$//17$ marks $(2+3+3+3+3+3)$

a$.$ Please list all the pre$-$conditions for a deadlock to occur $($general conceptual question, please

do not answer it based on the following parts of this question, you may use them as an

example though$).$

You are given $4$ tasks $-$ A$,$B$,$C and $D$ and $3$ resources $x,y$ and $z$ and their resource usage$/$ sharing.

Given $-$ A$,$B$,$C and D have the same priority, they can request the resources in any order and

cannot relinquish a resource till finished with the use.

b$.$ Can the above situation lead to a deadlock? Please explain your answer based on the

preconditions in part a$.$

c$.$ Now in addition to all above details, $c$ also needs to use resource $x.$ Can this situation lead to

a deadlock $?$ Please explain your answer based on the preconditions in part a$,$ i$.$e$.$ what

changed or did not change enough to cause or avoid a deadlock.

d$.$ Now consider the situation in part c$.$ But now it is given that the tasks may request any

combination of resources but must do so in order i$.$e$.x$ before $y$ before $z.$ Can this situation

lead to a deadlock $?$ Please explain your answer based on the preconditions in part a$,$ i$.$e$.$

what changed or did not change enough to cause or avoid a deadlock. Can you give one

reason why you think this $($enforcing ordering of requests$)$ is a good design choice or not $?$

e$.$ Now consider the situation in part $c.$ But now the tasks have different priorities i$.$e$.A=1,B=$

$2,C=3,D=4($Lower number $=$ higher priority$)$ and scheduling is priority based preemptive.

We use priority inheritance to avoid priority inversion. Can it cause a deadlock $?$ Please

explain your answer based on the preconditions in part a$,$ i$.$e$.$ what changed or did not change

enough to cause or avoid a deadlock.

f$.$ Why do you think might it be a good or bad idea to solve a deadlock after it happens by

making a process relinquish an acquired resource that is part of the deadlock? How does the

priority ceiling protocol fare in this aspect?