Concurrent Collections

java.util.concurrent ships a set of collections built for code where more than one thread reads and writes the same data structure at the same time. They're designed to give you correct behavior under concurrent use without forcing you to wrap every operation in a synchronized block or pay the price of a single global lock like Hashtable did. This lesson walks through the four families you'll use most often: ConcurrentHashMap, the copy-on-write list and set, the non-blocking lock-free queues, and the blocking queues used for producer-consumer flows.