AlarmManager not working in several devices

Question

My app uses AlarmManager and it has been working since 4 years ago. But I noticed it started failing in some devices.

I\'m pretty sure code is right (I\'m using Wak

Answer 1

Most of modern Android devices come with an app or mechanism, which automagically tries to figure out how to save battery and as a result might kill certain 3rd party apps. This might result in removing scheduled tasks and jobs, (e.g. alarms not going off, push notification not working, etc.). In many cases this happens completely independent from battery saving mechanisms of Android, in my case i couldn't make more battery optimization when i detect some devices model, i redirect user to the start up manager to whitelist my application

You found in this link for every model the intent that you should invoke https://android-arsenal.com/details/1/6771

Answer 2

Are you listening for BOOT_COMPLETED? You need to set alarms again when a device is rebooted.

Answer 3

What version of Android are these devices running?

As of API 23, the OS itself will go into a low-power idle mode when it's been unused for a while, and in that mode alarms will not be delivered. There is a way for apps to explicitly say "I need this alarm to go off at this time regardless of battery usage," however; the new AlarmManager methods called setAndAllowWhileIdle() and setExactAndAllowWhileIdle().

From your description it sounds like this might not be the particular cause of your issues on certain OEMs' devices, but this is something that all developers using the Alarm Manager ought to be aware of.

Finally, many usages of the Alarm Manager are better addressed using the Job Scheduler's mechanisms. For backwards compatibility the Play Services "GCM Network Manager" is actually very close to the Job Scheduler in functionality -- it uses the Job Scheduler internally on newer versions of Android -- and is not necessarily about networking, despite the class's name.

Answer 4

I don't think killing the app will prevent the alarm manager from waking your app.

Its only when you "force stop" or disable the app you don't receive call backs from alarm manager.

The root cause might be something else.

Also on M... setExactAndAllowWhileIdle does throttling...that is if u schedule an alarm every 2 mins it won't be triggered. ..There needs to be 15 mins window. .

Answer 5

For Xiaomi you may need to enable AutoStart for your app. I am trying do to a list of Android modifications(usually from phone's manufacturer) that may effect a background process. If you have something new please add an answer here List of Android task killers

Answer 6

This might be late but I hope it helps someone.

I was stuck on the same problem for so long. But now I konw how to solve this problem. This is for anyone who might have the same problem. People keep saying that you have to enable AutoStart but I managed to it with out using auto start.

First of all, WakeFullBroadcastaReceiver is now deprecated and you should use BroadcastReceiver. Second of all, you have to use the ForegroudService instead of BackgroundService.

I will give you the example in the following:

IntentService.class

public class NotificationService extends IntentService {


//In order to send notification when the app is close
//we use a foreground service, background service doesn't do the work.



public NotificationService() {
    super("NotificationService");
}

@Override
public void onCreate() {
    super.onCreate();

}

@Override
public int onStartCommand(@Nullable Intent intent, int flags, int startId) {
    super.onStartCommand(intent, flags, startId);

    //There is no difference in the result between start_sticky or start_not_sticky at the moment
    return START_NOT_STICKY;
}

@Override
protected void onHandleIntent(@Nullable Intent intent) {

    //TODO check if the app is in foreground or not, we can use activity lifecyclecallbacks for this

    startForegroundServiceT();
    sendNotification(intent);
    stopSelf();
}


/***
 * you have to show the notification to the user when running foreground service
 * otherwise it will throw an exception
 */
private void startForegroundServiceT(){

    if (Build.VERSION.SDK_INT >= 26) {
        String CHANNEL_ID = "my_channel_01";
        NotificationChannel channel = new NotificationChannel(CHANNEL_ID,
                "Channel human readable title",
                NotificationManager.IMPORTANCE_DEFAULT);

        ((NotificationManager) 
   getSystemService(Context.NOTIFICATION_SERVICE)).createNotificationChannel(channel);

        Notification notification = new Notification.Builder(this, CHANNEL_ID)
                .setContentTitle("")
                .setContentText("").build();

        startForeground(1, notification);
    }
}

private void sendNotification(Intent intent){

    //Send notification
    //Use notification channle for android O+
}
}

start the foreground service in BroadcastReceiver.class

public class AlarmReceiver extends BroadcastReceiver {


@Override
public void onReceive(Context context, Intent intent) {


    Intent service = new Intent(context, NotificationService.class);
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        context.startForegroundService(service);
    } else {
        context.startService(service);
    }

}
}

And the setAlarms like this:

 public static void setAlarm(Context context, int requestCode, int hour, int minute){


    AlarmManager alarmManager =( AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
    Intent intent = new Intent(context//same activity should be used when canceling the alarm
            , AlarmReceiver.class);
    intent.setAction("android.intent.action.NOTIFY");

    //setting FLAG_CANCEL_CURRENT makes some problems. and doest allow the cancelAlarm to work properly
    PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 1001, intent, 0);

    Calendar time = getTime(hour, minute);

    //set Alarm for different API levels
    if (Build.VERSION.SDK_INT >= 23){
        alarmManager.setExactAndAllowWhileIdle(AlarmManager.RTC_WAKEUP,time.getTimeInMillis(),pendingIntent);
    }
    else{
        alarmManager.set(AlarmManager.RTC_WAKEUP,time.getTimeInMillis(),pendingIntent);
    }

Then you have to declare the receiver and the foregroundservice in the manifest.

       <receiver android:name=".AlarmReceiver"
        android:enabled="true"
        android:exported="true">
        <intent-filter>
            <action android:name="android.intent.action.NOTIFY">

            </action>
        </intent-filter>
    </receiver>
    <service
        android:name=".NotificationService"
        android:enabled="true"
        android:exported="true"></service>

I hope this helps some one.