Memory leak in removeItemAtPath:error:?

Question

I'm running an app on the iPhone that performs the following action:

+ (void)performWrite:(NSData *)data {
    [data retain];
    [data writeToFile:@"WriteTest.tst" atomically:YES];
    [[NSFileManager defaultManager] removeItemAtPath:@"WriteTest.tst" error:NULL];
    [data release];
}

When running in Instruments, however, I see a leak in every call to removeItemAtPath:error, with the following trace to the internal leak:

9 MyApplication +[StorageUtil performWrite:]
   8 Foundation -[NSFileManager removeItemAtPath:error:]
   7 Foundation +[NSFilesystemItemRemoveOperation filesystemItemRemoveOperationWithPath:]
   6 Foundation -[NSOperation init]
   5 CoreFoundation +[NSObject new]
   4 CoreFoundation +[NSObject alloc]

This stack trace is provided as the source of both a leak of an NSRecursiveLock, and of an _NSOperationData object. So what I'm wondering is whether or not I'm improperly using the removeItemAtPath:error: method, or whether there's truly a leak. I figured I'd check here before submitting it to Radar.

Note that the data argument is properly adhering to the retain/release cycle outside of this method call. I don't believe it is the source of the leak.

Answer 1

The function was being called in a separate thread (created using pthread_create()), and as such was not wrapped in an NSAutoreleasePool. Creating the pool before the method call and draining it afterwords took care of the leak.