Computer Science 432/563
Operating Systems

Spring 2016, The College of Saint Rose

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Disclaimer

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

Course Objectives

From the course catalog: "This course examines the concepts of modern and historical operating systems as a resource manager. Topics include multithreading, process management, CPU scheduling, process synchronization, deadlock, memory management, persistent storage management, and security. Significant programming projects using C in a Unix environment are required."

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.

Course Goals

1. Develop an understanding of computer operating system software.
2. Develop further proficiency in the C programming language.
3. Develop an understanding of concurrency, including the problems that can arise and solutions to manage those problems.
4. Learn how to use the command-line interface of a Unix-like environment.
5. Learn to use Unix system calls in C programs, including those for process (fork, semaphores) and thread (pthreads) management.
6. Understand the overall design of modern operating systems for devices ranging from handheld computers to supercomputers.

Prerequisites

• Computer Science 302, Data Structures or Computer Science 501, Data Structures and Algorithms, or equivalent.
• Computer Science 381, Programming Unix in C, not required, but strongly recommended. You should also be able to design and implement significant programs in C or C++, including appropriate documentation. We will refresh your C skills during early labs, with the assumption that you are most familiar with Java but have significant exposure to C.
• Computer Science 332, Microcomputer Architecture and Programming or Computer Science 502, Computer Organization is not a formal prerequisite but is helpful.

Texts

The required text for the course is Operating Systems Concepts Essentials, 2nd Edition (John Wiley & Sons, 2014, ISBN 978-1-118-80492-6) by Silberschatz, Galvin, and Gagne. This is available from the college bookstore and elsewhere. Be sure to get the correct edition, as there are a number of variations on this text.

You may also find it useful to purchase a C and/or Unix reference of your choice, though this is less essential than in the past with the vast online resources on these topics readily available.

Lectures

Everyone is expected to attend class and participate in discussions. Supplemental readings are listed on the lecture and reading schedule. Of course you are encouraged to do all of the reading, but all important topics will be covered in class or by lecture or lab assignments (some of which might require you to go back through the text for more detail than we have time to cover in class).

The notes I use to guide my in-class presentations are available as PDF files linked from the lecture and reading schedule.

Be prompt, prepared, and ready to focus on the day's topics. This should go without saying, but this means your phones and other devices not being used exclusively to follow along with class materials and/or to take notes must be powered off. You may bring food or drink to class, as long as you are not a distraction to your classmates or instructor. The exception is when you are using College computers, in which case no food or drink can be permitted.

Most lectures will include a small assignment due at the start of the next class. No late submissions of these "lecture assignments" will be accepted, as they will often be discussed in class on the due date. Some of these assignments will be graded for correctness, while others will be graded based on whether an honest effort was made.

Labs

Lab assignments will have a written and/or a programming component. The number of points available will vary with the complexity of the assignment. Programs will be graded on design, documentation, style, correctness, and efficiency. Answers to questions included in lab assignments are expected to be well-written.

Some lab assignments are "standalone" and are intended to give you experience with a particular concept, and should be able to be completed within a few hours. Others will serve to get you started on one of the larger programming projects. There will be 3 or 4 programming projects during the course of the semester for which you will develop larger programs.

You may develop programs for the lab and programming project assignments anywhere (in the lab, your own computers, etc.) but grading will be done using the College's Unix systems unless otherwise specified. It is your responsibility to ensure that your program works on the grading platform. Unless otherwise specified, you are permitted (and are in fact, encouraged) to get help from your instructor. You may discuss the labs and projects with your classmates, but the work you submit must be your own (and that of your teammates, for work done in groups).

Your submissions for lab and project assignments will include several types of items. Different requirements apply to each, as described below. It is important that you adhere to file format and naming requirements to facilitate grading. Submissions that do not meet these requirements will not be accepted.

Lab Questions

The answers to all "lab questions" for a particular lab should be included within a single plain-text file named labn.txt, where n is the lab number. The file should start with your name and the lab number, followed by line-wrapped text responses to each lab question in the assignment. Your file should be appropriately line-wrapped for easy reading in a window or on a printed page with a width of 80 characters.

Note: for lab questions that ask you to draw a memory diagram, you have a few options. You may attempt to represent the memory with plain text, but that is difficult to construct and read. Ideally, you would use a drawing program and submit a PDF file, but you are also permitted to draw the diagram on paper and submit a scan or photograph, as long as the diagram is legible in that form.

Output Captures

You will sometimes be asked to capture the output of an existing Unix command or one of your programs in a file for submission. The file name to use for each such task will be specified in the question.

Practice Programs

Your submissions for practice programs are graded primarily on correctness, but you will be required to include your name at the top of the program, and you must use the file name specified.

Programming Assignments

These are the most formal submissions and will be graded on design, documentation, style, correctness, and efficiency (where appropriate). A good design will use an appropriate algorithm, data structures, and language constructs to solve the problem. A well-documented program will include a comment at the top of each file that includes your name, the assignment, and a description of the contents of the file. There should also be comments for each structure definition, each function definition (including a brief description of the function's purpose, its parameters, and return value), each variable or group of related variables, and any section of code whose purpose and/or behavior is not obvious from context or the code itself. Style requirements include appropriate formatting (sufficient and consistent indentation, spacing, and punctuation, wrapping long lines of code), good use of constants, and meaningful and appropriate names for variables, functions, constants, and parameters. Correctness, of course, requires the expected output be produced for a set of test inputs (which will normally not be provided in advance). Efficiency will be more important in some assignments than others, and requires that the program does not do any unnecessary computation or use any more memory than needed. This includes returning memory to the system when using dynamic memory management. And, of course, you must use the file name specified.

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. 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 procedure specified on each lab handout. Please submit written work in portable formats (plain text where appropriate, PDF or postscript when needed). If in doubt about a file format, please check before submitting. Keep a copy of all submissions for yourself.

Exams

There will be a midterm exam during the semester, tentatively scheduled for early March, and a final exam. Details to be determined.

Final Project

For the last part of the semester, the workload of the regular lab assignments will be reduced 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 our final meeting(s) where you will present your projects to your classmates. Your final project submission (paper and software) will be due on the last day of classes. Those taking the course for graduate credit will be expected to complete a more significant project.

Grading

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 thresholds. The following thresholds may be adjusted downward (thereby raising grades) but will never be adjusted upward.

Attendance

Every college student should be motivated to attend every lecture and lab meeting for all the right reasons (e.g., desire for knowledge, desire to get the most out of every very expensive minute, etc.). As college students, you understand that regular attendance is essential to your ability to master the course material.

Therefore, there is no formal attendance policy. You are expected to attend regularly, and should still see the instructor about any excused absences. An excused absence may be any of the following:

1. A documented athletic or academic event that conflicts with a class meeting. The required paperwork must be presented in person at least one week prior to the event.
2. A family emergency.
3. Personal illness.

While there is no formal penalty for unexecused absences, missing class regularly, frequent tardiness, or being distracted in class (e.g., checking your phone or Facebook) will be considered a sign that you are not taking the course seriously. Common sense suggests and experience validates that students who are frequently absent, late, or inattentive perform poorly on graded work. Do not expect compassion when final grades are assigned or extensive extra help if you do not understand a topic that was covered while you were absent without a valid excuse.

Disability Accommodations

If you are a student with a documented disability and require academic accommodations please register with Lynn Cantwell, the Director of Services for Students with Disabilities, located in the Academic Support Center on the 2nd floor of St. Joseph Hall (campus extension 2335 or 518-337-2335, off campus) for disability verification and for determination of recommended reasonable academic accommodations. After you have made arrangements with that office, please see me to discuss your accommodations. Please remember that timely notice will help avoid a delay in your receipt of accommodations.

Academic Integrity

You are encouraged to discuss the concepts related to course assignments and exams with your classmates. This is an essential part of a healthy academic environment. However, work submitted for grading must be your own (or the combined work of group members, for group assignments). Any unauthorized copying or collaboration is considered a breach of academic integrity and will not be tolerated. Plagiarism, cheating, academic misconduct, or any other submission of another's work as one's own are unacceptable. Students working in groups are each individually responsible for the academic integrity of the entire group project. Academic dishonesty cases are unpleasant and uncomfortable for everyone involved. You are responsible for reading and understanding The College of Saint Rose Policy on Plagiarism and Academic Integrity.

The minimum penalties for a first violation will include failure (0 grade) for the assignment or exam in question and the filing of a Academic Dishonesty Report Form with the Registrar's office. A second violation will result in failure of the course and a second Academic Dishonesty Report Form.

If there is any doubt about the degree of collaboration allowed or the permitted sources for a particular assignment, please ask for clarification before collaborating or consulting the source. Any such collaborations or sources must be cited properly.

The relationship among an academic institution and its faculty and its students is central to the entire concept of modern higher education. Each party has responsibilities that must be met in order for the degrees conferred to have meaning to the outside world.

The Institution

• Certifies that the faculty it employs are qualified to carry out instruction in their fields of expertise, and have developed appropriate and rigorous programs of study.
• Certifies that the students it admits are prepared for their chosen courses of study.
• Certifies the successful completion of the program of study by students who earn degrees from the institution.
• Provides student support beyond that provided by faculty (listed below), though academic, advising, and other support services.

The Faculty

• Provides courses that meet a set of learning outcomes that, together, form a rigorous program of study.
• Certifies, through course grades, the degree to which students have demonstrated mastery of the learning outcomes.
• Supports student learning through course materials, effective use of class time, and other means outside of class time (e.g., office hours, responding to email questions, etc.).
• Takes all reasonable steps to ensure that the work submitted for grading is completed honestly by the student who submits it.

The Students

• Honestly represent their pre-college (or pre-graduate school) preparation when applying for admission.
• Put forth the effort needed to complete the coursework, and do so with honesty and integrity.
• Represent the college and the degree earned in positive manner out in the "real world" after graduation.

Note especially the dual role of the faculty as defenders of the integrity of the degrees our institutions confer and as primary facilitators to the students to be able to earn those degrees. Too often students view faculty and the courses they teach as obstacles between the student and the degree. While faculty do have a responsibility to make sure only students who have shown through their own honest work earn the degree, it is the faculty's goal to help ensure that every student (who is willing to put in the effort along the way) has the chance to earn that degree. But without the faculty defending the integrity of the college degree by making sure only students who have demonstrated compentency in their chosen program of study, that degree would soon be rendered meaningless.