Hold a wake lock during app startup and shutdown.

briar-android/src/main/java/org/briarproject/briar/android/BriarService.java

@@ -19,12 +19,15 @@ import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult;
 import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.bramble.api.system.AndroidWakeLockManager;
+import org.briarproject.bramble.api.system.WakefulIoExecutor;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.logout.HideUiActivity;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.android.LockManager;
 
 import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Logger;
 
@@ -48,6 +51,7 @@ import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.ALREADY_RUNNING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.SUCCESS;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
 import static org.briarproject.briar.android.BriarApplication.ENTRY_ACTIVITY;
 import static org.briarproject.briar.api.android.AndroidNotificationManager.FAILURE_CHANNEL_ID;
 import static org.briarproject.briar.api.android.AndroidNotificationManager.FAILURE_NOTIFICATION_ID;
@@ -80,6 +84,11 @@ public class BriarService extends Service {
 	AccountManager accountManager;
 	@Inject
 	LockManager lockManager;
+	@Inject
+	AndroidWakeLockManager wakeLockManager;
+	@Inject
+	@WakefulIoExecutor
+	Executor wakefulIoExecutor;
 
 	// Fields that are accessed from background threads must be volatile
 	@Inject
@@ -108,10 +117,12 @@ public class BriarService extends Service {
 			return;
 		}
 
+		// Hold a wake lock during startup
+		wakeLockManager.runWakefully(() -> {
 			// Create notification channels
 			if (SDK_INT >= 26) {
 				NotificationManager nm = (NotificationManager)
-					getSystemService(NOTIFICATION_SERVICE);
+						requireNonNull(getSystemService(NOTIFICATION_SERVICE));
 				NotificationChannel ongoingChannel = new NotificationChannel(
 						ONGOING_CHANNEL_ID,
 						getString(R.string.ongoing_notification_title),
@@ -129,7 +140,7 @@ public class BriarService extends Service {
 					notificationManager.getForegroundNotification();
 			startForeground(ONGOING_NOTIFICATION_ID, foregroundNotification);
 			// Start the services in a background thread
-		new Thread(() -> {
+			wakefulIoExecutor.execute(() -> {
 				StartResult result = lifecycleManager.startServices(dbKey);
 				if (result == SUCCESS) {
 					started = true;
@@ -142,7 +153,7 @@ public class BriarService extends Service {
 					showStartupFailureNotification(result);
 					stopSelf();
 				}
-		}).start();
+			});
 			// Register for device shutdown broadcasts
 			receiver = new BroadcastReceiver() {
 				@Override
@@ -156,6 +167,7 @@ public class BriarService extends Service {
 			filter.addAction("android.intent.action.QUICKBOOT_POWEROFF");
 			filter.addAction("com.htc.intent.action.QUICKBOOT_POWEROFF");
 			registerReceiver(receiver, filter);
+		}, "LifecycleStartup");
 	}
 
 	@Override
@@ -179,8 +191,8 @@ public class BriarService extends Service {
 			i.putExtra(EXTRA_NOTIFICATION_ID, FAILURE_NOTIFICATION_ID);
 			b.setContentIntent(PendingIntent.getActivity(BriarService.this,
 					0, i, FLAG_UPDATE_CURRENT));
-			Object o = getSystemService(NOTIFICATION_SERVICE);
+			NotificationManager nm = (NotificationManager)
-			NotificationManager nm = (NotificationManager) o;
+					requireNonNull(getSystemService(NOTIFICATION_SERVICE));
 			nm.notify(FAILURE_NOTIFICATION_ID, b.build());
 			// Bring the dashboard to the front to clear the back stack
 			i = new Intent(BriarService.this, ENTRY_ACTIVITY);
@@ -205,14 +217,17 @@ public class BriarService extends Service {
 
 	@Override
 	public void onDestroy() {
+		// Hold a wake lock during shutdown
+		wakeLockManager.runWakefully(() -> {
 			super.onDestroy();
 			LOG.info("Destroyed");
 			stopForeground(true);
 			if (receiver != null) unregisterReceiver(receiver);
 			// Stop the services in a background thread
-		new Thread(() -> {
+			wakefulIoExecutor.execute(() -> {
 				if (started) lifecycleManager.stopServices();
-		}).start();
+			});
+		}, "LifecycleShutdown");
 	}
 
 	@Override
@@ -257,12 +272,14 @@ public class BriarService extends Service {
 	}
 
 	private void shutdownFromBackground() {
+		// Hold a wake lock during shutdown
+		wakeLockManager.runWakefully(() -> {
 			// Stop the service
 			stopSelf();
 			// Hide the UI
 			hideUi();
 			// Wait for shutdown to complete, then exit
-		new Thread(() -> {
+			wakefulIoExecutor.execute(() -> {
 				try {
 					if (started) lifecycleManager.waitForShutdown();
 				} catch (InterruptedException e) {
@@ -270,7 +287,8 @@ public class BriarService extends Service {
 				}
 				LOG.info("Exiting");
 				System.exit(0);
-		}).start();
+			});
+		}, "BackgroundShutdown");
 	}
 
 	/**