Re: RFC - Alternatives to gengtype

[Florian Weimer <fweimer at redhat dot com>]

On 11/23/2012 10:45 AM, Jonathan Wakely wrote:

> > Actually, this observation may favor a real garbage collector. Marking GC as
> > simple as ggc+gengtype usually have one (or a few) mark bits, so can consume
> > only a few bits (or perhaps a byte in some mark array) per object. Copying
> > GC could avoid consuming any more storage per object. Of course useless
> > object may stay in memory for a while -until the GC deletes them or reuse
> > their memory-
>
> The research shows significantly higher memory usage when relying on
> GC in large systems.

I believe the research treats reference counting as a form of GC. 8-)

It would be an interesting project to instrument GCC to obtain the 
precise point when any object becomes unreachable, synthesize a sequence 
of malloc()/free() calls from that, and run it against a traditional 
malloc implementation.  I believe this is how some of the early research 
into GC memory overhead was done (at much, much smaller heap sizes for 
sure).

--
Florian Weimer / Red Hat Product Security Team