Comments on: Flex optimization tip: ArrayCollection.removeAll() vs. ArrayCollection.source = new Array(). Is this a bug ?

By: InF3rN0

InF3rN0 — Fri, 18 Jun 2010 19:26:18 +0000

Thanks a lot for this. It was exactly what I was looking for. Very nice way to solve it.

CHeers.

By: arpit

arpit — Tue, 09 Feb 2010 14:29:53 +0000

@RajPrabha
1) obj will only get gc-ed if no other object has added an event listener to it. Make sure nothing else is forcing its existance.

2)Objects running code like Timers, Enterframe listeners etc cannot be garbage collected until those stop. See http://www.gskinner.com/blog/archives/2006/07/as3_resource_ma_1.html

3)Also note, objects marked for Garbage Collection may not be collected immediately. The Flash Player marks them for collection until the next GC cycle but that may take a few frames.

By: RajPrabha

RajPrabha — Tue, 09 Feb 2010 10:25:55 +0000

I am using arrayCollection.source = new array[]. But the old objects are not being garbaget collected. Can anyone please help me?

var obj:Object = new Object;
obj.name = “something”;
arraycollection.addItem(obj);

after some time,

arraycollection.source = new Arrray();

but ‘obj’, still exists in memory. Please help me

By: Chris Brown

Chris Brown — Fri, 21 Aug 2009 07:11:27 +0000

Thanks for this article.
For my project I extended the ArrayCollection class and overrode the removeall() function.

Also, When I called removeAll on and arrayCollection it didn’t seem to dispatch an event, am I missing something? Anyway, in my class I also made it dispatch and event when removeall is called.

By: Joel

Joel — Tue, 24 Mar 2009 20:05:19 +0000

I appreciate you blogging this. It helped me solve the same kind of problem. Thanks.

By: arpit

arpit — Sat, 27 Sep 2008 22:30:44 +0000

@Paul,
How many items are you removing at a time? The removeAll() function seems to need some process time that is dependent on the number of items being removed at one time (It basically runs in a for loop removing event listeners which becomes processor intensive for large ArrayCollection objects). If you are removing 10 at a time that should not be a big deal.
Its more likely that you may be removing those objects from the ArrayCollection but these objects aren’t being garbage collected (maybe you have an event listener of your own that is not using weak references), so after a while, just having these objects in memory may cause a performance hit. Try using the Flex profiler to see if the objects are being garbage collected correctly.

By: Paul

Paul — Thu, 25 Sep 2008 10:40:25 +0000

Hi I have an app increases the rows in arraycollection (manually), usually there are only a max of 10 rows added. When the process completes I use Removeall() as discussed. I may be doing this x 1000 times per session. It has been noted that the application appears to be slowing down after 600 / 700 processes. Does anyone think that the removeAll() function could have a cumalitive effect on the app?

By: FLEX OPTIMIZATION TIP: ARRAYCOLLECTION.REMOVEALL() VS. ARRAYCOLLECTION.SOURCE = NEW ARRAY(). IS THIS A BUG ? « Tekitwa’s Weblog

Mon, 08 Sep 2008 04:27:06 +0000

[...] FLEX OPTIMIZATION TIP: ARRAYCOLLECTION.REMOVEALL() VS. ARRAYCOLLECTION.SOURCE = NEW ARRAY(). IS THIS A BUG ? FLEX OPTIMIZATION TIP: ARRAYCOLLECTION.REMOVEALL() VS. ARRAYCOLLECTION.SOURCE = NEW ARRAY(). IS THIS… [...]

By: code zen » Blog Archive » Why open-source : The LogBook Story

code zen » Blog Archive » Why open-source : The LogBook Story — Mon, 19 May 2008 19:03:03 +0000

[...] = new Array(), the performance went back to normal. Details of the bug/fix can be found here but this situation was never discovered internally. Had we not open-sourced LogBook we could have [...]

By: biju

biju — Wed, 27 Feb 2008 06:05:44 +0000

@maliboo,
Nope, although I cant imagine that it will help. All that is supposed to do is disable CollectionChange Events broadcasts (instead putting them in an internal array to be broadcast on enableAutoUpdate). removeAll() triggers only one CollectionChange Event (RESET). So the problem doesnt seem to be a view receiving too many updates.