Question

I am having a memory leak, and can’t figure it out. Basically, what I am doing here is pulling in images to a Mutable Dictionary and returning the dictionary.

- (NSMutableDictionary *)loadImageDataGroup:(NSUInteger)index {

int lim = 5;
int sta = 0;
if (index > lim) {
    sta = index-lim;
}
int fin = (((lim*2)+1)+sta);
if (fin > [self imageCount]) {
    sta = ([self imageCount]-((lim*2)-1));
    fin = [self imageCount];
}

BOOL firstTime = NO;
if ([imagesLoaded count] == 0) {
    firstTime = YES;
}

NSMutableDictionary *tempDict = [[[NSMutableDictionary alloc] init] autorelease];

for (int i = sta; i < fin; i++) {

    NSString *imageName = [self imageNameAtIndex:i];

    if ([imagesLoaded valueForKey:imageName] == nil) {

        // This is the Memory Leak...at least that is where Leaks is pointing me.
        NSData *imageData = [NSData dataWithContentsOfURL:[NSURL URLWithString:imageName]];
        [tempDict setObject:imageData forKey:imageName];

    } else {
        [tempDict setObject:[imagesLoaded valueForKey:imageName] forKey:imageName];
    }

}

return tempDict;

}

The leak is in the NSData = *imageData spot, and when I pull it up in leaks, it points to NSConcreteData.

Answer 1

Looking at your code, I’m not seeing anything obviously wrong. Be aware that Instruments can produce false positives.

See the following:

Instruments showing false leak?