I am experiencing some odd behaviour - I have a property "key" being released in an object's dealloc, this works fine when I am debugging the app on my iPad.
But, when I launch the app "normally" i.e. without running it via XCode, it crashes immediately and from looking at the crash log, I can see it's because the "key" property is throwing an BAD ACCESS error where it is being released.
Does anyone know why my app might behave differently in these two scenarios?
I can obviously fix the bug, but I am not sure even why it is happening...
Related
Good afternoon,
I was doing some Instruments testing on my iOS app that I'm about to release, but I noticed some VERY strange memory leaks, that appear to be coming from System libraries.
When I ran Instruments I got this leak:
Which is extremely weird from my point of view! I went to the Call Tree of these leaks and they all appear to be deep C++ system calls.
What confuses me even more is that this project has ARC enabled, and I ran it through the Analyzer and no problems showed up.
Even more weird is that this DOES NOT happen on the Simulator, nor on my real iPad, but on my iPhone this problem happens.
And when I check "Show Obj-C only" and "Hide System Libraries" the call trace disappears which leads me to believe my code is not responsible for the leak.
Why is this happening and what can I do to fix it?
Thanks guys.
The above leak is not a leak inside your app and it is inside apple's library which you dont have to worry about. If you have fixed all the leaks inside your app, you are fine. Apple will not reject your app just because of this small leak.
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.
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.
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.
Right now my app should only supports Portrait. On Summary/Supported Device Orientations I have only selected Portrait so I'm hoping that my app will not rotate. I was testing the app on a device and suddenly I'm getting the following error randomly:
[UIButtonContent deviceOrientationDidChange:]: unrecognized selector sent to instance
It happens when I rotate the device SOMETIMES, is not consistent, and is not always over UIBUttonContent. I supposed that if I only select Portrait, deviceOrientationDidChange should not be called or should be ignored.
Other times my app crashes with an EXC_BAD_ACCESS (code=1, address=something) but it happens when I rotate the device so I'm guessing that both errors are related.
I don't know what to do with this, it's hard to debug because I don't have feedback, the All Exceptions Breakpoint is not being called, so I don't know where and exactly why this is happening. Any idea on how to debug this is welcome.
These are the classic signs of a memory management error. You have over-released some object and it has been deallocated while something else still references it. Later, something messages it. In some cases a new object has taken its place, but that object doesn't understand the messages it's receiving. In other cases, there's no valid object and you get a crash.
Edited to second the advice to use the Zombies instrument to find the over-release.
Do you have a class that should be called with deviceOrientationDidChange:? When this happens, it usually means that you have a dangling reference to a deallocated object. You should try profiling your app with Instruments in "Zombies" mode.
I solved this issue a long time ago, but I think is good to share what actually helped me on this case.
After trying everything with no results with Instruments I started debugging old-school. I had an idea of "where" the error was so I just commented all the code on that section. I was right, the bug just disappeared along with some functionalities. After that I made "binary uncommenting" (uncomment one half) till I got the bug line. It was a third party library, I had an object that was not being released properly.