Question

For the system described below, given that all of the devices are of the same type, and using the definitions presented in the discussion of the Banker’s Algorithm, answer these questions:

a. Calculate the number of available devices.

b. Determine the remaining needs for each job in each system.

c. Determine whether each system is safe or unsafe.

d. If the system is in a safe state, list the sequence of requests and releases that will make it possible for all processes to run to completion.

e. If the system is in an unsafe state, show how it’s possible for deadlock to occur.

This system has 16 devices.



Job No Devices Allocates Maximum Required Remaining Needs
1 5 8
2 3 9
3 4 8
4 2 5

Answer 1

(a)

no of available devices = 16 - (5+3+4+2) = 16 - 14 = 2

(b)

Job No Devices Allocates Maximum Required Remaining Needs

1 5 8 3

2 3 9 6

3 4 8 4

4 2 5 3

(c)

It is in unsafe state because to complete smallest requirement , we need at least 3 devices.

(e)

it is in unsafe state because it need at least 3 devices to complement the smallest requirement and we have 2 devices free initially. so that devices will be in deadlock initially. to solve that we need at least 3 devices free initially. If we got 3 devices free initially than there will be no deadlock

Step-by-step explanation: