Broken software using ULTRIX 1.2

John Bruner jdb at mordor.ARPA
Fri Jul 11 07:02:19 AEST 1986


>>> We recently "upgraded" ... to ULTRIX 1.2.  ... the following don't work  ...
>>> uw (windows program)
>>
>>Structures in the kernel have changed (you would find the same
>>"problems" upgrading to 4.3BSD, I suspect).  Recompile.
>
>This may not work either.....

I can't speak for other window programs, but as the author of UW
perhaps I can shed a little light on its problems.

When I distributed UW v2.10 in November, my VAX was running 4.3BSD.  I
recoded the server to use the data types and macros defined in 4.3BSD's
<sys/types.h>.  Since the FD_SET, FD_ISSET, etc. macros were not
defined in 4.2BSD, I added some conditional code to define them.  In
so doing, I made a stupid incorrect assumption.  Since VAX 4.2BSD was
limited to 30 file descriptors (because of the layout of bits in page
table words), I assumed that no 4.2BSD or 4.2BSD-derived implementation
supported more than 30 file descriptors.  This is wrong.  I tried out
the UW server on the only machines available to me (4.2 and 4.3 VAX,
Sun, Integrated Solutions) and it worked.

I do not know how many file descriptors ULTRIX 1.2 allows, but this
is a possible source of problems.  One cheap-hack workaround is to
replace the call to "getdtablesize()" with the constant 30.  A better
fix is to recode the definitions of FD_SET, etc.

I know that some implementations of 4.2BSD have had trouble with UW's
UNIX-domain datagrams (used to pass file descriptors from one process
to another).  If UNIX-domain sockets aren't implemented (or are
buggy), then "uwtool" won't work, but the UW server is still useable.
-- 
  John Bruner (S-1 Project, Lawrence Livermore National Laboratory)
  MILNET: jdb at mordor [jdb at s1-c.ARPA]	(415) 422-0758
  UUCP: ...!ucbvax!decwrl!mordor!jdb 	...!seismo!mordor!jdb



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