iPhone SDK Limitations: Multitasking, Java, Emulators

MacRumors · Mar 8, 2008

As people delve into the details of Apple's iPhone SDK, a few interesting issues are emerging. One developer guideline that is generating some concern is from Apple's Human Interface Guidelines for iPhone:

Only one iPhone application can run at a time, and third-party applications never run in the background. This means that when users switch to another application, answer the phone, or check their email, the application they were using quits. Its important to make sure that users do not experience any negative effects because of this reality. In other words, users should not feel that leaving your iPhone application and returning to it later is any more difficult than switching among applications on a computer.

To be fair, for most applications, this would be preferred behavior. There is no reason for Super Monkey Ball (for example) to continue running in the background, using up CPU cycles and Memory. Instead, as Apple suggests, the current state should be saved and returned when the application is relaunched.

However, this has raised concerns about the feasibility of an application such as AOL's AIM client, which typically does run in the background to alert the user of incoming messages. Based on one comment, however, this only appears to be a design guideline and not an absolute technical limitation:

I'm a programmer and I just tried it [using the iPhone SDK] and you can keep your app running in the background in the normal way ApolloIM and iFob do it. I.e. overriding applicationSuspend.

Another possibility could involve individual applications launching smaller background-tasks (daemons) short of full applications, but the feasibility of this is unknown at this time.

What this brings us back to is Apple's SDK license limitations and their editorial discretion with the iTunes App Store. From Apple's license agreement, this multitasking workaround is forbidden:

Applications must comply with the Human Interface Guidelines and other Documentation provided by Apple.

Even Sun's plans to bring Java to the iPhone is not technically allowed, despite their claims:

An Application may not itself install or launch other executable code by any means, including without limitation through the use of a plug-in architecture, calling other frameworks, other APIs or otherwise.

This could also restrict announced plans for a PC emulator for the iPhone.

It's still too early to say how strictly Apple will enforce these restrictions when approving applications for the iTunes App Store. By serving as the sole distributor for iPhone applications, Apple understandably wants to restrict malicious applications, but whether these limitations begin to encroach upon genuinely useful applications remains a concern. Apple's iTunes App Store launches in June 2008 alongside the new iPhone 2.0 firmware.

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La Porta · Mar 8, 2008

Interesting. Part of it is restricting, yet at the same time it makes sure that there is a smooth transition from app to app. Having a slowed-down iPhone/iPod wouldn't do anyone any good. That's one reason that these things don't have hard drives in the first place.

HaGG · Mar 8, 2008

Interesting read for sure

Eraserhead · Mar 8, 2008

Apple will make Sun force Java apps to come through the App Store.

mwwlse · Mar 8, 2008

It'd be nice if a program would link the 3G data connection (in the future) to bluetooth so that you could use the iPhone's data connection with a laptop via bluetooth. Is this remotely possible? I know you can do it with a few windows mobile phones (blackjack).

severe · Mar 8, 2008

I view my iPhone as a cell phone, first and foremost. Anything that may slow down this basic function would be a concern to me and probably to Apple. So, yea, restrictions and quality control are important factors here.

levitynyc · Mar 8, 2008

As long as AIM works ok, then I am fine.

notjustjay · Mar 8, 2008

I feel it's always better to set high standards, and say "we'll make an exception for you", rather than set lower standards and deal with apps that toe the line even then.

indiekiduk · Mar 8, 2008

Haha I posted that comment on Gizmodo. Macrumors have some sharp eyes indeed.

gwangung · Mar 8, 2008

notjustjay said:
I feel it's always better to set high standards, and say "we'll make an exception for you", rather than set lower standards and deal with apps that toe the line even then.

I think, for a consumer device, that may be the best path. Yes, it IS constricting---but that applies for the tech savvy, which is a more limited market. If Apple's aim is to bring the power of the smartphone feature set to a wider audience, then the needs of the general consumer market will drive the development, not the needs of the more tech savvy.

Which is how Apple has ALWAYS been.

156457 · Mar 8, 2008

If there's an MSN Messenger app, I sure hope that would be allowed to run in the background, and a counter in the top bar (where the time is) to tell you if you have a new message.

dagamer34 · Mar 8, 2008

The only application that I care about running in the background is instant messaging. I'm sure AIM will petition some sort of deal for chat (or make an official iChat client for the iPhone).

joseph2166 · Mar 8, 2008

mwwlse said:
It'd be nice if a program would link the 3G data connection (in the future) to bluetooth so that you could use the iPhone's data connection with a laptop via bluetooth. Is this remotely possible? I know you can do it with a few windows mobile phones (blackjack).

I've woundered about this before, but it seems unlikely, if only because the phone companies probably had to be pursuaded to allow unlimited data plans by apple promising not to allow such things. Otherwise you could use sooo much data with torrents etc. unless they put a cap.

That's why its unlikely that apple would allow a torrent app as well as people could steal gb (with a lot of patience) for 'free'. (Wasn't there somethin on Steve's list of apps to be banned about resource/network hogging or similar?)

azdude · Mar 8, 2008

Why has nobody yet brought up the question of iPhone Apps synchronizing content to the desktop? There's so much potential here, but I have heard no discussion on whether or not any of it will be possible:

- Yojimbo for iPhone
- OmniFocus or any other Tasks app
- iBank (though here I suppose the iPhone could access the QFX data directly)
- Delicious Library
- ...

Telp · Mar 8, 2008

My only concern, like everyone else, would be the AIM client. I hope Apple allows a workaround for this one.

sjo · Mar 8, 2008

MacRumors said:
There is no reason for Super Monkey Ball (for example) to continue running in the background, using up CPU cycles and Memory. Instead, as Apple suggests, the current state should be saved and returned when the application is relaunched.

yeah, windows 2.0 was such an awesome os, no-one ever wanted to have a program in the background eating all the resources...

seriously speaking, modern operating system such as os x would not allocate any cpu cycles to a process idling in the background. it should also be able to manage the memory in such a way that a process in the background would not affect the processes on the foreground.

in other words, considering that iphone is touted having the most advanced operating system of all the smart phones, this is really bizard and makes one wonder what exactly they had to do to make the mini-osx feasible.

or is this apples' way of ensuring dominance over the small software vendors. say someone introduces a killer program, but it lacks some features due inability to run in the background. then it's easy for apple to make similar program, although slightly better, having the ability to run in the background.

speaking of restriction, i've understood that there is no access to file system, making word processors etc impossible to implement. this and the no 3rd party apps during phone calls would be a serious blow to enterprise usage, when users need to make notes to word processor or spreadsheet or check things while on the phone.

stadidas · Mar 8, 2008

azdude said:
Why has nobody yet brought up the question of iPhone Apps synchronizing content to the desktop? There's so much potential here, but I have heard no discussion on whether or not any of it will be possible:

- Yojimbo for iPhone
- OmniFocus or any other Tasks app
- iBank (though here I suppose the iPhone could access the QFX data directly)
- Delicious Library
- ...

This is a big one for me. Apple say they provide SQL support, and advise that you use that rather than creating documents.
Being able to sync documents through iTunes would be awesome; it would allow an app on the iPhone to run as a great companion to a desktop app.

addicted44 · Mar 8, 2008

sjo said:
yeah, windows 2.0 was such an awesome os, no-one ever wanted to have a program in the background eating all the resources...

seriously speaking, modern operating system such as os x would not allocate any cpu cycles to a process idling in the background. it should also be able to manage the memory in such a way that a process in the background would not affect the processes on the foreground.

in other words, considering that iphone is touted having the most advanced operating system of all the smart phones, this is really bizard and makes one wonder what exactly they had to do to make the mini-osx feasible.

OSX is plenty capable of allocating memory smartly. I think, the issue is not memory, but battery life. 1 critical power saving aspect of most chips is putting the chip to sleep when there is nothing happening. A background process messes with this drastically, since it could be running while the user is not using the phone for anything, thereby destroying battery life (since the chip cannot sleep).

This is more a result of Apple using a new paradigm in computing, which a) recognizes the inability of a user to multitask on a 3" screen (which is why the HIG restricts background apps, while it is still technically possible.) and b) makes things the way they should be, not requiring users to worry about quitting applications.

The application quitting process is poor design that should never have come into being. Apple is trying to break developers from this habit on the iphone, so the developers have to worry about when their application should be consuming resources rather than the user.

Aussie John · Mar 8, 2008

What is the situation now if you are downloading a Mail attachment and a call comes in, does mail quit and the download stop?

rjflyn · Mar 8, 2008

Sounds like there is going to be some jailbreaking and installing of apps around the restrictions.

rj

asdavis10 · Mar 8, 2008

Apple will give trusted developers special rights to that functionality that will allow apps to run in the background. Otherwise, AOL's instant messaging (along with many other apps) would not be able to be developed. I don't see any reason why enterprise users won't be allowed to have their programs run in the background. There are many reason why they would need their apps to constantly run. Mail is currently the only app to do this, but it won't be the only one.

Eraserhead · Mar 8, 2008

asdavis10 said:
Apple will give trusted developers special rights to that functionality that will allow apps to run in the background. Otherwise, AOL's instant messaging (along with many other apps) would not be able to be developed. I don't see any reason why enterprise users won't be allowed to have their programs run in the background. There are many reason why they would need their apps to constantly run. Mail is currently the only app to do this, but it won't be the only one.

If Mail is set to get Mail every 15 minutes it kills the battery on my iPod Touch, so that is why background apps are taboo. If they are really needed (IM is an example) I think Apple will grant an exception.

ThanatosId · Mar 8, 2008

Makes sense to me that it be restricted. We've all seen the stability of Safari running while listening to music.

LiveForever · Mar 8, 2008

As a user these things are fine by me. I don't want scores of things running in the background slowing it down. My PC (which this is being typed on at the moment) has lots of things running in the background-half of which I don't know what they are doing and a third I don't want running in the background-they just have been configured by the sneaky app developers to automatically start up.

This is why I'm glad apple are setting some standards as after all this thing must be a quick responding phone in the end. I wouldn't want it to wait seconds before I could answer a call.

There are going to be two classes of iphone/touch user.

Those who just use the apple approved apps. OK they may lag behind 'awesome apps' the second group has but they should have a reliable iphone which isn't slow or prone to crashes and viruses.

The second jaibreaking group who have all the wonderous apps under the sun like solitaire, (written by developers who want to give them away for free so they will have to resort to other ways, perhaps more underhand, to make their money..) but their phones are slow, always crashing, riddled with viruses and trojans and frequently bricked. Boy will they winge..

Just my 2 cents bu the 2.0 thing is a Da Vinci Code like clue hanging in the Louvre for the World to see, about the next 3 maybe 4 g model as well as the new update. (look you can make out 3G if you squint and turn your head 30 degrees clockwise) and Its so obvious its staring us all in the face but they don't actually say it out loud. I would bet money on it. If they want a true enterprise product they have to have a worldwide product. A restricted phone is no good for multinationals with offices in US, UK, Europe, Singapore , Bejing and Sydney-sorry chaps our solution doesn't work for all your territories yet- this won't wash with the corporate buyers of these things

Eraserhead · Mar 8, 2008

LiveForever said:
There are going to be two classes of iphone/touch user.

Those who just use the apple approved apps. OK they may lag behind 'awesome apps' the second group has but they should have a reliable iphone which isn't slow or prone to crashes and viruses.

The second jaibreaking group who have all the wonderous apps under the sun like solitaire, (written by developers who want to give them away for free so they will have to resort to other ways, perhaps more underhand, to make their money..) but their phones are slow, always crashing, riddled with viruses and trojans and frequently bricked. Boy will they winge..

I think you've just won the discussion.

iPhone SDK Limitations: Multitasking, Java, Emulators

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