How to keep a service alive using AlarmManager.setInexactRepeating()?

Question

I have some existing code that spawns a service intent which does a bunch of stuff in the background. This code does work...

Intent serviceIntent = new Intent(context, APMService.class);
serviceIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

context.startService(serviceIntent);

My question is: how to change this to use the AlarmManager.setInexactRepeating(...) methods?

I have changed the above code to this:

Intent serviceIntent = new Intent(context, APMService.class);
serviceIntent.putExtra("STARTED_BY", starter);
serviceIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

//Set up recurring alarm that restarts our service if
// it crashes or if it gets killed by the Android OS
AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
PendingIntent pi = PendingIntent.getService(context, 0, serviceIntent, 0);
//am.cancel(pi);

am.setInexactRepeating(
        AlarmManager.ELAPSED_REALTIME_WAKEUP    //wake up the phone if it's asleep
        , cal.getTimeInMillis()
        , 10000
        , pi);

And I have added these permissions to AndroidManifest.xml...

<uses-permission android:name="com.android.alarm.permission.SET_ALARM"/>
<uses-permission android:name="com.android.alarm.permission.WAKE_LOCK"/>

My understanding is that this is supposed to start the service immediately and then try to restart it again every 10 seconds. But this code isn't working properly.

Using this new code, the service never starts at all and I cannot see why not. To complicate matters the debugger never seems to attach to the app in time to see what's going on.

Can anyone see what I'm doing wrong?

Answer 1

Your service is not starting because of AlarmManager.ELAPSED_REALTIME_WAKEUP, while it should be using AlarmManager.RTC_WAKEUP

If you want to run every 10s keep in mind that above API 21 alarm intervals below 60s are rounded up to 60s.

Also, consider using WakefulIntentService https://github.com/commonsguy/cwac-wakeful