| Kevin Elphinstone
||Lecturer in Charge
Note: Unless the issue is personal in nature, please use Piazza to ask
questions instead of emailing course staff directly. This is so answers
can benefit others.
Note: Consultation times are available
on the the course web page.
Units of Credit: 6
COMP3231/9201/3891/9283 are taught in parallel. The lectures are
common for all courses.
For students doing Extended Operating Systems (COMP3891/9283), your
tutorial is an advanced tutorial where lecture topics are covered in
extended depth, and new topics are introduced and discussed.
Operating systems are an essential part of computer systems, a course on
operating systems is an essential part of any computer science or computer
engineering program. This course exposes students to the essential
concepts and issues that underlie operating systems and their design.
In general terms, the course aims to educate students in the basic
concepts and components of operating systems, the relevant characteristics
of hardware, and the trade-offs between conflicting objectives faced by
the operating systems in efficiently supporting a wide range of
This course provides an understanding of the underlying
operating systems which students have implicitly relied upon
when developing applications in the foundational courses within
Computer Science and Engineering. The knowledge gained will
continue to be relevant in future careers when developing
systems and applications. The course also builds upon
COMP2121/9032 Microprocessors and Interfacing by
illustrating how more complex software systems are supported on
Specific Aims and Outcomes
Understand the key concepts and mechanisms of modern
- processes and process management, including threads and concurrency
- physical and virtual memory management techniques ,
- on-line storage methods (file systems),
- security and protection (optional),
Understand the reasons why operating systems are built the
way they are, and what the implications and lessons are for other software
systems. Specific learning objectives are:
- appreciation of design trade-offs and design decisions and their
dependence on the target environment;
- appreciation of the distinction between mechanisms and policies, and
why this is important;
- exposure to low-level code;
- exposure to current trends in operating systems research and
The tutorial format gives students the opportunity to present
and discuss course content to an audience of their peers. Furthermore, the whole course encourages
critical examination and analysis of "standard" solutions.
The assignments give students an opportunity to develop the skills required
to work as a team on a technical project, and the opportunity to work with
a substantial body.
Our approach to teaching operating systems is
- introducing operating system theory in the lecture component of the
course, including case studies of real systems
- actively engaging students in the practical application of that
theory through challenging assignments, including assessment and
feedback on their efforts.
- We also seek engagement of students by encouraging dialogue between
staff and students both in lectures and tutorials to re-enforce concepts
- Students also are encouraged to learn collaboratively through group
assignments, which also hones their skills as "team players" for future
entry into the workforce.
We strive to continually improve this course by actively seeking feedback
both during session, and via various evaluation surveys (CATEI and my own)
at the end of the course. The results of surveys and any feedback are
taken seriously and are actively used as input to further improvements in
the course. See the survey archive (http://cgi.cse.unsw.edu.au/~cs3231/surveys.html)
for what students thought about the course, and how the course is evolving
based on their feedback.
It is assumed that the student is familiar with the organisation of a
general-purpose computer (in particular, CPU, memory, bus, registers,
machine instructions, interrupts/exceptions).
Students are also assumed to be competent in the C
programming language. More specifically, students should understand
pointers, function pointers, memory allocation (malloc()), and
be comfortable navigating around an existing code base.
COMP2521 or COMP1927
These are the foundational data struture and algorithms courses.
You should be able to use standard data structures and algorithms
such as trees, hashing, heaps, sorting, etc...
COMP2121 or ELEC2142 or COMP1521.
These are Microprocessors and Interfacing courses or Systems programming courses. We expect you
to be comfortable with low-level microprocessor-based hardware,
registers, interrupts, memory, devices, and programming in
- COMP9024 Data Structures and Algorithms
- COMP9032 Microprocessors and Interfacing
- As for COMP3231. Additionally, we would expect students enrolled
in Extended OS would have achieved a WAM of at least 75.
- As for COMP9201. Additionally, we would expect students enrolled
in Extended OS would have achieved a mark of at least 70 in each
- COMP9201/9283 Operating Systems (for COMP3231/3891)
- COMP3231/3891 Operating Systems (for COMP9201/9283)
Broadly, the course consists of lectures, tutorials, assignments, and a
The lecture delivery (3 hours per week) and material covered is common
for all operating system students, independent of the course code enrolled under.
Lectures will cover roughly the following topics (although not in this
- Introduction and Overview
- Introduction to operating systems, computer systems structures,
operating system structures
- execution abstraction, state, context, preemption, scheduling,
- Process Management
- resources, address spaces, multi-threading
- Storage Management
- memory management, virtual memory, file systems
A detailed list of lecture topics and the slides used for the lectures will
be posted on the course website as session progresses.
- drawn from UNIX, Linux, Windows and OS/161 will be used throughout
Tutorials start in Week Two. Part of the allocated tutorial time will be
devoted towards solving problems and discussing solutions related to
lecture topics. The remaining time will be used to discuss topics
relevant to assignments.
Students will be required to present tutorial problems under the
guidance of the tutor.
For students doing Extended Operating Systems (COMP3891/9283), the tutorial
is an advanced tutorial where lecture topics are covered in extended depth,
and new topics are introduced and discussed.
There will be three assignments (plus a warm up exercise for bonus
marks), due approximately in weeks 5,9, and 13. Note that the first
assignment is a really trivial familiarisation exercise, and should not be
used to judge the difficulty of the other assignments. Except for the
first familiarisation assignment, the three main assignments are done in
groups of two. Assignments will use the OS/161 educational operating
system running on a simulated MIPS R3000 computer called System/161. Both
the operating system and the simulator were developed at by the Systems
Research at Harvard group. The simulator is relatively platform
independent and runs on Unix as well as Windows systems. Assignment
solutions will be submitted in C code. Details will be released in due
The last 2 assignments have advanced components which provide
a significantly higher level of challenge than the standard assignments
(which most students find fairly challenging already). We want students to
do the advanced assignments for the challenge rather than the marks,
therefore the opportunity to earn marks is
intentionally kept small compared to the amount of extra work required.
The marks are limited to 10% of the class mark component of the
course, see the Assessment section below for details.
Students enrolled Extended Operating Systems (COMP3891/9283) are required
to attempt an explicit subset of the advanced assignment components, and marks awarded form part
of their assessment.
Students have, unfortunately, a tendency to underestimate the time
required to do the assignments. Experience from the last few years shows
that the assignments in this course are considered challenging, and they
consume a fair amount of time. It is important to start early. If you
start on them on the weekend before the deadline you'll almost certainly
miss the deadline. As a tip, the majority of the assignment is learning
how to solve the problem (approx. 75% of the effort). The programming
component is actually the minority of the work required (approx 25%).
In order to encourage students to start early, we are also offering 10%
bonus marks (10% of the raw mark awarded) for submitting their final
solution one week before the deadline (i.e., the bonus
marks are lost if the assignment is re-submitted less than a week before the deadline). Such bonus
marks will allow students to make up for missed marks in the same assignment
(i.e., one cannot get above the full marks for the assignment).
Penalty for late submission of assignments will be 4%
(of the worth of the assignment) subtracted from the raw mark per day of
being late. In other words, earned marks will be lost. For
example, assume an assignment worth 25 marks is marked as 20, but had been
submitted two days late. The late penalty will be 2 marks, resulting
in a mark of 18 being awarded. No
assignments will be accepted later than one week after the deadline.
The late penalty is purposely lenient due to the tendency of students to
underestimate the work required.
- Assignments will be marked as a group, i.e. groups of one will be
marked the same as groups of two or three.
- All group members are expected to contribute equally to
EACH assignment.. In submitting an assignment, the group is
agreeing that all members have contributed equally unless we
receive an agreed-to statement from all group members
identifying differing levels of contribution.
Academic Honesty and Plagiarism
UNSW has an ongoing commitment to fostering a culture of learning
informed by academic integrity. All UNSW staff and students have a
responsibility to adhere to this principle of academic
integrity. Plagiarism undermines academic integrity and is not
tolerated at UNSW. Plagiarism at UNSW is defined as using the words
or ideas of others and passing them off as your own.
If you haven't done so yet, please take the time to read the full text of
The pages below describe the policies and procedures in more detail:
There will be no mid-session quiz.
A two hour written final examination will be conducted. Note: Extended
and normal OS have different exams with approximately 75% common content.
Supplementary exams will only be awarded in well justified cases, in
accordance with School policy for Special Consideration, not
as a second chance for poorly performing students. In particular, it is
unlikely that a supplementary will be awarded to students who have
actually sat the proper exam. Make up your mind whether or not you are
sick before attempting the exam!
The final assessment is based on a "class mark" (C) and a final exam (E).
The class mark is based on the assignment work and any bonuses accrued
during the semester.
- For COMP3231/9201 the class mark is formed as follows:
(asst1 + asst2 + asst3)/9*10 + warm_bonus +
- Note: the assignments are out of 90 (asst1
+ asst2 + asst3) and scaled to a mark out of 100.
- For COMP3891/9283 the class mark is formed as follows: (asst1
+ asst2 + asst3 + asst2_adv + asst3_adv) + warm_bonus +
- (asst1 + asst2 + asst3 +
asst2_adv + asst3_adv) is out of 100.
As described above, any early bonuses contribute to the applicable
individual assignment (which is capped at max marks for that assignment).
(Note that the class mark is capped at 100, irrespective of how many
bonus marks you have accumulated.) The exam will be the second component
of the final assessment. The weighted harmonic mean of the ``class mark'',
C, and the final exam mark, E, is used to
determine the final mark, M, according a 40/60 weighted
harmonic mean (40% class mark, 60% exam) as shown below.
A final mark of 50% is required in order to pass.
We reserve the right to moderate mark components of the individual
courses (COMP3231/9201/3891/9283) separately where appropriate.
More information on harmonic means in general is available here.
- A. Tannenbaum, Modern Operating Systems, 3rd
ed., Prentice Hall, 2008
For Operating Systems:
For the C language:
- A. Silberschatz, P.B. Galvin and Greg Gagne, Operating System
Concepts, 7th ed. (2004)
- William Stallings, Operating Systems: Internals and Design
Principles, 5th edition, 2005, Prentice Hall.
- A. Tannenbaum, A. Woodhull, Operating Systems--Design and
Implementation,3rd ed., Prentice Hall, 2006
- John O'Gorman, Operating Systems, MacMillan, 2000
- Uresh Vahalla, UNIX Internals: The New Frontiers, Prentice
- B Kernighan and D. Ritchie, The C Programming Language, 2nd
ed, Prentice Hall.
- S. Harbison and G. Steele, C: A Reference Manual, Prentice
Copies of lecture slides and other information can be found under the
course's WWW home page at URL http://www.cse.unsw.edu.au/~cs3231/.