[usocket-devel] usocket on LispWorks (non-win32 and no multiprocessing)

[Erik Huelsmann]

On Tue, Oct 21, 2008 at 1:24 PM, Chun Tian (binghe)
<binghe.lisp at gmail.com> wrote:
> Hi, usocket-devel
>
> (testing 0.4 branch)
>
> In LispWorks Professional and Enterprise Edition, user can save a
> image without thread support. When such a lispworks image started, all
> function in MP package is there but no thread running:
>
>        binghe at binghe-debian:~$ lispworks-cli
>        LispWorks(R): The Common Lisp Programming Environment
>        Copyright (C) 1987-2008 LispWorks Ltd.  All rights reserved.
>        Version 5.1.1
>        Saved by binghe as lispworks-5-1-1-64-bit-cli, at 12 Jun 2008 14:50
>        User binghe on binghe-debian.local
>
>        CL-USER 1 > (mp:list-all-processes)
>        NIL
>
>        CL-USER 3 > mp:*current-process*
>        NIL
>
> When there's no thread support in LispWorks, USOCKET:WAIT-FOR-INPUT
> cannot be used (on non-win32 platform) because it calls MP:PROCESS-
> WAIT on current thread, that will cause a UNKNOWN-ERROR:

Nice catch!

> USOCKET 9 > (wait-for-input x)
>
> Error: The condition #<UNKNOWN-ERROR 405008A5B0> occurred
>   1 (abort) Return to level 0.
>   2 Restart top-level loop.
>
> Type :b for backtrace, :c <option number> to proceed,  or :? for other
> options
>
> USOCKET 10 : 1 > :b
> Call to ERROR
> Call to RAISE-USOCK-ERR
> Call to SIGNAL
> Call to ERROR
> Call to MP::WITHOUT-PREEMPTION-ERROR
> Call to MP:PROCESS-WAIT
> Call to WAIT-FOR-INPUT-INTERNAL
> Call to WAIT-FOR-INPUT
> Call to WAIT-FOR-INPUT
> Call to EVAL
>
> I think may be there're some way not use MP-related function to
> achieve the same effect, i.e. direct call select() or turn to use
> LispWorks' SYS:WAIT-FOR-INPUT-STREAMS [1] instead (which works on all
> platform include win32 but just for stream usocket).

Well, that would severely limit the usability of WAIT-FOR-INPUT,
because it wouldn't be usable with listening sockets or udp sockets.

Could we just error out when someone tries to use WAIT-FOR-INPUT
without MP support? I mean... Are there any problems with requiring
the apps be built with mp support? (licensing from LW, for example)

Bye,

Erik.