A Highly Safe Self-Stabilizing Mutual Exclusion Algorithm

Conventional self-stabilizing algorithms cannot be used for safety-critical systems due to the period of vulnerability that exists after a transient failure occurs till the system stabilizes. In this paper, we consider a highly safe self-stabilizing system where the vulnerability problem is tackled. The design principles we use to achieve this goal include sobriety test and processor specialization. Sobriety test is used to prevent the system from performing incorrect actions when the system state may be faulty. Specialization disables individual processors from making faulty moves. We have developed a self-stabilizing mutual exclusion algorithm that guarantees mutual exclusion with a very high probability even in the presence of failures.