Fix BroadcastReceiver leakage

This CL ensures that a shared PackageMonitor is unregistered when a
settings activity pauses.

Bug: 34541282
Test: Manually installing/uninstalling AOSP LatinIME.apk while
      Settings app is/isn't running, then search AOSP. Verified that
      intent receiver isn't leaked from Settings app.
Test: Add assertion to Robolectric test to ensure intent receiver
      isn't leaked. Build RunSettingsRoboTests and verify all passed.
Change-Id: I5bacdfe478eaa750c61341c14e79eb2cd3fdef3a

src/com/android/settings/search/DynamicIndexableContentMonitor.java

@@ -62,8 +62,9 @@ public final class DynamicIndexableContentMonitor implements
     // Shorten the class name because log TAG can be at most 23 chars.
     private static final String TAG = "DynamicContentMonitor";
 
-    @VisibleForTesting
+    private static final long DELAY_PROCESS_PACKAGE_CHANGE = 2000;
-    static final long DELAY_PROCESS_PACKAGE_CHANGE = 2000;
+    // A PackageMonitor shared among Settings activities.
+    private static final PackageChangeMonitor PACKAGE_CHANGE_MONITOR = new PackageChangeMonitor();
 
     // Null if not initialized.
     @Nullable private Index mIndex;
@@ -87,7 +88,8 @@ public final class DynamicIndexableContentMonitor implements
     @VisibleForTesting
     static void resetForTesting() {
         InputDevicesMonitor.getInstance().resetForTesting();
-        PackageChangeMonitor.getInstance().resetForTesting();
+        AccessibilityServicesMonitor.getInstance().resetForTesting();
+        InputMethodServicesMonitor.getInstance().resetForTesting();
     }
 
     /**
@@ -123,20 +125,23 @@ public final class DynamicIndexableContentMonitor implements
             Log.w(TAG, "Skipping content monitoring because user is locked");
             return;
         }
-        mContext = activity;
+        final Context context = activity.getApplicationContext();
+        mContext = context;
         mIndex = index;
 
-        mHasFeaturePrinting = mContext.getPackageManager()
+        PACKAGE_CHANGE_MONITOR.register(context);
+        mHasFeaturePrinting = context.getPackageManager()
                 .hasSystemFeature(PackageManager.FEATURE_PRINTING);
         if (mHasFeaturePrinting) {
             activity.getLoaderManager().initLoader(loaderId, null /* args */, this /* callbacks */);
         }
 
         // Watch for input device changes.
-        InputDevicesMonitor.getInstance().initialize(mContext, mIndex);
+        InputDevicesMonitor.getInstance().initialize(context, index);
 
         // Start tracking packages.
-        PackageChangeMonitor.getInstance().initialize(mContext, mIndex);
+        AccessibilityServicesMonitor.getInstance().initialize(context, index);
+        InputMethodServicesMonitor.getInstance().initialize(context, index);
     }
 
     /**
@@ -149,6 +154,7 @@ public final class DynamicIndexableContentMonitor implements
     public void unregister(Activity activity, int loaderId) {
         if (mIndex == null) return;
 
+        PACKAGE_CHANGE_MONITOR.unregister();
         if (mHasFeaturePrinting) {
             activity.getLoaderManager().destroyLoader(loaderId);
         }
@@ -237,33 +243,9 @@ public final class DynamicIndexableContentMonitor implements
         // Null if not initialized.
         @Nullable private PackageManager mPackageManager;
 
-        private PackageChangeMonitor() {}
+        public void register(Context context) {
-
-        private static class SingletonHolder {
-            private static final PackageChangeMonitor INSTANCE = new PackageChangeMonitor();
-        }
-
-        static PackageChangeMonitor getInstance() {
-            return SingletonHolder.INSTANCE;
-        }
-
-        @VisibleForTesting
-        synchronized void resetForTesting() {
-            if (mPackageManager != null) {
-                unregister();
-            }
-            mPackageManager = null;
-            AccessibilityServicesMonitor.getInstance().resetForTesting();
-            InputMethodServicesMonitor.getInstance().resetForTesting();
-        }
-
-        synchronized void initialize(Context context, Index index) {
-            if (mPackageManager != null) return;;
             mPackageManager = context.getPackageManager();
 
-            AccessibilityServicesMonitor.getInstance().initialize(context, index);
-            InputMethodServicesMonitor.getInstance().initialize(context, index);
-
             // Start tracking packages. Use background thread for monitoring. Note that no need to
             // unregister this monitor. This should be alive while Settings app is running.
             register(context, null /* thread */, UserHandle.CURRENT, false);
@@ -271,13 +253,13 @@ public final class DynamicIndexableContentMonitor implements
 
         // Covers installed, appeared external storage with the package, upgraded.
         @Override
-        public void onPackageAppeared(String packageName, int uid) {
+        public void onPackageAppeared(String packageName, int reason) {
             postPackageAvailable(packageName);
         }
 
         // Covers uninstalled, removed external storage with the package.
         @Override
-        public void onPackageDisappeared(String packageName, int uid) {
+        public void onPackageDisappeared(String packageName, int reason) {
             postPackageUnavailable(packageName);
         }
 
@@ -440,6 +422,7 @@ public final class DynamicIndexableContentMonitor implements
                 }
             }
 
+            // TODO: Implements by JobScheduler with TriggerContentUri parameters.
             // Watch for related content URIs.
             mContentResolver.registerContentObserver(UserDictionary.Words.CONTENT_URI,
                     true /* notifyForDescendants */, this /* observer */);

tests/robotests/src/com/android/settings/search/DynamicIndexableContentMonitorTest.java

@@ -102,7 +102,6 @@ import java.util.List;
 )
 public class DynamicIndexableContentMonitorTest {
 
-    private static final int USER_ID = 5678;
     private static final int LOADER_ID = 1234;
     private static final String A11Y_PACKAGE_1 = "a11y-1";
     private static final String A11Y_PACKAGE_2 = "a11y-2";
@@ -151,6 +150,10 @@ public class DynamicIndexableContentMonitorTest {
 
     @After
     public void shutDown() {
+        mMonitor.unregister(mActivity, LOADER_ID);
+        // BroadcastReceiver must be unregistered.
+        assertThat(extractPackageMonitor()).isNull();
+
         DynamicIndexableContentMonitor.resetForTesting();
         mRobolectricPackageManager.reset();
     }
@@ -187,6 +190,11 @@ public class DynamicIndexableContentMonitorTest {
 
         // No destroy loader should happen.
         verify(mLoaderManager, never()).destroyLoader(anyInt());
+        // BroadcastReceiver must be unregistered.
+        assertThat(extractPackageMonitor()).isNull();
+
+        // To suppress spurious test fail in {@link #shutDown()}.
+        mMonitor.register(mActivity, LOADER_ID, mIndex, true /* isUserUnlocked */);
     }
 
     @Test
@@ -220,6 +228,7 @@ public class DynamicIndexableContentMonitorTest {
         /*
          * Nothing happens on successive register calls.
          */
+        mMonitor.unregister(mActivity, LOADER_ID);
         reset(mIndex);
 
         mMonitor.register(mActivity, LOADER_ID, mIndex, true /* isUserUnlocked */);
@@ -259,74 +268,59 @@ public class DynamicIndexableContentMonitorTest {
     public void testAccessibilityServicesMonitor() throws Exception {
         mMonitor.register(mActivity, LOADER_ID, mIndex, true /* isUserUnlocked */);
 
-        final PackageMonitor packageMonitor = extractPackageMonitor();
-        assertThat(packageMonitor).isNotNull();
-
         verifyRebuildIndexing(AccessibilitySettings.class);
 
         /*
          * When an accessibility service package is installed, incremental indexing happen.
          */
-        installAccessibilityService(A11Y_PACKAGE_1);
         reset(mIndex);
 
-        packageMonitor.onPackageAppeared(A11Y_PACKAGE_1, USER_ID);
+        installAccessibilityService(A11Y_PACKAGE_1);
-        Robolectric.flushBackgroundThreadScheduler();
 
         verifyIncrementalIndexing(AccessibilitySettings.class);
 
         /*
          * When another accessibility service package is installed, incremental indexing happens.
          */
-        installAccessibilityService(A11Y_PACKAGE_2);
         reset(mIndex);
 
-        packageMonitor.onPackageAppeared(A11Y_PACKAGE_2, USER_ID);
+        installAccessibilityService(A11Y_PACKAGE_2);
-        Robolectric.flushBackgroundThreadScheduler();
 
         verifyIncrementalIndexing(AccessibilitySettings.class);
 
         /*
          * When an accessibility service is disabled, rebuild indexing happens.
          */
-        ((PackageManager) mRobolectricPackageManager).setApplicationEnabledSetting(
-                A11Y_PACKAGE_1, PackageManager.COMPONENT_ENABLED_STATE_DISABLED, 0 /* flags */);
         reset(mIndex);
 
-        packageMonitor.onPackageModified(A11Y_PACKAGE_1);
+        disableInstalledPackage(A11Y_PACKAGE_1);
-        Robolectric.flushBackgroundThreadScheduler();
 
         verifyRebuildIndexing(AccessibilitySettings.class);
 
         /*
          * When an accessibility service is enabled, incremental indexing happens.
          */
-        ((PackageManager) mRobolectricPackageManager).setApplicationEnabledSetting(
-                A11Y_PACKAGE_1, PackageManager.COMPONENT_ENABLED_STATE_DEFAULT, 0 /* flags */);
         reset(mIndex);
 
-        packageMonitor.onPackageModified(A11Y_PACKAGE_1);
+        enableInstalledPackage(A11Y_PACKAGE_1);
-        Robolectric.flushBackgroundThreadScheduler();
 
         verifyIncrementalIndexing(AccessibilitySettings.class);
 
         /*
          * When an accessibility service package is uninstalled, rebuild indexing happens.
          */
-        uninstallAccessibilityService(A11Y_PACKAGE_1);
         reset(mIndex);
 
-        packageMonitor.onPackageDisappeared(A11Y_PACKAGE_1, USER_ID);
+        uninstallAccessibilityService(A11Y_PACKAGE_1);
 
         verifyRebuildIndexing(AccessibilitySettings.class);
 
         /*
          * When an input method service package is installed, nothing happens.
          */
-        installInputMethodService(IME_PACKAGE_1);
         reset(mIndex);
 
-        packageMonitor.onPackageAppeared(IME_PACKAGE_1, USER_ID);
+        installInputMethodService(IME_PACKAGE_1);
 
         verifyNoIndexing(AccessibilitySettings.class);
     }
@@ -335,9 +329,6 @@ public class DynamicIndexableContentMonitorTest {
     public void testInputMethodServicesMonitor() throws Exception {
         mMonitor.register(mActivity, LOADER_ID, mIndex, true /* isUserUnlocked */);
 
-        final PackageMonitor packageMonitor = extractPackageMonitor();
-        assertThat(packageMonitor).isNotNull();
-
         verifyRebuildIndexing(VirtualKeyboardFragment.class);
         verifyRebuildIndexing(AvailableVirtualKeyboardFragment.class);
 
@@ -350,11 +341,9 @@ public class DynamicIndexableContentMonitorTest {
         /*
          * When an input method service package is installed, incremental indexing happen.
          */
-        installInputMethodService(IME_PACKAGE_1);
         reset(mIndex);
 
-        packageMonitor.onPackageAppeared(IME_PACKAGE_1, USER_ID);
+        installInputMethodService(IME_PACKAGE_1);
-        Robolectric.flushBackgroundThreadScheduler();
 
         verifyIncrementalIndexing(VirtualKeyboardFragment.class);
         verifyIncrementalIndexing(AvailableVirtualKeyboardFragment.class);
@@ -362,11 +351,9 @@ public class DynamicIndexableContentMonitorTest {
         /*
          * When another input method service package is installed, incremental indexing happens.
          */
-        installInputMethodService(IME_PACKAGE_2);
         reset(mIndex);
 
-        packageMonitor.onPackageAppeared(IME_PACKAGE_2, USER_ID);
+        installInputMethodService(IME_PACKAGE_2);
-        Robolectric.flushBackgroundThreadScheduler();
 
         verifyIncrementalIndexing(VirtualKeyboardFragment.class);
         verifyIncrementalIndexing(AvailableVirtualKeyboardFragment.class);
@@ -374,12 +361,9 @@ public class DynamicIndexableContentMonitorTest {
         /*
          * When an input method service is disabled, rebuild indexing happens.
          */
-        ((PackageManager) mRobolectricPackageManager).setApplicationEnabledSetting(
-                IME_PACKAGE_1, PackageManager.COMPONENT_ENABLED_STATE_DISABLED, 0 /* flags */);
         reset(mIndex);
 
-        packageMonitor.onPackageModified(IME_PACKAGE_1);
+        disableInstalledPackage(IME_PACKAGE_1);
-        Robolectric.flushBackgroundThreadScheduler();
 
         verifyRebuildIndexing(VirtualKeyboardFragment.class);
         verifyRebuildIndexing(AvailableVirtualKeyboardFragment.class);
@@ -387,12 +371,9 @@ public class DynamicIndexableContentMonitorTest {
         /*
          * When an input method service is enabled, incremental indexing happens.
          */
-        ((PackageManager) mRobolectricPackageManager).setApplicationEnabledSetting(
-                IME_PACKAGE_1, PackageManager.COMPONENT_ENABLED_STATE_DEFAULT, 0 /* flags */);
         reset(mIndex);
 
-        packageMonitor.onPackageModified(IME_PACKAGE_1);
+        enableInstalledPackage(IME_PACKAGE_1);
-        Robolectric.flushBackgroundThreadScheduler();
 
         verifyIncrementalIndexing(VirtualKeyboardFragment.class);
         verifyIncrementalIndexing(AvailableVirtualKeyboardFragment.class);
@@ -400,10 +381,9 @@ public class DynamicIndexableContentMonitorTest {
         /*
          * When an input method service package is uninstalled, rebuild indexing happens.
          */
-        uninstallInputMethodService(IME_PACKAGE_1);
         reset(mIndex);
 
-        packageMonitor.onPackageDisappeared(IME_PACKAGE_1, USER_ID);
+        uninstallInputMethodService(IME_PACKAGE_1);
 
         verifyRebuildIndexing(VirtualKeyboardFragment.class);
         verifyRebuildIndexing(AvailableVirtualKeyboardFragment.class);
@@ -411,10 +391,9 @@ public class DynamicIndexableContentMonitorTest {
         /*
          * When an accessibility service package is installed, nothing happens.
          */
-        installAccessibilityService(A11Y_PACKAGE_1);
         reset(mIndex);
 
-        packageMonitor.onPackageAppeared(A11Y_PACKAGE_1, USER_ID);
+        installAccessibilityService(A11Y_PACKAGE_1);
 
         verifyNoIndexing(VirtualKeyboardFragment.class);
         verifyNoIndexing(AvailableVirtualKeyboardFragment.class);
@@ -528,6 +507,20 @@ public class DynamicIndexableContentMonitorTest {
         return contentObserver;
     }
 
+    private void enableInstalledPackage(String packageName) {
+        ((PackageManager) mRobolectricPackageManager).setApplicationEnabledSetting(
+                packageName, PackageManager.COMPONENT_ENABLED_STATE_DEFAULT, 0 /* flags */);
+        extractPackageMonitor().onPackageModified(packageName);
+        Robolectric.flushBackgroundThreadScheduler();
+    }
+
+    private void disableInstalledPackage(String packageName) {
+        ((PackageManager) mRobolectricPackageManager).setApplicationEnabledSetting(
+                packageName, PackageManager.COMPONENT_ENABLED_STATE_DISABLED, 0 /* flags */);
+        extractPackageMonitor().onPackageModified(packageName);
+        Robolectric.flushBackgroundThreadScheduler();
+    }
+
     private void installAccessibilityService(String packageName) throws Exception {
         final AccessibilityServiceInfo serviceToAdd = buildAccessibilityServiceInfo(packageName);
 
@@ -540,6 +533,10 @@ public class DynamicIndexableContentMonitorTest {
                 .getAccessibilityServiceIntent(packageName);
         mRobolectricPackageManager.addResolveInfoForIntent(intent, serviceToAdd.getResolveInfo());
         mRobolectricPackageManager.addPackage(packageName);
+
+        extractPackageMonitor()
+                .onPackageAppeared(packageName, PackageMonitor.PACKAGE_PERMANENT_CHANGE);
+        Robolectric.flushBackgroundThreadScheduler();
     }
 
     private void uninstallAccessibilityService(String packageName) throws Exception {
@@ -554,6 +551,10 @@ public class DynamicIndexableContentMonitorTest {
                 .getAccessibilityServiceIntent(packageName);
         mRobolectricPackageManager.removeResolveInfosForIntent(intent, packageName);
         mRobolectricPackageManager.removePackage(packageName);
+
+        extractPackageMonitor()
+                .onPackageDisappeared(packageName, PackageMonitor.PACKAGE_PERMANENT_CHANGE);
+        Robolectric.flushBackgroundThreadScheduler();
     }
 
     private void installInputMethodService(String packageName) throws Exception {
@@ -568,6 +569,10 @@ public class DynamicIndexableContentMonitorTest {
         final Intent intent = DynamicIndexableContentMonitor.getIMEServiceIntent(packageName);
         mRobolectricPackageManager.addResolveInfoForIntent(intent, resolveInfoToAdd);
         mRobolectricPackageManager.addPackage(packageName);
+
+        extractPackageMonitor()
+                .onPackageAppeared(packageName, PackageMonitor.PACKAGE_PERMANENT_CHANGE);
+        Robolectric.flushBackgroundThreadScheduler();
     }
 
     private void uninstallInputMethodService(String packageName) throws Exception {
@@ -582,6 +587,10 @@ public class DynamicIndexableContentMonitorTest {
         final Intent intent = DynamicIndexableContentMonitor.getIMEServiceIntent(packageName);
         mRobolectricPackageManager.removeResolveInfosForIntent(intent, packageName);
         mRobolectricPackageManager.removePackage(packageName);
+
+        extractPackageMonitor()
+                .onPackageDisappeared(packageName, PackageMonitor.PACKAGE_PERMANENT_CHANGE);
+        Robolectric.flushBackgroundThreadScheduler();
     }
 
     private AccessibilityServiceInfo buildAccessibilityServiceInfo(String packageName)