Computer Science 432 Operating Systems Williams College Fall 2006

Everything on this syllabus is subject to change. Changes will be announced in class and updated in the online version of the syllabus.

The course is about the design and implementation of operating systems. We will consider

• Historical aspects of operating systems development
• Process scheduling
• Synchronization of concurrent processes
• Memory Management and Virtual Memory
• I/O and file systems
• System Security
• Distributed operating systems

We will use Unix-like operating systems as a model to help understand operating system concepts and consider other operating systems of historical or modern interest at times as well.

• Computer Science 136, Data Structures and Advanced Programming, or equivalent.
• Computer Science 237, Computer Organization.
• You should also be able to design and implement significant programs in the C language, including appropriate documentation. I will work with those less familiar with C early in the semester to get you up to speed. This is a project course, so expect significant programming.

The required text for the course is Operating Systems Concepts, Seventh Edition (John Wiley & Sons, Inc. ISBN 0-471-69466-5) by Silberschatz, Galvin, and Gagne. This is available from Water Street Books. Be sure to get the correct edition, as this book is the latest in a long series.

You may also find it useful to purchase a Unix reference of your choice. Unix references will be available for your use in the lab.

Students are expected to attend class and participate in discussions. Come to class prepared. Assigned readings are listed on the lecture and reading schedule. Lectures will assume you are familiar with the material in the readings. Most lectures will include a small assignment due at the start of the next class. No late submissions of these assignments will be accepted, as they will often be discussed in class on the due date.

Labs in this course do not meet formally, but expect to spend a significant amount of time working in the lab. You will have lab assignments approximately weekly.

Lab assignments will have a written and/or a programming component. The number of points available will vary with the complexity of the assignment. Most if not all lab programming assignments will be designated as "laboratory programs." See the honor code guidelines at the end of this document for details. Programs will be graded on design, documentation, style, correctness, and efficiency. Answers to questions included in lab assignments are expected to be well-written.

You may develop programs for the lab assignments anywhere (in the lab, your own computers, etc.) but grading will be done using the Computer Science FreeBSD systems unless otherwise specified. It is your responsibility to ensure that your program works on the grading platform. You will have 24-hour access to the lab with your Williams ID.

Unless otherwise specified, lab assignments may be turned in with a penalty computed as 1.08^h%, where h is the number of hours late. Extensions will only be granted in serious situations and must be arranged through the Dean's office. You can find a C program that prints out a table of the late penalties here. Work turned in after solutions have been made available cannot receive credit.

All assignments and projects are to be submitted electronically using the turnin utility unless otherwise specified. Please submit writtren work in portable formats (plain text where appropriate, PDF or postscript when needed, avoid Word documents). If in doubt about a file format, please check with me first. Keep a copy of all submissions for yourself.

There will be two take-home exams. The first will take place after Fall Reading Period. The second will take place after the Thanksgiving break.

For the last part of the semester, regular lab assignments will become smaller and you will focus your efforts on a large project on a relevant topic of your own choosing. The project will include a proposal, a progress report, a paper and a presentation. Most projects will also involve significant software development. Details will be made available around mid-semester, but you should expect a series of intermediate due dates during the last few weeks of the semester and a minisymposium during reading period where you will present your projects to your classmates. The final project submission will be near the beginning of the exam period.

Grades for individual assignments and exams are not scaled. Any scaling deemed appropriate will take place at the end of the semester by adjusting the above thresholds. The following thresholds may be adjusted downward (thereby raising grades) but will never be adjusted upward.

The Honor Code as it applies to non-programming assignments is outlined in the Student Handbook.

For programming assignments in Computer Science courses, the honor code is interpreted in very specific ways. When a program is assigned, your instructor will identify it as a "practice," "test," "laboratory," or "team" program. The Honor Code applies differently to each with respect to collaboration or assistance from anyone other than the TAs or instructors:

understanding of a topic, and are not graded. Guideline: Help on these programs is unrestricted.

treated exactly as a take-home, open-book test. You are allowed to read your textbook, class notes, and any other source approved by your instructor. You may not consult anyone other than your instructor. The instructor encourages the asking of questions, but reserves the right not to answer, just as you would expect during an exam. Guideline: Any work that is not your own is considered a violation of the honor code.

work of the individual student, designed and coded by him or her alone. Help locating errors is allowed, but a student may only receive help in correcting errors of syntax; help in correcting errors of logic is strictly forbidden. Guideline: Assistance from anyone other than the TAs or instructors in the design or coding of program logic will be considered a violation of the honor code.

worked on in teams of two or more students. You are allowed to discuss team programs with your partners, but work with others is otherwise restricted by the appropriate rules above. Guideline: Any work that is not the work of your team is considered a violation of the honor code.

If you do not understand how the honor code applies to a particular assignment, consult your instructor.

Students should be aware of the Computer Ethics outlined in the Student Handbook. Violations (including uninvited access to private information and malicious tampering or theft of computer equipment or software) are subject to disciplinary action.

Guideline: To protect your work dispose of printouts and diskettes carefully, and avoid leaving your programs on hard disks in labs and other public storage areas.

The Department of Computer Science takes the Honor Code seriously. Violations are easy to identify and will be dealt with promptly.