Question

I have a table view with 10 cells displaying an image. Everytime I scroll, the app allocates more memory (but doesn’t show this in leaks) but in allocations, I can see that memory increases by like 2 megabytes with each scroll.

This is the code which leaks, specifically the line where i set the imageview’s image (if I comment it out, it doesn’t leak):

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (!cell) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    }
    cell.imageView.image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"background_stripes" ofType:@"png"]];
    return cell;
}

UPDATE: I created a simple new project with 1 view controller:

- (void)viewDidLoad {
    [super viewDidLoad];
    self.tableView.rowHeight = 130.f;

}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return 16;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (!cell) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    }

    cell.imageView.image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"background_stripes" ofType:@"png"]];


    return cell;
}

Very simple…I don’t see any problem here…but leaks when I scroll, the memory consumption grows over time…

Answer 1

The problem is that there is no leaks =). The top graph illustrates the allocations and not leaks. Leaks are in the bottom graphics and their graph is red, so there is NO memory leaks. You’d probably thought that “Overall Bytes” stands for memory leaks but it’s not, it’s just the number of bytes that program allocated during runtime.