COP 5611, Operating Systems, Spring, 2003
Department of Computer Science, Florida State University
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Points: 100
Due: Thursday, March
6, 2003
Problem 1 (5 points) Problem 6.1 in the textbook (p. 148).
Problem 2 (10 points) Problem 6.2 in the textbook (p. 148).
Problem 3 (15 points) Problem 6.4 in the textbook (p. 149).
Problem 4 (15 points) Problem 6.7 in the textbook (p. 149).
Problem 5 (15 points) Compare the number of messages per critical section and synchronization delay of the centralized mutual exclusion algorithm, Lamport’s algorithm, Ricart-Agrawala’s algorithm, and Suzuki-Kasami’s algorithm for distributed mutual exclusion. For each algorithm, give the best and worst case performance and the scenario where the best/worst performance is achieved.
Problem 6 (20 points) In a distributed system consisting of three sites, which uses Lamport’s algorithm for distributed mutual exclusion, design a scenario where the following case occurs: A site enters its critical section without receiving all the REPLY messages from other sites. You need to show all the messages and queues at different stages.
Problem 7 (20 points) In a distributed system consisting of three sites, which uses Suzuki-Kasami’s algorithm for distributed mutual exclusion, design a scenario where the following case occurs: A REQUEST message is outdated in that the message is not used in scheduling the token. You need to show all the messages and sequence number at each site and the queue and the sequence number at the token at different stages.