[thelist] JS memory leak detection?

VOLKAN ÖZÇELİK volkan.ozcelik at gmail.com
Sun Oct 23 05:09:14 CDT 2005

> so, i play with JS a lot, and i have a pretty good feel for writing
> scripts, but i'm not so good with tracking down memory leaks...

As Jeff has said "welcome to the dark side" :) The next stage is
washing your dishes with ajax (okay yet another bad joke).

> i've read these two articles, and am having a little trouble
> determining if and how they can be applied:
> http://novemberborn.net/javascript/event-cache
> http://laurens.vd.oever.nl/weblog/items2005/closures/

The memory leakage issue is not a myth. IE does experience it, but you
will hardly recognize it if you are not attaching several hundereds of
events on window.onload (and most of them create circular-references
to each other.)

imho, you usually do not generate a circular reference to a DOM node like


I don't generally create relations like this (to avoid a duel between
another paragraph's fiance and darling -- okay no more jokes :) - I
have a flu and my body is a bit over-heated, I guess that's because of

In short, I did not observe any circular references in your code.

> essentially, i am looking for some JS genius-level feedback on the
> modified code i am using here and what i can do to optimize it:
> http://algonquinstudios.com/js/flyoutnav.js

I had also implemented a registy mechanism somewhat similar to the
referenced article:


and I use it none the less to be on the safe side (actually my cross
browser EventHandler object


handles the registry issues on the back end, so I do not need to think
about it any more. Actually I have almost forgotten about it until
this post)


My humble suggestion:
Optimization without observation is of no use. Open your task manager.
Without closing the browser, try refreshing the page several thousand
times (or use a meta refresh). note the delta in CPU an ram
If after half an hour your CPU has reached near 100%, then you do have
a leakage problem and need to implement a event registry of some sort.

Volkan Ozcelik
+>Yep! I'm blogging! : http://www.volkanozcelik.com/volkanozcelik/blog/
+> My projects/studies/trials/errors : http://www.sarmal.com/

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