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2 C 60093
Part C

Answer any five questions.
Each question carries 4 marks.

Write short notes on time sharing operating systems.

Explain about the fundamental state transitions for a process with a neat diagram.
How we can prevent the occurrence of a deadlock ?

Explain how semaphores can be used to solve the critical section problem.

Explain readers-writers problem. How will you solve this problem by introducing the concept of
semaphore variables ?

Write various steps to handle a page fault by considering a page replacement policy.

Explain about various file allocation methods.

Explain about various mechanisms available for implementing security in an operating system.
(5 x 4 = 20 marks)

Part D
Answer any five questions.
Each question carries 8 marks.
Explain a deadlock avoidance algorithm.
Consider the following set of processes, with the length of the CPU burst time given in milliseconds

Process Burst time Priority
1 हर 10 3
P2 - 1 1
P3 ‏چس‎ 2 3
P4 ஸ்‌ 1 4
6 es 5 2

The processes are assumed to have arrived in the order P1, P2, P3, P4 and P6 all at time 0:
(a) Draw Gantt charts illustrating the execution of these process using FCFS, SJF, a non-
pre-emptive priority (a smaller priority number implies a higher priority) and RR
(quantum = 1) scheduling.
(b) What is the turnaround time of each process for each of the scheduling algorithms
specified in a.