From: schorsch at schorsch.com (Georg Mischler)
Date: Tue, 06 Apr 1999 16:35:14 GMT
Subject: Select weirdness on Solaris 2.4
References: <199904011625.LAA28154@python.org> <199904011702.MAA06784@eric.cnri.reston.va.us>
Message-ID: <7edd41$5gi$1@nnrp1.dejanews.com>
Content-Length: 1741
X-UID: 230                                                  

In article <199904011702.MAA06784 at eric.cnri.reston.va.us>,
  Guido van Rossum <guido at CNRI.Reston.VA.US> wrote:
> Georg Mischler wrote:
>
> > So the question now turns away from asyncore and towards python
> > internals. Can anyone spot the crucial difference between the
> > following C (compiled with -lsocket -lnsl) and what python does
> > with the 6 lines from above?
>
> Here's another suggestion.  Aren't there two socket implementations in
> Solaris?  One SysV compatible and one BSD compatible?  Does Python
> link with the same set of libraries as your little C program?


Thanks for all the suggestions from everybody.

I finally gave up when I found the following in asyncore.py:

if os.name == 'mac':
        # The macintosh will select a listening socket for
        # write if you let it.  What might this mean?
        def writable (self):
            return not self.accepting
    else:
        def writable (self):
            return 1

This showed me that the problem is not unique to my system,
and also pointed me to the solution. My derived class now
overwrites:

def writable(self):
    return not self.accepting

Since I know that the dispatcher will never write anything
to any socket (why should it?), this is save and will end
my headaches. I still don't understand the behaviour of
select in this case, but I leave that to the socket experts
to ponder...

as-long-as-it-works-don't-ask-why-ly yrs

-schorsch

--
Georg Mischler  --  simulation developper  --  schorsch at schorsch.com
+schorsch.com+  --  lighting design tools  --  http://www.schorsch.com/

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