Re: [Linphone-users] what is "Enable service notification" exactly?

[Greg Troxel]

Brian & Jennifer Murrell <address@hidden> writes:

> On Tue, 2019-03-26 at 06:02 -0400, Brian J. Murrell wrote:
>> 
>> Maybe I need to dig out my Nexus 5 with Lineage 15.1 on it to
>> understand functionality without aggressive battery management.
>
> So, LineageOS 15.1 should be free of any of the vendor aggressive
> battery management techniques so should be a good platform to test on.

It's also free of google code.  If you didn't add in microg, or gapps,
then there will be no GCM/FCM support.

> My experience is that I need either "Background mode" or "Enable
> service notification" enabled to get calls while the phone screen is
> off.  Both seem to result in the same behaviour -- that push calls work
> while the phone screen is off and it's sleeping.

Are you really sure there is FCM push going on in this case?

As I understand it "background mode" is telling linphone to keep the
service running when the screen is off.  I would expect that to either
keep tthe service or register for push.  I would expect it not to
register for push without that, as it's a request from the user to get
calls when not running, and by implication a request not to be
registered when not running.

> But with neither enabled, calls won't ring the phone when Linphone is
> not up and running on the screen.
>
> Is that accurate?

Without background mode, linphone stops on exit for me, which is what I
expect.

Service notification is about becoming a foreground service that is less
likely to be killed by the OS.  My not-well-tested belief is that this
will only really matter if the phone has memory pressure.  An old phone
not being used is likely to keep running a background service.

> If so, why are even one of those necessary?  I thought push was
> supposed to allow an app to be completely killed (i.e. in the normal
> course of Android resource management because resources are needed for
> other apps, or even being killed by the user) and it will get started
> back up when a "data" push is sent.

I have read somewwhere that there are issues with selecting and
deselecting push in that there are bugs in the linphone code.  But I'm
not clear on that.

> Additionally, if one of those is really necessary, is one of those
> modes ("Background mode" and "Enable service notification") better than
> the other for any reason?

Enable service notification should be more robust against killing.  But
really that should be grayed out unless background mode is enabled.