Question

I have a leak in the following code which uses GCD. Note: I am not using ARC. The leak is exactly at

__block NSMutableArray *newImages = [NSMutableArray new];

dispatch_async(serialQueue, ^{

    for (NSDictionary *imageData in results) {

        NSURL *url = [NSURL URLWithString:[imageData objectForKey:@"url"]];
        NSURLRequest *request = [NSURLRequest requestWithURL:url];

        NSError *error = nil;
        NSHTTPURLResponse *response = nil;
        NSData *imageData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

        if (error == nil && imageData != nil && response.statusCode == 200) {
            UIImage *image = [UIImage imageWithData:imageData];
            [newImages addObject:image];
        }

        else {
            self.errorLabel.text = @"An error has occured downloading some images.";
            [self.spinner stopAnimating];
        }
    }
});

According to instruments, I am leaking at: [newImages addObject:image];. Why is this leaking? newImages is an autoreleased object as shown above.

Answer 1

newImages is not autoreleased. new returns an owning reference — it’s equivalent to [[SomeClass alloc] init].