Multitasking is the apparent simultaneous execution of two or more tasks by a computer. Relevant implementation and usage details vary per operating system and programming language, so always add tags for both the OS and language when using this tag. Multitasking questions must be programming related.
Questions tagged [multitasking]
1008 questions
367
votes
10 answers
Invalid Bundle Error - "requires launch storyboard"
I keep getting this error when I try to submit my app to the store using Xcode:
ERROR ITMS-90475: "Invalid Bundle. iPad Multitasking support requires launch storyboard in bundle 'com.companyname.appname.'"
Anyone know what this error really means?

matthias_b_nz
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193
votes
12 answers
Handling applicationDidBecomeActive - "How can a view controller respond to the app becoming Active?"
I have the UIApplicationDelegate protocol in my main AppDelegate.m class, with the applicationDidBecomeActive method defined.
I want to call a method when the application returns from the background, but the method is in another view controller.…

Calvin
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110
votes
5 answers
Proper use of beginBackgroundTaskWithExpirationHandler
I'm a bit confused about how and when to use beginBackgroundTaskWithExpirationHandler.
Apple shows in their examples to use it in applicationDidEnterBackground delegate, to get more time to complete some important task, usually a network…

Eyal
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103
votes
7 answers
Max number of goroutines
How many goroutines can I use painless? For example wikipedia says, in Erlang 20 million processes can be created without degrading performance.
Update: I've just investigated in goroutines performance a little and got such a results:
It looks like…

OCyril
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84
votes
3 answers
Android singleTask or singleInstance launch mode?
I have an app that has a list as its main activity and then you can click items which opens a detailed view of that item. I also have a search activity that is similar to the main activity and works as intended.
However I want this search activity…

Kman
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82
votes
4 answers
Is it possible to opt your iPad app out of multitasking on iOS 9
I have a large app that I will need some time to optimize for iOS9.
Edit: What I am worried about is all the UI getting squeezed together when the app window size is reduced. So my question is, is there any way to force full screen for the app?

Zia
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75
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3 answers
When an iOS application goes to the background, are lengthy tasks paused?
Yes, I know if I wish my app to be responsive to users' multitasking actions, such as switch to another app, I should deal with
- (void)applicationWillResignActive:(UIApplication *)application
- (void)applicationDidBecomeActive:(UIApplication…

Jackson Tale
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74
votes
24 answers
Difference between multitasking, multithreading and multiprocessing?
Whats the difference between multitasking, multiprogramming & multiprocessing
This comes regularly for my university OS exams and I can't find a good answer.
I know quite a bit about multitasking and multiprogramming, but need to confirm it.

Jaison Varghese
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74
votes
4 answers
iOS - Ensure execution on main thread
I want to know how to call my function on the main thread.
How do I make sure my function is called on the main thread?
(this follows a previous question of mine).

user236739
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72
votes
3 answers
How does the OS scheduler regain control of CPU?
I recently started to learn how the CPU and the operating system works, and I am a bit confused about the operation of a single-CPU machine with an operating system that provides multitasking.
Supposing my machine has a single CPU, this would mean…

Edwin Dalorzo
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68
votes
7 answers
iPhone - Backgrounding to poll for events
For quite a while I'd been looking into a way in my iPhone app to poll every X minutes to check the data counters. After much reading of the Background Execution documentation and a few trial apps I'd dismissed this as impossible without abusing the…

NeilInglis
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57
votes
5 answers
iOS 9 : Warning "All interface orientations must be supported unless the app requires full screen" for universal app
I'm working on an universal app with all orientations on iPad and only portrait on iPhone. The app works well with split-screen multitasking on iOS 9 compatible iPad, but I have this warning:
All interface orientations must be supported unless the…

Zaphod
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53
votes
6 answers
What is starvation?
In multitasking systems, some abnormal conditions prevent progress of executing processes or threads. I'll refer to both processes and threads simply as "processes". Two of these conditions are called dead-lock and live-lock.
The former refers to…

Daniel C. Sobral
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51
votes
16 answers
Detect if app is running in Slide Over or Split View mode in iOS 9
In iOS 9, is it possible to detect when an app is running in iOS 9's Slide Over or Split View mode?
I've tried reading through Apple's documentation on iOS 9 multitasking, but haven't had any luck with this…
I ask because I might have a feature in…

Matias Korhonen
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51
votes
6 answers
Executing multiple functions simultaneously
I'm trying to run two functions simultaneously in Python. I have tried the below code which uses multiprocessing but when I execute the code, the second function starts only after the first is done.
from multiprocessing import Process
def func1:
…

user2739601
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