Re: Re: [Dynapi-Dev] Continuing Freeing memory

[Barre B. <ba...@ho...>]

hmm.... I wonder if this is still true... that garbage 
collection is done by reference counting...
This would be very wierd since there are circular 
references already in host objects! (Like subobjects of 
window that point back at window.)
But.. this would explain IE:s general memory leak I guess.
I wonder if delete solves this problem?
At any rate, the destroy method would have to be recursive, 
like:

function destroy(obj){

}


> Sounds like we need a "null cycle killer".  Damn sure 
circular references a
> playing a big roll in our leak...
> 
> >
> 
> This problem with cycles is the price that must be paid 
for a simple,
> lightweight, portable garbage collection scheme. The only 
way to prevent
> this problem is by manual intervention. If you create 
code in which A refers
> to B, B refers to C, and C refers to A, then you must be 
able to recognize
> that you've created a cycle, and take steps to force the 
cycle to be garbage
> collected when it is no longer needed.
> 
> When you know that the objects in your cycle are no 
longer in use, you can
> force them to be garbage collected by breaking the cycle. 
You can do this by
> picking one of the objects in the cycle and setting the 
property of it that
> refers to the next object to null. For example, suppose 
that A, B, and C are
> objects that each have a next property, and the value of 
this property is
> set so that these objects refer to each other and form a 
cycle. When these
> objects are no longer in use, you can break the cycle by 
setting A.next to
> null. This means that object B no longer has a reference 
from A, so its

> reference count can drop to zero and it can be garbage 
collected. Once it
> has been garbage collected, then it will no longer refer 
to C, so its
> reference count can drop to zero and it can be garbage 
collected. Once C is
> garbage collected, A can be garbage collected.
> 
> Note, of course, that none of this can happen if A, B, 
and C are stored in
> global variables in a window that is still open, because 
those variables A,
> B, and C still refer to the objects. If these were local 
variables in a
> function, and you broke their cycle before the function 
returned, then they
> could be garbage collected. But if they are stored in 
global variables, they
> will remain referenced until the window that contains 
them closes. In this
> case, if you want to force them to be garbage collected 
you must break the
> cycle and set the variables to null:
> 
> 
> A.next = null;      // break the cycle
> A = B = C = null;   // remove the last remaining external 
references
> 
> 
> 
> 
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