Hi,
I've compiled and run ASST1 and it seems to run fine except I can't get
programs to run with the p command. I haven't yet implemented the things
we are supposed to write in asst1, is it supposed to be doing this?
For instance running p/sbin/poweroff gives me (this used to work with
asst0), not turning off the system:
OS/161 kernel [? for menu]: p /sbin/poweroff
Operation took 0.005717120 seconds
OS/161 kernel [? for menu]:
Running p with something bogus gives garbled output, as if different
threads are getting mixed up, or sometimes crashes:
OS/161 kernel [? for menu]: p bogus
Operation took 0.000601320 seconds
OS/R161 kerneunning prlog [? for mram failenu]: ed: error 6
However, running q works correctly:
OS/161 kernel [? for menu]: q
Shutting down.
The system is halted.
sys161: 304461662 cycles (198663214k, 0u, 105798448i)
sys161: 121078 irqs 2659 exns 0r/0w disk 13r/873w console 0r/0w/1m emufs
0r/0w net
sys161: Elapsed real time: 74.267268 seconds (4.09954 mhz)
sys161: Elapsed virtual time: 12.178466480 seconds (25 mhz)
Is this something I should worry about or is this what happens when ASST1
has not yet been completed?
Thanks!
Octavian
hi all!
if yer "strickly unix", ignore this mail...
but if you prefer to read your code in a win32
environment, you might get stuck trying to "install"
the code on your machine due a file having an "illegal
name" from windows' perspective.
the offending file is:
/src/man/dev/con.html
the problem is:
"con" is a reserved word (a device name), wrt win32
file names.
possible fixes include:
1) staying strickly unix.
or
2) renaming that file to legal file name (eg.
"cons.html") from unix, then copying into win32.
note:
if you opt for (2), don't forget to update the
now-404 references to "con.html", in:
d:/161/code/src/man/dev/index.html
d:/161/code/src/man/dev/lscreen.html
d:/161/code/src/man/dev/lser.html
i got derailed by this problem twice:
1) attempting ftp transfer from unix into win32.
2) unzipping tar-ball directly in win32.
__________________________________________________
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i noticed two typo's which slightly change the meaning
of what i meant to ask.
please ignore previous, and read this one instead.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
hi all!
i'm a little confused as to what constitutes a single
transaction w/ a librarian, and whether or not a
reader can do things like:
EXAMPLE 1:
- enter the library.
- stand in line to obtain a librarian.
- obtain a librarian.
- return books 1, 2, and 3, to the librarian, then
(try to) check out book 4 (if its on the shelves) from
the librarian.
- release its librarian.
- leave the library.
EXAMPLE 2:
- enter the library.
- obtain a librarian immediately (i.e. stand in empty
line).
- checkout books 1 thru 5 since they're all on the
shelves.
- release librarian.
- exit library.
it says in ASST1 4.3.3 (Harry Potter
Synchronization):
"If no librarian is immediately available to accept a
returned book...the reader will not return the book
but go ahead and check the next one out..."
but to "check out the next one", you'd have to
"obtain a librarian" (by possibly first standing in
line), correct?
if we stay in the simpler universe of libraries
without "book returns", then "having obtained a
librarian" is a necessary pre-condition of BOTH
"checking the next one out" AND returning a book,
right?
if so, couldn't the reader return their old book(s)
at the point of having obtained a librarian so as to
check out their new book(s)?
i know it says:
"they will not queue up to return books"
but it doesn't say:
they will not queue up to BOTH checkout a new book
AND return old books all at once.
nor does it define what constitutes a legal single
transaction between a reader and a librarian. i see
eight possible interpretations as to what constitutes
the elements of a legal single transaction:
a) checkout single book XOR return single book.
b) checkout single book XOR return multiple books.
c) checkout single book OR return single book.
d) checkout single book OR return multiple books.
e) checkout multiple books XOR return single book.
f) checkout multiple books XOR return multiple books.
g) checkout multiple books OR return single book.
h) checkout multiple books OR return multiple books.
my best guess is that we're supposed to be
constrained by interpretation (a).
thus, my silly questions:
QUESTION 0:
can a reader checkout multiple books at once, or are
they only able to possess one un-read book at a time?
QUESTION 1:
which of the eight possibilities above best defines
"a legal single transaction" between reader and
librarian?
QUESTION 2:
should we infer that obtaining a librarian entitles
you to:
one-and-only-one transaction, after which you would
have to go back and re-queue in order to conduct a
second transaction?
or can you:
conduct multiple-transactions with an obtained
librarian before releasing that librarian?
thanks!
__________________________________________________
Do You Yahoo!?
Send FREE Valentine eCards with Yahoo! Greetings!
http://greetings.yahoo.com
hi all!
i'm a little confused as to what constitutes a single
transaction w/ a librarian, and whether or not a
reader can do things like:
EXAMPLE 1:
- enter the library.
- stand in line to obtain a librarian.
- obtain a librarian.
- return books 1, 2, and 3, to the librarian, then
(try to) check out book 4 (if its on the shelves) from
the librarian.
- release its librarian.
- leave the library.
EXAMPLE 2:
- enter the library.
- obtain a librarian immediately (i.e. stand in empty
line).
- checkout books 1 thru 5 since they're all on the
shelves.
- release librarian.
- exit library.
it says in ASST1 4.3.3 (Harry Potter
Synchronization):
"If no librarian is immediately available to accept a
returned book...the reader will not return the book
but go ahead and check the next one out..."
but to "check out the next one", you'd have to
"obtain a librarian" (by possibly first standing in
line), correct?
if we stay in the simpler universe of libraries
without "book returns", then "having obtained a
librarian" is a necessary pre-condition of BOTH
"checking the next one out" AND returning a book,
right?
if so, couldn't the reader return their old book(s)
at the point of having obtained a librarian so as to
check out their new book?
i know it says:
"they will not queue up to return books"
but it doesn't say:
they will not queue up to BOTH checkout a new book
AND return old books all at once.
nor does it define what constitutes a legal single
transaction between a reader and a librarian. i see
eight possible interpretations as to what constitutes
the elements of a legal single transaction:
a) checkout single book XOR return single book.
b) checkout single book XOR return multiple books.
c) checkout single book OR return single book.
d) checkout single book OR return multiple books.
e) checkout multiple books XOR return single book.
f) checkout multiple books XOR return multiple books.
g) checkout multiple books OR return single book.
h) checkout multiple books OR return multiple books.
my best guess is that we're supposed to be
constrained by interpretation (a).
thus, my silly questions:
QUESTION 0:
can a reader checkout multiple books at once, or are
they only able to possess one un-read book at a time?
QUESTION 1:
which of the eight possibilities above best defines
"a legal single transaction" between reader and
librarian?
QUESTION 2:
should we infer that obtaining a librarian entitles
you to:
one-and-only-one transaction, after which you would
have to go back and re-queue in order to conduct a
second transaction?
or can you:
obtain and conduct multiple-transactions with an
obtained librarian before releasing that librarian?
thanks!
__________________________________________________
Do You Yahoo!?
Send FREE Valentine eCards with Yahoo! Greetings!
http://greetings.yahoo.com
A bug in the queue code was found yesterday by a sharp-eyed student.
The fix has been posted on the web site (in the downloads area) as
os161-1.03-patch1.txt. It is a one-line change.
(A patch is a file created using diff or cvs diff that contains
descriptions of changes to files. You can "apply" the patch, that is,
get the changes made automatically, by using the "patch" program.
Further directions are on the web page. Or you can make the changes by
hand instead if you prefer.)
While this bug remained in the system and the solution sets for eight
months without ever being noticed, it has the potential to cause
serious problems, so we recommend that you apply the patch (or make
the change by hand) before you start working on assignment 1.
--
- David A. Holland | VINO project home page:
dholland(a)eecs.harvard.edu | http://www.eecs.harvard.edu/vino
when a process A is interrupted, and its registers' state is saved in a
jmp_buf of size 11 (see pcb.h and setjmp.h), why is $ra one of the registers
that is saved?
thank you!
sanjay and josh
hi!
1) are we supposed to create main/hello.c and modify
main/main.c at:
a) ~/cs161/src/kern
or
b) ~/cs161/os161/kern
i'm assuming (b), since 0.11.3 says to "modify
conf/conf.kern", and there is no conf directory under
/src/
2) i accidentally created hello.c and modified main.c
under ~/cs161/src (1a).
a) am i screwed?
b) do i need to undo what i did (which is no big
deal, since the changes are trivial)?
3) should i "cvs add hello.c" and "cvs co main.c", and
if so, from in which directory (1a or 1b)?
4) i guess the common thread here is that basically
i'm confused about the "tree" under cs161 in my home
directory:
a) where is my local copy of the source?
b) where is the master copy of the source?
c) where is the result of a build/make?
i.e.
d) whats the difference between and function of the
directories: os161, root, src?
i.e.
e1) where should i cvs update/add/remove/commit from?
e2) where do i end up cvs update/add/remove/commit
to?
e3) where should i build/make from?
e4) where do the results of build/make end-up (i.e.
where do i run from?)
sorry to ask for you to "point out the obvious", but i
think its important i get my bearings early on.
thanks!
thanks!
__________________________________________________
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hey --
This is one, a test to make sure that cs161-list is running and that
people are getting mail
Two, a message to note that there have been a number of corrections posted
to the web site about assignment 0. Almost all of them are minor, but
worth noting. They can be found at:
http://www.courses.fas.harvard.edu/~cs161/assignments/index.html
Also, feel free to use this list to ask questions amongst yourselves about
the assignment. Try to stay reasonably on-topic, though.
good luck,
-mike
