GATE - 2006 | OS | Consider the following snapshot of a system running n processes.

GATE - 2006 [Operating System]

Question:

Consider the following snapshot of a system running n processes. Process i is holding x_i instances of a resource R, 1 ≤ i ≤ n. Currently, all instances of R are occupied. Further, for all i, process i has placed a request for an additional y_i instances while holding the x_i instances it already has. There are exactly two processes p and q such that y_p = y_q = 0. Which one of the following can serve as a necessary condition to guarantee that the system is not approaching a deadlock?

A	min (xp, xq) < maxk≠p,qyk
B	xp + xq ≥ mink≠p,qyk
C	max (xp, xq) > 1
D	min (xp, xq) > 1

   

Solution:

Option (B) is Correct.

Deadlock refers stops the execution of process due to non-availability of resources.
→ When two (or) more processes waiting for another process to release the resources.
→ P and Q can execute if they have sufficient resources, they don’t wait for extra resources (i.e., X_p+ X_q) required.
→ Option B can satisfies the corresponding equation i.e., X_p+ X_q >= min(Y_k) where k != p and k != q.
Here we have sufficient resources.

 

Thank You