Question

What is the most "favored execution" of an unblocked process in deadlock detection by process-resource graphs?

(Please help, Operating system question, 6 points)

Answer 1

Process- Resourse graph comes under the technique of Deadlock Detection and recovery.

• In case of deadlock detection, If the resources have single instance available then we can check an algorithm to check for cycle. Presence of cycle will confirm the deadlock.
• In case of deadloack detection, If the resources have multiple instance available then detection of cycle is necessary but not sufficient condition for deadlock detection. In this case system may or may not be in deadlock.
• In case of Recovery, Killing all the process involved in deadlock. After killing each process, check the deadlock again keep repeating the process till the system recover.
• In case of Recovery, Resources are preempted from the process involved in deadlock. The resources which are preempted allocated to other processes so there is a possiblity of recovery the system from deadlock.
• Algorithm related to deadlock detection contains three data strucutres; Available, Allocation, and Request.
• Hence it contains both the algorithm of deadlock detection and recovery. For deadlock detection Banker's Algorithm is used.