Administrative Information

Professor

TAs

Final Exam

Course Description

Operating systems control all of a computer's resources and present users with the equivalent of virtual machines that are easier to program than their underlying hardware. This course provides an overview of fundamental operating system principles, complemented with discussions of concrete modern systems to help you understand how these principles are applied in real OSs. Topics covered include an overview of the components of an operating system, mutual exclusion and synchronization, implementation of processes, scheduling algorithms, memory management and file systems.

Although the main learning objective of the course is to understand the requirements, design and implementation of modern operating systems, at a higher level the course aims to provide you with a good grasp of basic abstractions employed in system-level software (such as processes, threads, virtual memory, caching, etc.), while uncovering the ``magic'' that happens inside the box.

The course has a strong project component intended to provide essential experience in designing and implementing complex systems and working as part of a team. In designing the projects and estimating their required effort/hours, I am assuming you are (1) familiar with basic computer organization and data structures and (2) capable of programming in C in UNIX (or UNIX-like) systems (experienced with pointers, explicit dynamic memory allocation, multi-file projects, etc.).

Location and Time

• Lectures:
  Tuesdays and Thursdays 2:00-3:20PM.
  1890 Maple, Room 381.
• TA Sessions:
  Wednesdays 6:00-7:20PM.
  1890 Maple, Room 381.

In compliance with Section 504 of the 1973 Rehabilitation Act and the Americans with Disabilities Act, Northwestern University is committed to providing equal access to all programming. Students with disabilities seeking accommodations are encouraged to contact the office of Services for Students with Disabilities (SSD) at +1 847 467-5530 or ssd@northwestern.edu. SSD is located in the basement of Scott Hall. Additionally, I am available to discuss disability-related needs during office hours or by appointment.

Course Prerequisites

• CS-311 Data structures and data management. - Required
• CS-213 Introduction to Computer Systems - Highly recommended; taking this course will make your life a lot easier.
• Familiarity with basic computer architecture concepts and proficiency in C programming in UNIX systems.

Communication Channels

There are a number of communication channels set up for this class:

• We will use the course web site to post homework assignments, projects, course-related announcements, etc. You should check this regularly.
• There will be a newsgroup (cs.343 at news.cs.northwestern.edu). This particular channel is intended to foster communication among you, the students. You'll find that someone else in the class will have thought of the same problem that you have and will perhaps have some valuable insight that will prove helpful. The staff will be monitoring the discussion threads and will step in with guidance when appropriate.
• Finally, there is an email alias (cs-343-ta@cs) for the TA that you should use for questions that would be inappropriate to post on the newsgroup (source code being a good example).

Textbook and Other Readings

• Modern Operating Systems, 2nd Ed., A. S. Tanenbaum, Prentice-Hall, Upper Saddle River, NJ, 2001 (Textbook).
• Supplemental Reading. A set of papers I will make available providing a deeper historical perspective of operating systems, in-depth treatment of some of the topics I can only briefly cover in class, and some useful practical advice in designing and implementing complex systems. You will not be responsible for this; it is only intended for those specially interested in the given topic.
• Advanced Programming in the Unix Environment, R. Stevens, Addison-Wesley, 1992. A basic book for anyone writing programs that run under Unix (Recommended).
• The C Programming Language, 2nd Ed., B. W. Kernighan and D. M. Ritchie, Prentice Hall, 1988. ``The'' reference book (Recommended).
• The Practice of Programming, Brian W. Kernighan and Rob Pike. Addison-Wesley, 1999. There is more to writing a program than getting the syntax right, fixing the bugs you have noticed, and making it run fast enough. Programs are read not only by computers but also by programmers. A well-written program is easier to understand, grade, and modify than a poorly-written one. This book is packed with great practical advice on style, design, interfaces, testing and debugging, maintenance, ...; all issues that programmers must deal with in the real world (Recommended).
• I am collecting some pointers on C/Unix resources.

Optional Readings

• OS Structure - Edsger W. Dijkstra, The Structure of the "THE" Multiprogramming System, Communications of the ACM, 11(5), May 1968.
• Multics and the "computer utility" - F.J. Corbató and V. A. Vyssotsky, Introduction and Overview of the Multics System, In Proc. of the AFIPS Fall Joint Computer Conference 27, 1965.
• UNIX History - Peter H. Salus, UNIX at 25, Byte, 19, October 1994.
• Threads and scheduling - T. Anderson, B. Berhsad, E. Lazowska and H. Levy, Scheduler activations: effective kernel support for the user-level management of parallelism, In Proc. 13th SOSP, 1991.
• Priority inversion and what really happend on Mars? - Mike Jones' nicely written article on priority inversion and its part in the Mars Pathfinder mission What really happend on Mars?, December 1997.

CTEC Course Evaluation

You have the opportunity to register your opinions of this class. Please do so. I will use your comments for improving the course and your fellow students will refer to them when selecting classes and instructors.

The evaluations for the class will be completely anonymous; there will collected electronically and you may enter them from the computer in your room, the library or the labs.

When evaluating the TAs please use the following codes:

• Stefan Birrer - 331
• Yi Qiao - 212

You may access the CTEC online page anytime between Nov. 22 and Dec. 12 at midnight.

Announcements

Remember to check this regularly

• The quarter is over!

Course Organization

The course is organized as a series of lectures, TA sessions, reading, homework, projects and exams:

• Lectures - A set of lectures through which I present the core of the material.
• TA Sessions - Discussion sessions held by the TAs to answer questions about the lecture, readings, homework assignments, and projects.
• Readings - Textbook reading in preparation for (not substitution of) the lecture and additional reading for those interested in delving further into some topics.
• Homework - Five homework assignments with questions from (or similar to those in) your textbook, aimed at reinforcing the material covered in the reading and the lectures.
• Projects - Four programming projects to give you a better understanding of the subject matter and some experience with system level programming including thread-level programming.
• Exams - Two exams, a midterm and a final exam. These exams cover the material presented in the lecture, homework assignments and projects. You'll be able to bring one page of notes to assist you during the exam.

Homework

There will be two kinds of homework assignments given throughout the class: reading assignments and textbook-style questions. You should have finished the assigned reading before coming to lecture. In addition, there will be a set of written homework assignments that must be done alone and turned in at the end of class on the due date (see course policies below).

To upload your homework solutions please use this url.

Help on reading a research paper and writing a summary
You may find the following brochure useful: Efficient reading of papers in Science and Technology by Michael J. Hanson, 1990, revised 2000 Dylan McNamee.

Your summary should include at least:

1. Paper title and its author(s).
2. Brief one-line summary.
3. A paragraph of the most important ideas: perhaps a combination of their motivations, observations, interesting parts of the design, or clever parts of their implementation.
4. A paragraph of the largest flaws; maybe an experiment was poorly designed or the main idea had a narrow scope or applicability. Being able to assess weaknesses as well as strengths is an important skill for this course and beyond.
5. A last paragraph where you state the relevance of the ideas today, potential future research suggested by the article, etc.

Projects

As you can deduce from the allocation of weights for grading, programming projects make up a major portion of this class. There will be four (4) projects. Except for the first ``warm-up'' assignment on which you will work by yourself, all other projects are to be done by teams of two (2) people. Both partners should work cooperatively on the design, implementation, and testing of their solution.

To upload your projects please use this url.

Exams

There will be a midterm and a final exam. Exams will be in-class, closed-book (except for one page of notes you are allowed to bring in), and will cover materials from lecture, required readings and projects. The final exam will not be cumulative.

Grading

I use a criterion-referenced method to assign your grade; in other words, your grade will be based on how well you do relative to predetermined performance levels, instead of in comparison with the rest of the class. Thus, if a test has 100 possible points, anyone with a score of 90 or greater will get an A, those with scores of 80 or greater will get a B, those with scores of 70 or greater will get a C, and so on. Notice that this means that if everyone works hard and gets >90, everyone gets an A.

Total scores (between 0 and 100) will be determined, roughly, as follows:

• Homework 10%
• Projects 50%
• Exams (20% each) 40%

A note about class participation: while not explicitly included as an item in the previous list, your participation in class will be taken into consideration throughout the quarter and when granting partial and final scores/grades.

Course Outline and Approximate Dates

Because one has to be an optimist to begin an ambitious project, it is not surprising that underestimation of completion time is the norm.
-- Fernando J. Corbató, ``On Building Systems that Will Fail'', 1990 Turing Award Lecture.

Policies

Late policy:

Unless otherwise indicated, homework assignments and projects are due by the end of lecture on their due date. If you hand in an assignment late, we will take off 10% for each day (or portion thereof) it is late.

Cheating vs. Collaboration:

Collaboration is a really good thing and we encourage it. On the other hand, cheating is considered a very serious offense. When in doubt, remember that it's OK to meet with colleagues, study exams together, and discuss assignments with them. However, what you turn in must be your own (or for group projects, your group's own) work. Copying code, solution sets, etc. from other people or any other sources is strictly prohibited.