A time-out based resilient token transfer algorithm for mutual exclusion in computer networks

Two algorithms, control token transfer algorithm (CTTA) and regenerate, are proposed to realize mutual exclusion in a computer network environment using a resilient circulating token. The algorithm CTTA uses a message called token to transfer the privilege of entering a critical region among the participating sites. The algorithm regenerate checks whether the token is lost during system failures, and regenerates it if necessary. Failures in a computer network are classified into three types. The execution of these two algorithms is described for each type of system failure. To detect system failures, a time-out mechanism based on message delay is used