(Are you looking at a stale web page? Try refreshing your
browser.)
(
Latest Revision --
Nov 23, 2006
)
(Nov 23: modified statement of the readers-writers problem)
(Sep 20: modified apportionment of HW#2 and HW#3)
Homework Problems for CS 3750
Doing the homework properly will likely raise your course grade by one full
letter grade or more (e.g. from C to B, or from B to A). I will grade the
homework "generously." I urge you to take advantage of the opportunity to do
well in the course.
Directions for homework submissions
You'll get good grades on the homework if you show mastery of the
material. Give thoughtful and complete answers. Explain
your answers so as to demonstrate and prove to a skeptical reader that they
are correct.
Put things into your own words. Do not copy, quote, or closely
paraphrase the textbook or other people's writings.
Write so as to be understandable to a certain intended readership -- an
intelligent person who has completed the prerequisites for CS 3750 but who has
not yet taken CS 3750.
If I don't feel that what you write is understandable to that audience then
you will lose substantial credit.
You will need to keep an extra copy of everything you turn in. Homework will
typically be due on the class day just prior to a test day. I will discuss
answers to the homework immediately after collecting it. You will not receive
graded homework back until sometime after you take the test.
Form and Format
- Everything except source code (including "psuedo-code"): Turn in a
hard copy. Put it on the 'counter' in front of me before the beginning
of class on the due date. DOUBLE SPACE. Make margins of between 1" and
1-1/4" on sides, top and bottom. Use a font size from 10 to 14. (I
prefer a fixed-width font.)
- Source code: Turn in neat, compilable code. No more than 70
characters per line. Turn in one hard copy and one e-mail copy. Put the
hard copy on the 'counter' in front of me before class starts. Send the
e-mail before midnight on the due date. No attachments, please. Just
put the text in-line into the message.
Send e-mail to: john@ishi.csustan.edu
DUE DATES
For all homework due dates, see:
the class schedule.
WARNING ABOUT PROBLEM NUMBERS
If you have an old edition of the textbook, or even a foreign version of the
current edition, then the problem numbers in your book may not correspond
exactly to those in the official course text. It is your responsiblity to
make sure you work the right problems.
Homework Assignment #1
Chapter #01 -- Introduction
- Write 250 words or more describing the interplay between
operating system software and the interrupt mechanism. In your writing
show that you understand A) how interrupts "drive" the actions of the
operating system, and B) how the interrupt mechanism in a modern
computing system actually works (what hardware devices do to cause an
interrupt and the sequence of events that take place between the time
that the currently running program is interrupted and the time that
program resumes execution).
Chapter #02 -- Operating System Structures
- Using information gleaned from chapters one and two, write 500 words or
more describing the important functions and responsibilities of a modern
multi-user, time-sharing operating system.
- Using information from section 2.7 write 250 words or more describing
several different approaches to designing operating system structure.
Discuss the advantages and disadvantages of each approach.
Chapter #03 -- Processes
- Write 250 words on the topic of programs and processes. Define what a
program is and what a process is. Explain what the
differences and similarities are between the two concepts. Explain
and/or speculate on what operating system data structures must be
employed in order to maintain and preserve a program. Answer the
same question for a process. Give attention to similarities and
differences regarding the data structures too. Use information distilled
from your readings of chapter 3 to help you answer this question, and add
whatever else you know that you think will be helpful. (Keep in mind the
"intended readership" described in the directions above.)
Chapter #04 -- Threads
- Rewrite the essay you wrote in answer to the question for chapter #03.
The directions are the same except that this time you must cover three
concepts: program, process, and thread. In addition
to adding information about threads, since you know more now you should
be able to improve on what you said before about programs and processes.
WARNING ABOUT PROBLEM NUMBERS
If you have an old edition of the textbook, or even a foreign version of the
current edition, then the problem numbers in your book may not correspond
exactly to those in the official course text. It is your responsiblity to
make sure you work the right problems.
Homework Assignment #2
Chapter #05 -- Scheduling
- Do problem 5.4 on page 187 (this involves making Gantt charts and
calculating measures of the performance of several scheduling
algorithms).
- Do problem 5.7 on page 188. (The problem starts with:
"Consider a system running ten I/O-bound ...")
Chapter #06 -- Process Synchronization
- Do the problem in the file
hymanProb.html
in this directory. Please take note of the example "scenario" described
in the problem statement. Make sure that the solution you construct is
the same kind of specific and detailed scenario.
- Propose a solution to
the "second readers-writers problem" which is described in section 6.6.2
of the text.
the following variation on the "readers-writers problem" which is
described in section 6.6.2 of the text: readers and writers must be given
access to the [database] resource in the order in which they request it.
Readers share the resource to the greatest extent possible. Each writer
accesses the resource exclusively.
Write up the proposed solution using the same format as figures 6.12 and
6.13 (and the declarations of shared variables above figure 6.12). In
other words write pseudo code that shows what the shared variables are,
pseudo code for writer processes, and pseudo code for reader processes.
Also, like the solution shown in figures 6.12 to 6.13, use only
semaphores for synchronization.
Assumptions:
- The total number of readers and writers does not exceed some fixed
bound N.
- You can declare and use as many semaphore variables as you need.
- The semaphores work as defined in 6.5.2
- The list S in each semaphore is a FIFO queue.
In addition to enforcing exclusive writes and allowing shared reads, your
solution should be starvation free, and satisfy the progress & bounded
waiting requirements for solutions to critical section problems. (See
section 6.1.)
Chapter #07 -- Deadlocks
- Do problem #7.11 on page 270. (The problem starts with: "Consider the
following snapshot of a system ...") Show all your work (in detail). Use
the same kind of
format you see here.
Chapter #08 -- Memory Management
- Do problem 8.3 on page 310 (It starts "Given five memory partitions ...
").
- Remember the possibility of using holes created by previous
allocations),
- Assume that for each allocation, the first-fit algorithm starts its
search again at the beginning of the list.
- Do problem 8.5 on page 311 (It starts: "Compare the main memory
organization ..."
- Do problem 8.9 on page 311 (It starts: "Consider a paging system with the
page table stored in memory."
- Do problem 8.12 on page 312 (It starts: "Consider the following segment
table"
Chapter #09 -- Virtual Memory
- Do the following problem. Show all work in detail.
A virtual address of 76543656 (hex) appears in a program that is being run on
a computer that does demand paging. The computer has 24-bit physical
addresses, 32-bit virtual addresses, and a 1K-word page-size. How many
physical frames are there? How many virtual pages are there? What are the
page number and the offset corresponding to the virtual address? (Give the
last two both in hex notation and decimal notation.)
- Do problem 9.5 on page 366 (It starts: "Assume that we have a
demand-paged memory. The page table is held in registers. ...").
Chapter #10 -- File-System Interface
- Do problem 10.1 on page 408 ("Consider a file system where a file ...")
- Do problem 10.9 on page 409 ("Some systems provide file sharing by ...")
WARNING ABOUT PROBLEM NUMBERS
If you have an old edition of the textbook, or even a foreign version of the
current edition, then the problem numbers in your book may not correspond
exactly to those in the official course text. It is your responsiblity to
make sure you work the right problems.
Homework Assignment #3
Chapter #10 -- File-System Interface
- Do problem 10.1 on page 408 ("Consider a file system where a file ...")
- Do problem 10.9 on page 409 ("Some systems provide file sharing by ...")
Chapter #11 -- File-System Implementation
- Do problem 11.2 on page 447 ("What are the advantages of the variant
...")
- Do problem 11.5 on page 448 ("Discuss how performance optimization ...")
- Do problem 11.6 on page 448 ("Consider a file system on a disk that has
...")
Chapter #12 -- Mass-Storage Structure
- Do problem 12.2 on page 489-490 ("Suppose that a disk drive has 5000
...")
- Do problem 12.15 on page 492 ("Discuss the relative advantages and ...")
- Do problem 12.21 on page 493 ("Suppose that a one-sided 5.25-inch
optical-disk ...")
Chapter #13 -- I/O Systems
- Do problem 13.6 on page 526 ("Describe three circumstances under ...")
Chapter #14 -- Protection
- Do problem 14.5 on page 556 ("Describe the strengths ... access lists
that are associated with objects.")
Chapter #15 -- Security
- Do problem 15.14 on page 605 ("Discuss how the asymmetric encryption
algorithm can be used to achieve the following goals ...")
Chapter #16 -- Distributed System Structures
- Do problem 16.2 on page 638 ("Contrast the various network topologies in
terms of ...")
- Do problem 16.4 on page 638 ("Explain why doubling the speed of the
systems on an Ethernet ...")
- Do problem 16.6 on page 639 ("In what ways is using a name server better
...")