Chapter 28 Flashcards
What is RAG algorithm
It is resource allocation graph algorithm. It has request and assignment edges
What is claim edge in RAG algorithm
Claim edge converts to request edge when a process request a resource. And when a resource is released by a process, assignment edge reconverts to a claim edge.
What is assignment edge in RAG algorithm
When a resource is assigned to a process, request edge reconverts to an assignment edge.
What is RAG algorithm deadlock avoidance with single instance resource type
Request is hold by algorithm in resource allocation graph. if there is chance of becoming cycle and system went into unsafe state
What is deadlock avoidance algorithm with multiple instance resource type
It is bankers algorithm. It may request all the instance of resource type during its execution. When a process request a resource it may have to wait so that it might not go into unsafe state.
Does allocation and need n x m matrix
Yes
What is the role of safety algorithm
It checks weather system goes into unsafe state
How banker algorithm works
When a request is made by process to bankers algorithm checks 2 things. One is request is less than need vector and second is the request vector is less than or equal to what is available in system at this time. If both conditions are true then request is granted. Then it calls safety algorithm. Safety algorithm checks the safe sequence in the system. If yes then bankers algorithm is informed. And banker algorithm acts accordingly.
