GATE - 2010 | OS | The following program consists of 3 concurrent processes and 3 binary
Posted on 13-02-2022
GATE - 2010 [Operating System]
Question:
The following program consists of 3 concurrent processes and 3 binary semaphores.The semaphores are initialized as S0 = 1, S1 = 0, S2 = 0.
How many times will process P0 print '0'?
|
A |
At least twice |
|
B |
Exactly twice |
|
C |
Exactly thrice |
|
D |
Exactly once |
Solution:
Option (A) is Correct.
S0=1
S1=0
S2=0
P0 enters the critical section first,
prints (‘0’)
releases S1,S2(i.e., S1=1 & S2=1)
Now P1 & P2 both can enter critical section releases S0 & prints (‘0’)
This process continues, hence the number of zero’s printed ≥2.