CSCI 3500: Operating Systems - Class Page

Fall 2021

Daily Seat Tracking: cs.slu.edu/seats/

1. Course Description
2. Prerequisites
3. Lecture
4. Studios
5. Labs
6. Course Schedule
7. SLU Git Repository
8. Textbooks and Other Resources
9. Grading
10. Attendance
11. COVID-19 Considerations for Fall 2021
12. Fall 2021 Mask Policy
13. Academic Integrity
14. Title IX Statement
15. Academic Support
16. Disability Services
17. Writing Center
18. Basic Needs Security

Course Description

Operating systems are the bridge between computer hardware and the software programs we create and use. As a concept, operating systems are one of the oldest software disciplines, yet they continue to adapt and reinvent themselves as the computing landscape evolves. Modern operating systems must tackle the same challenges of the original mainframes, but must also meet the varied needs of personal computers, severs, mobile/embedded devices, and virtualized systems.

The four elements of this course are lectures, studios, labs, and exams. Studios are short assignments intended to be completed primarily within class time and to augment lecture topics. Labs are longer assignments that will ask students to apply and analyze OS mechanisms. Lectures will be delievered asynchronously via recording. Most class periods will be a mix of questions and answers over lecture material, deep-dives into one or more of the lecture topics or practical demonstrations, and pair programming time for studios. Expect a lab assignment approximately every two weeks.

Topical outline:

• The operating system, system libraries, and user applications
• System calls and interrupts
• User programs, processes, and threads
• Processor sharing and operating system scheduling
• Race conditions, locks, and mutual exclusion
• The address space abstraction and virtual memory address translation
• Virtual memory via paged memory and historical approaches
• File systems and disk organization
• 7-layer OSI and 4-layer TCP/IP networking models
• Sockets programming
• Read, write, and execute permissions and institutional access models

Assessment Objectives- at the completion of this course, students will be able to:

• Describe how operating systems facilitate and interact with system libraries and user space programs
• Describe the purpose and implementation of major operating system abstractions: processes, threads, virtual memory, and the network stack
• Identify the presence/absence of race conditions and resolve race conditions with locking
• Write simple concurrent and multi-threaded programs (e.g. with fork() and Pthreads)
• Write simple networked programs (e.g. with sockets programming)

Catalog Description:Theory and practice of operating systems, with emphasis on one of the UNIX family of operating systems. File organization and database systems. Focus on a multi-user system in the client-server model. Hands-on experience.

Prerequisites

• CSCI 2100 - Data Structures
• One of: CSCI 2400 - Computer Architecture or ECE 3217 - Computer Architecture and Organization
• Some experience: C or C++
• Some experience: object-oriented programming
• Studios and lab assignments are constructed around the Linux terminal, prior experience is beneficial but not required

Please see the instructor if you're missing a prerequisite or uncertain about your preparation for this course.

Studios

Computer science is an eminently practical discipline, and studios are daily assignments intended to complement and reinforce lectures through practice. Studios will be completed in a team of two students. Students from different teams may discuss studios, but sharing of code or solutions is strictly prohibited.

Studios will be submitted via the Git repository. Every student should have a copy of their studio solutions in their own repository, even if you work with a group.

Studios are due Friday of the week after they are assigned. The midterm exam and other cirumstances may modify this, see the complete course schedule below.

Studios will be graded on a trimodal scale: complete, partial credit, or no credit. Studios that are turned in late or not turned in at all will receive no credit, studios graded as partial will receive 60% credit.

Labs

There will be five lab assignments for this course. These are programming assignments whose purpose is to apply course concepts and to analyze operating system mechanisms. As such, each lab will require a written report detailing your findings in addition to a code submission.

Some labs will require a team of two students, while others are individual projects. Students from different teams may discuss the lab assignments only during course meeting times. Students from the same team are of course encouraged to discuss and work on lab assignments at any time.

Labs submitted on time (as determined by electronic time stamp) are eligible for full credit. Labs submitted up to 24 hours late will be given a ten percent penalty. Labs submitted between 24 and 48 hours late will be given a twenty percent penalty. Labs submitted after 48 hours late will not be given credit, except in the case of extenuating circumstances pre-approved by the instructor.

Course Schedule

SLU Git Repository

All studios and labs will be submitted via individual course Git repositories that are housed at SLU. You will find your repository already has a directory structure that provides a place for all lab and studio assignments. Your work must be in the appropriate location for the instructor to find it and count it for credit.

A short guide to using SLU's git resources

Textbook and Class Resources

Reccomended Course textbook: Modern Operating Systems by Tanenbaum and Bos. Either the 3rd or 4th Edition works fine. A classic computing textbook on the fundamentals of operating systems, with a bent towards Unix-like operating systems. This book is not required for the course, rather it is a secondary source of information that provides a more comprehensive and textbook-like presentation of the material for students who prefer this. I will not be assigning homework from the book or taking test questions from the book. Access to the book's companion website is not required and will not be used during this course.

Linux skills references:

References for Linux software development.

• vi tutorial

• Another vi tutorial

• emacs tutorial

• Another emacs tutorial

Software resources:

• Secure Shell: My favorite terminal client- runs through the Chrome browser on nearly any platform. Gives a great, consistent interface between Windows, Mac, and Linux. If you've only ever used PuTTY you should really try something else!

• Google Search for Shell Emulators: Find something that works for you!

• WinSCP: Easily transfer files between your Windows machine and the departmental Linux machines.

• scp manual page: Transfer files between your Mac/Linux machine and the departmental Linux machines.

Linux kernel hacking references:

We aren't doing any kernel hacking in this course, but these are great references if you're interested.

• Linux Kernel Development by Robert Love, 2010. This is an excellent, compact, and inexpensive text that gives the reader a good understanding of kernel design and critical kernel source code. Written by a Linux kernel veteran.

• Understanding the Linux Kernel by Bovet and Cesati, 2006. This is a more exhaustive reference to the kernel than Love's book, covering many data structures and code snippets in detail. Available online for free through the university's subscription to the O'Riley Safari service.

• Linux Device Drivers by Corbet, Rubini, and Kroah-Hartman, 2005. The definitive book on hardware device drivers for Linux. Contains some useful reference material over kernel modules, kernel development, kernel locking, timing, and other topics. Available online for free through lwn.net.

• LWN.net is a news and information outlet for the open source community. They often run very high quality articles about kernel development, kernel architecture, and kernel mechanisms. When I can't find any good references, searching for "LWN (my_topic)" is usually helpful.

• Linux Journal is a magazine covering the Linux community. They often run very high quality articles about kernel development, kernel architecture, and kernel mechanisms. Similar to above, searching for "Linux Journal (my_topic)" often yields good results.

• Linux Cross Reference by free-electrons.com This tool easily allows you to browse the Linux source code as well as search for identifiers.

• kernel.org the go-to website for Linux kernel source code.

Grading

There are three activities for which you will receive credit in this course: studios, labs, and exams. Studios are daily guided assignments primarily designed to familiarize students with course concepts and development tools (i.e. knowledge and comprehension tasks). Lab assignments will ask students to apply general course concepts and analyze OS design alternatives. A midterm and final exam will evaluate your technical understanding of course concepts.

Studios are graded on the following scale: complete, partial credit, or no credit. Studios will not be turned back with detailed comments. Labs and exams will be graded on a points scale and will be turned back with comments. My goal is to return lab assignments to you within nine days of the deadline, which is an additional 48 hours for late submissions plus one week for grading time. Similarly, my goal is to return exams to you within one week.

Extensions on labs and studios are generally not granted aside from major unexpected events. You have at least a week to complete and submit any studio in this course, and at least two weeks for any lab assignment- it is assumed that this is sufficient for you to work around things such as sporting events or academic conferences on your own time. Please note the automatic 48-hour late policy for lab assignments.

I am happy to work with you on rescheduling exams if you are away from campus for slu-sponsored travel, but you must notify me at least two weeks ahead of time (and note that the exam dates are provided as of the first day of class). Make up exams outside of this policy will only be given for severe and documented reasons.

Your grade will be determined as follows:

Grading is done on a straight scale (uncurved). The following scores are guaranteed. The grading scale may be curved upwards (in your favor) at the discretion of the instructor.

• 93% guarantees an A
• 90% guarantees an A-
• 87% guarantees a B+
• 83% guarantees a B
• 80% guarantees a B-
• 77% guarantees a C+
• 73% guarantees a C
• 70% guarantees a C-
• 60% guarantees a D

Most work assigned in this course, other than exams and some labs, is expected to be completed collaboratively. Student teams may change from assignment to assignment, but the sharing of written work or significant portions of code between teams is strictly prohibited.

Some specific guidelines for this course:

• Code you submit as solutions to the programming assignments must be written by you or your team. You are not allowed to copy code from other students.
• Copying pieces of code from in-class examples is allowed, but you must cite the source of such code with a comment denoting the start and finish of the copied section.
• Copying small pieces of code from man pages, online references or other sources is generally acceptable, but to be safe you should check with me first. Code from such sources must be cited with a comment denoting the start and finish of the copied section. Knowing how to use online references effectively is an essential skill for modern software developers and I don't want to discourage you from using such sources for understanding APIs and how to call complex functions. It is often the case that there is an expected "right way" to accomplish a specific task such as creating a pThreads thread or binding a socket to an address- lookups of this nature are equivalent to using a textbook or language reference and are fine. Looking up "How do I write my own malloc()" or "How to build my own shell" on the other hand is cheating. If you are in doubt, ask first!
• Copied code that is not cited will be considered plagiarism and will be treated as cheating. Citing your code protects you from this. However, copying large portions of code is still grounds for a reduction in grade, even if it is not cheating. Please check with the instructor if you are copying more than a line or two of code!

Attendance

Successful students attend all or mostly all class sessions. This is true in my experience and has been demonstrated in large scale studies as well. In that study, even students who attended nine out of ten class periods had measurably lower class performance than those who attended all classes. However, there is no attendance requirement for this class, and you do not need to get permission when you do miss class. You are an adult and have the freedom to manage your time in whatever way you feel is most useful. Job interviews, conferences, tests in other courses, etc. are all reasonable cases for being absent.

Note that in-class assignments such as tests or quizes cannot be made up outside of class without prior approval from the instructor. All such activities will be listed course schedule with ample time to prepare (i.e. there are no "pop quizes").

If you do miss class you should refer to the course schedule to see what was missed and arrange to get course notes from another student. I am always happy to answer questions but I do not repeat full class periods in office hours.

2021-2022 Mandatory Syllabus Statement on In-Person Class Attendance and Participation

The health and well-being of SLU’s students, staff, and faculty are critical concerns, as is the quality of our learning environments. Accordingly, the following University policy statements on in-person class attendance are designed to preserve and advance the collective health and well-being of our institutional constituencies and to create the conditions in which all students have the opportunity to learn and successfully complete their courses.

1. Students who exhibit any potential COVID symptoms (those that cannot be attributed to some other medical condition the students are known to have, such as allergies, asthma, etc.) shall absent themselves from any in-person class attendance or in-person participation in any class-related activity until they have been evaluated by a qualified medical official. Students should contact the University Student Health Center for immediate assistance.
2. Students (whether exhibiting any of potential COVID-19 symptoms or not, and regardless of how they feel) who are under either an isolation or quarantine directive issued by a qualified health official must absent themselves from all in-person course activities per the stipulations of the isolation or quarantine directive.
3. Students are responsible for notifying their instructor of an absence as far in advance as possible; when advance notification is not possible, students are responsible for notifying each instructor as soon after the absence as possible. Consistent with the University Attendance Policy, students also are responsible for all material covered in class and must work with the instructor to complete any required work. In situations where students must be absent for an extended period of time due to COVID-19 isolation or quarantine, they also must work with the instructor to determine the best way to maintain progress in the course as they are able based on their health situation.
4. Consistent with the University Attendance Policy, students may be asked to provide medical documentation when a medical condition impacts a student’s ability to attend and/or participate in class for an extended period of time.
5. As a temporary amendment to the current University Attendance Policy, all absences due to illness or an isolation/quarantine directive issued by a qualified health official shall be considered “Authorized” absences.

COVID-19 Considerations for Spring 2021

Notification of absences: You do not need to notify the instructor that you are missing a regular class meeting. Notify the instructor as early as possible if you have a conflict with exam times.

Student Absences: It is the responsibility of the student to accommodate their absence. Make arrangements in advance with another student to get a report of synchronous class activities and their notes for the day.

Late work: Severe illness is a reasonable basis to request an extension on lab assignments. However, my experience is that extensions tend to do more harm than good for many as once you get behind on work it can be difficult to catch up. All students would be well-served by starting assignments early especially with the uncertainty due to COVID-19.

Grading policy changes: If circumstances require it, certain graded elements of the course may be eliminated or replaced with a substitute. In the case of substitution the new assignment will have the same point-values as the old assignment: for example if the midterm exam is replaced with a programming project that programming project will be worth 15% of your final grade. In the case of elimination the point-values assigned to the activity group will not change: for example if we eliminate one of the five lab assignments then the remaining four will collectively still be worth 50% of the final grade.

Mandatory Syllabus Statement on Face Masks (2021-2022)

Throughout the COVID-19 pandemic, key safeguards like face masks have allowed SLU to safely maintain in-person learning. If public health conditions and local, state, and federal restrictions demand it, the University may require that all members of our campus community wear face masks indoors.

Therefore, any time a University-level face mask requirement is in effect, face masks will be required in this class. This expectation will apply to all students and instructors, unless a medical condition warrants an exemption from the face mask requirement (see below).

When a University-wide face mask requirement is in effect,the following will apply:

• Students who attempt to enter a classroom without wearing masks will be asked by the instructor to put on their masks prior to entry. Students who remove their masks during a class session will be asked by the instructor to resume wearing their masks.
• Students and instructors may remove their masks briefly to take a sip of water but should replace masks immediately. The consumption of food will not be permitted.
• Students who do not comply with a request by a SLU instructor to wear a mask in accordance with the University’s Interim Policy on Face Masks may be subject to disciplinary actions per the rules, regulations, and policies of Saint Louis University, including but not limited to those outlined in the Student Handbook. Non-compliance with this policy may result in disciplinary action, up to and including any of the following:
• dismissal from the course(s)
• removal from campus housing (if applicable)
• dismissal from the University
• To immediately protect the health and well-being of all students, instructors, and staff, instructors reserve the right to cancel or terminate any class session at which any student fails to comply with faculty or staff request to wear a mask in accordance with University policy.

When a University-wide face mask requirement is not in effect, students and instructors may choose to wear a face mask or not, as they prefer for their own individual comfort level.

ADA Accommodations for Face Mask Requirements
Saint Louis University is committed to maintaining an inclusive and accessible environment. Individuals who are unable to wear a face mask due to medical reasons should contact the Office of Disability Services (students) or Human Resources (instructors) to initiate the accommodation process identified in the University’s ADA Policy. Inquiries or concerns may also be directed to the Office of Institutional Equity and Diversity. Notification to instructors of SLU-approved ADA accommodations should be made in writing prior to the first class session in any term (or as soon thereafter as possible).

Academic Integrity

Academic integrity is honest, truthful and responsible conduct in all academic endeavors. The mission of Saint Louis University is "the pursuit of truth for the greater glory of God and for the service of humanity." Accordingly, all acts of falsehood demean and compromise the corporate endeavors of teaching, research, health care, and community service via which SLU embodies its mission. The University strives to prepare students for lives of personal and professional integrity, and therefore regards all breaches of academic integrity as matters of serious concern.

The governing University-level Academic Integrity Policy was adopted in Spring 2015, and can be accessed on the Provost's Office website at: https://www.slu.edu/provost/policies/academic-and-course/policy_academic-integrity_6-26-2015.pdf.

Additionally, each SLU College, School, and Center has adopted its own academic integrity policies, available on their respective websites. All SLU students are expected to know and abide by these policies, which detail definitions of violations, processes for reporting violations, sanctions, and appeals. Please direct questions about any facet of academic integrity to your faculty, the chair of the department of your academic program, or the Dean/Director of the College, School or Center in which your program is housed. Specific College of Arts and Sciences Academic Honesty Policies and Procedures may be found here.

Title IX Statement

Saint Louis University and its faculty are committed to supporting our students and seeking an environment that is free of bias, discrimination, and harassment. If you have encountered any form of sexual harassment, including sexual assault, stalking, domestic or dating violence, we encourage you to report this to the University. If you speak with a faculty member about an incident that involves a Title IX matter, that faculty member must notify SLU’s Title IX Coordinator and share the basic facts of your experience. This is true even if you ask the faculty member not to disclose the incident. The Title IX Coordinator will then be available to assist you in understanding all of your options and in connecting you with all possible resources on and off campus.

Anna Kratky is the Title IX Coordinator at Saint Louis University (DuBourg Hall, room 36; anna.kratky@slu.edu; 314-977-3886). If you wish to speak with a confidential source, you may contact the counselors at the University Counseling Center at 314-977-TALK or make an anonymous report through SLU’s Integrity Hotline by calling 1-877-525-5669 or online at http://www.lighthouse-services.com/slu. To view SLU’s policies, and for resources, please visit the following web addresses: https://www.slu.edu/about/safety/sexual-assault-resources/index.php and https://www.slu.edu/general-counsel.

IMPORTANT UPDATE: SLU’s Title IX Policy (formerly called the Sexual Misconduct Policy) has been significantly revised to adhere to a new federal law governing Title IX that was released on May 6, 2020. Please take a moment to review the new policy and information on the following web address: https://www.slu.edu/about/safety/sexual-assault-resources/index.php. Please contact the Anna Kratky, the Title IX Coordinator, with any questions or concerns.

Supporting Student Success

In recognition that people learn in a variety of ways and that learning is influenced by multiple factors (e.g., prior experience, study skills, learning disability), resources to support student success are available on campus. The Student Success Center, a one-stop shop, which assists students with academic and career related services, is located in the Busch Student Center (Suite 331). Students can visit https://www.slu.edu/life-at-slu/student-success-center/ to learn more about tutoring services, university writing services, disability services, and academic coaching.

Disability Services

Students with a documented disability who wish to request academic accommodations must contact Disability Services to discuss accommodation requests and eligibility requirements. Once successfully registered, the student also must notify the course instructor that they wish to access accommodations in the course.

Please contact Disability Services, located within the Student Success Center, at Disability_services@slu.edu or 314-977-3484 to schedule an appointment. Confidentiality will be observed in all inquiries. Once approved, information about academic accommodations will be shared with course instructors via email from Disability Services and viewed within Banner via the instructor’s course roster.

Note: Students who do not have a documented disability but who think they may have one are encouraged to contact Disability Services.

University Writing Services

Students are encouraged to take advantage of University Writing Services in the Student Success Center; getting feedback benefits writers at all skill levels. Trained writing consultants can help with writing projects, multimedia projects, and oral presentations. University Writing Services offers one-on-one consultations that address everything from brainstorming and developing ideas to crafting strong sentences and documenting sources. For more information, visit https://www.slu.edu/life-at-slu/student-success-center/ or call the Student Success Center at 314-977-3484.

Basic Needs Security

Students in personal or academic distress and/or who may be specifically experiencing challenges such as securing food or difficulty navigating campus resources, and who believe this may affect their performance in the course, are encouraged to contact the Dean of Students Office (deanofstudents@slu.edu or 314-977-9378) for support. Furthermore, please notify the instructor if you are comfortable in doing so, as this will enable them to assist you with finding the resources you may need.