +418,7 @@ public class AccessibilitySettings extends DashboardFragment implements
                 prefCategory = mPreBundledServiceComponentToCategoryMap.get(componentName);
             }
             prefCategory.addPreference(preference);
-            mServicePreferenceToPreferenceCategoryMap.put(preference, prefCategory);
+            mServicePreferences.add(preference);
         }
 
         // Update the order of all the category according to the order defined in xml file.
diff --git a/tests/robotests/src/com/android/settings/accessibility/AccessibilitySettingsTest.java b/tests/robotests/src/com/android/settings/accessibility/AccessibilitySettingsTest.java
index 93159952ea7..91d7d91c833 100644
--- a/tests/robotests/src/com/android/settings/accessibility/AccessibilitySettingsTest.java
+++ b/tests/robotests/src/com/android/settings/accessibility/AccessibilitySettingsTest.java
@@ -503,9 +503,8 @@ public class AccessibilitySettingsTest {
     }
 
     private String getPreferenceCategory(ComponentName componentName) {
-        return mFragment.mServicePreferenceToPreferenceCategoryMap.get(
-                        mFragment.getPreferenceScreen().findPreference(
-                                componentName.flattenToString())).getKey();
+        return mFragment.getPreferenceScreen().findPreference(
+                componentName.flattenToString()).getParent().getKey();
     }
 
     private AccessibilityServiceInfo getMockAccessibilityServiceInfo(ComponentName componentName) {