GATE - 2010 | OS | A system has n resources R0,...,Rn-1,and k processes P0,....Pk-1.
Posted on 13-02-2022
GATE - 2010 [Operating System]
Question:
A system has n resources R0,...,Rn-1,and k processes P0,....Pk-1.The implementation of the resource request logic of each process Pi is as follows:
if (i % 2 == 0) {
if (i < n) request Ri
if (i+2 < n) request Ri+2
}
else {
if (i < n) request Rn-i
if (i+2 < n) request Rn-i-2
}
In which one of the following situations is a deadlock possible?
|
A |
n = 40, k = 26 |
|
B |
n = 21, k = 12 |
|
C |
n = 20, k = 10 |
|
D |
n = 41, k = 19 |
Solution:
Option (B) is Correct.
Consider the case where i = 10 & i = 11, n = 21 & k = 12
P10 requests R10 & R11
P11 requests R10 & R8
Hence P10 & P11 inorder in deadlock.