Operating System Practice Test 2

Question 1 of 20

1. What is the main disadvantage of spinlocks?

they are unreliable sometimes

they are too complex for programmers

they require busy waiting

they are not sufficient for many process

Question 1 of 20

Question 2 of 20

2. Under multiprogramming, turnaround time for short jobs is usually ________ and that for long jobs is slightly ___________

Shortened; Lengthened

Shortened; Shortened

Lengthened; Shortened

Shortened; Unchanged

Question 2 of 20

Question 3 of 20

3. A binary semaphore is a semaphore with integer values ____________

0.5

0.8

-1

Question 3 of 20

Question 4 of 20

4. Mutual exclusion implies that ____________

none of the mentioned

if a process is executing in its critical section, then no other process must be executing in their critical sections

if a process is executing in its critical section, then all the resources of the system must be blocked until it finishes execution

if a process is executing in its critical section, then other processes must be executing in their critical sections

Question 4 of 20

Question 5 of 20

5. Which one of the following is the deadlock avoidance algorithm?

karn's algorithm

elevator algorithm

round-robin algorithm

banker's algorithm

Question 5 of 20

Question 6 of 20

6. Bounded waiting implies that there exists a bound on the number of times a process is allowed to enter its critical section ____________

before a process has made a request to enter its critical section

none of the mentioned

after a process has made a request to enter its critical section and before the request is granted

when another process is in its critical section

Question 6 of 20

Question 7 of 20

7. For non sharable resources like a printer, mutual exclusion ____________

must exist

may exist

must not exist

none of the mentioned

Question 7 of 20

Question 8 of 20

8. A minimum of _____ variable(s) is/are required to be shared between processes to solve the critical section problem.

one

four

three

two

Question 8 of 20

Question 9 of 20

9. For sharable resources, mutual exclusion ____________

is required

may be or may not be required

is not required

none of the mentioned

Question 9 of 20

Question 10 of 20

10. At a particular time of computation the value of a counting semaphore is 7.Then 20 P operations and 15 V operations were completed on this semaphore. The resulting value of the semaphore is? (GATE 1987)

Question 10 of 20

Question 11 of 20

11. Which is the most optimal scheduling algorithm?

RR - Round Robin

SJF - Shortest Job First

None of the mentioned

FCFS - First come First served

Question 11 of 20

Question 12 of 20

12. The circular wait condition can be prevented by ____________

defining a linear ordering of resource types

all of the mentioned

using pipes

using thread

Question 12 of 20

Question 13 of 20

13. What are the operations that can be invoked on a condition variable?

continue & signal

signal & hold

wait & signal

hold & wait

Question 13 of 20

Question 14 of 20

14. Which of the following concurrency control protocols ensure both conflict serializability and freedom from deadlock?
I) 2-phase locking
II) Timestamp ordering

I only

II only

Both I and II

Neither I nor II

Question 14 of 20

Question 15 of 20

15. To avoid deadlock ____________

inversion technique can be used

there must be a fixed number of resources to allocate

resource allocation must be done only once

all deadlocked processes must be aborted

Question 15 of 20

Question 16 of 20

16. A procedure defined within a ________ can access only those variables declared locally within the _______ and its formal parameters.

monitor, monitor

process, semaphore

semaphore, semaphore

process, monitor

Question 16 of 20

Question 17 of 20

17. What is Response time?

none of the mentioned

the total time taken from the submission time till the first response is produced

the total time taken from the submission time till the completion time

the total time taken from submission time till the response is output

Question 17 of 20

Question 18 of 20

18. Scheduling is done so as to ____________

keep the waiting time the same

decrease the waiting time

increase the waiting time

none of the mentioned

Question 18 of 20

Question 19 of 20

19. The system periodically performs checkpoints that consists of the following operation(s) ____________

all of the mentioned

putting all modified data residing in main memory onto stable storage

Putting all the log records currently in main memory onto stable storage

putting a log record onto stable storage

Question 19 of 20

Question 20 of 20

20. What are Spinlocks?

CPU cycles wasting locks over critical sections of programs

Locks that work better on multiprocessor systems

All of the mentioned

Locks that avoid time wastage in context switches

Question 20 of 20

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