[Sussex] the who/what/why/when of processes ( proc-i ? ;)

[dunk fordyce]

hmmmm... think im going to have to digest this for a while 

thanks

On Thu, 5 Sep 2002 09:11:26 -0400
Steve Dobson <SDobson at manh.com> wrote:

> Dunk
> 
> > From: dunk fordyce
> 
> I have also just noticed <sfx: egg on face> that this is a SLUG
> post not an INSIDE post.
> 
> > its actually a irc bot that sits there and listens and 
> > responds to commands.
> 
> > i want to be able to start a new process for different rooms 
> > and also for things like searching the web ( i dont want the 
> > bot to stop responding while its searching ).
> 
> I don't know IRC or its protocol but I do see a problem here.
> When you fork() the child shares the file descriptors with the
> parent.  This is great as you want your bots to keep talking to
> the same IRC server, yes.
> 
> Now it depend upon IRC protocol (TCP/IP or UDP/IP protocol), and
> if different connections/sockets (file descriptors are the handles
> to them) are being used.
> 
> Lets suppose that each room has its own connection/socket/file desc.
>   If you're in two rooms then your client while be select(2)ing on
>   both fds because it has no way of knowing which will receive next.
>   If you fork() a new child for each room how are you going to know
>   which fd is the socket for the room that bot is monitoring?
> 
>   If only one connection/socket/fd is the link to the server then if
>   both your IRC client and the bot both select(2) on that fd only ONE
>   while get the message.  Who knows, the kernel will decide at run-
>   time.  But I guarantee that when it is a message you want the bot
>   to handle it will be your client that receives and vice versa.
> 
> Writing to the server is almost as bad.  Both will work but the
> kernal may mix the data streams.  There has to be a protocol between
> the processes as who as the "right" to write to the server.  If this
> is a stock IRC client then I'm guessing that it doesn't support such
> a protocol.
> 
> > does that make more sense now?
> Yes.  Do my responses make sense to you.
> 
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