Objective C: Code freezes when loading series of images - objective-c

Question

My first post to the forums but I have been using answers posted here for the last several months and find the answers incredibly useful! I'm still learning objective c and still learning some basics.
My code is several hundred lines right so I don't want to the post the whole code. The basic premise of the code is to load a series of random images to random locations on the screen.
When I was trying to figure out how to deal with this idea I made a simple test version that would add one balloon when a button is pressed and then when you hit pop balloons delete all the balloon images that were created.
This balloon code worked just fine, and then I added this same concept into my main code. However now when I use it only a larger scale the code would freeze at 99% cpu usage and 18.5 MB memory. The code never failed but would sit frozen. The larger version is basically just adding multiple balloons when a button is pressed instead of one. Sometimes as many as 15 images.
Is there any reason a code of this style would not work on a larger scale? Or how do you go about problem solving an issue when the code freezes and no error is given.
.h file
#interface ViewController : UIViewController
{
// Holds an array of images of the balloons
NSMutableArray *BalloonArray;
// Holds an array file names of the balloon PNG files
NSMutableArray *BalloonNames;
}
-(void)AddBalloon:(id)sender;
-(void)PopBalloons:(id)sender;
#end
.m file
#interface ViewController ()
#end
#implementation ViewController
-(void)viewDidLoad
{
// Allocates memory for the array
BalloonArray = [[NSMutableArray alloc] init];
// Allocates memory and inputs the names of the images
BalloonNames = [NSMutableArray arrayWithObjects:[UIImage imageNamed:#"pink.png"],[UIImage imageNamed:#"blue.png"],[UIImage imageNamed:#"green.png"], nil];
[super viewDidLoad];
}
-(void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
}
-(void)AddBalloon:(id)sender
{
int x; // x position of the balloon image created
int y; // y position of the balloon image created
int i; // Random index value to pull a random balloon image out
// Random number generator for the x and y position
x = arc4random_uniform(230) + 30;
y = arc4random_uniform(400) + 150;
// Random index value from 0 to 2
// Random based on how many images there are to chose from
i = arc4random_uniform(3);
// Uses the image from the index value previously randomnized
UIImage *Balloon = [BalloonNames objectAtIndex:i];
// Places the UIImage in a UIImageView
UIImageView *BalloonView = [[UIImageView alloc] initWithImage:Balloon];
// Sizes the image to the correct size
BalloonView.frame = CGRectMake(0, 0, 50, 100);
// Centers the image using the x and y coordinates
BalloonView.center = CGPointMake(x,y);
// Adds the image view to the view
[self.view addSubview:BalloonView];
// Adds the image view to the array
[BalloonArray addObject:BalloonView];
}
-(void)PopBalloons:(id)sender
{
// Removes each image in the array out of the main view
for(UIImageView *Test in BalloonArray)
{
[Test removeFromSuperview];
}
// Removes all object from the array
[BalloonArray removeAllObjects];
}
#end

Answer 1

Make the method -(void)AddBalloon:(id)sender to run on a Separate Thread. Perhaps you can use [NSThread detachNewThreadSelector:#selector(myThreadMainMethod:) toTarget:self withObject:nil];. Have a look at Apple Documentation