RTS/Garbage Collector idea

John Meacham john at repetae.net
Thu Jul 5 19:24:48 EDT 2007

On Mon, Jun 18, 2007 at 02:00:02PM +0100, Simon Marlow wrote:
> Isaac Dupree wrote:
> >I was thinking, since we have a copying garbage collector that reassigns
> >all pointers anyway, could we detect the "identical" heap objects and
> >for each set of identical ones, have all thunks that pointed to any of
> >them, now point to the single one that is created in the target space?
> I think what you're proposing is often called "hash consing", except that 
> hash-consing is usually done at construction time, you want to do it at GC 
> time.
> My take is it would only be worthwhile if there was a *lot* of sharing to 
> be gained by doing it, and in most cases there wouldn't be.  This is just a 
> guess based on my experience poking around in the heap though - feel free 
> to try it out and prove me wrong :-)

it might be worthwhile to do in a couple specific cases, like a cache of
small Ints or the ascii characters.


John Meacham - ⑆repetae.net⑆john⑈

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