UNIVERSITY EXAMINATIONS: 2019/2020
EXAMINATION FOR THE DEGREE OF BACHELOR OF SCIENCE IN
INFORMATION TECHNOLOGY
BIT 1106A: OPERATING SYSTEMS
DISTANCE LEARNING
DATE: AUGUST, 2019 TIME: 2 HOURS
INSTRUCTIONS: Answer Question One & ANY OTHER TWO questions.
QUESTIONS ONE(COMPLUSORY)
a) What are the four conditions required for deadlock to occur? (8 Marks)
b) List and describe the three memory allocation algorithms? (6 Marks)
c) What are the advantages of multi-programming? (2 Marks)
d) What is a semaphore? Explain the two types (4 Marks)
e) Explain demand paging (2 Marks)
f) i) What are CPU schedulers? (2 Marks)
ii) Describe various types of schedulers. (6 Marks)
QUESTION TWO
a) Describe the three state process model, describe what transitions are valid between the
three states, and describe an event that might cause such a transition. (6 Marks)
b) i) What is a process? (2 Marks)
ii) What are attributes of a process? (4 Marks)
c) What is the function of the ready queue? (3 Marks)
d) What is a race condition? Give an example? (3 Marks)
e) What are monitors and condition variables? (2 Marks)
QUESTION THREE
a) Describe the following scheduling algorithms
FCFS
Round Robin
Shortest Job First (6 Marks)
b) Given the following processes and burst times
PROCESS Burst time
Calculate the average wait time when each of the above scheduling algorithms is used?
Assume that a quantum of 8 is being used. (9 Marks)
c) Which scheduling algorithm, as an operating systems designer, would you implement?
(5 Marks)
QUESTION FOUR
a) Describe the Producer/Consumer problem. (3 Marks)
b) Describe the problems associated with producing a software solution to the producer/
consumer problem. (5 Marks)
c) Show a possible solution to the above problem, stating any assumptions that you make.
(8 Marks)
d) Describe the benefits of a mono-programming operating system. (4 Marks)
QUESTION FIVE
a) Describe the four generations of computing and how operating systems developed as a result.
(8 Marks)
b) Describe the two general roles of an operating system, and elaborate why these roles are
important. (4 Marks)
c) There is some debate as to what will constitute a fifth generation computer. Assume such a
computer is available. What do you think will differentiate it from the computers of today?
(8 Marks)
