3 ms·

Thats somewhat similar. But iOS and Android apps are built to pause/sleep, which is somewhat different to a kill. A paused Android/iOS app might get killed, but

Thats somewhat similar. But iOS and Android apps are built to pause/sleep, which is somewhat different to a kill. A paused Android/iOS app might get killed, but it might also get un-paused, and then it has to carry on (in the users eyes) as if it was never interfered with at all.

fusiongyro 14y ago
As it happens, there's also SIGSTOP and SIGCONT. The responsibility to write the app correctly is always going to fall on the app developer. It's just that for phone apps, it's a lot more obvious that you need to. But it doesn't have to be that way, and frameworks to facilitate writing apps like this would be a totally userland proposition, just using traditional Unix signals that are rarely used today.
- codeulike 14y ago
  Thats interesting. But then my question would be: will the phone be restricted to running apps that behave graciously by handling those signals?
  - fusiongyro 14y ago
    There's no way to know a priori without introducing some pretty onerous restrictions.
ajross 14y ago
If you want presistent state in your GUI app then yes, you have to have that in the app framework. Ubuntu for Phones is using a new (and so-far closed source!) Qt5-based framework, so I can't speak to their choice there. I suspect they've picked something sane, though. This is, however, a tangent. The ability for an app to persist state and "start" in the last state the user saw has nothing to do with the OS's ability to kill an app to conserve memory. And note again that the requirement for an app to survive an unexpected failure (i.e. you can't expect to have been "paused" -- this is true on Android and iOS too!) is still there, there's nothing that extra layers of API will do to fix that.
- codeulike 14y ago
  > The ability for an app to persist state and "start" in the last state the user saw has nothing to do with the OS's ability to kill an app to conserve memory. I'd say it does. Pausing apps (as opposed to killing them) is another way of conserving memory, and battery, while preserving usability. But as you say perhaps Qt5 will handle this. Is the Ubuntu Phone restricted to only running Qt5 apps? I'm not clear on that.

fusiongyro 14y ago

As it happens, there's also SIGSTOP and SIGCONT. The responsibility to write the app correctly is always going to fall on the app developer. It's just that for phone apps, it's a lot more obvious that you need to. But it doesn't have to be that way, and frameworks to facilitate writing apps like this would be a totally userland proposition, just using traditional Unix signals that are rarely used today.

codeulike 14y ago
Thats interesting. But then my question would be: will the phone be restricted to running apps that behave graciously by handling those signals?
- fusiongyro 14y ago
  There's no way to know a priori without introducing some pretty onerous restrictions.

ajross 14y ago

If you want presistent state in your GUI app then yes, you have to have that in the app framework. Ubuntu for Phones is using a new (and so-far closed source!) Qt5-based framework, so I can't speak to their choice there. I suspect they've picked something sane, though. This is, however, a tangent. The ability for an app to persist state and "start" in the last state the user saw has nothing to do with the OS's ability to kill an app to conserve memory. And note again that the requirement for an app to survive an unexpected failure (i.e. you can't expect to have been "paused" -- this is true on Android and iOS too!) is still there, there's nothing that extra layers of API will do to fix that.

codeulike 14y ago
> The ability for an app to persist state and "start" in the last state the user saw has nothing to do with the OS's ability to kill an app to conserve memory. I'd say it does. Pausing apps (as opposed to killing them) is another way of conserving memory, and battery, while preserving usability. But as you say perhaps Qt5 will handle this. Is the Ubuntu Phone restricted to only running Qt5 apps? I'm not clear on that.