[kaffe] Threads & Boehm GC

[Helmer Krämer]

On Sat, 24 Jul 2004 11:59:40 +0200
Guilhem Lavaux <guilhem at kaffe.org> wrote:

> Helmer Krämer wrote:
> 
> >On Sat, 24 Jul 2004 09:38:08 +0200
> >Guilhem Lavaux <guilhem at kaffe.org> wrote:
> >
> >Hi,
> >
> >  
> >
> >>It seems that the Boehm-GC needs to catch a number of pthread calls. 
> >>This is not evident to implement in kaffe but I think I can do the 
> >>following:
> >>[...]
> >>Any comments ?
> >>    
> >>
> >
> >why does the gc_pthread_redirects.h thing from boehm not
> >work? I mean if kaffevm/gc.h included a header file called
> >"gc-impl.h" from kaffevm/kaffe-gc or kaffevm/boehm-gc and
> >unix-pthreads/thread-impl.c included kaffevm/gc.h (and thus
> >boehm-gc/gc-impl.h), it should work, shouldn't it?
> >
> >  
> >
> Yes, but I'd like not to have to include any boehm specific includes in 
> pthreads.
> If I do this, the unix-pthreads will be stuck with the boehm-gc once it 
> is compiled.
>
> If we want to have a '-Xkaffe-gc' to switch to the standard GC we may 
> not be able to do so if we chose this way.

Note that there will be a lot more problems if we wanted to implement
such an option. For example, if you wanted to be able to switch between
an incremental and a conservative GC you would have to modify the vm
itself so it properly tells the gc whenever a pointer is written (or
accept a huge overhead). Therefore, I'd rather select boehm or kaffe
at compile time and have -X options only for options specific to the
selected implementation. Just because it will be easier. Why would one
have to switch between kaffe and boehm at runtime, anyways?

Regards,
Helmer