Efficient Non-blocking Radix Trees

Radix trees belong to the class of trie data structures, used for storing both sets and dictionaries in a way optimized for space and lookup. In this work, we present an efficient non-blocking implementation of radix tree data structure that can be configured for arbitrary alphabet sizes. Our algorithm implements a linearizable set with contains, insert and remove operations and uses single word compare-and-swap (CAS) instruction for synchronization. We extend the idea of marking the child edges instead of nodes to improve the parallel performance of the data structure. Experimental evaluation indicates that our implementation out-performs other known lock-free implementations of trie and binary search tree data structures using CAS by more than 100% under heavy contention.