A Simple Way to Verify Linearizability of Concurrent Stacks

Abstract: Linearizability is a commonly accepted correctness criterion for concurrent data structures. However, verifying linearizability of highly concurrent data structures is still a challenging task. In this paper, we present a simple and complete proof technique for verifying linearizability of concurrent stacks. Our proof technique reduces linearizability of concurrent stacks to establishing a set of conditions. These conditions are based on the happened-before order of operations, intuitively express the LIFO semantics and can be proved by simple arguments. Designers of concurrent data structures can easily and quickly learn to use the proof technique. We have successfully applied the method to several challenging concurrent stacks: the TS stack, the HSY stack, and the FA stack, etc.