Reading material

pages 51-66


Assume that the set of processes is partitioned in such a way that no pair of subsets is disjoint. Give a mutual exclusion algorithm which sends request messages to only those processes which are in the same partition as the requesting process (for example, process 1 sends only request messages to processes 2, 4 and 5). Show that the algorithm achieves mutual exclusion. Discuss its performance (number of messages needed to acquire the resource; time between releasing the resource by one process and acquiring the resource by the next process).