Re: [sigc] Strange crashes in sigc::trackable on Mac OS X

[Murray Cumming <murrayc murrayc com>]

On Thu, 2006-07-20 at 10:19 -0500, Michael Ekstrand wrote:
> Hello all,
> 
> I am experiencing some strange crashes in sigc::trackable on Mac OS X  
> 10.4, using Apple's GCC 4.0.1 and libsigc++-2.0.17 from Fink.

Is that the same version of g++ that was used by the Fink package?

Have you tried using valgrind, or getting a gdb backtrace, or reducing
it to a simpler test case?

> My program has an object model that uses libsigc++ to monitor object  
> state so that other objects, UI elements, etc. can be notified when  
> an object's saved state changes.  It can be a fairly twisted network  
> of signals sometimes, but it should work and does work on Linux.  If  
> it's relevant, the object model also uses a reference counting  
> mechanism, using hand-rolled reference counting smartpointers (and  
> corresponding weak pointers, using libsigc++ for the callback  
> mechanism to notify weak pointers of object destruction).  The memory  
> management stuff seems to be working flawlessly.
> 
> The problem occurs when the object model representation for a  
> document is being destroyed (e.g., the document is closed).  It  
> crashes with one of illegal instruction, bus error, or segmentation  
> fault (usually illegal instruction) when it's destroying some of the  
> objects.
> 
> The illegal instruction error (by far the most common, and the one  
> I've investigated most thoroughly) happens when destroying a  
> slot_base (and its rep_).  It's frequently (usually?) in the rep's  
> destroy() method, at the line:
> 
> if (destroy_) (destroy_)(this);
> 
> If I tell gdb to print *destroy_, it says that it cannot access  
> memory.  I don't know if this is because the destroy_ pointer is bad,  
> or if gdb can't dereference function pointers.
> 
> Any insight into this problem would be most appreciated.
> 
> -Michael
> _______________________________________________
> libsigc-list mailing list
> libsigc-list gnome org
> http://mail.gnome.org/mailman/listinfo/libsigc-list
-- 
Murray Cumming
murrayc murrayc com
www.murrayc.com
www.openismus.com