Time limit for an IBAction? - objective-c

It may sound as a dumb question. In fact, I am still thinking if that might be the cause but working with XCode and having set iOS 4.3 as my Deployment Target and iPad as my Device I am getting an unexpected error.
While running my app through the Simulator I can get it working. But when I run it through my iPad a single IBAction, fired when user taps an UIButton, that takes almost 4 minutes is not completing. In fact it's getting stopped at the same point, in a for loop.
I searched for memory leaks using XCode and it didn't find any, therefore I'm asking if there's a time limit for IBActions. I read there are 10 minutes limit for methods in background but I didn't find anything related to IBActions in foreground yet.

I think the user gets tired of waiting for a response long before the system. Normally, a button press or similar should finish after one second at most (well, maybe 1.5s), or the user thinks that the system is "slow".

I would make sure that you have your button outlets properly hooked up. It is possible that it just isn't throwing the exception so you get a slow system. Put NSLog displays in your IBAction method and make sure it is executing it properly. You should be able to track it back to figure out what is going on.

Related

Resolving deadlock in iOS app

So I'm trying to convert a project to ARC. The first attempt, I just converted everything and I had this problem on one of my views, it just hangs. I cannot click on any UI element, and nothing is printed to the console, and it doesn't crash. It just sits there.
So in order to start troubleshooting it, I converted all the simple classes and viewControllers, and then for some of the more complex model classes and UIViewController classes, I set the compiler flag for -fno-objc-arc. My app runs better, but it still just gets in this state where it hangs. I've never seen this on it prior to converting to ARC. I was wondering if anyone else has had this problem and what I can do to troubleshoot it. Thanks~
I would press "pause" in the debugger and look at the call stacks for all threads in your app. This can point out why your app is locked up.

"Multiple locks on web thread" error thrown inconsistently

I'm getting a strange error in my iOS app. The error message is as follows:
bool _WebTryThreadLock(bool), 0x22c820: Multiple locks on web thread not allowed! Please file a bug. Crashing now...
The odd thing is that it happens inconsistently -- sometimes clicking a certain button or textField will cause the crash, and other times the same steps won't cause a crash. I originally had a few UIWebViews in one viewController, but I've commented out everything related to them, so as far as I know, I'm not accessing the web thread at all. Even when I did have these UIWebViews in my project, the error often occurred in viewControllers unrelated to the webView. I also got the error once when my app was open on the device and I received an email. The push notification from the email seemed related. Any ideas what might be causing this?
I am suspicious that this might be related to the way we are currently segueing between viewControllers. We are using modal segues and manually dismissing one viewController upon loading another. Is that a bad idea?
Any input would be greatly appreciated.

Facebook Connect Login Dialog crashing app

Of the many problems I've been having with my current app, this is one of the most annoying.
In the simulator the login dialog works fine, however on a device it's just a frozen white box and the console prints the following:
void SendDelegateMessage(NSInvocation*): delegate
(webView:resource:willSendRequest:redirectResponse:fromDataSource:)
failed to return after waiting 10 seconds. main run loop mode: kCFRunLoopDefaultMode
I've looked this up but I'm still not sure what it means.
If I try switching
[self authorizeWithFBAppAuth:NO safariAuth:NO];
to
[self authorizeWithFBAppAuth:NO safariAuth:YES];
it switches to the safari app to verify but this somehow kills my app with an error which says ReturnNotPermittedKillClient.
Has anyone experienced a similar problem? On my last app it just worked without any of these issues, and as far as I can see I've done everything the same way this time. However this project was inherited from someone else so there may be underlying causes that I am not aware of.
Edit: Just tried moving the login request from didFinishLaunchingWithOptions to a point in the intro screen class where everything else has already been loaded, just in case it was a memory issue caused by too many tasks trying to run at the same time. This time the error message didn't appear, however the login box still remained white and then closed the app a few seconds later.
Edit2: Seems like it's simply a memory error. I changed all variables which I had previously released to be retained, which has fixed the problem on my 3GS. However on my iPad 1 the problem persists. Incidentally, when changing shouldAutorotateToInterfaceOrientation from using landscaperight to using landscaperight or landscapeleft, when I rotate the iPad I get a memory warning and then the same crash. In both cases there are no debug error messages other than the memory warning, and the app just closes down - there is no breakpoint etc to see where the issue lies.
if you are using the webview then we need to do this first b4 moving to next view .delegate = nil;
This might be what you want:
There are other branches of this in NSObject in the documentation.
Code:
[self performSelector: withObject: afterDelay: ]
The problem was simply down to memory. After changing the way it loads images, sounds etc the problem has gone away.

iPad crash after fast restart, when performing task at exit

I'm working on an iPad app, targeting iOS 3.2 (so everyone can run it), and when the user presses the Home button, the app gets an applicationWillTerminate: message and it sends usage data to a server before it exits.
This all works fine. But if you exit and then restart the app before it's done exiting, it appears to crash.
The 5 seconds you get to clean up when the app is exiting begins once you get the applicationWillTerminate: message, but the app disappears immediately from the device, giving the user the opportunity to launch it again.
I think what's happening, is that they're just reactivating the app before it's done exiting, and so they're just jumping back into the first instance of the app just before it actually exits. So the second instance of the app appears to be crashing.
There is no crash log, and putting a log message into the application:didFinishLaunchingWithOptions: doesn't produce any logs in the console from that second launching of the app. This is why I'm pretty sure it's not actually creating a second instance but just re-entering the first instance which is almost done exiting.
So are there any ideas out there about how to avoid this situation? It seems odd that you are given 5 seconds to perform actions on exit, but then this odd behaviour happens as a result.
I'm worried part of the problem is that the app is targeting iOS 3.2 and is actually exiting when the HOME button is pressed, and if it were just going into the background, this wouldn't be an issue. Sadly, changing that behaviour is just not an option at this moment.

Problem: restarting App

My App is a view-based application. At the beginning I show my logo and after a delay of a few seconds it changes into another view. from then on the user can switch to a lot of different views.
Sooooo.. My Problem: The thing is, when I restart my App. [..well closing and reopen by touching the icon..] the app itself doesnt restart in the sence of jumping to the very first view. to the contrary: at restart the user just returns to the last view that was open.
So I dont know why this is.
Is it normal to somehow manually tell the app to return to the very first view after restart? And if so, how do I have to do that?
PS.
I have so no idea what to do.. Maybe my problem has to do with the timer i used in the first view to change after a delay of time?
Please, is there anyone, who can help me?
Your problem is that, as of iPhone 4, returning to the home screen does not terminate your app. It's just made inactive, so opening it again reactivates it. In most cases, this is a good thing. If it doesn't work for your app, you can add the UIApplicationExitsOnSuspend key to your Info.plist with a value of YES.
(As I said, you should only do this if it really helps usability. If it's just about getting your splash screen shown again, most users and possibly Apple will frown upon it.)
iOS 4.0 and greater have a fast-start thing that allows apps to restart back from where they were upon restarting. There are several ways to deal with this:
1.) your App Delegate receives info about being but into the background and resumed. - (void)applicationDidBecomeActive:(UIApplication *)application and - (void)applicationDidEnterBackground:(UIApplication *)application are the relevant functions here. Check the docs.
2.) You can also disable the background, inactive state completely by including UIApplicationExitsOnSuspend in you Info.plist as Chuck already pointed out.
Overall, you should check the application state docs on Apple's Side.