Remove event listeners - memory leak

[ludinov]

Had memory leak on removing elements from the dom (switching views, ng-switch ...)
Solved it partially by tweaking jqlite implementation.

When jqlite remove event listeners it passes wrong function reference
(not the same it passed on add listener).
Actually it try to pass array of functions - so it doesn't remove it properly.
https://github.com/angular/angular.js/blob/master/src/jqLite.js#L218
https://github.com/angular/angular.js/blob/master/src/jqLite.js#L224

To fix it I replaced it with actual handler that was added:

removeEventListenerFn(element, type, handle);

It is very easy to check by breakpoints these lines..

https://github.com/angular/angular.js/blob/master/src/jqLite.js#L652

eventHandler.elem = element;

Why we need additional reference to the element for the handler function.
As I can see it never used ...
Maybe it's safe to delete this line.

Now app consume less memory and event listeners released properly.
But I still see growing number of dom elements...
Looks like on removing it from the dom it still have some references unreleased...

[tbosch]

Thanks for reporting. Here is a jsfiddle showing that calling $element.off('click', handler) does not call removeEventListener of the original element: http://jsfiddle.net/VmTsD/

[tbosch]

Please note that there is a memory leak problem with V8 and Angular: See #4864.
However, if you find other reasons like the one in this bug, we would be glad to know about them!

[ludinov]

As I can see eventHandler.elem from https://github.com/angular/angular.js/blob/master/src/jqLite.js#L652 used only for angular.mock (so not for prod apps) to remove all listeners - maybe it can be done like this:

if (angular.mock) eventHandler.elem = element;

or use another approach in mock module...

[IgorMinar]

just fyi: the mem leak reported in #4864 turned out to be a dev tools issue: https://code.google.com/p/chromium/issues/detail?id=304689

[GabrielDelepine]

+1

[btford]

This isn't actually an issue. See #5281 (comment)