Note: Consultation times will be announced on the course web page.
Units of Credit: 6
Note that COMP3231/9201/3891/9283 are taught in parallel. The
lectures are common for all courses. We cater for the differing needs
of postgraduate and undergraduate students by weighting assessment
components more flexibly in the case of postgraduate students. See the
section on assessment below for details.
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 is oriented
towards exposing students to the essential concepts and issues that
underly 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 tradeoffs between conflicting
objectives faced by the operating systems in efficiently supporting a
wide range of applications.
This course provides an understanding of the underlying operating
systems which students have implicitly relied upon in developing
applications in foundational courses within Computer Science and
Engineering, and will rely on in their 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 microprocessor-based
Specific Aims and Outcomes
Make students understand the key concepts and mechanisms of
modern operating systems:
- processes and process management,
- memory management techniques aimed at optimising system
utilisation and responsiveness,
- on-line storage methods (file systems),
- security and protection,
- concurrency issues,
Make students 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 formats will give students practice in the
presentation of solutions to an audience of peers, and will challenge
them to critique peer technical presentations. Furthermore, the whole
course encourages critical examination and analysis of "standard"
The assignments give students an opportunity to develop skills
required to work as a team on a technical project, and the opportunity
to work with a substantial body of code created by a third-party.
Our approach to teaching operating systems is
- introducing operating system theory in the lecture component of
the course, including case studies of real systems
- and active engaging students in the practical application of
that theory through challenging assignments, including assessment
and detailed 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 being taught.
- Students also are encouraged to learn collaboratively through
group assignments, which also hones their skills as "team players"
for future entry into the works force.
We strive to continually improve this course, and actively seek
feedback both during session, and via various evaluation surveys 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.
It is assumed that the student is familiar with the general
organisation of a general-purpose computer (in particular, CPU,
memory, bus, registers, machine instructions,
Students are also assumed
to be competent in the C programming language.
- As for COMP3231 with minimum mark of 70 in each
- As for COMP9201 with minimum mark of 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 final exam.
The lecture delivery (3 hours per week) and material covered is
common for all operating system students, independent of the course
code your enrolled under.
Lectures will cover roughly the following topics (although not in
A detailed list of lecture topics and the slides used for the lectures
will be posted on the course website as session progresses.
- 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
- Protection and Security
- goals of protection, access matrix and its implementations,
capabilities, authentication, encryption, design for security,
- Case Studies
- drawn from UNIX, Linux, Windows-2000 and OS/161 will be used
throughout the course.
Tutorials start in Week Two. Part of the allocated tutorial time
will be devoted towards solving problems and discussing solutions
related to lecture topics, while the remaining time will be used to
discuss topics relevant to assignments.
Students will be required to present tutorial problems (approx.
10 min/student) under the guidance of the tutor. Written submissions
are required for some portion of the tutorials. Individual student
contribution (presentation, critiquing solutions and suggesting
alternatives) in tutorials will be assessed and forms part of the
final mark for the course(COMP3231 only). To obtain the tutorial marks, you have to
attend your registered tute. Other tutors cannot award participation
Note that tutorial marks will be based on
participation only, there are no marks allocated just for
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.
There will be three assignments, due approximately in weeks 5, 9
and 12. The 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, it runs on Unix as well as Windows systems. Assignment
solutions will be submitted in C code. Details will be released in due
Assignments will generally have advanced options which
provide a significantly higher level of challenge than the standard
assignments (which most students find fairly challenging
already). There will be bonus marks available for students solving the
advanced parts. However, we want students to do the advanced
assignments for the challenge rather than the marks, therefore the
number of bonus marks is intentionally kept small compared to the
amount of extra work required.
For students doing Extended Operating Systems (COMP3891/9283), your
are expected to attempt the advanced assignment components.
In order to minimise cheating we attempt not re-run unmodified
assignments from earlier years. This implies that there are some new
assignment specifications. Even though we will not release the
specifications until we have a prototype solution, this does not
guarantee that there are no problems with the specification. In order
to minimise the impact of specification problems to average students
we will offer 5% bonus marks to students solving the assignment within
48 hours of release. Such submissions will have to be demonstrated and
discussed with a tutor. This procedure should then help to iron out
all problems with the spec before most students start on the
assignment. These bonus marks can be used to make up lost marks in the
same or other assignments (and are in addition to the early submission
Students have, unfortunately, a tendency to underestimate the time
required to do the assignments. Experience from the last few years
show 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.
In order to encourage students to start early, we are also
offering 10% bonus marks for submitting their final solution one
week before the deadline (i.e., you lose the bonus marks if you
re-submit less than a week before the deadline). Such bonus marks will
allow you to make up for missed marks in the same assignments (i.e.,
you cannot get above the full marks for the assignment that way).
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 expect to contribute equally. In
submitting your assignment, you are agreeing you have contributed
equally unless we recieve an agreed-to statement from all group
members identifying differing levels of contribution.
What is Plagiarism?
Plagiarism is the presentation of the thoughts or work of another
as ones own.
- direct duplication of the thoughts or work of another,
including by copying material, ideas or concepts from a book,
article, report or other written document (whether published or
unpublished), composition, artwork, design, drawing, circuitry,
computer program or software, web site, Internet, otherelectronic
resource, or another persons assignment without appropriate
- paraphrasing another persons work with very minor changes
keeping the meaning, form and/or progression of ideas of the
- piecing together sections of the work of others into a new
- presenting an assessment item as independent work when it has
been produced in whole or part in collusion with other people, for
example, another student or a tutor; and
- claiming credit for a proportion a work contributed to a group
assessment item that is greater than that actually contributed.
For the purposes of this policy, submitting an assessment item
that has already been submitted for academic credit elsewhere may be
Knowingly permitting your work to be copied by another student may
also be considered to be plagiarism.
Note that an assessment item produced in oral, not written, form,
or involving live presentation, may similarly contain plagiarised
The inclusion of the thoughts or work of another with attribution
appropriate to the academic discipline does not amount to
The Learning Centre website is main repository for resources for
staff and students on plagiarism and academic honesty. These
resources can be located via: www.lc.unsw.edu.au/plagiarism
The Learning Centre also provides substantial educational written
materials, workshops, and tutorials to aid students, for example,
- correct referencing practices;
- paraphrasing, summarising, essay writing, and time management;
- appropriate use of, and attribution for, a range of materials
including text, images, formulae and concepts.
Individual assistance is available on request from The Learning
Students are also reminded that careful time management is an
important part of study and one of the identified causes of plagiarism
is poor time management. Students should allow sufficient time for
research, drafting, and the proper referencing of sources in preparing
all assessment items.
We always check for cheating (i.e. plagiarism), and while
we will never catch all cheaters, we always catch a
significant number. We deal with them severely. Don't take chances!
This is no idle threat. We catch and penalise cheaters to
protect the reputation and integrity of the University, and the
interests of those who get their marks through honest work.
* Note: full penalty was not 0FL prior to
There will be nomid-session quiz.
A two hour written final examination will be conducted.
Supplementary exams will only be awarded in well justified cases,
in accordance with School policy, 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!
Supplementary exams will be oral. The supplementary final
exam will be held after the written supplementary exams held for other
Tutorial participation (COMP3231 only) and assignments will determine the
``class mark'' component towards the final assessment. (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 to
- For COMP3231/3891:
The harmonic mean is weighted 50/50.
- For COMP9201/9283:
The final mark will be M
= max(M1,M2), where
M1 is a 50/50 weighted harmonic mean as above, and
M2 is a 20/80 weighted harmonic mean (20 class, 80
exam) as shown below.
This method of weighting is to cater for postgraduates working
full time who are unable to invest significantly in assignment work
(hence 20/80 weighting), while not penalising postgraduates who do
commit to the assignment component of the course (50/50
For COMP3231 students the class mark is determined as the weighted
arithmetic mean of tutorial participation (10%) and assignments (90%)
For COMP9201/3891/9283 students the class mark is determined as
the sum of the assignment marks normalised to 100 plus bonuses.
COMP9201 students who wish to participate in tutorials can arrange
with their tutor to recieve a participation mark, in which case, the
class component of their mark will be calculated as for COMP3231.
A final mark of 50% is required in order to pass, however, it is
furthermore required for a pass that a minimum of 40% is achieved in
the exam E component.
We reserve the right to scale 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
ed., Prentice Hall, 2001
For Operating Systems:
For the C language:
- A. Silberschatz and P.B. Galvin, Operating
Concepts, 6th ed., Addison Wesley
- William Stallings, Operating Systems:
Internals and Design
Principles, 4th edition, 2001,
- A. Tannenbaum, A. Woodhull, Operating
Implementation, Prentice Hall, ???
- John O'Gorman, Operating Systems,
- Uresh Vahalla, UNIX Internals: The New
- B Kernighan and D. Ritchie, The C
Language, 2nd ed, Prentice
- 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/.