[usocket-devel] Questions about exported symbols...

[Patrick Stein]

On 2013-04-17, at 2:55 AM, Chun Tian (binghe) wrote:

> I think it's reasonable to export more interfaces for WAIT-FOR-INPUT to make it more efficiency for advanced users, but some of exist symbols (i.e. STATE) may be too simple that it could be conflict with other packages or user application, therefore I'm thinking a prefix WFI- or just WAIT- for all these potential new exports. Do you have any suggestion?

To me, I think the most reasonable would be to export WAIT-LIST-WAITERS and a SOCKET-READABLE-P function that returns whether the state is :READ or not.  Of course, it wouldn't be obvious that one has to WAIT-FOR-INPUT to make sure the SOCKET-READABLE-P is up-to-date.  Another approach might be to have WAIT-FOR-INPUT take a function to call on the readable sockets.  This would discourage anyone from disassociating the WAIT-FOR-INPUT and the READABLE state.

  (labels ((handle-socket-input (socket)
              … do something …))
    (wait-for-input my-wait-list :timeout 0 :ready-func #'handle-socket-input))

and inside WAIT-FOR-INPUT:

  (when ready-func
    (dolist (sock (wait-list-waiters socket-or-sockets))
      (when (eq (state sock) :read)
        (funcall ready-func sock)))

I could go either way….


I just noticed that each USOCKET instance tracks which WAIT-LIST (if any) it is part of.  I wasn't expecting that.  I was expecting to be able to keep several WAIT-LISTs around (which may overlap) and use different ones at different times.  Hmmm.  Of course, with a quick look, I'm not seeing how it's being used on the front-end in any way except in ADD-WAITER, REMOVE-WAITER, and REMOVE-ALL-WAITERS.  Maybe it's used on the backend?  I'll have to look closer.

Anyhow, you asked in the thread with Faré's patch if anyone would like to co-maintain.  I'm pretty busy myself, but I wouldn't mind helping out.  USOCKET is one of my favorite libs out there.

Thanks,
Patrick