Newsgroups: comp.parallel.pvm
From: mapdjb@bath.ac.uk (D J Batey)
Subject: Re: can PVM be multiuser ?
Organization: School of Mathematical Sciences, University of Bath, UK
Date: Mon, 24 Apr 1995 18:20:22 GMT
Message-ID: <D7JxLz.G2z@bath.ac.uk>

One way of making pvm multiuser (modulo the unix group of your
multiple users) is to hack pvmbeatask in lpvm.c, and mksocs in
startup.c so that it creates its address and authentication files in
/tmp with mode 660 rather than 600. I made some notes last time I
tried this which might be handy if you want to have a go:

- As well as changing the modes from 600 to 660, I had to replace all
  calls to getuid() with getgid(), so that the address and log files
  get named in a group identifiable way 

- I had to use -DNOTMPNAM, otherwise these Sparcs I'm on give
  temporary names for the authorisation files in /var/tmp (rather than
  good ol' /tmp where the address and log files get put) which has the
  setgid bit set so that all files in there are created with group
  'staff'...

- all users have to have umask 002, otherwise the permissions get
  mangled on the address, log and authorisation files (ok, so there's
  probably a better way around this, but it was fast ;^)

- I had to recompile *everything*, not just the pvmd, because the
  client creates authorisation files, which the pvmd then has to
  try to open

- When 'reset'ing or 'halt'ing the PVM, of course only those processes
  spawned from the pvmd, or started by the same user, are killed off.


-- Duncan Batey ----------------------------- School of Mathematics, --
-- Postgraduate Research Student ------ University of Bath, England. --
--"I'm suffering from mood poisoning; it must be something I hate..."--




