Reading material
 
pages 51-66
Assignments

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).