Allowing the phone to sleep while using RTC alarm

问题:

I've been seeing some strange issues using the Alarm manager in Android, despite the fact that I'm using RTC (non Wakeup) the phone will reliably send the PendingIntents on the correct repeating intervals.

Details of my test

• Device is not charging, just sitting on my nightstand while I slept
• My service woke up on its repeat interval (30 minutes, an extreme I know) EVERY TIME
• The service logged its activity in a file so I could read it in the morning

Now from my understanding the phone should be sleeping unless I wake it up and my Alarms should not be sent until the phone is awake.

• Why was my service executing?
• If another service is misbehaving and using the _WAKEUP variants of the alarm will my service wake up too?
• Can I avoid being woken by another service, and just awake from the user turning the screen on?

回答1:

Why was my service executing?

Presumably something else was having the device awake at those moments.

If another service is misbehaving and using the _WAKEUP variants of the alarm will my service wake up too?

Yes, though "misbehaving" is in the eye of the beholder.

Can I avoid being woken by another service, and just awake from the user turning the screen on?

Not directly via AlarmManager. You can watch for ACTION_SCREEN_OFF and ACTION_USER_PRESENT broadcasts, and perhaps disable your alarms between those.

回答2:

I've just spent an hour trying to find out why my RTC alarm sends PendingIntents even when my phone is sleeping. And the answers is very simple, because it was pluged with USB so the phone had status "charging".

Presumably something else was having the device awake at those moments.

A lot of applications with notification ads (like AirPush, Leadbolt ect) wake up the device.