Constant RMR System-wide Failure Resilient Durable Locks with Dynamic Joining

Prasad Jayanti, Siddhartha Jayanti, Anup Joshi

Abstract: We design two Recoverable Mutual Exclusion (RME) locks (a.k.a. durable locks) for the system-wide crash model. Our first algorithm requires only O(1) space per process, and achieves O(1) worst-case Remote Memory Reference (RMR) complexity in the Cache-Coherent (CC) model. Our second algorithm enhances the first algorithm to achieve (the same) O(1) space per process and O(1) worst-case RMR complexity in both the CC and Distributed Shared Memory (DSM) models. Furthermore, both algorithms allow dynamically created threads of arbitrary names to join the protocol and access the locks. To our knowledge, these are the only RME locks to achieve worst-case O(1) RMR complexity assuming nothing more than standard hardware support. In light of Chan and Woelfel's Ω(log n / log log n) worst-case RMR lower bound for RME in the individual crash model, our results show a separation between the system-wide crash and individual crash models in worst-case RMR complexity in both the CC and DSM models.