Consider an arbiter that uses the priority scheme described in Problem 7.13. What happens if one device requests service repeatedly. Compare the behavior of this arbiter to one that uses a fixed-priority scheme.

Problem 7.13

[E] An arbiter controls access to a common resource. It uses a rotating-priority scheme in responding to requests on lines R1 through R4. Initially, R1 has the highest priority and R4 the lowest priority. After a request on one of the lines receives service, that line drops to the lowest priority, and the next line in sequence becomes the highest-priority line. For example, after R2 has been serviced, the priority order, starting with the highest, becomes R3, R4, R1, R2. What will be the sequence of grants for the following sequence of requests: R3, R1, R4, R2? Assume that the last three requests arrive while the first one is being serviced.