setExactAndAllowWhileIdle - is not exact as of developer reference

Question

AlarmManager on API19 has the method setExact() to set an exact alarm.

Exact means --> If I set an alarm to 2:01 p

Answer 1

I was trying to create an automation system running in the background. My frequency range was between 1-15 minutes. My wish was not to use a foreground service. By looking at the name of the method "setExactAndAllowWhileIdle", I thought that yeah it is safe to go with one-time alarms, scheduling the next one when done.

However, I couldn't find a way to run code in doze mode with alarms running more frequent than 15 minutes. Instead, I choose to start a foreground service when doze mode gets activated and stop that foreground service when phone awakes. User won't be seeing your foreground notification while using his/her phone. I don't care much about the ones in doze mode.

PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    if(intent.getAction().equals("android.os.action.DEVICE_IDLE_MODE_CHANGED")){
        if (pm.isDeviceIdleMode()) {
            //startAutomationForegroundService();
        } else {
            //stopAutomationForegroundService();
            return;
        }
        AutomationReceiver.completeWakefulIntent(intent);
        return;
    }
}

You need to register "android.os.action.DEVICE_IDLE_MODE_CHANGED" intent filter into your WakefulBroadcastReceiver. Care putting it into manifest may not help.