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Date: Wed, 31 Jan 2001 17:17:14 +0200
Message-Id: <200101311517.RAA12062@linux.>
From: "Ehud Karni" <ehud AT unix DOT simonwiesel DOT co DOT il>
To: vic DOT cross AT veejoe DOT com DOT au
Subject: Re: Possible problems in select() under Win95/98/ME
CC: cygwin AT cygwin DOT com
In-reply-to: <004801c08b79$cb06d460$1300a8c0@veejoe.com.au> (message from Vic
	Cross on Wed, 31 Jan 2001 21:34:37 +1000)
Organization: Simon & Wiesel Insurance agency
Reply-to: ehud AT unix DOT simonwiesel DOT co DOT il
References:  <004801c08b79$cb06d460$1300a8c0 AT veejoe DOT com DOT au>
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On Wed, 31 Jan 2001 21:34:37 +1000, Vic Cross
    <vic DOT cross AT veejoe DOT com DOT au> wrote:
> 
> The usual process of building a file descriptor set (containing the
> file descriptors for the listener socket and any connected clients)
> and entering a blocking select() call works flawlessly under Linux,
> but under Cygwin the select() appears to ignore the connected clients 
> -- that is, select() does not unblock for incoming data on a client, 
> and a new connection must be initiated to force select() to unblock
 [snip]

I have written a small proxy that use blocking select() and it works
fine on W95/98 (not checked on ME). I've checked ssh and it is also
working with blocking select (it is in packet.c). So, at least in some
cases, select() is working on W95/98.

> This workaround uncovered another problem in select() -- every time
> select() returns, a TCP loopback connection is created and sits in
> TIME_WAIT status until it ages out.  Various methods and tests have
> shown that the spurious connection is *definitely* co-incident with
> the return from select().

I checked with netstat (on W95) and there seems to be some (2 to 4)
loopback connections created. I never so more than 4 connections.

As it happens I had time-out in my proxy for the select(), set to 30
seconds, I changed it to 1 and 3 second and ran my proxy. There seem
to be loopback connection created for each select() return. Then I had
some net activity (not related to the proxy or Cygwin) and the creation
of the loopback connection CEASED !. I then changed the time-out to
300 milliseconds, and no loopback connection was created.

Ehud.


-- 
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