Re: cygwin hang problem

[Christopher Faylor <cgf at redhat dot com>]

On Mon, Jul 15, 2002 at 12:44:48PM -0400, Joe Buehler wrote:
>I am using Cygwin to run a build system.  I have spent a couple weeks
>and fixed a couple Cygwin problems,

I hope to see the patches for these soon.

but am in the midst of
>one that is very difficult to pin down.
>
>The problem is that processes will sometimes just hang in a Win32
>API call for no apparent reason.  Here is an example stack trace
>of an invocation of "rm" that is hung (I have added the names for
>the system dll stuff at top of stack):
>
>(gdb) bt
>#0  0x77f67a1b in _system_dlls__ ()_NtFsControlFile@40
>#1  0x77f686de in _system_dlls__ ()_RtlpValidateCurrentDirectory@4
>#2  0x77f65df6 in _system_dlls__ ()_RtlGetFullPathName_Ustr@24
>#3  0x77f658fe in _system_dlls__ ()_RtlDosPathNameToNtPathName_U@16
>#4  0x77dc2f05 in _system_dlls__ ()_GetFileSecurityW@20
>#5  0x77dc3018 in _system_dlls__ ()_GetFileSecurityA@20

Hmm.  Interesting debug output.  I don't recall ever seeing the
actual NT or win32 function names in gdb before.  How did you manage
this?  Another unpublished patch?

>It is not apparent to me why GetFileSecurity() would hang.  According
>to the "handle" utility available from sysinternals on the net,
>nothing has the file temp.ar.327 open except the "rm" process itself.
>
>I have also seen similar hangs in calls to GetFileSecurity().
>
>Any ideas what might be going on here?
>
>The hang is on a dual-processor NT 4 machine running service pack 5.

Service pack 5 of what W2K?

>The same test ran fine a half-dozen times over the weekend
>on a single-processor XP machine.

It sounds like you may be looking in the wrong thread for the hang.
info threads will show all of the threads and "thread n" will switch
to thread n.

cgf