1-15-1998 Ben Woodard <bwoodard@cisco.com>
While you have all been limping along with the current version of npadmin. I
have been really busy quitely working on it. The biggest change is
that I made was I made the program handle multiple printers on the
command line. The way that I implemented this was to make the program
multithreaded. Yes every bad thing that people say about threads is
true. They are a real pain to debug but I think that I have finally
gotten the knack of it. Overall, I am very pleased with the
performance. I was able to query literally hundreds of printers
without putting undue strain on my workstation. In the past, the only
way to do this was to basically forkbomb a your computer. You would
fork off a whole bunch of npadmin's and it would really tax your
system for a couple of minutes. With this new multithreaded
implementation I can very easily query 200 printers without phasing my 
workstation. 

I expect that this multithreading is going to introduce some porting
problems. One knob that might need to be set differently on different
OS's is found in npadmin.C and is called MAXTHREADS. This is the
number of concurrent worker threads that npadmin can have. On my
laptop running Linux I have had no problem with setting this to 100
which seems to be just fine. I expect that other OS's which don't have 
quite as generous threads implementation will need this turned down a
bit. In general, the higher this number can be the faster npadmin can
be when given large numbers of IP addresses.

The purpose for this change is so that I can do some rather nifty
scripts that find out the status of a whole bunch of printers all at
once. I need to do this to do some interesting things at Cisco.