This is the mail archive of the
cygwin-xfree@cygwin.com
mailing list for the Cygwin XFree86 project.
RE: ORBit install
- From: "O'BRIEN,STEVE (HP-UnitedKingdom,ex1)" <steve_obrien at hp dot com>
- To: 'Robert Collins' <robert dot collins at itdomain dot com dot au>,cygwin-xfree at cygwin dot com
- Date: Mon, 25 Feb 2002 09:53:27 -0000
- Subject: RE: ORBit install
Thanks for the hints Rob. I'll have a look at this again as soon as I get
the chance. It will be some time before I will have a chance to build a
debug cygwin1.dll though.
Steven
> -----Original Message-----
> From: Robert Collins [mailto:robert.collins@itdomain.com.au]
> Sent: 21 February 2002 12:25
> To: O'BRIEN,STEVE (HP-UnitedKingdom,ex1); cygwin-xfree@cygwin.com
> Subject: RE: ORBit install
>
>
>
>
> > -----Original Message-----
> > From: O'BRIEN,STEVE (HP-UnitedKingdom,ex1)
>
> > Hi Rob
> > I didn't mean to suggest that there is a problem with the
> > cygwin pthread
> > implementation.
>
> There may be :}. I'm not concerned if there is or is not, but
> rather with the fault you see - when we examine that we can
> lay blame :}.
>
> > Sometimes I get:
> > GThread-ERROR **: file gthread-posix.c: line 55
> > (g_mutex_new_posix_impl):
> > error Device or resource busy during pthread_mutex_init
> > ((pthread_mutex_t *)
> > result, ((void *)0))
>
> What does gthread-posix.c line 55 look like.
>
> > Sometimes I get a segmentation fault
>
> Can you duplicate this with gdb, or with strace, or with JIT
> debugging (see how-debuging-works.txt in the cygwin source
> directory.You'll need a debug cygwin1.dll for tracking this down.
>
> > Sometimes the test completes ok
> >
> > Failures appear at different points in the program, so I
> > can't even say that
> > the "resource busy" always occurs at X and segmentation fault
> > always occurs
> > at Y.
>
> Thats ok. If we can pin one down with a good backtrace, it
> may make the fault visible.
>
> > When running in gdb the debug symbol table becomes corrupted, so the
> > function names it reports do not match the file:lineno
> > reported - so the
> > program is clearly trashing memory on its way.
>
> Optimisation can also cause that, I wouldn't assume that the
> symbol table is necessarily corrupt. What does bt full, and
> info threads show?
>
> > I *think* that a mutex is not being set properly, or is being
> > corrupted when
> > the memory managment error kicks in, so that two threads
> > attempt to free the
> > same memory, or one uses memory that is already freed by
> another. All
> > guesswork though, because I have not been able to trace the
> > execution in
> > gdb.
>
> Yah, single stepping with threads is iffy at best, they tend
> not do show the fault. Breakpoints are your friend :}.
>
> ROb
>