DISTRIBUTED ALGORITHMS FOR MULTIPLE ENTRIES TO A CRITICAL SECTION WITH PRIORITY

The distributed Mutual Exclusion (M.E.) algorithms for multiple entrie s to a critical section (C.S.) proposed in previous publications adopt an FCFS discipline to serialize M.E. requests, i.e., the ordering of the M.E. requests is done at their virtual generation time or physical arrival time. The insertion of priority disciplines such as Short-Job -First, Head-Of-Line, Shortest-Remaining-Job-First, etc., could be use ful in many applications to optimize some performance indices. A drawb ack is that priority disciplines are prone to starvation. This paper s hows how to insert a priority-based serialization discipline in token- based M.E. algorithms for multiple entries to a C.S. avoiding starvati on. Moreover, we investigate its implementation overhead in the algori thm and the number of messages per C.S. entry.