headlesstask wake-lock consumes battery

[atlanteh]

I have a headless task that wakes up every 30 minutes. does some work for 1-2 seconds and finishes. However I see that the wake-lock is held much much longer than necessary. The battery is draining like crazy. I thought this might be something with my code, so I created an empty project with just my headless task code, but the wake-lock keeps draining the battery. I added logs and I see that the services is destroying after the task is done, so it's releasing the wake-lock acquired in the receiver. So either I'm doing something wrong, or the problem is in react-native.

I uploaded my demo example here:
https://github.com/atlanteh/headlesstask-battery-consumption-example

• React Native version: 0.41.2
• Platform: android
• Development Operating System: windows

[atlanteh]

Why did you close this issue? Is it solved?

[atlanteh]

@hramos Can you please explain why you closed this issue? It still happens to me..

[oriharel]

@atlanteh maybe you need to call onHeadlessJsTaskFinish() instead of stopSelf() directly.

[atlanteh]

I don't think so. onHeadlessJsTaskFinish() is meant after a task is finished, not when it was never executed. I left this specific task a long time ago, but now I see that some other modules implement it and you can see here, for example, that they don't call stopSelf() or anything, just return null. so maybe this is the problem.
Do you have any insights on this?

[oriharel]

I haven't got this far with HeadlessJsTaskService. My issues revolve around ReactContext created not on the main thread. see #15915.

However, I did notice that inside HeadlessJsTaskService.startTask() there is already a call to acquireWakeLockNow(). So with your call from the receiver that makes it 2 calls. Maybe you can drop the call from the receiver (I know we are told to do so from the documentation but worth a shot).

[oriharel]

Also, maybe try to update React Native to latest and see if it reproduces.

[atlanteh]

I must call the acquireWakeLockNow in the broadcast receiver. See the docs:

If you start your service from a BroadcastReceiver, make sure to call HeadlessJsTaskService.acquireWakeLockNow() before returning from onReceive().

This is to prevent the phone from falling asleep before actually starting the service.