Crash on CLConnection::sendMessageInternal - ios

Question

I need help trying to figure out this crash.
I have a common crash (#1 crash, ~300 devices affected) that seems to occur when my app is checking CLLocation authorization status:
The 'start' method is as follows:
-(BOOL)start {
if ([self isDenied]) {
return NO;
} else {
_manager = [[CLLocationManager alloc] init];
_manager.delegate = self;
if ([_manager respondsToSelector:#selector(requestAlwaysAuthorization)] && [self isNotDetermined]) {
[_manager requestAlwaysAuthorization];
} else {
[self startUpdatingLocation];
}
return YES;
}
}
The 'isNotDetermined' method, from which the application seems to switch to a different thread and crash, is:
- (BOOL)isNotDetermined {
return CLLocationManager.authorizationStatus == kCLAuthorizationStatusNotDetermined;
}
Maybe also relevant, the isDenied method; according to the documentation, the CLLocationManager should not be created if the authorization status is Denied or Restricted:
- (BOOL)isDenied {
return CLLocationManager.authorizationStatus == kCLAuthorizationStatusDenied;
}
Could it be that the app crashes because I create a CLLocationManager while the authorizationStatus is Restricted? I'd expect the crash to occur in the CLLocationManager init method in that case.

Answer 1

I / we have managed to find the problem. The problem was twofold:
stopUpdatingLocation was not called when the application entered the background.
When the application entered the foreground, the CLLocationManager was re-initialized, without first stopping the old instance. Two bits of code:
// called in both didFinishLaunching and applicationWillEnterForeground
-(void) start {
_manager = [[CLLocationManager alloc] init];
// other setup code
}
// Called in applicationDidEnterBackground
-(void)stop {
// this variable was never false
if (_updateBackgroundLocations) {
[_manager stopUpdatingLocation];
}
}
What I did to fix it:
-(void) start {
if (_manager == nil) {
_manager = [[CLLocationManager alloc] init];
}
// other setup code
}
-(void)stop {
[_manager stopUpdatingLocation];
}
This fixed... several thousand crashes. They probably occurred when the application was already in the background, since we never did get complaints about frequently occurring crashes from our users.