[time0ut]

Interesting. A lot of care went into this. Thank you for sharing.

Is there a reason you chose not implement java.util.Queue?

[vitpro2213]

Implementing Queue would mean also implementing Collection and Iterable, and this would bring pains and ugliness, especially with the concurrent code.

Look e.g. at the disclaimers at the size method of java.util.concurrent.ConcurrentLinkedQueue.