The Processor Identity Problem

Abstract This paper investigates the problem of assigning unique identifiers to processors that communicate through shared memory. Solutions to fundamental multiprocessor coordination problems such as the Mutual Exclusion Problem and the Choice Coordination Problem often rely on unique identifiers. We present a probabilistic protocol that solves this Processor Identiy Problem for asynchronous processors that communicate through a common shared memory. This protocol requires no central arbiter, and all processors start in exactly the same state. The use of our protocol simplifies shared memory processor design by eliminating the need to encode processor identifiers in system hardware or software structures.