Grade Graph (Assignment 1, 2, 3, & 4 + MT1, 2)Assuming similar performance in final exam and A5

0

5

10

15

20

25

30

35

100+ A

93- 100A

90- 93 A-

87- 90 B+

83- 87 B

80- 83 B-

75- 80 C+

70- 75 C

65- 70 C-

0- 65 Misc

Score Ranges

number of students

Actual DistributionExpectation from Survey I

Performance is better than expectation in (A, A-) range

CSCI 4061Introduction to Operating System

Final Review

Rules • Five/Four students form a group.

• After the questions show up, the team raises the # card first to get called on and MUST start to answer the question when TA calls on them with in 10 seconds (otherwise lost points)

• Each team gets one AND ONLY ONE answer per question (within reasonable time bound).

Difference from normal Jeopardy! game

• Questions are given, you provide the answer. (not vise versa)

• At most answer two questions in a row for a group. After that, all groups are allowed to compete for the next question.

• When you hear the bell you start to compete

• Only The Jeopardy Round and Final Jeopardy round– In final jeopardy round, you can bet up to

all you have

Other logistics• Gayn is charge of book keeping on white

board (one score per group)

• Priyesh is charge of identify the group that raise the card first and decided time-out

• Lecturer make FINAL decision whether an answer is correct or not, we can resolve disagreement later. No hard feeling ;)

• Some questions would be related to the final

Trophies at stake– The winning team wins 5$ starbuck card

per member. You can enjoy together after class.

Click to begin.

Click here for Final Jeopardy

Category AProcesses

Category BIO

Category D Comm.

Category EMisc.Level

100 $

200 $

300 $

400 $

500 $

100 $ 100 $ 100 $ 100 $Easy

200 $ 200 $ 200 $ 200 $Medium

300 $

400 $

500 $

300 $ 300 $ 300 $Hard

400 $ 400 $ 400 $Daunting

500 $ 500 $ 500 $ Impossible

Category CConcurrency

Question 1aWhen a process will experience an

involuntary context switch.

Answer 1aQuantum (allocated time) expired

Question 2aDetermine the screen output for following commands: variable="Dennis"echo '$variable'

Answer 2a$variable

Question 3aHow c-shell evaluates #?var ?

Answer 3a$?VAR gives “1” if VAR is set, “0” if not.

Question 4aWhich signal is generated when a privileged instruction is executed in user mode?

Answer 4aSIGILL

Question 5a In CSH/BASH, if you run following four commands: cd /mydirectory ls –l | wc -l find . –name *.txt > a.txt Echo success!How many processes the shell creates (not include shell itself).

Answer 5a3 processes

Question 1bThe name of the block that contains overarching

information about a file system such as size status. Total number of inodes, free blocks counter and so on.

Answer 1bSuperblock

Question 2btianhe@dio (/home/fac26/tianhe) % ls -l prw------- 1 tianhe mess 0 Dec 8 17:07 trace

What the first character P stands for?

Answer 2bNamed PIPE

first-in, first-out (FIFO) special file.

Question 3b A condition where the system spends most of the time transferring pages to and fromthe disk and little time making progress on

application computations;

Answer 3bThrashing

Question 4bWith in a directory, you create 5 symbolic links and 7 hard-links. How many free free-inode are used after these operations?

Answer 4b5

Because hard-link only add a (name, pointer-to-iNode) pair within the

directory file.

Question 5bConsider a file c (size of 10 bytes) in the Unix file system named /a/b/c. What is the minimum number of reads of data blocks are required to get first byte of

file c?

Answer 5b4

Note directory is a fileData block of /

Data block of a/ Data block of b/Data block of c

Question 1cA OS term describes the condition in which a process is indefinitely delayed, because other processes are always given preference.

Answer 1cstarvation

Question 2c Name at least two necessary conditions

for deadlock

Answer 2cHold and wait, circular wait, non-preempt, mutual exclusion

Question 3cA condition whereby the output and/or

result of the process is unexpectedly and dependent on the order or timing

of other events

Answer 3cRace Condition

Question 4cWhat is the name of the lock

where the thread simply waits in a loop repeatedly checking until the lock

becomes available.

Answer 4cSpinlock

Question 5cint i = 0;While(i < 100) { execlp("echo", "echo", “Hello World\n", NULL); i=i+2;}

How many lines of text will be print out

Answer 5c

1

Question 1dList three main elements in protocol design.

Answer 1dFormat, Order, and Action (FOA)

Question 2dThe server that listens to port Number

21

Answer 2dFTP

Question 3dHow many sockets are created when 11 users query a DNS server at both client and server sides

Answer 3d1 at the UDP server side, 11 at the client side, totally 12.

Question 4dThe name of a UNIX shell command used to query Internet domain name

servers

Answer 4dnslookup

Question 5dThe name of ports 49,152 through 65,535

Answer 5dEphemeral ports

Port 0 is reserved

Ports 1 - 1023 are named "well-known" ports

Ports 1024 - 49,151 are registered ports.

Ports 49,152 - 65,535 are ephemeral ports

Question 1eDOS was the first widely-installed operating system for personal computers. What does DOS stand for?

Answer 1eDisk Operating System

Question 2eThe name of problem a 32 bit time_t data structure

would cause?

Hint( it records the seconds elapsed since January 1, 1970 )

Answer 2eYear 2038 Problem

It overflows after 03:14:07 UTC on Tuesday, January 19, 2038.

Question 3eThe name of a small privileged OS core that provides process scheduling, memory management, and communication services and relies on other processes to perform some of the functions traditionally associated with the operating system kernel.

Answer 3emicrokernel

Question 4eA form of IO technique that permits

computation to continue before the IO operation (e.g. read/write) has finished.

Answer 4eAsynchronous I/O

Question 5eName at least 4 UNIX-Like OS.

Answer 5eGNU, FreeBSD, NetBSD, OpenBSD, SunOS/Solaris MacOS, Linux, HP-

UX, AIX, UnixWare, IRIX

Question 1f

Answer 1f

Question 2f

Answer 2f

Question 3f

Answer 3f

Question 4f

Answer 4f

Question 5f

Answer 5f

Make your wager up to what you have

Write down the wager along with the answer on the back of the index card.

Finish in 3 minutes!!!

Final QuestionConsider the following piece of code.

int main(int argc, char ** argv){int i;for (i = 0; i < 3; i++) {

fork();printf("#%d, ", i);

}printf("\n");

} What is printed to standard output? Why?

Final Answer#0, #1, #2, #0, #1, #2, #0, #1, #2, #0, #1, #2, #0, #1, #2, #0, #1, #2, #0, #1, #2, #0, #1, #2,

This is because printf has an internal user level buffer that gets copied, when the fork happens, and since stdout isn’t flushed untilit sees a newline (or fills up the internal buffer), all 8 processes wind up with 0, 1, and 2 in their buffer. When they exit, the buffers are flushed.

Formal Class Evaluation Instructor: Tian He Term: Fall Current Year: 2007Department: Computer Science Course NO: 18087 Section: 1 Class: CSCI 4061 TA: Gyan Ranjan and Priyesh Jain

Your positive feedback is very important to me and TAs!

Thank you for taking this course.