1.7.5: Occasional failure of CreatePipe or signal handing due to thread-unsafe code in cwdstuff::set
Tue Sep 14 17:58:00 GMT 2010
On Sep 14 18:11, Corinna Vinschen wrote:
> On Sep 14 10:12, Corinna Vinschen wrote:
> > On Sep 13 19:47, John Carey wrote:
> > > Anyway, it looks to me as if overwriting the path in an existing
> > > VistaCwd instance would confuse RtlGetCurrentDirectory_U() and
> > > probably other Win32 API functions. (It may be that the same is
> > > true for the handle member; I have not tried to find that out.)
> > > Cygwin should probably allocate a new VistaCwd instance,
> > > as does the Win32 SetCurrentDirectory() implementation.
> > Hmm, I'm still wondering. In theory we don't have to replace the
> > directory name. We just have to InterlockedExchange the handle, since
> > we only need to replace the original handle which does not allow
> > sharing-for-delete with our own handle which does.
> > All other border cases (virtual dir, directory with restricted rights)
> > can be rightfully handled by setting the Win32 CWD to \\?\PIPE\ again.
> > That's at least worth a try, isn't it?
> I applied the below patch to Cygwin CVS and it appears to work nicely.
Sorry, that wasn't what I was trying to say. Actually, I'm using this
code just locally for now and put it up here for discussion and for
curious testers. I intend to apply it only, if we can agree that it's
> The only potential race I can think of is, if another thread of the same
> Cygwin process calls SetCurrentDirectory. I'm inclined to let this
> situation slip through the cracks since SetCurrentDirectory will already
> mess up a mixed-mode Cygwin process.
> The "wincap.has_transactions ()" is just for testing. If we can use
> that code, I would replace is with something like
> "wincap.has_messed_up_cwd_handling()" or so.
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Project Co-Leader cygwin AT cygwin DOT com
Problem reports: http://cygwin.com/problems.html
Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
More information about the Cygwin