[wp-hackers] JS memory leaks
adam at batkin.net
Tue Oct 3 11:26:34 GMT 2006
> Perhaps someone a bit more savvy with JS than I could take a look at
I'm not sure that the above article applies to WordPress. If you visit
the website of the FF extension used to generate the leak reports (see
http://dbaron.org/mozilla/leak-monitor/) you find this text:
"This Firefox extension detects one very specific type of leak in chrome
by native code after the window is closed."
Basically the extension looks to be for firefox and firefox plugin devs,
not website authors.
around the web. In particular, IE seems to have trouble reclaiming
memory in certain instances.
http://laurens.vd.oever.nl/weblog/items2005/closures/ looks like fun. If
you find that mozilla/firefox is not reclaiming memory after you
navigate away from a page, that is a bug in firefox and should be fixed.
Of course there isn't a good way to test this, so probably not worth
worrying about unless someone finds a specific instance that is causing
A quick digression:
It is not always necessary for a program to "clean up" after itself. For
example, if I were writing a small utility in C and (for example) I
malloc() the size of a particular file, read the file in and count the
number of lines and print out the total count (I know there are more
efficient ways to write this, plus I could just use the wc program)
there is no reason for me to call free(). Sure, a leak manager will
report that my program "leaks" memory but since the program isn't
designed to sit around, as soon as it terminates the memory will be
reclaimed by the OS (if the OS forgets to reclaim that memory, that is a
bug in the OS, NOT the program). All operating systems that I know of do
The same applies to web browsers. If I were designing a webapp where the
user never navigates away from a page and all interaction is done
through AJAX (like gmail?), I would be concerned about memory leaks. But
so long as the JS implementation cleans up once I navigate away (and
everything I have read indicates that at least firefox seems to do this
properly in most cases) memory management/leaks shouldn't matter.
Of course, a browser restart will always fix everything.
Summary: I don't think any cycles need to be wasted looking at JS leaks.
WP doesn't even use _that_ much JS in the grand scheme of things.
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