Question

In a system, there are three types of resources: E, F and G. Four processes $P_0,P_1,P_{2}and{P}_3$ execute concurrently. At the outset, the processes have declared their maximum resource requirements using a matrix named Max as given below. For example Max$[P_2.F]$ is the maximum number of instances of F that $P_2$ would require. The number of instances of the resources allocated to the various processes at any given state is given by a matri named Allocation.
Consider a state of the system with the Allocation matrix as shown below and in which 3 instances of E and 3 of F are the only resources available.

Allocation
	E	F	G
$P_0$	1	0	1
$P_1$	1	1	2
$P_2$	1	0	3
$P_3$	2	0	0

Max
	E	F	G
$P_0$	4	3	1
$P_1$	2	1	4
$P_2$	1	3	3
$P_3$	5	4	1

From the perspecitve of deadlock avoidance, which one of the following is true?

• A. The system is in safe state.
• B. The system is not in safe state, but would be safe if one more instance of E were available.
• C. The system is not in safe state, but would be safe if one more instance of G were available.
• D. The system is not in safe state, but would be safe if one more instance of F were available.

Answer 1

The correct option is A The system is in safe state.

Max Need				Current allocation			Current available			Remaing need
	E	F	G	E	F	G	E(3)	F(3)	G(3)	E	F	G
$P_0$	4	3	1	1	0	1	4	3	1	3	3	0
$P_1$	2	1	4	1	1	2	5	3	4	1	0	2
$P_2$	1	3	3	1	0	3	6	4	6	0	3	0
$P_3$	5	4	1	2	0	0	8	4	6	3	4	1

Safe sequence :$P_0,P_2,P_1,P_3$
Hence, system is in safe state.