Some thoughts about the ObjectRegistry, now that this is the last source
of memory leaks (at least in my small examples):
As a reminder: maps written like the following:
registry[hash] = obj
with an ever-changing hash-value leak at least on IE7, even after correct
deletion of key/value pairs.
(Note that there are other places than the ObjectRegistry using such
hash-map constructs as well - but most of them could be replaced with an
Array.push/pop() )
I think that there are two approaches to fix this:
1) Reuse hashes. After object-disposal no object should be bothered if the
hash-key is reused again. If instances still hold hash-keys after object
disposal and make use of them, than it's a bug, that needs to be fixed.
These parts would fail somewhen also without a change.
Caching freed hashes is a no-brainer in the Object-Registry
--- ObjectRegistry.register ----
hash = obj.$$hash = this.__freeHashes.pop();
if (!hash) {
hash = obj.$$hash = (this.__nextHash++).toString(36);
}
------------------
Of course you need 2 other lines - one for the declaration of __freehashes
and one for filling it on unregistering objects.
The nice thing about this approach is, that it indirectly fixes all other
parts in the code where hash-maps are used as well.
And indeed - with this change (and the ones in the post yesterday) I can
create and destroy 20.000 Labels (as always in blocks of 500 'concurrent'
Labels) without any leak.
OK - say it leaks less than 0,2MB, it can't be measured too exactly when
its that low.
And to be pedantic - actually this doesn't fix the leak, it just limits it
to the maximum number of concurrent living objects.
2) Write your own complete HashMap-implementation without leaks.
Seems to be too much work now before the API freeze.
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