Resource-Allocation Graph

• Process

• Resource Type w/ 4 instances

• Pi requests instance of Rj

• Pi is holding an instance of Rj

QUESTION:

• How would you know if there's a DEADLOCK based on the resource allocation graph?

ANSWER:
If graph contains no cycles => no deadlock.
If graph contains a cycle

• if only one instance per resource type, then deadlock (meaning if the cycle goes on a single path, it will result to a DEALOCK).

• if several instances per resource type, possibility of deadlock (meaning if the resource allocation graph has several cycles it has a POSSIBILITY for DEADLOCK).