IE6 slowdown, memory leak

[bill]

Every time you reload themeTester.html IE6's memory usage goes up 10M, and it takes 4s longer to parse the page then before.

[bill]

Problem goes away if you remove the destroyRendering() call from Widget.destroy(), thus leaving the widgets in the document making it easier for IE to garbage collect.

But, the ability to dynamically create/destroy widgets (including their dom nodes) is important for long running apps like yahoo mail.

Will try tracking all dojoAttachPoints and deleting them on widget destruction. dojoAttachEvent calls are already being released...

[bill]

(In [10049]) Remove references from widget (JS object) to the DOM nodes in the widget before destroying the DOM nodes, to fix IE6 memory leak. Fixes #4047

[bill]

Hmm, didn't work...

[guest]

Attached a patch to remove dojo.forEach calls with inline functions. Function setup and tear down is expensive in tight loops. If we aren't gaining code reuse, dojo.disconnect for example, I would suggest removing inlined forEach calls.

schallm

[bill]

(In [10064]) Revert last change to track attach points. Didn't really make sense. Refs #4047.

[bill]

(In [10065]) Second try to fix memory leak on IE6. Never give a DOM node a pointer to a widget (creates circular references). Fixes #4047.