1. (a) Write a regular grammar for the following :

(i) Set of strings of a’ s, b’ s and c’ s
For example (aaa, aab,……… ccc)

(ii) Looping statements of Pascal.

(b) Explain which of the following are reasonable long term scheduling algorithms and which are reasonable short term scheduling algorithms.

· First Come-First Served.
· Round Robin
· Shortest Job First
· Highest Priority First
· Longest Process First

(c) Write an algorithm/program recursively to find out whether a word/sentence is palindrome or not?

(d) Write UNIX commands for the following :

(i) To find out how many super users there are in installation.

(ii) Find out all lines in a file with words longer than 8 letters, assuming that words are separated by spaces except at the beginning or and of line.

2. (a) What are conditions that characterize deadlock? Explain the occurrence and avoidance of deadlock graphically among 3 processes and 3 resources.

(b) List four strategies the operating system designers can adopt vis-à-vis the problem of deadlock.

3. (a) What is meant by pre-emptive scheduling? How does it affect system performance in comparison to non-pre-emptive scheduling?

(b) Discuss various scheduling objectives and their meanings. Show how different objectives can at times be contradictory.

4. (a) Discuss H/W support (including associative memory) for address translation, sharing and protection in a paging system.

(b) Why is the page size normally some power of two?

5 Explain the important features of the following:

· 4 GLs
· Object oriented programming
· RDBMS
· CASE tools

6. (a) Discuss H/W support for mutual exclusion.

(b) Discuss mechanisms for structured form of inter-process communication and synchronization.