Memory Management Issue

I have a pretty big method here that I think has a leak somewhere.

Running the allocation instrument shows that every time a new "category" is passed to this method, the amount of memory being taken up increases. This shouldn't happen, as concurrently with a "category" being opened, another one is getting closed, and thus the amount of memory being taken up should remain fairly steady.

Something interesting about it is that the memory being taken up only increases if the category has not yet been opened before. Does anyone have any suggestions as to why this would be?

Header with my IVars.

Code:

@interface Keyboard : UIScrollView
{
    NSArray         *characters;
    NSMutableArray  *favorites;
    NSTimer         *holdTimer;
    BOOL            justFavored;
    BOOL            timerToStop;
    BOOL            viewingFavorites;
    UIButton        *spaceKey;
    UIButton        *deleteKey;
}

The method:

Code:

- (void)openCategory:(NSString*)category
{
    [self.subviews enumerateObjectsUsingBlock:^(id obj, NSUInteger index, BOOL *stop)
     {
         if ([obj isKindOfClass:[UIButton class]])
         {
             [obj removeFromSuperview];
         }
     }];
    
    if ([category isEqualToString:@"Favorites"])
    {
        characters = favorites;
        self.backgroundColor = [UIColor colorWithRed:0.72 green:0.53 blue:0.15 alpha:1.0];
        viewingFavorites = YES;
    }
    
    else
    {
        NSString *path = [[NSBundle mainBundle] pathForResource:category ofType:@"txt"];
        NSString *string = [NSString stringWithContentsOfFile:path encoding:NSUTF16BigEndianStringEncoding error:NULL];
        characters = [string componentsSeparatedByString:@"\n"];
        self.backgroundColor = [UIColor colorWithRed:0.22 green:0.33 blue:0.83 alpha:1.0];
        viewingFavorites = NO;
    }
    
    [characters enumerateObjectsUsingBlock:^(id obj, NSUInteger index, BOOL *stop)
     {
         UIButton *key = [UIButton buttonWithType:UIButtonTypeRoundedRect];
         key.frame = CGRectMake((index%6)*(self.frame.size.width/6.0),
                                (floor(index/6.0))*(self.frame.size.width/6.0),
                                self.frame.size.width/6.0,
                                self.frame.size.width/6.0);
         [key setTitle:obj forState:UIControlStateNormal];
         [key setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
         if ([favorites containsObject:obj])
         {
             [key setBackgroundImage:[UIImage imageNamed:@"favorNormal"] forState:UIControlStateNormal];
             [key setBackgroundImage:[UIImage imageNamed:@"favorPress"] forState:UIControlStateHighlighted];
         }
         else
         {
             [key setBackgroundImage:[UIImage imageNamed:@"keyNormal"] forState:UIControlStateNormal];
             [key setBackgroundImage:[UIImage imageNamed:@"keyPress"] forState:UIControlStateHighlighted];
         }
         [key addTarget:self action:@selector(startTimer:) forControlEvents:UIControlEventTouchDown];
         [key addTarget:self action:@selector(stopTimer) forControlEvents:UIControlEventTouchDragExit];
         [key addTarget:self action:@selector(keyPress:) forControlEvents:UIControlEventTouchUpInside];
         [self addSubview:key];
     }];
    
    spaceKey = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    spaceKey.frame = CGRectMake(self.frame.size.width/6.0,
                             (ceil([characters count]/6.0))*(self.frame.size.width/6.0),
                             self.frame.size.width*2.0/3.0,
                             self.frame.size.width/6.0);
    [spaceKey setTitle:@" " forState:UIControlStateNormal];
    [spaceKey addTarget:self action:@selector(keyPress:) forControlEvents:UIControlEventTouchUpInside];
    [self addSubview:spaceKey];
    
    deleteKey = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    deleteKey.frame = CGRectMake(self.frame.size.width*5.0/6.0,
                             (ceil([characters count]/6.0))*(self.frame.size.width/6.0),
                             self.frame.size.width/6.0,
                             self.frame.size.width/6.0);
    [deleteKey setTitle:@"⌫" forState:UIControlStateNormal];
    [deleteKey setTitleColor:[UIColor redColor] forState:UIControlStateNormal];
	[deleteKey setTitleColor:[UIColor redColor] forState:UIControlStateHighlighted];
	deleteKey.titleLabel.font = [UIFont fontWithName:@"Helvetica-Bold" size:17.0];
    [deleteKey addTarget:self action:@selector(deletePress) forControlEvents:UIControlEventTouchUpInside];
    [self addSubview:deleteKey];
	
	if (viewingFavorites == YES)
	{
		[spaceKey setBackgroundImage:[[UIImage imageNamed:@"favorNormal"] stretchableImageWithLeftCapWidth:25 topCapHeight:0] forState:UIControlStateNormal];
		[spaceKey setBackgroundImage:[[UIImage imageNamed:@"favorPress"] stretchableImageWithLeftCapWidth:25 topCapHeight:0] forState:UIControlStateHighlighted];
		[deleteKey setBackgroundImage:[UIImage imageNamed:@"favorNormal"] forState:UIControlStateNormal];
		[deleteKey setBackgroundImage:[UIImage imageNamed:@"favorPress"] forState:UIControlStateHighlighted];
	}
	else
	{
		[spaceKey setBackgroundImage:[[UIImage imageNamed:@"keyNormal"] stretchableImageWithLeftCapWidth:25 topCapHeight:0] forState:UIControlStateNormal];
		[spaceKey setBackgroundImage:[[UIImage imageNamed:@"keyPress"] stretchableImageWithLeftCapWidth:25 topCapHeight:0] forState:UIControlStateHighlighted];
		[deleteKey setBackgroundImage:[UIImage imageNamed:@"keyNormal"] forState:UIControlStateNormal];
		[deleteKey setBackgroundImage:[UIImage imageNamed:@"keyPress"] forState:UIControlStateHighlighted];
	}
    
    self.contentSize = CGSizeMake(self.frame.size.width, ((ceil([characters count]/6.0))+1)*(self.frame.size.width/6.0));
	[self flashScrollIndicators];
}

Any help would be much appreciated!

 

I thought that maybe the issue was with the buttons like you suggested, but releasing them in the enumeration block causes the app to crash, so I guess not.

I haven't tried it with the leaks tool, I suppose I'll do that now.

Edit: Okay, trying with the leaks tool reveals no leaks. So I guess my code is sound?

New question:

How do I find out if my code leaks when it's closing? IE, if I alloc/init stuff in the init method, but in the dealloc method don't dealloc the stuff I own, I've leaked, right? But if the app is terminating at that moment, there's no way for instruments to catch that, is there?

 

Hmmm... looking through my code, characters doesn't need to be an ivar, so I changed it to a local variable.

Those get used in other methods. While I'm sure I could come up with some work around for ivars (IE: assign tags to them,) I think ivars will work fine.

Yes. Instruments reports no leaks right now.

A question I have is, though, is whether or not Instruments will report leaks that occur while my program is closing? IE, if I alloc/init an array in my class init method, but then forget to include the release in the class dealloc method, would that cause a leak and would Instruments report it or not notice it?