Re: MPS: native comp

[Andrea Corallo <acorallo@gnu.org>]

Gerd Möllmann <gerd.moellmann@gmail.com> writes:

> Andrea Corallo <acorallo@gnu.org> writes:
>
>> I think is not correct to add ephemral relocs to the compilation unit.
>> They are not reachable by the GC from that path on purpose, so that
>> after the load procedure they get GCed.
>
>>
>> If MPS is scanning the stack as our GC does it should just work.  Are we
>> sure this modification was necessary?
>
> Yes.
>
> I've read that comment.
>
>       /* Note: data_ephemeral_vec is not GC protected except than by
> 	 this function frame.  After this functions will be
> 	 deactivated GC will be free to collect it, but it MUST
> 	 survive till 'top_level_run' has finished his job.  We store
> 	 into the ephemeral allocation class only objects that we know
> 	 are necessary exclusively during the first load.  Once these
> 	 are collected we don't have to maintain them in the heap
> 	 forever.  */
>
> The problem is not liveness, it's the existence of untraced references
> there.

Yes but this way seems that there's no way to tell the GC that something
exists other than making it reachable from the heap.  There's really no
better way to tell MPS at runtime that a certain obj was allocated and
needs to be tracked?

Thanks

  Andrea