Process Synchronization Questions

MCQ bookmark_border

21.

What are the two atomic operations permissible on semaphores?

A

wait

B

stop

C

hold

D

none of the mentioned

Correct Answer: A

None.

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

22.

What are Spinlocks?

A

CPU cycles wasting locks over critical sections of programs

B

Locks that avoid time wastage in context switches

C

Locks that work better on multiprocessor systems

D

All of the mentioned

Correct Answer: D

None.

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

23.

What is the main disadvantage of spinlocks?

A

they are not sufficient for many process

B

they require busy waiting

C

they are unreliable sometimes

D

they are too complex for programmers

Correct Answer: B

None.

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

24.

The wait operation of the semaphore basically works on the basic _______ system call.

A

stop()

B

block()

C

hold()

D

wait()

Correct Answer: B

None.

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

25.

The signal operation of the semaphore basically works on the basic _______ system call.

A

continue()

B

wakeup()

C

getup()

D

start()

Correct Answer: B

None.

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

26.

If the semaphore value is negative ____________

A

its magnitude is the number of processes waiting on that semaphore

B

it is invalid

C

no operation can be further performed on it until the signal operation is performed on it

D

none of the mentioned

Correct Answer: A

None.

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

27.

The code that changes the value of the semaphore is ____________

A

remainder section code

B

non-critical section code

C

critical section code

D

none of the mentioned

Correct Answer: C

None.

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

28.

Two processes, P1 and P2, need to access a critical section of code. Consider the following synchronization construct used by the processes.

Process P1 :
while(true)
{
w1 = true;
while(w2 == true);
Critical section
w1 = false;
}
Remainder Section
 
Process P2 :
while(true)
{
w2 = true;
while(w1 == true);
Critical section
w2 = false;
}
Remainder Section

Here, w1 and w2 have shared variables, which are initialized to false. Which one of the following statements is TRUE about the above construct?

A

It does not ensure mutual exclusion

B

It does not ensure bounded waiting

C

It requires that processes enter the critical section in strict alternation

D

It does not prevent deadlocks but ensures mutual exclusion

Correct Answer: D

None.

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

29.

What will happen if a non-recursive mutex is locked more than once?

A

Starvation

B

Deadlock

C

Aging

D

Signaling

Correct Answer: B

If a thread which had already locked a mutex, tries to lock the mutex again, it will enter into the waiting list of that mutex, which results in a deadlock. It is because no other thread can unlock the mutex.

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

30.

What is a semaphore?

A

is a binary mutex

B

must be accessed from only one process

C

can be accessed from multiple processes

D

none of the mentioned

Correct Answer: C

None.

Check Answer report_problem Report forum Discussion