So, I'm a java developer and love love love ConcurrentLinkedQueue. 
This class does about the same thing, using OSAtomic.h and Objective-C objects.
This is version 1 of the Michael & Scott paper; a non-blocking (wait-free) linked queue.
I didn't implement the size and iteration features you might
expect from a java collection, mostly because they don't run very safely in
multi-threaded environments anyway.

see also - http://www.cs.rochester.edu/u/michael/PODC96.html