Re: Garbage collection

[James McCartney <asynth@...>]

On Sunday, November 3, 2002, at 07:55  AM, Thatcher Ulrich wrote:

> > It is not "an unsorted bag of different-sized chunks."
> > The treadmills are segregated into size classes.
>
> Sorry, my mistake.  I suppose you can always keep a count of free
> chunks and sweep if it grows too big, to avoid consuming too much of
> the C heap.

In one version I had one treadmill for finalizers, which were small 
objects that caused their referents to be finalized when they were 
collected*. I would sweep that free list incrementally. I also would 
incrementally sweep the large size classes. But the small size classes 
are not swept.

*An object that wants to be finalized creates one of these finalizer 
objects and points to it, the finalizer object points back to the 
object to be finalized, so you have a small loop. When the finalizer 
object gets collected, then the other object must be garbage too, so it 
calls that object's finalize method. This trick allowed me to only have 
to sweep a short list of objects that need to be finalized, instead of 
all newly freed objects each time.

--
--- james mccartney   james@audiosynth.com   <http://www.audiosynth.com>
SuperCollider - a real time synthesis programming language for the 
PowerMac.


--
--- james mccartney   james@audiosynth.com   <http://www.audiosynth.com>
SuperCollider - a real time synthesis programming language for the 
PowerMac.
<ftp://www.audiosynth.com/pub/updates/SC2.2.16.sea.hqx>