Re: [Gnash-dev] GC: status report & call for test

[Eric Hughes]

At 08:41 AM 7/5/2007, strk wrote:
> Users (ActionScript coders) can still change this relationship.
> a function's "constructor" member is a pointer to self, but
> might be changed to point to something else:
>
>         A = function() {}
>         B = function() {}
>         A.prototype.constructor = B.prototype.constructor;
>         delete A;

I had commented briefly about this situation a while ago, when it was 
certainly premature then.  My proposal to this would be to initialize 
".constructor" members with a weak pointer.  The assignment in line 3 above 
would overwrite that weak pointer with an ordinary GC pointer.  Thus in the 
ordinary case, reference counting would destroy a constructor member when 
its function goes out of scope, but in the general case the GC would catch it.

The reason that this may still be premature is that it presumes a proper 
managed_ptr class with multiple variants hiding behind it (say, gc_ptr, 
rc_ptr, weak_ptr) so that this upgrade in capability happens silently at 
the point of assignment.

Eric