A set of vertices V and a set of edges E.
· V is partitioned into two types:
» P = {P1, P2, …, Pn}, the set consisting of all the processes in the system.
» R = {R1, R2, …, Rm}, the set consisting of all resource types in the system.
· Request Edge – directed edge P1 -> Rj
· Assignment Edge – directed edge Rj -> Pi
· Process
· Resource Type With 4 Instances
· Pi request instance of Rj
· Pi holding an instance of Rj
How Would You Know If There's a Deadlock Based on the Resource Allocation Graph?
RESOURCE ALLOCATION GRAPH
· Process
· Pi request instance of Rj
· Pi holding an instance of Rj
How Would You Know If There's a Deadlock Based on the Resource Allocation Graph?
·If graph contains no cycles - no deadlock.
·If graph contains a cycle :
» if only one instance per resource type, then deadlock.
» if several instances per resource type, possibility of deadlock.
0 comments:
Post a Comment