This project shows how to create a bounded and unbounded queue in iOS. They simplify
prpducer/consumer pattern. I have checked in a fully working app. But, you will be most
ineteresed in these files:

- UnboundedBlockingQueue.m
- BoundedBlockingQueue.m


These classes closely mimic Java's  LinkedBlockingQueue and ArrayBlockingQueue classes. This
should help you port any Android app to iOS.