A template trait for mutable maps that allow concurrent access.

This is a base trait for all Scala concurrent map implementations. It provides all of the methods a Map does, with the difference that all the changes are atomic. It also describes methods specific to concurrent maps.

Note: The concurrent maps do not accept null for keys or values.

A concurrent hash-trie or TrieMap is a concurrent thread-safe lock-free implementation of a hash array mapped trie. It is used to implement the concurrent map abstraction. It has particularly scalable concurrent insert and remove operations and is memory-efficient. It supports O(1), atomic, lock-free snapshots which are used to implement linearizable lock-free size, iterator and clear operations. The cost of evaluating the (lazy) snapshot is distributed across subsequent updates, thus making snapshot evaluation horizontally scalable.

For details, see: http://lampwww.epfl.ch/~prokopec/ctries-snapshot.pdf