In VisualWorks, the place where objects that are likely never garbage
live is called perm space. You get a GC speedup roughly proportional to
the fraction of the image that is perm space (because you don't have to
scan it or mark it), as long as the GC is not global (i.e.: when you
also want to get rid of perm space garbage).
On 5/24/11 7:29 , Igor Stasenko wrote:
On 24 May 2011 15:20, Toon Verwaest<[email protected]> wrote:
On 05/24/2011 02:57 PM, Igor Stasenko wrote:
On 24 May 2011 14:46, Chris Cunnington<[email protected]>
wrote:
"But if the dependents are stored in some global dictionary from model to
sequence of dependents then the
reference from the global dictionary keeps both the model and the
dependents
alive."
When I hear "global dictionary" I think of a namespace. Perhaps
namespaces
could add efficiency to the GC.
I don't see how this could improve anything.
During full GC, it has to mark all reachable objects, because those
which won't be marked will be reclaimed.
So, how presence of namespaces could make GC faster?
If you know up-front that the namespace doesn't disappear, you could
separate those objects from the rest of the objects (in a separate heap) and
avoid marking/sweeping altogether. Basically a multi-heap generational GC;
with namespaces rather than just generations based on age.
Pointers going from one heap to another would have to go over a handle
table, as is usual...
Yes. Object spaces with gates between them.
But this is orthogonal to Ephemerons.
