Question $3[6\%]$

Consider the methods used by processors P$1$ and P$2$ for accessing their critical sections when

required, as given in the table. The initial values of shared Boolean variables S$1$ and S$2$ are

randomly assigned. Which one of the following statements describes the properties achieved

and why?

a$)$ Mutual exclusion only

b$)$ Progress only

c$)$ Neither

d$)$ Both