Special thanks to Jimmy Yap, editor at iMerlion.com, for his time and insight in this episode!

This week we discuss what’s multi-tasking, how it’s done and where is it going?? Enjoy!

-NTT, Daniel and Naveen

Show Notes.

A few wikipedia articles for reference.
Hyper-threading.
Multi-tasking.

If you’re interested in know more about the hardware, check out the MIT OCW course on Computer Architecture

Security Now Podcast from TWiT.tv. For the Series of Episodes on Designing your own PC check out Ep233, Ep235, Ep357, Ep239, Ep241..

Apple recently announced iPhone OS 4.0 enabling “multitasking” of a sorts. I want to dig slightly deeper into understanding what they actually mean by this “multitasking”, without talking too much about the nitty gritty details.

There are 7 kinds of “services” they expose for multitasking:

• Background Audio
• Voice over IP
• Background Location
• Push Notifications
• Local Notifications
• Task Completion
• Fast App Switching

Among all 7 “services” exposed, 6 of them are somewhat already available in the system itself, one way or another, with hidden APIs not exposed for public developer usage. Let’s take a look at each of them, and how they might “save battery” without “slowing down the system”.

Background Audio

The background audio is simply what the iTunes application already does, which is to play audio in the background without having the iTunes application open. This simply means they just expose what iPhone can already do to developers. This does not make any changes to slowing down the system in any way, since people have been using the iTunes application to play background music since the first iteration of the iPhone and iPod Touch. However, understand that the application does not remain open at all, only a small portion of the “application” remains streaming the music.

Voice over IP

Voice services has been around ever since the beginning of the iPhone (duh?!?) with the Phone application, running constantly in the background to “receive” calls. This, in fact, is also not a full fledged application at all, but a small part of code that “reacts” to an action by the OS (namely the voice service) to load up the application and “receive” the action to do something about it.

Background Location

Similarly with the voice service, it is simply a “reaction” or a “response” to an action that the OS has prompted, in this case, your GPS or Wifi location based services. This is probably one of the things that will drain your battery pretty quickly, since these services do take a lot of resources. However, since the control lies with the OS of how and when to serve up this reaction and NOT the application that decides to take over your entire GPS and Wifi location based services into their hands and drain your battery dry, the OS will probably have some battery consideration when location is required, hopefully not letting the application go rogue.

Push Notifications

What can I say? It’s been done, and been available since the last iPhone OS 3.0 release. I think it’s just put here for good measure. Once again, it is a “reaction” and not true multitasking.

Local Notifications

This is simply the same thing as your “scheduled task” or “timer” for those familiar with the terminologies. This, too, isn’t having your entire application open, but simply just a small part of it that you register to a scheduler to run it when required.

Task Completion

This is slightly interesting because it isn’t a “reaction” to something, but letting a “thread”, “process”, or keeping with this post’s terminology “a small part of the app” running in the background, and when that finishes it just automatically closes the application. This has potential for having a rogue application that simply just continuously have an infinite loop to keep the application open. I’m curious to find out how much is exposed, or only certain services like “downloading” and “uploading” are available.

Fast App Switching

This is ALSO not true multitasking, where the application once lost focus will save its state, close itself, and not “run” at all. Only after reopening, the state is restored, and the application is once resumed again. So in fact, anything running will have to be resumed, for example connection to the internet and so on. This means that it does not actually continue to run at all. However, with what was covered in the previous 6 ways of multitasking, you can very well achieve seamless “multitasking” with “Task Completion”, “Local Notifications” and so on.

Summary

What does this all mean? Steve Jobs has redefined what multitasking actually means and converted the meaning to a consumer terminology. Consumers do not want true multitasking, but a pseudo-version of it with all the benefits of multitasking, and also the benefits of a fast and responsive OS. But does this mean that developers will have more to worry about, trying to work around what’s available to them to create a seamless so-called “multitasking” application? Most of what Apple has announced isn’t anything new at all to the iPhone OS, it is simply just exposing it with a tight grip, disallowing developers to go rogue.

Do note that all this right now is speculation based on what makes sense to me until I actually see the SDK.

Source: JustinLee.SG – High-Level Analysis of iPhone OS 4.0 Multitasking

Just for fun, I did an unboxing video for an iPhone 3G case, the Vulcan by SwitchEasy, a case I got for Christmas which Jerrick and I picked together.

DK, Farinelli, Justin & Justin

Stories this week

[1:40] StarHub to offer iPhone
[7:55] Google investing in a mobile future with AdMob
[10:00] Google Has Acquired Gizmo5
[15:00] Google’s Go: A New Programming Language That’s Python Meets C++
[23:10] ZiiLABS ZMS-08 offers Cortex A8-powered Full HD and Flash acceleration for netbooks
[30:20] Xbox 360 Facebook, Twitter, Last.fm hit Nov. 17
[36:10] Tech65 website was hacked on monday night
[38:00] HackerSpace.SG

[43:20] Byte of the week: Prezi

Farinelli, DK and I have been playing this new iPhone game from ngmoco recently called Eliminate. We had another round last night and I decided to film us (okay, me) playing since whenever we played, I realised we’d have funny moments. Unfortunately, the camera failed on me for some reason, and I only got a few minutes of footage.

Nevertheless, hope you guys enjoy whatever that’s left of this video!

By the way, we are just kidding about the title.

Daniel, DK, Justin, Nicole

Stories this week

[1:15] Windows 7 has landed in Singapore
[8:30] Easing XP Netbook owners’ path to Windows 7
[10:52] Amazon: Windows 7 is ‘the biggest pre-order product of all time
[13:30] Linus Torvalds Gives Windows 7 a Thumbs Up
[14:22] Apple Targets Windows 7 With Three New ‘Get a Mac’ Ads
[17:00] Microsoft partners with Facebook, Twitter on search
[19:18] Google strikes a Twitter search deal, too
[20:43] Barnes & Noble Nook dual-screen reader officially announced
[25:05] Apple redesigns iMac and 13-inch MacBook, revamps Mac Mini
[36:35] Nokia sues Apple for patent infringement
[39:05] Dell Adamo XPS Can Only Be Opened By Rubbing It

[45:56] Bonus: Leave a comment and stand a chance to win one of the three T-Shirt (Thanks to Kevin)

Based on popular demand, I’ve decided to update our classic How To video on creating audio books on iTunes. What’s an audio book, you ask?

It’s a special audio file that is organised separately from your music, and has the ability to automatically bookmark itself so that you can always carry on from where you left off, and the ability for you to control the speed of a speaker without distorting his or her voice. In otherwords, an audio file designed specially for long spoken audio!

Daniel, DK, Farinelli, Jerrick, Justin, Nicole

Stories this week:

[1:05] SingTel vs Local iPhone Developers
[7:10] MOE Adopts Open Standard Internet Email and Collaboration Services for Over 30,000 Teachers
[15:10] Sony Ericsson’s motion activated MH907 headset could change things forever (update: or not)
[17:50] Phoenix Instant Boot BIOS starts loading Windows in under a second

[21:35] Byte of the week: Chrome Frame on IE

DK, Farinelli, Justin

Stories this week:

[1:42] Tech21 iBand is the MUST Protection for Your iPhone, iPod Touch with d30 Technology
[5:28] M1 buys Qala for $14.9m
[11:04] Free 1mbps wireless@sg from September 1st
[16:37] Google Sells Company Merchandise Online
[21:57] Creative announces first touchscreen player
[27:42] HTC Hero First Look (HD Video)