Q60,paper3,J13 Suppose S and Q are two semaphores initialized to 1. P1 and P2 are two processes which are sharing resources.

P1 has statements

P2 has statements

wait(S) ;                                                 wait(Q) ;

wait(Q) ;                                                 wait(S) ;

critical- section 1;                                   critical- section 2;

signal(S) ;                                               signal(Q) ;

signal(Q) ;                                               signal(S) ;

Their execution may sometimes lead

to an undesirable situation called

(A) Starvation

(B) Race condition

(C) Multithreading

(D) Deadlock

Answer D.

Explanation.

Suppose s is critical section of P1 and

Q is in the critical section of p2.

Process p1 wants resources Q held by P2.

Process p2 wants resources S held by p1.

P1 and p2 both needs resources and are not relinquishing the resources.