Operating Systems

Question

To check that a mutual exclusion algorithm  is not free from deadlock,is it necessary to check if the entire processes in the system are in deadlock-

If there are 5 processes in the system- P₀,P₁,P₂,P_3,P₄ and if we have to prove that the particular mutual exclusion algorithm is not deadlock free, do we have to show that all processes P₀,P₁,P₂,P₃,P₄ are in involved in deadlock and if just the processes P₀,P₁,P₂ are involved in deadlock then mutual exclusion algorithm is free from deadlock?

 

According to Galvin, if a resource allocation graph contains a cycle and each resource involved in the cycle has only 1 instance of its type then system is definitely in deadlock- This means it is not necessary for all processes in the system to be in deadlock to say deadlock has occurred?

Comments

According to Galvin, if a resource allocation graph contains a cycle and each resource involved in the cycle has only 1 instance of its type then system is definitely in deadlock.

Yes, for the single instance graph if there is cycle then It's Deadlock.

But for the multi-instance graph, it is not the case. It may be or may not be.