MCA (III Yr)
Term-End Examination
June, 1999
CS13 : Operating Systems
Time: 3 hours
Maximum Marks: 75
Note : Question No. 1 is compulsory. Answer any three questions from the rest.
1 (a). Explain First come, First served (FCFS) and Round Robin scheduling algorithms.
(b). Consider the following set of processes, with the length of the CPU burst time given in milliseconds:
Process Burst Time
P1 10
P2 29
P3 3
P4 7
P5 12
All five processes arrive at time 0, in the order given. Draw Gantt charts illustrating the execution of the processes using FCFS, SJF and RR (quantum=1) scheduling. What is the turnaround time of each process for each of the scheduling algorithms? Also find the average waiting time for each algorithm.
(c). Write about the performance evaluation of FCFS, SJF and Round Robin scheduling algorithms.
2 (a). What is a scheduler? Explain the primary objective of scheduling. How many types of schedulers coexist in a complex operation system? Explain.
(b). Explain common performance measures and optimization criteria that schedulers may use in attempting to maximize system performance.
3. Describe the necessary conditions for a deadlock occurrence. Discuss deadlock avoidance using Banker’s Algorithm. And also discuss data structures for implementing this algorithm.
4 (a). Explain the important features of a monitor that are lacking in semaphore.
(b). Show how a monitor can be implemented with semaphore.
5 (a). Mention the advantages of multiprocessors and explain the different classifications of parallel computer architectures.
(b). Outline the basic architectures of cross bar connected Compare their features with respect to scalability.
6 (a). discuss the common failures in distributed system.
(b). Describe an algorithm for election of a successor and evaluate its performance.
