Question

P1 executes the code:

while (1) {
c1=1
while (c2) //
CS
c1=0
...
}

p2 executes the code:
while (1) {
c2=1
while (c1) //
CS
c2 =0
..
}

Which requirement is violated in the above solution?
a) Mutual exclusion not guaranteed.
b) Lockout is possible.
c) Starvation is possible.
d) Deadlock is possible.

Answer 1

The requirement violated in the above code is deadlock, which occurs when both processes enter a waiting loop and neither proceeds, leading to a standstill.

Step-by-step explanation:

The code provided represents two processes (p1 and p2) attempting to enter critical sections (CS) simultaneously. The requirement violated in the above solution is d) Deadlock is possible.

This situation occurs because each process sets its own flag (c1 or c2) to 1 and enters a waiting loop if the other's flag is also set to 1.

If both flags are set to 1 at the same time, both processes will wait indefinitely for the other to set the flag to 0, which never happens, leading to a deadlock.