ubuntu-phone team mailing list archive
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Message #03760
Re: Running background services
The state of an application is transparent to the user. Behind the
scenes, the system can decide to stop/kill non-focused apps at its own
discretion. Whenever the system alters the state of an app to "not
running" it offers an archive such that the app can persist its state.
With that, a user ideally never realizes that an app has been stopped
or killed.
Thomas
On Wed, Aug 14, 2013 at 10:08 AM, Tobias Havla <tbhavla@xxxxxxxxx> wrote:
> On 14.08.2013 10:04, Thomas Voß wrote:
>> On Wed, Aug 14, 2013 at 9:56 AM, Tobias Havla <tbhavla@xxxxxxxxx> wrote:
>>> On 14.08.2013 09:54, Thomas Voß wrote:
>>>> On Wed, Aug 14, 2013 at 9:41 AM, Michael Zanetti
>>>> <michael.zanetti@xxxxxxxxxxxxx> wrote:
>>>>> On Wednesday 14 August 2013 09:31:31 Daniel Holbach wrote:
>>>>>> Hello,
>>>>>>
>>>>>> On 14.08.2013 09:29, Michael Zanetti wrote:
>>>>>>> On Wednesday 14 August 2013 09:07:52 Thomas Voß wrote:
>>>>>>>> Hey Fabio,
>>>>>>>>
>>>>>>>> no, applications are not allowed to run in background. Our application
>>>>>>>> lifecycle is strict in this respect and we only guarantee focused
>>>>>>>> applications to be running.
>>>>>>> Does that mean I will have an Ubuntu Edge phone with 4GB of RAM, 8 CPU
>>>>>>> cores and cannot do multitasking on it?
>>>>>> I don't think anyone specified the phone to have 8 CPU cores - where did
>>>>>> you read that?
>>>>> Nowhere... I think you get my point...
>>>>>
>>>>>> How is "app authors can write daemons" = multitasking?
>>>>> How does this relate? Thomas said there will be no running apps in the
>>>>> background / minimzed apps, which to me means there will be no multitasking.
>>>>>
>>>>>
>>>> We have had this conversation multiple times in the past, and version
>>>> 1 of our application lifecycle will not allow to run arbitrary
>>>> applications in the background. Instead, we will provide selected
>>>> services to hand over to the system for certain tasks, e.g.,
>>>> downloads, alarms, music playback. Please note that this is a policy
>>>> targetted towards the "mobile phone" usage scenario and swapping
>>>> policies at runtime when transitioning to different usage scenarios is
>>>> one of the primary goals of the lifecycle architecture.
>>>>
>>>> Version 2 of the lifecycle will then allow applications to run their
>>>> own background tasks, UI less, with restrictions on
>>>> CPU/Memory/resources in general.
>>>>
>>>> Thomas
>>>>
>>>>> --
>>>>> Mailing list: https://launchpad.net/~ubuntu-phone
>>>>> Post to : ubuntu-phone@xxxxxxxxxxxxxxxxxxx
>>>>> Unsubscribe : https://launchpad.net/~ubuntu-phone
>>>>> More help : https://help.launchpad.net/ListHelp
>>> If Ubuntu Touch doesn't support multi task it is far behind iOS,
>>> Android, Windows Phone and Blackberry. Sorry, I thought it would be a
>>> modern system that requires a lot of power, so we can do the same things
>>> as on our PCs.
>> Okay, let's be clear here: Multitasking and application lifecycle are
>> related but distinct topics. Obviously, Ubuntu Touch will support
>> multi-tasking, but an application lifecycle architecture that allows
>> for controlling resource consumption of applications by the system is
>> sorely needed to ensure a long-running _mobile_ device. It is not
>> sufficient to assume that app authors will get it right and it is
>> important to note that users always "blame" the platform for bad
>> battery life. And that is for a good reason: It's the platform's/OS's
>> responsibility to put mechanisms in place to manage a device's
>> resources!
>>
>> Our application lifecycle policies and state machines allow us to
>> exercise this level of control for specific usage scenarios, but they
>> do not touch on general multi-tasking capabilities and we can leverage
>> the full process state spectrum to ensure a seamless operation.
>>
>> Thomas
> So can two or three applications run at the same time and other gets
> closed/suspended or can I switch between two applications only with
> reloading the application?
> We have a gesture to quick switch between apps, so if we have to reload
> apps while we are multitasking this gesture makes no sense. A good way
> would be suspending apps like Android does (/Greenify). The doesn't
> notice that and the battery life is good.
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