اسئلة الامتحان الشهر الاول نظري-صباحي

Q1/ Draw the resource-allocation graph depicts the following situation,
The sets P, R, and E:
- P={P1, P2, P3} - R={R1, R2, R3, R4}
- E={P1 ? R1,P2 ? R3,R1 ? P2,R2 ?P2,R2?P1,R3? P3,R4?P2, P3?R4}
• Resource instances:
-One instance of resource type R1 -Two instances of resource type R2
- One instance of resource type R3 -Three instances of resource type R4
Q2/ Consider the following snapshot of a system: A, B, C & D have 3, 16, 16 & 13 instances.
Allocation Max
A B C D A B C D
P0 0 1 1 0 0 2 1 0
P1 1 2 3 1 1 6 5 2
P2 1 3 6 5 2 3 6 6
P3 0 6 3 2 0 6 5 2
P4 0 0 1 4 0 6 5 6
a) What is the content of the matrix Available?
b) What is the content of the matrix Need?
c) If a request from process P1 arrives for (0,1,1,1), what will be the system state?

Q2/ Answer only one:
- There are two problems when applying the prevention protocols in hold and wait condition, explain it?
- What technique can be used to avoid resource-deadlock with single-instance resources? Explain it with example.

Q1/ Draw the resource-allocation graph depicts the following situation,
The sets P, R, and E:
- P={P1, P2, P3} - R={R1, R2, R3, R4}
- E={P1 ? R1,P2 ? R3,R1 ? P2,R2 ?P2,R2?P1,R3? P3,R4?P2, P3?R4}
• Resource instances:
-One instance of resource type R1 -Two instances of resource type R2
- One instance of resource type R3 -Three instances of resource type R4
Q2/ Consider the following snapshot of a system: A, B, C & D have 3, 16, 16 & 13 instances.
Allocation Max
A B C D A B C D
P0 0 1 1 0 0 2 1 0
P1 1 2 3 1 1 6 5 2
P2 1 3 6 5 2 3 6 6
P3 0 6 3 2 0 6 5 2
P4 0 0 1 4 0 6 5 6
d) What is the content of the matrix Available?
e) What is the content of the matrix Need?
f) If a request from process P1 arrives for (0,1,1,1), what will be the system state?

Q2/ Answer only one:
- There are two problems when applying the prevention protocols in hold and wait condition, explain it?
- What technique can be used to avoid resource-deadlock with single-instance resources? Explain it with example.