Qrb 501 Final Exam Answers
Name______ _________________________________
Student ID____ ________________________________
Homework 1
Due: Wednesday, February 23, 2011
All answers must be clear and to the point and on the page they were asked.
Do not repeat the question. Do not email the homework in. Bring it to class on or before the day it is do, otherwise put it in my mailbox.
1) Numbers can be represented in binary (using 2 symbols 0 and 1) and hexadecimal ( 16 symbols
0..9,1,A..F) amount other ways .
a) Represent the hexadecimal number 3F in decimal
63.
b) Represent the hexadecimal number 3F in Binary
111111.
c) Represent the decimal number 65536 in hexadecimal 10000 2) When resenting a decimal
number as like eight as “all lights on” and 0 as all lights on except the middle one, the login for the bottom line is: on for 0, 2,3,5,6,8,9 and off for 1,4,7 and you don’t care for number between 10 and 16 because that will never be the input.
Design a 4 input 1 out electronic device that will represent the bottom line of the digital display using gates.
3) Implement counting semaphores using only binary semaphores. That is, using only system implemented binary semaphores with corresponding P and V operations, create two functions CP(Counting P) and CV(Counting V) that behave the same as P and V for counting semaphores would.
4) a) In the Dijkstra’s Bankers algorithm, what is a safe state?
A safe state is considered as if it is possible for all processes to finish executing (terminate).
b) N processes share M resource units that can be reserved and release only one at a time. The maximum need of each process does not exceed M, and the sum of all maximum needs is less than M+N. Can a deadlock occur in the system (yes or no). Prove your answer.
5) a) Given process resource usage and availability as described in the table below, draw the resource allocations graph.
| Allocated | Outstanding Requests | Resources Available | Processes | R1 | R2 | R3 | R1 | R2 | R3 | R1 | R2 | R3 | P1P2P3P4 | 2310 | 0131 | 0001 | 1000 | 1001 | 0010 | 0 | 0 | 0 |
b) Is this system deadlocked? Show why or why not?
6) Invent you own question related to the each topics or processes, critical sections, deadlocks, paging etc. Then, answer it correctly. If it is a good test question, then it may be on a test for this class.
Note: a good test questions is one that: * can be answered somewhat quickly * if a student understands the topic very well, the student will get full credit * if a student understands the topic somewhat well, the student will get partial credit
- if the student doesn’t understand the topic, the student will not get any credit
Student ID____ ________________________________
Homework 1
Due: Wednesday, February 23, 2011
All answers must be clear and to the point and on the page they were asked.
Do not repeat the question. Do not email the homework in. Bring it to class on or before the day it is do, otherwise put it in my mailbox.
1) Numbers can be represented in binary (using 2 symbols 0 and 1) and hexadecimal ( 16 symbols
0..9,1,A..F) amount other ways .
a) Represent the hexadecimal number 3F in decimal
63.
b) Represent the hexadecimal number 3F in Binary
111111.
c) Represent the decimal number 65536 in hexadecimal 10000 2) When resenting a decimal
number as like eight as “all lights on” and 0 as all lights on except the middle one, the login for the bottom line is: on for 0, 2,3,5,6,8,9 and off for 1,4,7 and you don’t care for number between 10 and 16 because that will never be the input.
Design a 4 input 1 out electronic device that will represent the bottom line of the digital display using gates.
3) Implement counting semaphores using only binary semaphores. That is, using only system implemented binary semaphores with corresponding P and V operations, create two functions CP(Counting P) and CV(Counting V) that behave the same as P and V for counting semaphores would.
4) a) In the Dijkstra’s Bankers algorithm, what is a safe state?
A safe state is considered as if it is possible for all processes to finish executing (terminate).
b) N processes share M resource units that can be reserved and release only one at a time. The maximum need of each process does not exceed M, and the sum of all maximum needs is less than M+N. Can a deadlock occur in the system (yes or no). Prove your answer.
5) a) Given process resource usage and availability as described in the table below, draw the resource allocations graph.
| Allocated | Outstanding Requests | Resources Available | Processes | R1 | R2 | R3 | R1 | R2 | R3 | R1 | R2 | R3 | P1P2P3P4 | 2310 | 0131 | 0001 | 1000 | 1001 | 0010 | 0 | 0 | 0 |
b) Is this system deadlocked? Show why or why not?
6) Invent you own question related to the each topics or processes, critical sections, deadlocks, paging etc. Then, answer it correctly. If it is a good test question, then it may be on a test for this class.
Note: a good test questions is one that: * can be answered somewhat quickly * if a student understands the topic very well, the student will get full credit * if a student understands the topic somewhat well, the student will get partial credit
- if the student doesn’t understand the topic, the student will not get any credit