Copy-on-write collections in Java (CopyOnWriteArrayList etc)

Java copy-on-write collections Along with ConcurrentHashMap, Java 5 introduces a copy-on-write implementation of a list: CopyOnWriteArrayList. It also introduces CopyOnWriteArraySet, essentially a convenience wrapper around the list. An instance of CopyOnWriteArrayList behaves as a List implementation that allows multiple concurrent reads, and for reads to occur concurrently with a write. The way