[Gc] Re: GCJ, typed malloc, custom mark proc?

James Williams junk at giantblob.com
Mon Aug 3 03:43:19 PDT 2009


Andrew Haley <aph at ...> writes:

> 
> James Williams wrote:
<snip>
> >> Hmm, if I understand correctly you say it's completely broken...
> 
> It can't be.  We use it all the time in gcj.

Thanks - that's good to know. That means that I can concentrate on debugging my
code.
> 
> >> I use it (length-based only) for a long period (GC v7.2a2 or CVS) and
> >> never observed such things.
> >> The ways I use it, I've described in
> >>
http://permalink.gmane.org/gmane.comp.programming.garbage-collection.boehmgc/2679
> >
> > Thanks for the pointer.
> >
> > I have no reason to think Boehm GC is broken in this instance. I was
> > looking for reassurance that the GJC interface to libgc is a supported
> > public interface that I can safely use it from outside of the the GCJ
> > runtime.
> >
> > I think it's most likely that I'm just using GC_gcj_malloc wrongly -
> > perhaps my descriptors are in the wrong place or are wrongly constructed.
> 
> It should be trivially easy to find out.  What happened when you traced
> through the marking routine in a debugger?

Well, the descriptors look like the ones I placed in the vtables and the
collector is treating words in the objects as pointers where the corresponding
descriptor bits are set so I think it's behaving as advertised. I guess I must
somehow be setting the wrong bits in the descriptors.

Thanks for your time.
-- James
> 
> Andrew.
> 






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