multitasking

While running some tests I've noticed that when an app (with no background privileges, i.e. voip, gps, etc) enters the background state, any background threads (or concurrent NSOperations) running at the time seem to be paused (not terminated), and they continue when the app enters the foreground. I can't see this thread behaviour documented anywhere. Does anyone know if this behaviour is defined and can be counted on? It would be useful to not have to cancel tasks or get involved in task completion if the thread can safely continue when the app is re-opened. Especially for complicated

I have searched far and wide for documentation on how to record audio in the background and have come to the conclusion that specifying 'audio' in the plist file might work. But, because iOS 4 will terminate background apps when it runs low on memory, we must also take some steps to reduce our memory usage when we transition to the background. How do we reduce our memory usage? Also, does anybody know a sure shot way of recording audio in the background on iOS?? I unchecked the box in the Info.plist file that says "Application does not run in background" and also added the <key>

ok so on going to background I hide everything. I still get a failed to resume in time error when I switch back. Why is it crashing in drawRect if everything is hidden? Any ideas on how to deal with a "Failed to resume" error like this? Incident Identifier: 0E5ADFDF-1EB1-4ECC-9F02-57B37F1BBBA1 CrashReporter Key: 17186e938075dd5907223199eccdc85176f18698 Hardware Model: iPad1,1 Process: hexProto [2162] Path: /var/mobile/Applications/31D43A9F-0EF3-4D03-89AC-243B68F75D91/hexProto.app/hexProto Identifier: hexProto Version: ??? (???) Code Type: ARM (Native) Parent Process: launchd [1] Date/Time:

This is a follow on from IPhone App Submission Issues If I have a IOS3 compatible app, how does it handle in IOS4 in regards to Multitasking? i.e. When the IOS3 app is closed on an IOS4 phone and than they reopen it, will it restart or is it backgrounded/multitasked and when reloaded taken to where the user just was? Does anyone have advice on how i should go about this? I need to convert my current IOS4 compatible app back so that it is compatible with IOS3 quickly. Thanks If you compile an app using the 4.x SDK but with a deployment target of 3.x, then when running under iOS 4.0, suspend

I want to know how to run a progress bar and some other work simultaneously, then when the work is done, stop the progress bar in Python (2.7.x) import sys, time def progress_bar(): while True: for c in ['-','\\','|','/']: sys.stdout.write('\r' + "Working " + c) sys.stdout.flush() time.sleep(0.2) def work(): *doing hard work* How would I be able to do something like: progress_bar() #run in background? work() *stop progress bar* print "\nThe work is done!" You could run a thread in the background using the threading module . For example: def run_progress_bar(finished_event): chars = itertools

it's my first question here as I have a problem developing my first iOS app. It is one of the thousands of flashlight apps, however I'm trying to put as many features as possible to it. One of them is saving the state of the app when it goes to background or terminates. After going to foreground (iOS 4 or higher) or relaunching, I'm loading the settings from file and reapplying them. One of the settings is, obviously, the AVCaptureDevice.torchMode . However, I encounter the problem with this. I'm reapplying these settings in the applicationDidBecomeActive method. It all seems to work, but when