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Watch this space for important announcements.
Last updated:
Thu May 17 11:16:35 CDT 2007
- May 17
Project 5 has been graded.
Here is a summary of grades.
| Score | 55-59 | 60-64 | 65-69 | 70-74 | 75-79 | 80-84 | 85-89 | 90-94 | 95-99
|
| Count | 4 | 2 | 2 | 6 | 2 | 4 | 10 | 18 | 12
|
The mean grade was 84.80 and the median was 90.
- May 8
Project 4 has been graded.
Here is a summary of grades.
| Score | 5-9 | 50-54 | 60-64 | 70-74 | 75-79 | 80-84 | 85-89 | 90-94 | 95-99
|
| Count | 2 | 2 | 2 | 8 | 6 | 16 | 12 | 10 | 2
|
The mean grade was 78.97 and the median was 82.
- May 7
An improved version of FileTester.java is available. See
the project page for details.
- May 2
A bug in FileTester.java has been fixed. See
the project page for details.
- April 17
-
Project 3 has been graded.
Here is a summary of grades.
| Score | 85-89 | 90-94 | 95-99 | 100
|
| Count | 6 | 6 | 34 | 14
|
The mean grade was 96.73 and the median was 98.
- March 22
-
Students Cymen Vig and Jason Malinowski reported that there is still a lurking
race condition. This one is quite rare and only affects shutdown, causing
the program to hang when it's trying to terminate. Jason properly diagnosed
the problem: synchronized method Request.await() calls
synchronized method Warehouse.undo() and
synchronized method Warehouse.run(), calls
synchronized method Request.give() (indirectly, via algorithmN().
This is exactly the same sort of thing you were penalized for on project 2.
As Jason noted:
- the main thread is done running stuff and is interrupting the brewer
threads
- a brewer gets the interrupt, and fires off P3.getWarehouse.undo(alloc) to
undo the request, while simultaneously
- the Warehouse (which has a lock due to run()), is going to give that
brewer's request some stuff (the exact same request that is trying to be
aborted.)
This is an excellent object lesson on why it's a bad idea for a synchronized
method in one object to call a synchronized method in another object.
Too bad I didn't follow my own advice.
If you're still working on your project and you are seeing some runs hang,
you might want to grab new copies of
Request.java,
Warehouse.java, and
P3.java from
~cs537-1/public/html/source/p3.
- March 19
-
IMPORTANT: There was a bug in program P3 that could cause it to
deadlock under certain race conditions. Please fetch a new copy of
~cs537-1/public/html/source/p3/Request.java.
Many thanks to the alert students who diagnosed the bug and many apologies from
the addle-brained professor who created it. I guess you learned something from
project 2! Too bad I didn't :-(.
To make up for the time some of you wasted on this bug, I've extended the
due date to Tuesday, March 27.
- March 19
-
There is now a FAQ for project 3.
- March 16
-
The midterm exam has been graded.
Here is a summary of grades.
| Score | 50-54 | 60-64 | 65-69 | 70-74 | 75-79 | 80-84 | 85-89 | 90-94 | 95-99 | 100
|
| Count | 2 | 1 | 1 | 2 | 9 | 14 | 15 | 8 | 7 | 1
|
The mean grade was 83.83 and the median was 86.
- March 15
-
Project 2 has been graded.
Here is a summary of grades.
| Score | 55-59 | 65-69 | 70-74 | 75-79 | 80-84 | 85-89 | 90-94 | 95-99 | 100
|
| Count | 2 | 4 | 2 | 4 | 6 | 14 | 18 | 8 | 2
|
The mean grade was 86.03 and the median was 89.
- March 6
-
The midterm exam will be from 7:15 to 9:15 Thursday, March 15 in room
1240 Computer Sciences.
Here are some sample questions
of the kind that will be on the exam.
- March 6
-
The project 3 instructions are ready for
you to start work.
- Feb 19
-
Project 1 has been graded.
Here is a summary of grades.
| Score | 0-4 | 35-39 | 45-49 | 50-54 | 60-64 | 65-69 | 70-74 | 75-79 | 80-84 | 85-89 | 90-94 | 95-99
|
| Count | 1 | 1 | 1 | 1 | 2 | 2 | 8 | 8 | 14 | 8 | 11 | 5
|
The mean grade was 79.35 and the median was 82.
Comments on the grading are in the file
~cs537-1/handin/yourlogin/P1/p1_grade.txt.
You can find your current record and class standing in the file
~cs537-1/handin/yourlogin/grade.
- Feb 8
-
The project 2 instructions are ready for
you to start work. A
FAQ (frequently asked questions) page is
included.
- Feb 8
-
The class mailing list is
compsci537-1-s07@lists.wisc.edu.
This list includes all students enrolled in the course as well as both TAs and
the professor.
We may occasionally send
announcements to this list, but you should still be in the habit of checking
this web page frequently for news
about the course.
Messages to this list will be sent to your “official” UW address
NetId@wisc.edu.
You can arrange to have your mail forwarded to a different address (e.g.
your-login@cs.wisc.edu) by visiting My
UW-Madison and clicking on the My NetID link.
Anyone in the class can send mail to the whole list. However, please do not
mail to this list unless you think your message may be of interest to a
significant fraction of the class. Questions about ambiguities in project
specifications, etc. should probably be sent to the Professor and/or TAs.
One appropriate use of these lists would be to look for a partner for projects.
Messages previously sent to this list will be archived at
https://www-auth.cs.wisc.edu/lists/classes/compsci537-1-s07/.
- January 23
-
A previous version of this page incorrectly indicated that the midterm exam
would be “Thursday, March 13.” The correct date is Thursday,
March 15.
- January 16
-
If you have not previously used the Unix computing facilities in
the CS department at UW, you may find it helpful to attend one of the
Unix orientation sessions. They are offered
January 23, 24, and 25 at 4pm in room 1325 Computer Sciences.
The sessions will all be the same, so you only need to attend one of them.
If you are new to Unix, you should also purchase the CS 1000 handout at the
DoIT Tech Store.
CS 537 is intended as a general introduction to the techniques used
to implement operating systems and related kinds of systems software.
Among the topics covered will be
process management (creation, synchronization, and communication);
processor scheduling;
deadlock prevention, avoidance, and recovery;
main-memory management;
virtual memory management (swapping, paging, segmentation and page-replacement
algorithms);
control of disks and other input/output devices;
file-system structure and implementation;
and protection and security.
This course assumes familiarity with basic computer organization (e.g.,
processors, memory, and I/O devices as covered in CS354) and data structures
(e.g., lists and hash tables). You will need to be able to program in Java to
perform the assignments in the course.
|
|
| 11:00 - 12:15 | Tuesday and Thursday | 1221 Computer Sciences
|
| 2:25 - 3:15 | Tuesday | 1221 Computer Sciences
|
The Tuesday afternoon 2:25 session is listed in the timetable as “discussion”,
but it will generally be used as fourth hour of lecture, following in sequence
with the other lectures.
Each week, it will start with discussion of topics related to the
projects
and questions regarding points raised in the the lectures or the text,
but when all these questions have been answered, I will continue with the
regular lecture material.
Important announcements will be sent to the class mailing list or posted to the
News section of this web page above, so please read your
mail and check this page frequently (particularly around project time). You
are responsible for all such announcements, as well as announcements made in
lecture. Note that if you are not officially enrolled in the class, we cannot
add you to this mailing list because it is automatically generated.
Applied Operating Systems Concepts, Seventh Edition
by Abraham Silberschatz, Peter Baer Galvin, and Greg Gagne, John Wiley and Sons,
2004;
or
Applied Operating Systems Concepts with Java, Seventh Edition
by Abraham Silberschatz, Peter Baer Galvin, and Greg Gagne, John Wiley and Sons,
2007.
This text is only recommended rather than required, since the main “text”
for this course is a set of online lecture notes.
This book is useful for reference, for an alternative point of view, and for
those who like the security of having a large, heavy, and expensive book
to turn to. I chose this particular text because it has been used in recent
semesters, so used copies should be available at the bookstore.
Other editions may be used interchangeably for the purposes of this course.
Another recently used text book that covers the same material is
Modern Operating Systems, Second Edition
by Andrew S. Tanenbaum,
Prentice Hall, 2001.
The Java Programming Language, Fourth Edition
by Ken Arnold, James Gosling, and David Holmes,
Addison-Wesley, 2006.
There are literally thousands of books on the
Java
programming language and
I have only looked at only a few of them, so there may very well be a better
book, but this one is quite good.
The fourth edition also includes “Java 5” features, which we will be using
in this class. See also the
summary of new features on the Java web site.
I have written a set of online lecture notes.
Lots of additional helpful materials about Java are available on the web.
The following references are available online at the
Java home site.
You will be referring to the last of these particularly frequently.
There will be five programming projects, all in the
Java
programming language.
Unix workstations are provided for your use, but you may use any
computer to which you have access that implements the Java programming
language (version 1.5).
However, if you do not use the Computer Sciences Department's computers,
you will be responsible for transferring any required
data sets or software packages to your computer and for transferring programs
and results back to the CS department machines to hand them in.
The first assignment will be an easy “get acquainted” exercise designed
to help you become familiar with the computing environment and the
Java language, particularly the Thread feature of Java.
Subsequent projects will involve
process synchronization,
processor scheduling,
memory management,
and file-system implementation.
Each student should do the first assignment individually.
For the remaining projects,
students will be required to work in pairs.
Both members of a pair will receive the same grade on a project.
Feel free to discuss projects with anyone, but
you must not share code with anyone but your partner.
That means you may not use in any way code written by other students in this
class, code from previous semesters, or code from similar courses elsewhere.
In summary, the only Java code you may use is code you write, code we give you,
and Java classes from
the standard Java libraries.
Cheating will be vigorously punished.
See the Dean of Students'
Code of Conduct
for more details.
Enough said!
Programming assignment 3 is due at the start of lecture.
Other programming assignments are due at 1:00 a.m. on the dates indicated.
Sometimes the projects in this course are in C or C++, sometimes they are in
Java, and sometimes they are in a mixture of languages.
This semester, both lectures will be using Java.
There are several arguments in favor of Java, but two in particular are
most relevant to this course:
- Java is a more congenial programming environment.
Runtime errors such as bad subscripts, null pointers,
and uninitialized variables cause exceptions caught by the language runtime
rather than mysterious crashes or random behavior.
Java Strings are much easier to use than char *
arrays. Garbage collected storage management is extremely handy.
Using Java rather than C or C++ will make you more productive, allowing you
to spend more time on the concepts and algorithms and less time tracking down
obscure bugs. It allows me to assign more challenging and hopefully more
interesting projects.
- Java has “operating system” features built in.
In particular, it is the first widely-used programming language with
language-level support for concurrency (threads) and synchronization
(monitors).
On the other hand, there are some excellent arguments for using C and/or C++
in this course.
- Java hides what's really going on.
The essence of the study of operating systems is the relationship between
the hardware and software. The congenial Java programming environment is
provided by thick layer of software that cushions some of the nastier knobs and
hooks provided by the hardware and the operating system kernel.
- Systems programmers need to know C.
There's still a huge market for programmers trained in C and/or C++, for
operating systems and related fields such as networking and real-time and
embedded systems. It can be argued that a student with degree in Computer
Science who has not programmed in C has received a deficient education.
- Java is for wimps.
Real men and women use C.
This is actually a corollary to the other two points.
We will talk about the C-language interface to the operating system, but
in some sense, you do cannot fully appreciate the feel of of the low-level
interfaces without experiencing them first-hand.
In fact, there's a strong argument for requiring
some use of assembly language.
Learning C is not so much a matter of learning its syntax
and semantics (which are, after all, not all that different from Java),
but rather a matter of learning survival skills for this harsh world.
If you have a subscript out of bounds or dereference a null pointer in Java,
you get a nice traceback, telling you exactly where in the program you screwed
up. In C, you will probably get the error message, “Segmentation
fault”, which is about the only runtime error message that exists. It
means, roughly, “something went wrong somewhere.” And that's only if you're
lucky! If you're unlucky, your wild reference will damage some variable
totally unrelated to what you were doing. The injury
will lie in waiting until much later, when it will cause totally unpredictable
and unfathomable results. A real education in C would focus primarily on
avoiding the “gotchas” and on picking up the pieces when you don't.
Students who are familiar with Java and want to learn C++ should check out
CS 368.
This course will assume that all students are Java programmers at the level
of someone who has completed
CS 367 with an A or
AB.
If you are familiar with C++ but not Java, check out the excellent
introduction to Java and/or my
Notes on Java.
See The Java Tutorials and/or the
Java book for lots more information about Java.
There will be a midterm and a final exam, each of which will count for 19%
of your grade.
The midterm will be
7:15-9:15 PM Thursday, March 15, room 1240 Computer Sciences.
The final exam will be
12:25 - 2:25 PM, Wednesday, May 16, room 1240 Computer Sciences.
The first programming project (getting started) will count for 2% of your
grade.
The remaining four projects will account for the remaining 60% of your grade.
They may not all be equally difficult (generally they will get progressively
harder throughout the term), but they will all count equally.
The following schedule is tentative;
it may be updated later in the semester, so check back here frequently.
| Week | Dates | Topic
|
|---|
| Lectures
|
|---|
| 1 | Jan 23 - 25 | Introduction
|
| 2-6 | Jan 30 - Feb 27
| Processes, Synchronization, Processor Scheduling
|
| 6-11 | March 1 - Apr 10
| Memory Management and Virtual Memory
|
| 11-14 | Apr 12 - May 1
| File Systems and Disks
|
| 14-15 | May 3 - May 10
| Protection and Security
|
| Programming Assignments
|
|---|
| 3 | Wednesday, Feb 7 at 1:00 am
| Project 1 -- Shell
|
| 6 | Wednesday, Feb 28 at 1:00 am
| Project 2 -- Synchronization
|
| 9 | Tuesday, Mar 27 at the start of lecture
| Project 3 -- Performance
|
| 12 | Wednesday, Apr 18 at 1:00 am
| Project 4 -- File Systems, Part I
|
| 15 | Friday, May 11 at 1:00 am
| Project 5 -- File Systems, Part II
|
| Exams
|
|---|
| 8 | Thursday, March 15
| Midterm Exam, 7:15 - 9:15 pm,
Room 1240 Computer Sciences
|
| 16 | Wednesday, May 16
| Final Exam, 12:25 - 2:25 pm
Room 1240 Computer Sciences
|
