A protocol for wait-free, atomic, multi-reader shared variables

Abstract

A wait-free solution to the atomic (r, 1)-CRWW problem is presented. It uses (r+2)(8r+2+b)-1 safe, multi-reader bits to implement a 6-bit variable shared among r readers and 1 writer, solving an open question of Lamport [Lamport '85]. Thus, it closes a gap in the simulation of systems of shared variables for single writers. It differs from other approaches to this problem in that mutual exclusion is maintained between the writer and other processes on the copies of the shared variable used in the implementation.