Department of Computer Science
CPSC405: Introduction to Operating Systems
I really like Professor Dahlin’s description of his operating systems course:
“The crosscutting theme in this course is providing abstractions above imperfect hardware to make it usable by programmers and users. At the end of the course, students should understand a set of abstractions (concurrent programming, virtual addressing, memory protection, caching, transactions, …) that are useful in many large-scale software systems not just OS kernels. More important than memorizing specific abstractions used in operating systems of the past, students should understand these abstractions well enough to synthesize their own abstractions when faced with new problems.Another important goal of the course is for students to understand the computers they use and on which they build their applications. A student graduating with a CS degree should believe “there is no magic”: they should be able to describe the chain of events that occurs when they hit a key and cause a letter to appear on the screen from the register level (or logical gate level or transistor level) to the system architecture level to the operating system level to the application level. This is philosophically important, but it is also of practical interest to developers who need to figure out how to make a system do what they want it to do.”
- to develop the ability to read (and apply) program specifications and technical documentation.
- to develop the ability to meet coding deadlines
- to acquire a good understanding of the structure of operating systems including
- process synchronization
- memory management
- virtual memory
- file-system interface and other I/O
- gain basic core competencies in kernel development. This includes extending a barebones kernel to include executing user processes, paging, and file management.
- develop abilities to critically compare operating systems and assess emerging technologies.
- Operating Systems: Principles and Practice by Thomas Anderson and Michael Dahlin. Recursive Books 2012.
- Additional online readings assigned in class.
This is a programming intensive course.
I hear and I forget. I see and I remember. I do and I understand. — Confucius
This semester we will be working through a variety of programming projects. In 305, the architecture class, you gained experience with the C programming language. The first projects of this course (done individually) are intended to refresh your memory of C. One is a review of bitwise operators in C and the other is related to dynamic memory allocation.
The rest of the projects will be done in teams of two. It is your responsibility to select someone with whom you work well. It is also your responsibility to resolve any team problems. You must follow the pair programming methodology. In particular, both people must work together at the same time to understand the problem, come up with a solution, code the solution, and test the code. This works best when two people share one computer periodically swapping the keyboard as they change roles. In addition to improving your code this will enable both people to understand all aspects of the project. Quizes will have questions that require detailed knowledge of the projects.
The projects will be challenging. The programming labs are time intensive and you should plan your class schedule accordingly.
Projects can be developed on lab computers (Rosemary) or your own computer. Projects will be graded based on how they run on the lab computer environment. Be sure to test your code on a lab computer before submitting it.
Projects are due anytime on the due date. That is, if the due date is on a Saturday, you can submit the project up to midnight Sunday. Projects turned in by 8am the following day will likely incur a 7% penalty. Projects turned in between 8am the following day and midnight will likely receive a 15% penalty. Students unable to complete a project due to illness or family emergency should contact me as soon as possible.
Due date flexibility and slip days
Each team is allowed 4 slip days. The team can divide these slip days among projects anyway they wish to extend project deadlines. To help me keep track of slip days, the top of each project’s readme file must contain the following line:
Slip days used for this project ______ Total slip days used for all projects _______
Fractions of slip days may not be used. If your project is one hour late you must use a whole slip day.
Any team can appeal a project’s due date. The appeal must be supported by every member of the team and must be verbally presented at the beginning of a class period. The appeal must include 1) the source of why the project cannot be completed by the original due date, 2) offer an alternative due date, and 3) specify evidence that the proposed due date is reasonable. If an appeal is granted the new due date will be for the entire class. I also may extend due dates on my own.
Cooperation versus cheating
The lab you submit must be your team’s own work. There will be opportunity in class to discuss the projects in a general way with students in your group, but you may not examine any other team’s code. Sharing code on programming assignments is a form of academic dishonesty. Significant similarity of notation or form between submissions of different students or between a student’s work and solutions found on the web will be regarded as evidence of academic dishonesty. Also, you also should not google and find lab solutions for any similar course.
You should not look at the written work of another student (other than your team mate). This includes code and sketches of a solution drawn on paper or whiteboard. Having a discussion while one person is looking at written material is also not appropriate. When you are discussing the project with another student you should not be writing anything down, recording the conversation, or using a computer. Remembering what a person said without these aids is some indication that you actually understood the material.
As I mentioned, this is a programming intensive course, and I expect students to make a good-faith effort to complete the programming assignments.
During the first day of class, all students will be assigned to permanent teams. Throughout the course, teams will both take team tests and participate in joint activities. Team performance will be one component of your final grade.
Grading is based on a method developed by Professor Lee Sheldon at Indiana University. It is based on obtaining experience points (XP). The number of XP determines what level you are at. You start the class with 0 XP at Level 0. The level you obtain at the end of the semester determines your final grade. Here is the chart:
I differ from Professor Sheldon in offering students options on how to accumulate XP. There will be opportunities to earn at least 2350XP during the course. This gives each individual some flexibility in what tasks to do. You gain XP working individually, with a partner, and with your team.
If you are at Level Zero when midterm grades are due I will report your work as unsatisfactory.
Programming Projects – 750XP
There will be between 5 and 6 programming projects involving Intel assembly, C, and C++. Each project will be worth between 150 and 250XP.
Quizzes – 500XP
There will be approximately 5 short multiple-choice quizzes given during the course. Each quiz will be taken individually, then, immediately after, the same test will be taken as a team. Each individual quiz is worth on average 40 points; each team quiz is also worth on average 40XP. You will have advance notice of these quizzes.
Team Work (in-class) – 250XP each team member
There will be a variety of activities worth between 50-75XP. The vast majority of team work will be done during class time. However, to get maximum points on a particular task you may need to meet occasionally outside of class.
Partner Reading Presentation – 75XP
You will do a presentation on a section of the textbook or an assigned reading.
Individual HW – 350 XP
These can be either short programming problems or questions.
Team Participation – about 100XP
Each student will rate the helpfulness of all members of their team. Individual team participation scores will be the sum of the points they receive from other members of their team. Each team member distributes 100 points to other members of the team. The average team participation score will be 100 points. The rater must differentiate some of their ratings (they cannot assign the same rating to all members).
Exam – 400XP
The final will be a comprehensive take home final. Often the fate of what grade you receive for a class hinges on how well you perform on a final which is given at the last possible moment of the semester. Our final will work differently. Starting around the midpoint of the semester, I will be posting questions and problems which are part of the final for the course. You can elect to complete the work anytime between the time the problem is posted and our official final exam time. You will gain 10% more XP if you complete the work within a week of the problem being posted.
Announcements, discussions, and questions
I will communicate with the class via piazza and the course web page.
For questions about any aspect of the course including homeworks and labs, please use piazza rather than email. If you want you can tag questions as ‘private’.
You are responsible for checking your email and piazza every 24 hours and the web page at least weekly.
Avatar names, pseudonyms, noms de plume
During the first week of class I will ask you for your avatar name, pseudonym, whatever. This is the name that will appear on the Experience Point Google Spreadsheet that will be viewable by everyone in the class. If you wish to remain anonymous, don’t share your avatar name with anyone. On the other hand, if you would like recognition for achieving level 10 as an example (“a big shout out to tera miner for achieving level 10”), you can share your name. The decision is yours. To further protect the anonymity of those who wish to remain anonymous, the spreadsheet will also be populated by fictitious avatar names.
Accommodations for students with special needs
Any student with a documented disability may receive a special accommodation to complete any requirements of this course. If you are have a disability or believe you have one you may wish to self-identify. You may do so by providing documentation to the Office of Disability Services located in Room 203 of George Washington Hall (Phone: Voice 540-654-1266, Fax: 540-654-1163). Appropriate accommodations may then be provided for you. If you have a condition that may affect your ability to exit the premises in an emergency or that may cause an emergency during class, you are encouraged to discuss this in confidence with me and/or anyone at the Office of Disability Services. This office can also answer any questions you have about the Americans with Disabilities Act (ADA).
I assume you are an ethical student and a person with integrity. I expect that you will follow the university honor code (see http://rosemary.umw.edu/CSHonorCode.html). Please use common sense and ask yourself what would a person with integrity do? To help you, I would like to make three comments related to this:
Plagiarism means presenting some other person’s work as your own. This can mean using some other person’s words without acknowledging their source, or using some other person’s ideas. Copying another student’s work (homework or exam) is also plagiarism. Plagiarism will minimally result in an automatic zero for that submission.
Collusion is unauthorized collaboration that produces work which is then presented as work completed independently by the student. Collusion includes participating in group discussions that develop solutions which everyone copies. Penalties for plagiarism and collusion include receiving a failing grade for the course.
I ask that you respect the other people in the class. I recognize that your life circumstances may require you to receive cell phone calls during class. If this is the case please set your cell phone on vibrate and discretely leave the class to accept calls. During tests, if you walk out of the classroom, or consult/display your cell phone, I will assume you are done with the test and collect your grading sheet.
I expect students to attend classes regularly. That said, attendance is not taken and no XP will be awarded based directly on attendance. If you are going to miss a class, please be courteous and inform your team mates.
The class schedule is posted on the course website.