Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sources.redhat.com/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sources.redhat.com/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
X-Authentication-Warning: slinky.cs.nyu.edu: pechtcha owned process doing -bs
Date: Tue, 24 Sep 2002 09:49:48 -0400 (EDT)
From: Igor Pechtchanski <pechtcha AT cs DOT nyu DOT edu>
Reply-To: cygwin AT cygwin DOT com
To: Anthony Heading <aheading AT jpmorgan DOT com>
cc: cygwin AT cygwin DOT com, <rsync AT lists DOT samba DOT org>
Subject: Re: 2.5.5-1 rsync hangs
In-Reply-To: <20020924102940.GA25046@tkd-fires-02.ja.jpmorgan.com>
Message-ID: <Pine.GSO.4.44.0209240948580.15469-100000@slinky.cs.nyu.edu>
Importance: Normal
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII

On Tue, 24 Sep 2002, Anthony Heading wrote:

> On Mon, Sep 23, 2002 at 01:06:22PM -0700, Sudheer Tumuluru wrote:
> >
> >     I am having the same problem with rsync 2.5.5-1. I am
> > trying to rsync a couple of short text files between a linux server and
> > Win2k Professional boxes with cygwin. About 20% of the time, rsync freezes
> > at the end of the transfer, and I can't kill the rsync process in
> > cygwin even if I give it a 9 (SIGTERM) signal. This happens mostly on dual-processor
> > machines but it did happen once on the single proc machine as well.
>
> Me too.  I spent this afternoon debugging.  There doesn't appear to be
> anything wrong with rsync - looks rather more like something in cygwin
> signal delivery is ill.
>
> In my case I'm trying to pull files onto Windows(XP) from Unix(Solaris).
>
> rsync forks in this case; the parent process generates the filelisT
> while a child process does the receiving.  (Something like that, at
> least; I guess it's for deadlock avoidance)
>
> At the end, the parent process waves farewell to the remote server,
> and then does a kill(..., SIGUSR2) on the child pid to tell it to exit.
>
> This signal seems to get lost, as suggested above, some moderate
> percentage of the time.
>
> The child process is supposedly waiting for this signal inside
> msleep(), which calls select() to wait in 20ms bursts.  In the
> cases that the child manages to reach the select() in time to
> start waiting, I didn't observer any hangs.  But consistently
> if the kill was received before that point, the child process
> simply locks up.
>
> This suggests that hack workaround of adding a call to
> say msleep(30) just before the line kill(pid, SIGUSR2) in
> main.c:do_recv().
>
> With that kludge in, I haven't seen any hangs in a few hundred
> trials.  YMMV, but it might be a helpful bandaid until some
> cygwin expert has the chance fix things properly.
>
> Rgds
>
> Anthony

Hmm, how about a patch?
	Igor
-- 
				http://cs.nyu.edu/~pechtcha/
      |\      _,,,---,,_		pechtcha AT cs DOT nyu DOT edu
ZZZzz /,`.-'`'    -.  ;-;;,_		igor AT watson DOT ibm DOT com
     |,4-  ) )-,_. ,\ (  `'-'		Igor Pechtchanski
    '---''(_/--'  `-'\_) fL	a.k.a JaguaR-R-R-r-r-r-.-.-.  Meow!

"Water molecules expand as they grow warmer" (C) Popular Science, Oct'02, p.51


--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Bug reporting:         http://cygwin.com/bugs.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/