Q 65,paper 3,j 12.critical sections. The initial values of shared Boolean variables S1 and S2 are randomly assigned,

P1                                                          P2

while (S1 = = S2);                  while (S1 = = S2);

critical section                       critical section

S1 = S2;                                  S1 = S2;

Which one of the following statements describes the properties achieved ?

options

(A) Mutual exclusion but not progress

(B) Progress but not mutual exclusion

(C) Neither mutual exclusion nor progress

(D) Both mutual exclusion and progress,
Answer(A) 
Explanation.
let s1=1 and s2=2 .
p1 checks  and enters in critical section. and makes s1=s2.
and afters wards none of the process enters in critical section and  further no progress is achieved.