Consider the following scenario where two processes are sharing a common variable. Global setup int turn = 1; Process 1 while(1) { while(turn == 2); // lock // critical section turn = 2; // unlock // remainder section } Process 2 while(1) { while(turn == 1); // lock // critical section turn = 1; // unlock // remainder section } Which of the following statements about the given processes is correct?

(A) Process 1 and Process 2 will enter their critical sections simultaneously, leading to race conditions.

(B) Process 1 will always enter its critical section before Process 2.

(C) Process 2 will always enter its critical section before Process 1.

(D) Deadlock can occur if both processes try to enter their critical sections simultaneously.

Figure from the original question paper

(A) Option figure from the original question paper

(B) Option figure from the original question paper

(C) Option figure from the original question paper

(D) Option figure from the original question paper

Operating Systems Quiz 2: 16 March 2025 (January 2025 term)

Question 1

+4 marksOne correct option

Consider the following scenario where two processes are sharing a common variable.

Global setup

1int turn = 1;

Process 1

1while(1) {
2    while(turn == 2); // lock
3    // critical section
4    turn = 2; // unlock
5    // remainder section
6}

Process 2

1while(1) {
2    while(turn == 1); // lock
3    // critical section
4    turn = 1; // unlock
5    // remainder section
6}

Which of the following statements about the given processes is correct?

A
Process 1 and Process 2 will enter their critical sections simultaneously, leading to race conditions.
B
Process 1 will always enter its critical section before Process 2.
C
Process 2 will always enter its critical section before Process 1.
D
Deadlock can occur if both processes try to enter their critical sections simultaneously.

Also asked in Quiz 2 4 Aug 2024, Quiz 2 23 Nov 2025

Question 2

+2 marksOne correct option

Assume that two processes P1 and P2 are using a shared resource. If P1 and P2 are both waiting indefinitely to enter their critical sections because each keeps waiting for the other to release the resource, then which of the following conditions is not satisfied?

A
Mutual exclusion
B
Progress
C
Bounded waiting
D
None of these

Question 3

+2 marksOne correct option

14 more questions in this paper

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More on the Operating Systems Quiz 2 16 Mar 2025 paper

The IIT Madras BS Operating Systems (Operating Systems) Quiz 2 paper sat on 16 Mar 2025, in the January 2025 term: 17 questions for 50 marks in 120 minutes. The first 3 questions are below. Sign in with Google — it is free — to see the whole paper with its answers and explanations, in learning mode or as a timed mock test.

Feature	Operating Systems Quiz 2 16 Mar 2025 at a glance
Term	January 2025 term
Subject	Operating Systems
Course code	BSCS4022
Questions	17
Marks	50
Duration	120 min
MCQ	11
MSQ	2
Numerical	4
Official paper	IIT M IMPROVEMENT AN EXAM QIM2 16 Mar 2025
Negative marking	No negative marking.
Updated	25 Sept 2026