Because of the way GC works, I still think it is best for us to remove the listeners. GC is only on allocation so again, if someone had a handle to an object that got removed and twiddled a value, the notification code would run needlessly until GC kicked in.
However, I think you've come up with a great optimization for folks who know they are destroying everything all at once. ________________________________ From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Arpit Mathur Sent: Thursday, February 14, 2008 9:39 PM To: [email protected] Subject: Re: [flexcoders] Performance difference between ArrayCollection.removeAll() and ArrayCollection.source = [] Hmm, maybe I am missing something here? The only place I see addEventListener being called is protected function startTrackUpdates(item:Object):void { if (item && (item is IEventDispatcher)) { IEventDispatcher(item).addEventListener( PropertyChangeEvent.PROPERTY_CHANGE, itemUpdateHandler, false, 0, true); } } which has the weak-keys boolean flag turned on. Shouldnt that allow garbage collection to run without explicitly calling removeEventListener ? On Thu, Feb 14, 2008 at 11:54 PM, Alex Harui <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > wrote: Our code has to look like that otherwise if someone kept a reference to one of the objects that got removed, it would keep the ArrayList from being GC'd. We added listeners, so we should remove them. If the data objects are going away too, then you can probably reset the source, but if you see a memory leak later, I'd definitely check in that area. ________________________________ From: [email protected] <mailto:[email protected]> [mailto:[email protected] <mailto:[email protected]> ] On Behalf Of Arpit Mathur Sent: Thursday, February 14, 2008 8:27 PM To: [email protected] <mailto:[email protected]> Subject: [flexcoders] Performance difference between ArrayCollection.removeAll() and ArrayCollection.source = [] I was trying to debug an issue with the LogBook application we released a couple of days back. If you take a look at the interface on the main page at http://cimlogbook.googlecode.com <http://cimlogbook.googlecode.com/> (or if you have installed the application), you will see a clear logs button. Clicking on that clears an ArrayCollection that holds a series of LogObjects by calling a removeAll() function. However we got a bug saying the application would almost hang if it tried to clear a lot of messages. A quick patch was to reset the source like so: arrayCollection.source = [] . The performance became lightning fast. Looking deeper into the removeAll function and following the hierarchy to the ArrayList class, I see that the removeAll loops through the entire array, looking at each member to see if its an event dispatcher and if so calling a function to remove the propertyChange listener. Why is this implemented this way ? Is there any reason I shouldnt just use source = [] to reset the array ? Thanks -- Arpit Mathur Lead Software Engineer, Comcast Interactive Media --------------------------------------- post your flex tips on http://flextips.corank.com <http://flextips.corank.com/> -- Arpit Mathur Lead Software Engineer, Comcast Interactive Media --------------------------------------- post your flex tips on http://flextips.corank.com <http://flextips.corank.com/>
