2.5.5-1 rsync hangs

Igor Pechtchanski pechtcha at cs.nyu.edu
Tue Sep 24 13:50:14 EST 2002

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?
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