A Message-Passing and Adaptive Implementation of the Randomized Test-and-Set Object

This paper presents a solution to the well-known Test-and-Set operation in asynchronous systems prone to process crashes. Test-and-Set is a synchronization operation that, when invoked by a set of processes, returns "yes" to a unique process and returns "no" to all the others. Recently many advances in implementing Test and Set objects have been achieved, however all of them uniquely target the shared memory model. In this paper we propose an implementation of a Test-and-Set object for message passing distributed systems. This implementation can be invoked by any number p of processes. It has an expected step complexity in O(p) and an expected message complexity in O(np), where n is the total number of processes in the system. The proposed Test and Set object is built atop a new basic building block that allows to select a winning group among two groups of processes.