Question

I am stuck on a EXC_BAD_ACCESS” crash within my dealloc of a table view controller. The crash occurs when releasing an NSMutableArray that was given a retain property. I have a second NSMutableArray that was also given a retain property, but it’s release does not cause a crash. Please take a look at the following code to see if I am overlooking something about memory management. Thanks.

In my header file, I have the following:

@interface selectSourcesTableViewController : UIViewController  <UITableViewDelegate, UITableViewDataSource> {
    NSMutableArray *selectedNames;
    NSMutableArray *selectedAvailability;
}

@property (retain, nonatomic)   NSMutableArray  *selectedNames;
@property (retain, nonatomic)   NSMutableArray  *selectedAvailability;

In my implementation, I have the following:

@implementation selectSourcesTableViewController
@synthesize selectedNames;
@synthesize selectedAvailability;

- (void)viewDidLoad {

    NSArray *names = [selectedSourceFileContent objectForKey:@"selectedNames"];
    selectedNames = [[NSMutableArray alloc] initWithObjects: nil];

    NSArray *availability = [selectedSourceFileContent objectForKey:@"selectedAvailability"];
    selectedAvailability = [[NSMutableArray alloc] initWithObjects: nil];

    for (int i=0; i < [names count]; i++) {
        NSString *aName = [names objectAtIndex:i];
        [selectedNames addObject: aName];
        NSString *anAvailability = [availability objectAtIndex:i];
        [selectedAvailability addObject: anAvailability];
    }
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier: kCellIdentifier];

...

    for (int i=0; i < [selectedNames count]; i++) {
        if ([contentForThisRow isEqualToString:[selectedNames objectAtIndex:i]]) {
            cell.accessoryType = UITableViewCellAccessoryCheckmark;
        }
    }
}

- (void)dealloc {
    [super dealloc];
    [selectedNames release];
    [selectedAvailability release];
}

The code shown above shows the only uses of these two arrays.

So, nothing bad happens when selectedNames is released, but I get a EXC_BAD_ACCESS crash when selectedAvailability is released.

One last observation. There is no crash the very first time I run this code after launching xcode. Thereafter, it crashes every time I rerun the app.

Any thoughts?

Answer 1

[super dealloc]

needs to be called last, not first, in your own dealloc method.