Chapter $7$ Deadlocks

Q$4.$ Consider the following snapshot of a system:

Process Allocation Max Available Need

A B C D A B C D A B C D

P$0001200121520$

P$110001750$

P$213542356$

P$306320652$

P$400140656$

Answer the following questions using the banker$$s algorithm:

a$.$ What is the content of the matrix Need?

b$.$ Show whether the system is in a safe state?

c$.$ If a request from process P$1$ arrives for $(0,4,2,0),$ can the request be granted immediately?

Q$5.$ Consider the following snapshot of a system:

Allocation Max Need

A B C D A B C D

P$030145117$

P$122103211$

P$231213321$

P$305104612$

P$442126325$

Using the banker$$s algorithm, determine whether or not each of the following states is unsafe. If the state is safe, illustrate the order in which the processes may complete. Otherwise, illustrate why the state is unsafe.

a$.$ Available $=(0,3,0,1)$

b$.$ Available $=(1,0,0,2)$

Q$6.$ Consider the following snapshot of a system:

Allocation Max Available Need

A B C D A B C D A B C D

P$0200142123321$

P$131215252$

P$221032316$

P$313121424$

P$414323665$

Answer the following questions using the banker$$s algorithm:

a$.$ Illustrate that the system is in a safe state by demonstrating an order in which the processes may complete.

b$.$ If a request from process P$1$ arrives for $(1,1,0,0),$ can the request be granted immediately?

c$.$ If a request from process P$4$ arrives for $(0,0,2,0),$ can the request be granted immediately?