Cygwin issues: modify-window and hangs

Dave Dykstra dwd at
Fri Jan 24 23:19:01 EST 2003

I had a friend run some Cygwin tests and we found that --modify-window=1
works just as well as --modify-window=2 on FAT filesystems to copy files
from Unix and detect the difference in granularity.  FAT filesystems always
have timestamps that have an even number of seconds.  On the other hand,
NTFS filesystems can store the modification time down to the second,
whereas previously people on this mailing list thought it was just like
FAT for modification time.  Nevertheless, I decided to change the default
value for --modify-window to 1 on Cygwin rather than 0, under the thinking
that even on NTFS filesystems it wouldn't do any harm because it's highly
unlikely that any individual file will be modified again within one second
after it is copied by rsync.

While doing the tests we too experienced hangs at the end of copies.
We were going over openssh from a Solaris 9 box to Windows 2000 Cygwin.
We tried the test from
but it still experienced hangs.  It wasn't clear if the patch reduced
the frequency or not.

Has *anybody* been able to figure out a fix for this that really works?
It sure would be nice to get something into 2.5.6 but we're about out of
time for that because I need to put it out this weekend before I start a
new (temporary) job on Monday.  I imagine that the issue I was experiencing
could be a separate one and this patch really would help other hangs
people are having; can anybody give me an argument for putting in the
calls to "shutdown()" anyway?  I would make it only happen on Cygwin,
because it is unknown if they will cause harm on other platforms.

- Dave Dykstra

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