A Concurrent Red Black Tree

Abstract

With the proliferation of multiprocessor computers, data structures capable of supporting several processes are a growing need. Concurrent data structures seek to provide similar performance to sequential data structures while being accessible concurrently by several processes and providing synchronization mechanisms transparently to those processes. Red-black trees are an important data structure used in many systems. Unfortunately, it is difficult to implement an efficient concurrent red-black tree for shared memory processes; so most research efforts have been directed towards other dictionary data structures, mainly skip-lists and AVL trees. In this paper we present a new type of concurrent red-black tree that uses optimistic concurrency techniques and new balancing operations to scale well and support contention. Our tree performs favorably compared to other similar dictionaries; in particular, in high contention scenarios it performs up to 14% better than the best-known concurrent dictionary solutions.