when flex application starts, it gets an certain amount of memory from the system, garbage collector will not kick in right after a display object is removed from the list.

there are basically two rules, first is when the memory allocated are all used, GC will kick in, another is when the reference conunting table is full, GC will kick in.

so if you want to test with creating and removing popup windows, you might have to create 10000 windows at the same time (so the memory will all be consumed or reference table will be filled up) then remove them, you shall see the memory drops quickly.

The conclusion often leads to :

1. make sure you have no reference of the DisplayObject, it may be stored in an Array, Dictionary.

2. use weak reference in addEventListener(), otherwise garbage collector won’t clean it up.

I had personally experience memory leakage problems several times so now I’m very carefully handling all references (popup windows…etc) created.

This gonna haunt every flex developer (and after a short while, flash 9 users) in the years to come.

http://livedocs.macromedia.com/flex/2/docs/00000697.html#254176

did you notice that, after creating a new tab, the memory usage (from task manager) is keep increasing, even if we click the close button to close the tag, the memory remains the same.

it seems that it is memory leakage for flex 2.

do you have any idea on how to free up memory?

Thanks for the kind words, I didn’t post it on flexcomponents list because everyone there are also on flexcoders, no need to cross-posting.

I will add “view source” soon, thanks for the suggestion.

I’m just wondering why you don’t post your gem to flexcomponents mailing list — surely people will like it!