Re: [Freeciv-Dev] Forking of the client

[Trent Piepho <xyzzy@xxxxxxxxxxxxxxxx>]

On Fri, 12 Mar 1999, David Pfitzner wrote:
> Though I don't really see this impacting either way on
> the idea of having the server fork a process to communicate
> with each client.  But I don't know enough about 
> sockets/processes etc to comment on the pros/cons of that idea.

Well, I know plenty about sockets/processes, and this isn't as easy as it
looks.  First of all, when you fork a separate process it gets its own memory
image that is a copy of the parent.  This means that if one server process
changes its data structures, the other processes won't see this.

You also have to insure that only one process tries to write to/read from the
socket at once.  If once process is writing out a game map, and another tries
to send a unit info packet, they can write on top of each other and
scramble the data.  

So this means, you have to have some sort of locking mechanism if you want
to have to processes share the same socket.

It would be much easier to just have the server use non-blocking IO and select
to write to the sockets.