Mutual inclusion in asynchronous message-passing distributed systems

Abstract

In the mutual inclusion problem, at least one process is in the critical section. However, only a solution for two processes with semaphores has been reported previously. In this study, a generalized problem setting is formalized and two distributed solutions are proposed based on an asynchronous message-passing model. In the local problem setting (the local mutual inclusion problem), for each process P, at least one of P and its neighbors must be in the critical section. For the local problem setting, a solution is proposed with O(Δ) message complexity, where Δ is the maximum degree (number of neighboring processes) of a network. In a global setting (the global mutual inclusion problem), at least one of the processes must be in the critical section. For the global problem setting, a solution is proposed with O(|Q|) message complexity, where |Q| is the maximum size for the quorum of a coterie used by the algorithm, which is typically |Q|=n, where n is the number of processes in a network.