[Gc] gcc_support.c & WeakPointers

teelf@nymph.kyndig.com teelf@nymph.kyndig.com
Thu, 6 Nov 2003 14:12:42 -0600 (CST)


Now I understand why the WeakPointer functions wrap the pointer in a 
GC_MALLOC_ATOMIC object.  And I should still use the 
GC_call_with_alloc_lock function to get the pointer value of the 
WeakPointer?

I just tried a version of the WeakPointers with the code for Descriptors 
removed.  It seems to be working.  Since I don't any any finalizers, this 
should be ok? 

Thanks a lot for the help.

- Lee Faris

On Thu, 6 Nov 2003, Boehm, Hans wrote:

> You should almost certainly not be using gcc_support.c.  I just removed it
> from the distribution to avoid further confusion.  It was there to support
> an gcc extension which was never fully released.  I included it for a while
> in the hope that someone might resurrect it or be able to recycle pieces of it,
> and then forgot about it.
> 
> I haven't looked at the weak pointer class in gcc_support.c recently.
> You may be able to resurrect it.  If so, it might make sense to extract it
> and put it back in the distribution.  If you need simple weak pointers,
> and don't depend on the precise interaction with finalizers,
> GC_general_register_disappearing_link together with a pointer that's either
> disguised (HIDE_POINTER or in preferably a GC_MALLOC_ATOMIC object) allows
> you to do that fairly easily.
> 
> Hans
> 
> > -----Original Message-----
> > From: gc-admin@napali.hpl.hp.com [mailto:gc-admin@napali.hpl.hp.com]On
> > Behalf Of Lee Faris
> > Sent: Thursday, November 06, 2003 1:00 AM
> > To: gc@napali.hpl.hp.com
> > Subject: [Gc] gcc_support.c
> > 
> > 
> > I am not able to use gcc_support.c as I get an undefined reference to
> > __default_new_handler.    I can not find any mention of
> > __default_new_handler anywhere else.  It sounds like 
> > something that would be
> > defined in the stdc++ library (but apparently is not).  Or am 
> > I suppose to
> > set this value to something myself?
> > 
> > I get this error on both gcc 2.96 on linux 2.4.9 and in 
> > VS.net 2003.  Also,
> > in VS.net I get an undefined reference to __new_handler as 
> > well.  And a
> > related question, is gcc_support.c ok to use with visual 
> > studio even though
> > it's called gcc_support.c?  I am assuming so since it implements the
> > weakpointer class.
> > 
> > Thank you for any help with this.
> > 
> > - Lee Faris
> > 
> > 
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