Handle slice broadcasts on BG thread

There's no point for those to run on main thread and cause ANRs - we're
just rebroadcasting broadcasts.

This CL also enhances thread safety for the code running this.

Bug: 334767208
Flag: com.android.systemui.slice_broadcast_relay_in_background
Test: newly updated SliceBroadcastRelayHandler unit test
Change-Id: I11ef3e49458c4e66e4176a5ab64e0328264f889f
diff --git a/packages/SystemUI/aconfig/systemui.aconfig b/packages/SystemUI/aconfig/systemui.aconfig
index c979d05..c61002e 100644
--- a/packages/SystemUI/aconfig/systemui.aconfig
+++ b/packages/SystemUI/aconfig/systemui.aconfig
@@ -784,3 +784,13 @@
       purpose: PURPOSE_BUGFIX
     }
 }
+
+flag {
+    name: "slice_broadcast_relay_in_background"
+    namespace: "systemui"
+    description: "Move handling of slice broadcast relay broadcasts to background threads"
+    bug: "334767208"
+    metadata {
+      purpose: PURPOSE_BUGFIX
+    }
+}
\ No newline at end of file
diff --git a/packages/SystemUI/src/com/android/systemui/SliceBroadcastRelayHandler.java b/packages/SystemUI/src/com/android/systemui/SliceBroadcastRelayHandler.java
index 5bd85a7..429d3f0 100644
--- a/packages/SystemUI/src/com/android/systemui/SliceBroadcastRelayHandler.java
+++ b/packages/SystemUI/src/com/android/systemui/SliceBroadcastRelayHandler.java
@@ -14,6 +14,8 @@
 
 package com.android.systemui;
 
+import static com.android.systemui.Flags.sliceBroadcastRelayInBackground;
+
 import android.content.BroadcastReceiver;
 import android.content.ComponentName;
 import android.content.ContentProvider;
@@ -23,13 +25,19 @@
 import android.net.Uri;
 import android.os.UserHandle;
 import android.util.ArrayMap;
-import android.util.ArraySet;
 import android.util.Log;
 
+import androidx.annotation.GuardedBy;
+import androidx.annotation.WorkerThread;
+
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.settingslib.SliceBroadcastRelay;
 import com.android.systemui.broadcast.BroadcastDispatcher;
 import com.android.systemui.dagger.SysUISingleton;
+import com.android.systemui.dagger.qualifiers.Background;
+
+import java.util.concurrent.CopyOnWriteArraySet;
+import java.util.concurrent.Executor;
 
 import javax.inject.Inject;
 
@@ -42,14 +50,18 @@
     private static final String TAG = "SliceBroadcastRelay";
     private static final boolean DEBUG = false;
 
+    @GuardedBy("mRelays")
     private final ArrayMap<Uri, BroadcastRelay> mRelays = new ArrayMap<>();
     private final Context mContext;
     private final BroadcastDispatcher mBroadcastDispatcher;
+    private final Executor mBackgroundExecutor;
 
     @Inject
-    public SliceBroadcastRelayHandler(Context context, BroadcastDispatcher broadcastDispatcher) {
+    public SliceBroadcastRelayHandler(Context context, BroadcastDispatcher broadcastDispatcher,
+                                      @Background Executor backgroundExecutor) {
         mContext = context;
         mBroadcastDispatcher = broadcastDispatcher;
+        mBackgroundExecutor = backgroundExecutor;
     }
 
     @Override
@@ -57,21 +69,29 @@
         if (DEBUG) Log.d(TAG, "Start");
         IntentFilter filter = new IntentFilter(SliceBroadcastRelay.ACTION_REGISTER);
         filter.addAction(SliceBroadcastRelay.ACTION_UNREGISTER);
-        mBroadcastDispatcher.registerReceiver(mReceiver, filter);
+
+        if (sliceBroadcastRelayInBackground()) {
+            mBroadcastDispatcher.registerReceiver(mReceiver, filter, mBackgroundExecutor);
+        } else {
+            mBroadcastDispatcher.registerReceiver(mReceiver, filter);
+        }
     }
 
     // This does not use BroadcastDispatcher as the filter may have schemas or mime types.
+    @WorkerThread
     @VisibleForTesting
     void handleIntent(Intent intent) {
         if (SliceBroadcastRelay.ACTION_REGISTER.equals(intent.getAction())) {
-            Uri uri = intent.getParcelableExtra(SliceBroadcastRelay.EXTRA_URI);
+            Uri uri = intent.getParcelableExtra(SliceBroadcastRelay.EXTRA_URI, Uri.class);
             ComponentName receiverClass =
-                    intent.getParcelableExtra(SliceBroadcastRelay.EXTRA_RECEIVER);
-            IntentFilter filter = intent.getParcelableExtra(SliceBroadcastRelay.EXTRA_FILTER);
+                    intent.getParcelableExtra(SliceBroadcastRelay.EXTRA_RECEIVER,
+                            ComponentName.class);
+            IntentFilter filter = intent.getParcelableExtra(SliceBroadcastRelay.EXTRA_FILTER,
+                    IntentFilter.class);
             if (DEBUG) Log.d(TAG, "Register " + uri + " " + receiverClass + " " + filter);
             getOrCreateRelay(uri).register(mContext, receiverClass, filter);
         } else if (SliceBroadcastRelay.ACTION_UNREGISTER.equals(intent.getAction())) {
-            Uri uri = intent.getParcelableExtra(SliceBroadcastRelay.EXTRA_URI);
+            Uri uri = intent.getParcelableExtra(SliceBroadcastRelay.EXTRA_URI, Uri.class);
             if (DEBUG) Log.d(TAG, "Unregister " + uri);
             BroadcastRelay relay = getAndRemoveRelay(uri);
             if (relay != null) {
@@ -80,17 +100,23 @@
         }
     }
 
+    @WorkerThread
     private BroadcastRelay getOrCreateRelay(Uri uri) {
-        BroadcastRelay ret = mRelays.get(uri);
-        if (ret == null) {
-            ret = new BroadcastRelay(uri);
-            mRelays.put(uri, ret);
+        synchronized (mRelays) {
+            BroadcastRelay ret = mRelays.get(uri);
+            if (ret == null) {
+                ret = new BroadcastRelay(uri);
+                mRelays.put(uri, ret);
+            }
+            return ret;
         }
-        return ret;
     }
 
+    @WorkerThread
     private BroadcastRelay getAndRemoveRelay(Uri uri) {
-        return mRelays.remove(uri);
+        synchronized (mRelays) {
+            return mRelays.remove(uri);
+        }
     }
 
     private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
@@ -102,7 +128,7 @@
 
     private static class BroadcastRelay extends BroadcastReceiver {
 
-        private final ArraySet<ComponentName> mReceivers = new ArraySet<>();
+        private final CopyOnWriteArraySet<ComponentName> mReceivers = new CopyOnWriteArraySet<>();
         private final UserHandle mUserId;
         private final Uri mUri;
 
diff --git a/packages/SystemUI/tests/src/com/android/systemui/SliceBroadcastRelayHandlerTest.java b/packages/SystemUI/tests/src/com/android/systemui/SliceBroadcastRelayHandlerTest.java
index 7c121e1..d7bd59e 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/SliceBroadcastRelayHandlerTest.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/SliceBroadcastRelayHandlerTest.java
@@ -31,36 +31,57 @@
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.net.Uri;
-import android.testing.AndroidTestingRunner;
+import android.platform.test.annotations.DisableFlags;
+import android.platform.test.annotations.EnableFlags;
+import android.platform.test.flag.junit.FlagsParameterization;
 
 import androidx.test.filters.SmallTest;
 
 import com.android.settingslib.SliceBroadcastRelay;
 import com.android.systemui.broadcast.BroadcastDispatcher;
+import com.android.systemui.util.concurrency.FakeExecutor;
+import com.android.systemui.util.time.FakeSystemClock;
 
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
 import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
-@RunWith(AndroidTestingRunner.class)
+import java.util.List;
+
+@RunWith(Parameterized.class)
 @SmallTest
 public class SliceBroadcastRelayHandlerTest extends SysuiTestCase {
 
+    @Parameterized.Parameters(name = "{0}")
+    public static List<FlagsParameterization> getFlags() {
+        return FlagsParameterization.allCombinationsOf(
+                Flags.FLAG_SLICE_BROADCAST_RELAY_IN_BACKGROUND);
+    }
+
     private static final String TEST_ACTION = "com.android.systemui.action.TEST_ACTION";
+    private final FakeExecutor mBackgroundExecutor = new FakeExecutor(new FakeSystemClock());
+
     private SliceBroadcastRelayHandler mRelayHandler;
     private Context mSpyContext;
     @Mock
     private BroadcastDispatcher mBroadcastDispatcher;
 
+
+    public SliceBroadcastRelayHandlerTest(FlagsParameterization flags) {
+        mSetFlagsRule.setFlagsParameterization(flags);
+    }
+
     @Before
     public void setup() {
         MockitoAnnotations.initMocks(this);
         mSpyContext = spy(mContext);
 
-        mRelayHandler = new SliceBroadcastRelayHandler(mSpyContext, mBroadcastDispatcher);
+        mRelayHandler = new SliceBroadcastRelayHandler(mSpyContext, mBroadcastDispatcher,
+                mBackgroundExecutor);
     }
 
     @Test
@@ -80,6 +101,7 @@
         intent.putExtra(SliceBroadcastRelay.EXTRA_URI, testUri);
 
         mRelayHandler.handleIntent(intent);
+        mBackgroundExecutor.runAllReady();
         verify(mSpyContext).registerReceiver(any(), eq(value), anyInt());
     }
 
@@ -99,12 +121,14 @@
         intent.putExtra(SliceBroadcastRelay.EXTRA_FILTER, value);
 
         mRelayHandler.handleIntent(intent);
+        mBackgroundExecutor.runAllReady();
         ArgumentCaptor<BroadcastReceiver> relay = ArgumentCaptor.forClass(BroadcastReceiver.class);
         verify(mSpyContext).registerReceiver(relay.capture(), eq(value), anyInt());
 
         intent = new Intent(SliceBroadcastRelay.ACTION_UNREGISTER);
         intent.putExtra(SliceBroadcastRelay.EXTRA_URI, ContentProvider.maybeAddUserId(testUri, 0));
         mRelayHandler.handleIntent(intent);
+        mBackgroundExecutor.runAllReady();
         verify(mSpyContext).unregisterReceiver(eq(relay.getValue()));
     }
 
@@ -119,6 +143,7 @@
         Intent intent = new Intent(SliceBroadcastRelay.ACTION_UNREGISTER);
         intent.putExtra(SliceBroadcastRelay.EXTRA_URI, ContentProvider.maybeAddUserId(testUri, 0));
         mRelayHandler.handleIntent(intent);
+        mBackgroundExecutor.runAllReady();
         // No crash
     }
 
@@ -138,6 +163,7 @@
         intent.putExtra(SliceBroadcastRelay.EXTRA_FILTER, value);
 
         mRelayHandler.handleIntent(intent);
+        mBackgroundExecutor.runAllReady();
         ArgumentCaptor<BroadcastReceiver> relay = ArgumentCaptor.forClass(BroadcastReceiver.class);
         verify(mSpyContext).registerReceiver(relay.capture(), eq(value), anyInt());
         relay.getValue().onReceive(mSpyContext, new Intent(TEST_ACTION));
@@ -146,8 +172,10 @@
     }
 
     @Test
-    public void testRegisteredWithDispatcher() {
+    @DisableFlags(Flags.FLAG_SLICE_BROADCAST_RELAY_IN_BACKGROUND)
+    public void testRegisteredWithDispatcher_onMainThread() {
         mRelayHandler.start();
+        mBackgroundExecutor.runAllReady();
 
         verify(mBroadcastDispatcher)
                 .registerReceiver(any(BroadcastReceiver.class), any(IntentFilter.class));
@@ -155,6 +183,19 @@
                 .registerReceiver(any(BroadcastReceiver.class), any(IntentFilter.class));
     }
 
+    @Test
+    @EnableFlags(Flags.FLAG_SLICE_BROADCAST_RELAY_IN_BACKGROUND)
+    public void testRegisteredWithDispatcher_onBackgroundThread() {
+        mRelayHandler.start();
+        mBackgroundExecutor.runAllReady();
+
+        verify(mBroadcastDispatcher)
+                .registerReceiver(any(BroadcastReceiver.class), any(IntentFilter.class),
+                        eq(mBackgroundExecutor));
+        verify(mSpyContext, never())
+                .registerReceiver(any(BroadcastReceiver.class), any(IntentFilter.class));
+    }
+
     public static class Receiver extends BroadcastReceiver {
         private static BroadcastReceiver sReceiver;