[MUD-Dev] Re: Java I/O and threads.

Jo Dillon emily at thelonious.new.ox.ac.uk
Mon Jan 25 17:19:27 New Zealand Daylight Time 1999

Elis Pomales (pomales at caip.rutgers.edu) spake thusly:
> The current dilemma, is whether I should use threads on a per player (per
> socket) basis, or implement a polling loop and queue player commands,
> handling one command per player per loop cycle. The problem with having a
> thread per player is the context switching overhead. The problem with the
> polling loop is that I have to check each player to see if they have
> input. (There is no select() in Java.) Furthermore, processing one command
> per player may make the system very unresponsive??? Making it seem turn
> based? 

  I believe there's no non-blocking I/O either, so as you've foreseen
it wouldn't be a good plan. It could leave the mud locked up indefinitely,
in fact ;) With Java your best bet is one thread per socket, I should think.
> What solutions have you guys (and gals?) employed in your servers? 
> I guess one way to use the polling loop would be to keep each command as
> small as possible...
> PS. I would still use more threads, one for NPC's and one for the game
> world.
> PSS. Is having 100+ threads really that bad? (I would think so)

  Not necessarily - it depends on your hardware and OS. Java's designed
to use lots of threads so it's not too much of a worry.


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