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Date: Mon, 29 Jun 2009 11:28:57 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: [1.7.0-50] scp progress counter flies through first 175 MB or 	so
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On Jun 28 15:31, Christopher Faylor wrote:
> On Thu, Jun 25, 2009 at 10:50:05AM -0400, Christopher Faylor wrote:
> >On Thu, Jun 25, 2009 at 04:36:51PM +0200, Corinna Vinschen wrote:
> >>Looks like scp now stumbles over the pipe select() implementation.
> >
> >Yes.  Grumble.  That's a bad interaction between non-blocking writes and
> >our stupid-thanks-to-Microsoft select implementation.  I think I can
> >work around this particular problem though.  I'll get to that this
> >weekend.
> 
> This should be fixed in the latest snapshot.  I hated to do it because I
> think I've throttled pipe reads and writes somewhat but it should be
> more correct now.
> 
> However, the new implementation may play more nicely with things like
> rsync which hang on pipe writes.
> 
> Btw, Corinna, were you proposing turning the "FIXME" code in peek_pipe
> back on?

I'm a bit wary to do that, but...

>   I don't think I ever saw it fail myself after my last round
> of tweaks but I don't remember what the exact problem was.  Did it
> fail on some version of Windows NT/2000/XP/2003/2008/7?

...I just searched for the old threads and here's where the problem
starts:
http://cygwin.com/ml/cygwin/2004-09/msg00416.html

That led to:
http://cygwin.com/ml/cygwin-patches/2004-q3/msg00091.html

And then there was the Unison problem:
http://cygwin.com/ml/cygwin/2004-09/msg01131.html

Which was subsequently discussed here:
http://cygwin.com/ml/cygwin-patches/2004-q3/msg00133.html

I tested sftp with big files (Gigs) and it appears to work fine with the
FIXME code switched back to life.  I tested the unison command using
Cygwin's unison 2.31.4-2 under tcsh and it worked fine.  I tested
various combinations with pipes created by a native application and with
native applications on send and receive side of a Cygwin pipe and all my
testcases worked as expected.

So, maybe we should really give it a try again.  


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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