Home CS439

CS439 Spring 2017 Project Information


There will be five projects for this class, each emphasizing a different set of important skills. You will begin by writing a shell. Your other projects will exercise your knowledge of threads, user programs, virtual memory, and file systems.

You will work on all of these projects in teams of two or more (as specified in each project). You are responsible for forming a team with someone with whom you will work well and resolving any problems that arise during the partnership is your responsibility. If you are unable to resolve a serious problem, the instructor will arbitrate.

Your team must follow a pair programming methodology. In particular, both members (or, for the later projects, all members) of the team must work together to understand the problem, design your solution, enter code, and test your solution. For code entry, one member should type while the other(s) observes, detects tactical coding defects, and thinks strategically about the overall design. These roles must be frequently swapped. In general, studies [1, 2] suggest that pair programming works well:
  1. (counter-intuitively two programmers working together at one keyboard produce about as much functionality as two programmers working apart at two keyboards,
  2. the code produced in this manner is of higher quality than individually programmed code, and
  3. in an educational setting both team members learn more than they would separately.
Note that for these projects, these advantages of pair (or group) programming over disjoint work are especially likely to apply: it is vital that all team members understand all aspects of the implementation. Also be aware that the exams will have questions that required intimate knowledge of the project.

The projects will be challenging. We hope they will also be very satisfying. The instructor and TAs will work to help you succeed. Although the scope of the projects is ambitious, we will provide a framework to guide your efforts and to ensure that you don't have to spend a lot of time building uninteresting "glue" code. Our hope and expectation is that everyone that works hard on these projects will succeed. If you have other ideas for improving the project, please let us know. Good luck!

  • 2017-03-23: The Design Interview signup page is available---groups should sign up for one time slot together. Please be certain to signup according to the posted instructions, and you must signup for a time by Sunday, 3/26, at noon.

  • 2017-03-03: The Stack Check signup page is available. Please be certain to signup according to the posted instructions, and you must signup for a time by Sunday, 3/6, by noon.

  • 2017-02-27: I annotated the directions for hex_dump() and took a picture. Each item on the stack is color-coded to match the corresponding item in the directions. I hope it helps!
  • 2017-02-07: The distributed project had an error in mshref: when an unrecognized command was entered, "Command not found" was not printed. Get an updated version here.

Please review the Grading Criteria. All code must follow the C Style Guide.

Turning in your code? Please look over the Turnin Checklist!


Required Group Size
Group Registration Deadline
Relative Weight
Project 0: A Mini Shell
Become familiar with shells, fork(), exec(), and signals 2 Jan 27 Feb 10 10
Project 1: Threads
Understanding interrupts, thread state, and thread scheduling 2-3 Feb 15 Feb 24 20
Project 2: User Programs
Understanding how user programs interact with the OS 2-4 Mar 1 Mar 6/Mar 24 20
Project 3: Virtual Memory
Understanding paging, page replacement, and other virtual memory concepts 2-4 Mar 29 Apr 14 25
Project 4: File Systems
Understanding file systems, including directory structure, file growth, and multithreading 2-4 Apr 19 May 5 (No slip days!) 25