App freezes and crashes with kernel panic - - ios

Question

I have an app which displays some basic animation triggered by the playback of midi file. It works ok during the first playback but freezes during subsequent playbacks. The device then usually reboots generating a crash log indicating that a kernel panic took place. Occasionally it just hangs without a reboot.
The animation consists of an small png image which has the opacity changed from high to low to give a fading effect.
The freeze takes place on the line :[self performSelectorOnMainThread:#selector( setPitch: ) withObject:[NSNumber numberWithInteger:[note intValue]] waitUntilDone:YES];
Here is the method which contains this line:
- (void)log:(NSNotification *)notification {
[NSThread isMainThread];
NSDictionary* info = notification.userInfo;
NSNumber *note;
note = [info objectForKey:kNAMIDI_Note];
BRMidiNoteName *noteConverter = [[BRMidiNoteName alloc] init];
NSString *noteName;
noteName = [noteConverter nameFromNumber:[note intValue] withNotation:[defaults valueForKey:kSettingsNotation]];
[self.currentNoteLabel performSelectorOnMainThread: #selector( setText: ) withObject: noteName waitUntilDone: YES];
[self performSelectorOnMainThread:#selector( setPitch: ) withObject:[NSNumber numberWithInteger:[note intValue]] waitUntilDone:YES];
}
-(void) setPitch:(NSNumber*) pitchValue{
NSInteger visualPitchValue = [pitchValue intValue]- [_currentTrack.trackStartNote intValue] - voiceTransposeValue + 1;
if ([defaults boolForKey:kSettingsVisualiser]) {
//UIImageView *img = [[UIImageView alloc]init];
UIImageView *img;
if ((visualPitchValue > 0 )) {
// highlight new pitch
img = (UIImageView *)[self.view viewWithTag:visualPitchValue];
if (([pitchValue integerValue] < [currentVoice.bridgeLow integerValue])) {
[img setImage:[UIImage imageNamed:#"bar_green.png"]];
}
else if (([pitchValue integerValue] <= [currentVoice.bridgeHigh integerValue])) {
[img setImage:[UIImage imageNamed:#"bar_orange"]];
}
else{
[img setImage:[UIImage imageNamed:#"bar_blue.png"]];
}
[img setAlpha:1.0];
// Set up fade out effect
CABasicAnimation *fadeOutAnimation = [CABasicAnimation animationWithKeyPath:#"opacity"];
[fadeOutAnimation setToValue:[NSNumber numberWithFloat:_fadeToOpacity]];
fadeOutAnimation.fillMode = kCAFillModeForwards;
fadeOutAnimation.removedOnCompletion = NO;
CAAnimationGroup *group = [CAAnimationGroup animation];
group.fillMode = kCAFillModeForwards;
group.removedOnCompletion = NO;
// [group setAnimations:[NSArray arrayWithObjects:fadeOutAnimation, pathAnimation, nil]];
[group setAnimations:[NSArray arrayWithObjects:fadeOutAnimation, nil]];
group.duration = 0.7f;
group.delegate = self;
[group setValue:img forKey:#"imageViewBeingAnimated"];
[img.layer addAnimation:group forKey:#"savingAnimation"];
}
}
}

Answer 1

I found that changing the waitUntilDone from YES to NO stopped the device screen from freezing.
[self.currentNoteLabel performSelectorOnMainThread: #selector( setText: ) withObject: noteName waitUntilDone: NO];
[self performSelectorOnMainThread:#selector( setPitch: ) withObject:[NSNumber numberWithInteger:[note intValue]] waitUntilDone:NO];