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( Latest Revision -- Nov 27, 2005 )
( 11/27/05: added some of HW #5 )
( 11/17/05: added more of HW #4 )
( 11/16/05: added more of HW #4 )
( 11/13/05: added some of HW #4 )
( 10/26/05: moved back due date for HW #3 )
( 10/02/05: add the rest of homework #2 )
( 9/20/05: add some of homework #2 )
( 9/19/05: resolved due date for HW with schedule )

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 to 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

Send e-mail to: john@ishi.csustan.edu

Homework Assignment #1

Due Wednesday, September 21

Chapter #01 -- Introduction
  1. 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
  1. 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.

  2. 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
  1. 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.)

Homework Assignment #2

Due Monday, October 10

Chapter #04 -- Threads
  1. 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.
Chapter #05 -- Scheduling
  1. Do problem 5.4 on page 187 (this involves making Gantt charts and calculating measures of the performance of several scheduling algorithms).

  2. Do problem 5.7 on page 188.
Chapter #06 -- Process Synchronization
  1. 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.

  2. Propose a solution to the "second readers-writers problem" which is described in section 6.6.2 of the text. 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.


    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.)

Homework Assignment #3

Due Friday, October 28 Monday, October 31

Chapter #07 -- Deadlocks
  1. 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
  1. Do problem 8.3 on page 310 (It starts "Given five memory partitions ... ").
  2. Do problem 8.5 on page 311 (It starts: "Compare the main memory organization ..."

  3. Do problem 8.9 on page 311 (It starts: "Consider a paging system with the page table stored in memory."

  4. Do problem 8.12 on page 312 (It starts: "Consider the following segment table"

Chapter #09 -- Virtual Memory
  1. 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.)

  2. Do problem 9.5 on page 366 (It starts: "Assume that we have a demand-paged memory. The page table is held in registers. ...").

Homework Assignment #4

Due Friday, November 18

Chapter #10 -- File-System Interface
  1. Do problem 10.1 on page 408 ("Consider a file system where a file ...")
  2. Do problem 10.9 on page 409 ("Some systems provide file sharing by ...")
Chapter #11 -- File-System Implementation
  1. Do problem 11.2 on page 447 ("What are the advantages of the variant ...")
  2. Do problem 11.5 on page 448 ("Discuss how performance optimization ...")
  3. Do problem 11.6 on page 448 ("Consider a file system on a disk that has ...")
Chapter #12 -- Mass-Storage Structure
  1. Do problem 12.2 on page 489-490 ("Suppose that a disk drive has 5000 ...")
  2. Do problem 12.15 on page 492 ("Discuss the relative advantages and ...")
  3. Do problem 12.21 on page 493 ("Suppose that a one-sided 5.25-inch optical-disk ...")
Chapter #13 -- I/O Systems
  1. Do problem 13.6 on page 526 ("Describe three circumstances under ...")
Chapter #14 -- Protection
  1. Do problem 14.5 on page 556 ("Describe the strengths ... access lists that are associated with objects.")
Chapter #15 -- Security
  1. Do problem 15.14 on page 605 ("Discuss how the asymmetric encryption algorithm can be used to achieve the following goals ...")

Homework Assignment #5

Due Wednesday, December 07

Chapter #16 -- Distributed System Structures
  1. Do problem 16.2 on page 638 ("Contrast the various network topologies in terms of ...")
  2. Do problem 16.4 on page 638 ("Explain why doubling the speed of the systems on an Ethernet ...")
  3. Do problem 16.6 on page 639 ("In what ways is using a name server better ...")
Chapter #17 -- Distributed File Systems
  1. Do problem 17.11 on page 660 ("Describe some of the fundamental differences between AFS and NFS (see Chapter 11).") [Give proper attention to this - there is rather a lot to discuss. Write at least 350 words.]
Chapter #18 -- Distributed Coordination
  1. Do problem 18.5 on page 689 ("Your company is building a conmputer network, and you are asked to develop a scheme ...")