Question

A system has three resources of type A and two resources of type B. There are four processes, each of which requires two resources of type A and one resource of type B to complete. Show how Banker’s Algorithm can allocate resources to processes to avoid deadlock.

Answer 1

The Banker's Algorithm can be used to allocate resources in a way that avoids deadlock by ensuring a safe sequence of allocations. For the given system, the algorithm would allow for the complete allocation of resources to two processes at a time, ensuring all processes complete without deadlocks.

Step-by-step explanation:

The question deals with the Banker's Algorithm, a resource allocation and deadlock avoidance algorithm that tests for safety by simulating the allocation for predetermined maximum possible amounts of all resources, and then makes an "s-state" check to test for possible activities, before deciding whether allocation should be allowed to continue.

To use the Banker's Algorithm for the given system with three resources of type A and two resources of type B, and four processes each requiring two A and one B to complete, you will first establish the maximum demand of each process, then determine the available resources, followed by the allocation matrix.

1. Calculate Total Resources: 3 of A and 2 of B.
2. Establish Maximum Demand: Each process requires 2 of A and 1 of B.
3. Set Initial Allocation: This will often start at zero for all processes.
4. Craft a Need Matrix: Reflecting remaining needs for each process.
5. Check for the Safe State: Using the algorithm to find an order of execution that does not lead to deadlock.

In this scenario, initially, we can allocate the resources to two processes completely (since we have enough resources for at least two). After those two processes finish and release their resources, we have all our resources back, and we can allocate them to the remaining two processes. This procedure ensures a deadlock-free state.