One of my apps got rejected because it exceeded the startup time limit. The watchdog process killed it. Is there any way you can enable this watchdog component in debug mode? I've read somewhere that it's disabled for debugging purposes (which seems logical to me). Just wondering if you can manually enable it with some setting or something.
Btw, I know how to fix this problem, moving the whole startup code to a background thread did the trick.
Anyone got an idea?
Well it's active when you launch an app not through Xcode (i.e. with no debugger attached), so you could just install your app via Xcode, unplug it, launch the app. Then you'll see if it takes too long. But really, you shouldn't be thinking that you need that as a feature during debugging. You should just return ASAP from applicationDidFinishLaunching and do your work later like you have mentioned.
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I am facing a very weird issue: my iPhone is restarting.
This issue occurs in a particular scenario only.
Step 1: I have a sync process in which I'm loading data for the whole app. So I'm basically doing a heavy API call by uploading 4-5 camera captured images and syncing the app data;
Step 2: After syncing, I'm pressing the iPhone home button to make the app go in background;
Step 3: I'm locking the iPhone screen(by using side button);
After a few seconds I'm seeing the apple logo and the phone seems to restart. This is not replicating when the app is connected in debug mode. I checked the debug navigator app is using only 125 MB of memory, disk and network values is 0%. Energy Impact is showing high, I'm not sure this is due to high energy impact. I'm facing this issue only on iOS 12.4.
The fact that the phone (or possibly just springboard) restarts, and not just your application means this is Apple's bug. You're not supposed to be able to crash iOS even if you try.
Finding a likely cause will be hard since the system is not behaving the way it's supposed to. The device's logs may have more information from things other than your app. This may be a system API breaking due to any number of actions from your application.
Often with this kind of thing the next OS version will fix it, but if that's not the case or it's important to track down I would try removing ways you're interaction with the system (background APIs, notifications, etc.) and see if anything fixes the issue.
If you find the problem, you may even be doing things the "correct" way according to the documentation and have to find a workaround. If you have the time you can submit a bug to Apple so the underlying issue has a better chance of being fixed.
It seems when your app is in the background and phone locked, Automatic Reference Counting (ARC) closes some connection or deallocates a resource that makes the iPhone restart. Are you closing all connections and removing all references once the upload is complete?
Phones do not spontaneously restart just because of an app’s actions. You’re having an issue with your phone, not with a program. You need to repair or replace the phone.
There is a crash happen when coming back from background through app icon.
However I cannot see any detail info in console log. There is a signal to terminate, but we cannot find signal number.
<FBApplicationProcess: 0x117bcb930; Maixxxx; pid: 1762> exited abnormally via signal.
Process exited: <FBApplicationProcess: 0x117bcb930; Maixxx; pid: -1> -> <FBApplicationProcessExitContext: 0x17103f820; exitReason: signal; terminationReason: (none)>
The procedures to reproduce my crash is as follow:
Start app through click on app icon.
Use the app as normal user.
Press home to put it in background.
Wait for some minutes.
Click the app icon on springboard screen in order to use it again.
The app crash&exit.
Since the crash only happen when coming back from background, and required to enter background for some minutes, I cannot run in debug mode with lldb attached.
I didn't use any of background features.
Also, I didn't see any crash report in Fabric's Crashlytics. So I think signal handler could not be called neither?
How to investigate this kind of problem?
These things can be tough, I know that from similar experiences. Without knowing more about your app I can only offer hints and no definitive answer, but perhaps this helps you.
The fallback and tedious approach to use direct logging with print and so on notwithstanding there are a two ways to try to "catch" a process.
However, first let me stress that "background" is not always the same and people unfortunately use the term often loosely. Depending on what state transition causes your crash you might run out of luck and have to simply experiment using manual logging. Apps can be in background, i.e. not in the foreground, but still running. This is usually the case when the debugger is attached, otherwise it couldn't do its job. Alternatively they can be suspended (or even terminated) by the OS. The debugger prevents this, which you probably already figured out.
The two things that might help you are:
If you're using background fetch, i.e. "coming back from background mode" as you describe it happens automatically you can activate the "Launch due to a background fetch event" option in your build scheme's "Run" configuration section.
Run your app from the Home screen, put it into background with the Home button and wait a bit (you've probably done so in the past already to get a feeling for when the crash would happen). Your app should eventually go into the suspended state (but you have no way to actually see that anywhere AFAIK). Instead of getting it to the foreground again via the multitasking UI, simply attach the debugger again via the "Debug - Attach to process" menu. This should get your app from the suspended state back into the background state, where the crash probably really happens (if it were to happen when coming from background to foreground you probably would have been able to debug it as usual). Hopefully the debugger has finished attaching to it in time, otherwise I'm out of ideas. :(
I haven't run into this specific problem myself personally, but I know background stuff can be tricky. Maybe this discussion also helps you (I took part of my info from there as well).
Run the app in debug mode on a real device. Press the Home button to send the app to background and continue the debugging. Then you can bring the app to foreground and keep debugging, or put a breakpoint at applicationWillEnterForeground.
You can't debug this on the real device. When the debugger is attached, your apps will never go to background mode in the real device.
You can try to debug this on a simulator.
Anyway please check your class attributes and set attributes to strong to make sure this is not happened by missing attributes.
I have read several StackOverflow questions that have FBApplicationProcess. Usually, this one happened by missing array or something when the app started.
Best regards.
I have gone through all the above answers and all have given proper answers. Though, I would like to share my point of view.
If the app is running on any iOS real device with debug mode and wire plug-in or even on Simulator, App will never go in the background.
If the app is running without wire plug-in or run without Xcode(directly launch the app in iPhone) and then put the app in the background, the app will be running in the background of next 3 mins. After 3 mins, the App will automatically be suspended and removed from the main thread. Now, when we open the app again, It will be considered a fresh launch.
If your app having any Background Capabilities ON, then your app will be alive even in the background, but you can't do any UI changes during that time.
To keep app alive in the background, Background Capabilities must be handled properly. ie. If Location is used in your app with 'While-App is in Foreground' condition, app will not run more than 3 mins in background. So, If you want to run your app continuously in background, you must have to represent proper reason in Info.plist file with Battery drain word, or else, Apple will reject it.
Ping me for more detail on your question.
Thanks.
Crash logs still available on your test device.
To get the crash log try the following steps:
Connect your test device to the Mac through USB.
Launch Xcode. Go to Windows > Devices and Simulators.
Choose your device from the devices section on the left side of the screen.
Select View Device Logs button.
Identify and select the Crash Log to see the contents.
I've been testing an app for iOS in Xamarin Studio, however whenever I reach a breakpoint or an exception is thrown and I stay there for a few seconds without pushing the continue execution button, the debugging session will close as the app will close on my device. This is due to the process mentioned here, as it is occurring during the splash screen, and if the app pauses too long there, it will close the app because it failed to scene-create. I was wondering if it is possible to disable this when debugging with breakpoints, because I would like to look at the data flow through variables and such.
As matt guessed, it is a Xamarin issue. The response to my inquiry to Xamarin was this,
Xamarin does not currently use a native debugger, thus watchdog is not
disabled. They are looking into alternatives, but for now a potential
workaround is to not do anything until you've returned from the
FinishedLaunching method (i.e. start your launch code in a timer event
for instance), and debug that instead.
Update: the status on this bug is "fixed for the next major release." as of 12/29/15
I have an application that can be installed in two forms: .ipa file and a Cydia package. It works well on iOS5. But on iOS6 a strange thing is happening, when the app was installed from Cydia. When I press the Home button, iOS sends SIGSTOP and the app is terminated. I don't have UIApplicationExitsOnSuspend set to TRUE in Info.plist. Any ideas why it's happening and how to prevent this?
Also on iOS6, it became possible to delete a Cydia app from SpringBoard, which does not look like a good feature, because the app in Cydia is still shown as installed. Is there any flag to avoid this?
EDIT:
I found that my app was killed because of strange deadlock and crash report was not generated because device had too much crash dumps on filesystem (I found this in console log). After deleting few logs from FS, I came to this problem https://stackoverflow.com/questions/15164548/cocos2d-x-example-app-crashes-when-pressing-home. I'm not using cocos2d, but seems problem with OpenGL subsystem. It crashes even it's just initialised and not rendering anything. I was trying to call glFinish(), unload shader programs and [EAGLContext setCurrentContext:nil], but all of these do not help.
EDIT:
I solved this by full release of my rendering subsystem including OpenGL context when app is deactivated. Fortunately it was easy to do.
When I debug an app on my iPad, it's often the case that when I get back to it after some time has passed, the debugging session has already stopped but the app is still running.
It's very frustrating because I specifically baked some UIWebView debugging tools into the app like reloading external content on a swipe so I don't have to recompile it every time I change something.
I've looked at the settings and found nothing like “debugging timeout”.
What's the matter?
It turns out, the problem was in Auto Lock.
It unloads the application, and thus soft debugger's connection is lost.
Setting Auto Lock to 15 minutes solved my problem.