[usocket-devel] Re: (Lisp Support Call #35530) Sockets / COMM-package questions: select()-like function && UDP sockets

[Erik Huelsmann]

Almost two weeks ago I sent the mail below.

I've been looking for a good way to achieve my goal with what APIs I
found in LispWorks.

For Unix, I found a good way by using process-wait-with-timeout, the
right wait-function (which checks read-readyness of the server socket
using socket-listen) and mp:notify-fd.

When working on a solution that would work on Windows, I noticed that
socket-listen behaves very differently on windows: it won't return T
when a socket is ready to accept new connections. The unix variant
*does* include that behaviour.

Also, making a stream from the socket fd [make-instance
'comm::socket-stream] doesn't work either: it sends
system:wait-for-input-streams into endless recursion.

Now, I'm absolutely not afraid of a bit of Foreign Function Interface
programming, but if this is at all possible, I'd like a hint from your
side, hopefully to a function which already provides the
'wait-for-all-streams-including-passive-sockets(servers)-at-once'
behaviour.

Could you help me out please? I used the suggestion you gave me last
time to look in other sockets libraries on the net, but those don't
provide this functionality.

Thank you very much for any information you can provide.

bye,

Erik.

On 5/7/07, lisp-support at lispworks.com <lisp-support at lispworks.com> wrote:
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--------------------------------------------------------
Hi! Martin?

I've sent you mails before regarding the Lispworks COMM package
because of my work for the usocket project for a portable sockets
access implementation.

It turns out that I'm going to succeed to go where no portability
library has gone before: UDP sockets. I'm currently working on
'efficient multiple socket waiting' (ie select() call like behaviour)
and it looks like LispWorks provides something like it with its
wait-for-input-streams function. I do have questions about it though:

1) From the reference material I've concluded it's only available on
LispWorks 5.0. Is there anything you recommend using for 4.x?
2) When I've got a server socket retrieved through
create-tcp-socket-for-service, is that a stream object I can pass to
wait-for-input-stream?

And, although I haven't completed implementing the wait-behaviour yet,
I'm also collecting data on creation of UDP sockets. You can find what
I have so far on
http://trac.common-lisp.net/usocket/wiki/DatagramSockets. What you'll
find is that of all supported implementations, LispWorks is the only
one I haven't been able to identify a means to create (and use) UDP
sockets for. I'm hoping you can help me here, because the sources
you've referred me to in the past (acl-compat) don't 'do' UDP.

I hope you can give me some directions or direct help!

Thanks for your time in any case.

bye,


Erik Huelsmann
main author of usocket

PS: If you're interested: I've published a (work in progress) api
description at http://common-lisp.net/project/usocket/api-docs.shtml.