Push message cannot start service at once

Question

Context

We are developing an android app that is supposed to do the following:

the user installs the app, registers and closes the app
once or twice a year an admin sends a Firebase data message with priority high to the user containing a geo fence
the FCM message starts a JobService that locates where the phone is
if the phone is inside the given area an Activity is started and user interaction starts
if the phone is outside the area the service is stopped and the user is never disturbed

I developed the app based on the Firebase push example found here

The problem

The application works fine on my older phones but on my new test phone (android 8.1.0, LineageOS 15.1) we have a problem when the phone is in sleep mode. In this case the FCM message arrives instantly but the service is first started once the phone is unlocked. So the message is stuck between 2. and 3.

We need the app to respond at once - not when the user decides to use his phone 2 hours later.

I assume the problem is due to the Doze mode introduced with android 6. I tried to solve it by adding the app to the whitelist in settings->battery->battery optimization but this did not solve the problem.

Questions

Is it Doze mode that delays my app between 2. and 3.? If so why is it not solved when the app is in the whitelist?
Is there any other way to start the location service at once? This post suggests that a foreground service can do it but this requires that a notification is shown which breaks with 5.
Is there another way to start my service at once besides whitelist and foreground service?

try `startService()` instead of scheduling a `Job`.... though I don't know for sure whether it will work or not — riyaz-ali, Feb 21 '18 at 08:51
Please post the code of the message handler, where you start your JobService. — artkoenig, Feb 21 '18 at 14:33
@riyaz-ali That did the trick! Please post your comment as an answer and you will get the bounty. — Theis Borg, Mar 01 '18 at 16:23

score 1 · Answer 1 · answered Feb 26 '18 at 20:28

Is it Doze mode that delays my app between 2. and 3.?

From the documentation Doze mode affect Network access and blocks JobScheduler.

If so why is it not solved when the app is in the whitelist?

Also from the documentation: An app that is whitelisted can use the network and hold partial wake locks during Doze and App Standby. However, other restrictions still apply to the whitelisted app, just as they do to other apps.

So the blocking of JobScheduler still applies.

Is there any other way to start the location service at once? This post suggests that a foreground service can do it but this requires that a notification is shown which breaks with 5.

Ignore Battery Optimizations (for Internet access) in combination with an AlarmManager with setAndAllowWhileIdle() or setExactAndAllowWhileIdle() should work.

Be careful with Ignore Battery Optimizations

Google Play policies prohibit apps from requesting direct exemption from Power Management features in Android 6.0+ (Doze and App Standby) unless the core function of the app is adversely affected.

I think an important question here is: Do you really need to execute the JobScheduler immediately.

If a user leaves a device unplugged and stationary for a period of time, with the screen off, the device enters Doze mode.

If the device is in Doze mode, it means the user is not using it.

if the phone is inside the given area an Activity is started and user interaction starts

This is the step Doze blocks

We need the app to respond at once - not when the user decides to use his phone 2 hours later.

If the device is in Doze it means the user is not interacting with it. Even if you show the Activity the user is not using the phone, he will see it when he starts using it 2 hours later :)

score 1 · Accepted Answer · answered Mar 02 '18 at 05:18

Yes! you are right this may be due to the Doze and App Standby features introduced in API 23 Marshmallow.

As mentioned in the documentation, the system do ignore wakelocks and system doesn't allow JobScheduler to run, which effectively prevents your app from running the Job.

An easy and effective workaround would be to run Location detecting routine inside a normal background service and start it using startService() when you receive FCM push.

Note that you might still need to white-list your app because as mentioned in another post here, only a whitelisted app can use the network and hold partial wake locks.

Federico De Gioannini · Answer 3 · 2018-02-26T20:22:22.130

I still didn't try that, but you might use a WakefulBroadcastReceiver: https://developer.android.com/training/scheduling/wakelock.html https://developer.android.com/reference/android/support/v4/content/WakefulBroadcastReceiver.html

According with this links, you should declare your receiver as:

public class YourReceiver extends WakefulBroadcastReceiver {

Probably your receiver is already a WakefulBroadcastReceiver because notifications are showing..

In the receiver, you start the service (your service has to be an IntentService) using:

startWakefulService(context, your service);

Finally, remember to release the wake lock in the service:

@Override
  protected void onHandleIntent(Intent intent) {
      <Your_broadcast_receiver_class>.completeWakefulIntent(intent);
  }

I hope it helped

Push message cannot start service at once

3 Answers3