Andreas Junghans wrote:
> Am 01.08.2006 um 17:26 schrieb Sebastian Werner:
>
>> Dietrich Streifert schrieb:
>>>
>>> Sebastian Werner schrieb:
>>>> So the performance impact comes from the for-loop. I think there
>>>> is no
>>>> chance to make this greatly better. It's just a loop. Maybe the
>>>> delete
>>>> operator is that bad.
>
> for loops where one of the critical points in my tests with lots of
> objects (the IE garbage collector problem). It shouldn't affect
> Firefox though.
>
>>> So just nullifying the attributes is not enough, right?
>>>
>>> this[qx.OO.values[a[i]]] = null;
>> It's the same. And should have the identical performance.
>
> Not really. Delete actually removes the key from the internal hash
> map of the object. Setting the value to null only changes the value
> but leaves the collection of keys alone. I'd expect delete to work
> slower than nulling the references, but I didn't test it.
>
I'm following this thread closely because this is an issue for me as
well. Using a simple test of creating 50,000 Date objects, iterating
and testing first reference nulling then deleting, delete consistently
performed slower although significantly slower on IE. On average:
Firefox 1.5.0.5 (win64)
reference = null : 78ms
delete : 94ms
Firefox 1.5.0.4 (linux-x86)
reference = null : 88ms
delete : 110ms
IE 6.0.3790 (win64)
reference = null : 63ms
delete : 3765ms
Admittedly I'm ignorant as to the internals of the IE garbage
collector, but shouldn't simply nulling out the qx.core.Object._db be
sufficient for escape analysis (i.e. if this is the only point of
reachability for these objects, removing it should preclude any it's
contents from being marked as reachable)? Is the IE garbage collector
stubborn such that even though the objects are no longer reachable
they still have to be manually deleted recursively (in which case it's
not really a garbage collector)?
-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys -- and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
qooxdoo-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/qooxdoo-devel
