An Improved Algorithm for Distributed Mutual Exclusion by Restricted Message Exchange in Voting Districts

Abstract

This paper presents an improvement to the Maekawa¿s distributed mutual exclusion algorithm. The number of messages required by the improvised algorithm is in the range 3 M to 5 M per critical section invocation where M is the number of Intersection nodes in the system. This improvement does not introduce any additional overheads over the existing Maekawa¿s algorithm which requires 3 K to 5 K number of messages per critical section invocation, where K is the number of nodes in the voting district (M ¿ K). This reduction in number of messages is achieved by restricting the communication of any node which wants to execute critical section with the Intersection nodes of the voting district, without causing any modification of the basic structure of the algorithm. This improvisation preserves all the advantages of the original Maekawa¿s algorithm.