Multitasking on Android - Page 4 - maemo.org

imaginaryenemy | # 31 | 2016-06-27, 04:51 | Report

Originally Posted by sicelo View Post

Those saying VLC/Android can play while they do other tasks - yes, any phone (at least Nokia) with a music player can do that, even Nokia S40 (even the older versions such as in Nokia 6230i). This is clearly not the multitasking being referred to in this thread.

I don't think anyone would consider playing music in the background multitasking (though, I realize in the strictest sense it is). Since music is meant to be heard, not seen, if it couldn't be put into the background, I'm not sure many people would listen to music on their phones.

Playing VIDEOS in the background was only mentioned to demonstrate common misconceptions on multitasking on Android.

I agree, multitasking on mobile does not compare to multitasking on desktop. I just think the multitasking divide between Android and other more loved OSs is much smaller than many would like to think.

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Last edited by imaginaryenemy; 2016-06-27 at 05:24.

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beobachter | # 32 | 2016-06-27, 08:47 | Report

Hello, the closest You get to real multitasking on Android is the developer Android N version.

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wicket | # 33 | 2016-06-28, 00:53 | Report

Originally Posted by aegis View Post

If the app isn't doing anything then it saves state and releases resources saving your battery. It restores state back to where you left it when you resume it.

This is not true. If a process is idling in memory, it will not consume any additional power unless it is swapped out. Saving and restoring state requires copying data from RAM to non-volatile storage and back again. This action is similar to swapping and does consume extra power. When Android restarts an app from scratch and restores its state, it's quite likely that it uses more power due to extra instruction cycles and copy operations than swapping normally would.

Originally Posted by sicelo View Post

Finally, it's quite apparent that some of us, myself included, want the same type of multitasking as on a desktop, even though there might be a battery/power penalty to pay.

This is not entirely true either:

https://felipec.wordpress.com/2012/0...ic-vs-dynamic/

Last edited by wicket; 2016-06-28 at 05:48.

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sicelo | # 34 | 2016-06-28, 06:26 | Report

Originally Posted by wicket View Post

This is not true. If a process is idling in memory, it will not consume any additional power unless it is swapped out. Saving and restoring state requires copying data from RAM to non-volatile storage and back again. This action is similar to swapping and does consume extra power. When Android restarts an app from scratch and restores its state, it's quite likely that it uses more power due to extra instruction cycles and copy operations than swapping normally would.

This is not entirely true either:

https://felipec.wordpress.com/2012/0...ic-vs-dynamic/

Awesome. So those of us crying for 'real' multitasking aren't getting the worst deal after all

but then ... it could be that more recent android builds have overcome some of the issues raised on that post? I notice that was 2012.

Either way, I definitely like Maemo's multitasking better than anything else available on other mobile devices that I have had access to use/test.

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reinob | # 35 | 2016-06-28, 06:49 | Report

Originally Posted by sicelo View Post

but then ... it could be that more recent android builds have overcome some of the issues raised on that post? I notice that was 2012.

AFAIK Android has taken the "easy" way of not adapting the kernel to the actual hardware (like Nokia did with the N900), which of course means that the power consumption is much higher. Their solution is then to freeze apps (swap out, swap back, restart, etc.)

In the old days people complained that Windows didn't have real multitasking (it had "cooperative multitasking"). Now (other, but still) people claim that Android has real multitasking. But we claim that on mobile only Maemo has real multitasking.

As long as each group uses whatever definition they wish, then we cannot sensibly argue about this. FWIW and in my book: Android does not have multitasking.

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pichlo | # 36 | 2016-06-28, 06:55 | Report

Originally Posted by reinob View Post

FWIW and in my book: Android does not have multitasking.

Can you share a few pages from your book?

What we have established in this thread:

Android can run multiple processes simultaneously, as evidenced by running top or ps -aux.
(At least some versions of) Android can run multiple user applications simultaneously and give the user the multitasking experience.

What else is missing?

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aegis | # 37 | 2016-06-28, 08:04 | Report

Originally Posted by wicket View Post

This is not true. If a process is idling in memory, it will not consume any additional power unless it is swapped out. Saving and restoring state requires copying data from RAM to non-volatile storage and back again. This action is similar to swapping and does consume extra power. When Android restarts an app from scratch and restores its state, it's quite likely that it uses more power due to extra instruction cycles and copy operations than swapping normally would.

It is true.

Android first saves state IN RAM. IE. It just leaves an instance of the running app IN RAM. If it then runs out of RAM, it offloads that instance to storage.

Yes, it may use more instructions to restore state than to restore a swapped out process but you are getting the inbuilt protection of not having an app lose all its transient unsaved data.

Anyway, nobody wants their device to be continuously swapping. Nobody would argue that they'd rather have swapping for performance reasons.

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aegis | # 38 | 2016-06-28, 08:09 | Report

Originally Posted by reinob View Post

In the old days people complained that Windows didn't have real multitasking (it had "cooperative multitasking"). Now (other, but still) people claim that Android has real multitasking. But we claim that on mobile only Maemo has real multitasking.

That's a ridiculous analogy. You may as well claim that because Maemo has a terminal built in, it's closer to MS-DOS.

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Jordi | # 39 | 2016-06-28, 09:54 | Report

This is my use case of multitasking : I let run a gps tracking app during hours, sometimes up to 6-8 hours. Then I use (lightly) my phone for other tasks like answering a call, etc.

My experience is that Android does this as good as Meego or Sailfish, it usually consume about 5 to 7 percentage points of battery per hour (for a comparable battery), no gaps in the recording.

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mscion | # 40 | 2016-06-28, 11:51 | Report

Android seems to do multitasking better than it used to. Used to be when Android killed an app, like a document editor, I would lose the changes I made. Now if the same app is killed it looks like the changes are saved. Whether that is due to an improvement in the app or android itself, I can't say for certain. Regardless, I wish it was me that decided whether the app is killed and not android. I would prefer, if the situation arises that there is no enough free memory to run an app, that the system tell me that I need to close some given set of apps or risk getting them killed. I would also prefer having a better swapping capability, even at the expense of performance, as the phones are pretty fast anyways. Regardless this may be a moot point once the phones have 6 to 8 gb.

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