initWithContentsOfURL leaks memory within NSOperation subclass. Anyone else seeing this?

Question

I have been living on Instruments for last few hours staring at a puzzling memory leak. I have isolated it to this single line of code in an NSOperation subclass I wrote:

NSData *myData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:myURLString]];

Periodically this will leak 3500 bytes. Is anyone else seeing this? If so, is there a work around?

Thanks in advance.

UPDATE:

Here is the relevant section of code within the main() body of my NSOperation subclass:

- (void)main {

// ...

NSData *sequenceData = 
[[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:concatenatedURLString]];

NSString *sequenceString = 
[[NSString alloc] initWithBytes:[sequenceData bytes] length:[sequenceData length] encoding:NSUTF8StringEncoding];

NSDictionary *result = [NSDictionary dictionaryWithObjectsAndKeys:
self.chromosome, @"chromosome",
[NSNumber numberWithInt:self.basepairStart], @"basepairStart", 
[NSNumber numberWithInt:self.basepairEnd], @"basepairEnd", 
sequenceData, @"sequenceData", 
sequenceString,  @"sequenceString", 
nil];

[sequenceData   release];
[sequenceString release];

[self.target performSelectorOnMainThread:self.action withObject:result waitUntilDone:NO];


}

As you can see sequenceData and sequenceString are properly released. Also, I have confirmed that all ivars of this subclass (chromosome. etc.) are properly memory managed.

-Doug

Answer 1

You have to release or autorelease myData, otherwise it will leak according to the Cocoa Memory Management Rules