App crashed due to timer(Ivar, uint32_t doesn't support timer?)

App crashed due to timer(Ivar, uint32_t doesn't support timer?)

i am getting buttons name through this code:
[button addTarget:self action:@selector(buttonPressed:)
forControlEvents:UIControlEventTouchDown];
- (NSString *)nameOfIvar:(id)ivarPtr{
NSString *name = nil;
uint32_t ivarCount = 0;
Ivar *ivars = class_copyIvarList([self class], &ivarCount);
NSLog(@"ivarCount%i",ivarCount);
if(ivars)
{
for(uint32_t i=0; i<ivarCount; i++)
{
Ivar ivar = ivars[i];
id pointer = object_getIvar(self, ivar);
if(pointer == ivarPtr)
{
name = [NSString stringWithUTF8String:ivar_getName(ivar)];
break;
}
}
free(ivars);
}
return name;
}
- (void)buttonPressed:(id)sender {
NSString *buttonName = [self nameOfIvar:sender];
NSLog(@"%@",buttonName);
characterimage=buttonName;
}
and i have timer in my app, now the problem is when i press the button
during timer, app crashed and only this error "(lldb) " shows in debug
area. instead of timer, on button action app doesnot crash. i dont
understand what kind of error is this please guide me what is going wrong
in my code?