[usocket-devel] UDP support in usocket, ideas explained

[Erik Huelsmann]

When looking at usocket.lisp, you'll find there is a datagram-usocket
class commented out. I think this class (even without any additional
slot definitions) should be used for UDP sockets.

Then there's datagram-usocket-p, which should start returning T when
the passed in object is a true descendant of DATAGRAM-USOCKET.

Looking further, you'll find there are functions defined for creating
stream and stream-server objects. A function like that should be
created for UDP sockets.

I think it's only sane to extend WAIT-FOR-INPUT to apply to UDP
sockets as well as any of the currently supported sockets. The
LispWorks variant of this function (for win32) is still on my laptop.
I'll try to finish it up soon, so that you can all start testing it.


I propose we implement recv()/recvfrom() as one function:
SOCKET-RECEIVE. I think we shouldn't bother implementing recv() and
recvfrom() as separate interfaces: I think we should return the
recvfrom-address field as the second return value of SOCKET-RECEIVE.

I also propose we implement send()/sendto() as one function:
SOCKET-SEND. I think we should provide the sendto address as an
optional parameter to the SOCKET-SEND function.

Also, I think the function should check for connected-ness of the
datagram socket. If the sendto address is specified on a connected
socket AND the address specified is unequal to the connected address,
the function should error.

Oh. One last thing: local and peer address retrieval functions should
be adapted to apply to UDP sockets as well as the currently supported
stream sockets.

I hope this is all a bit clear! If you have (m)any questions, please
don't hesitate to ask.

Bye,


Erik.