652530 - Memory leak when updating widget's content

Status: RESOLVED FIXED

(Add-on SDK Graveyard :: General, defect, P1)

Description

[Hernán Rodriguez Colmeiro (:peregrino)]

Attachment: testcase

When trying to update the content of an already existent widget, it seems that the previous content is leaked. 

I attach a testcase that creates a widget and updates its content 1000 times, and the leak can be appreciated. With another testcase I could get Firefox to 1Gb RAM by updating a widget about 4000 times.

The workaround I found is to update the content by passing a message to the widget and listening to it on the contentScript.

Comment 1

[Myk Melez [:myk] [@mykmelez]]

Alex: can you take a look at this?

Comment 2

[Alexandre Poirot [:ochameau]]

Attachment: Unit test to check this leak

Nice catch Hernán!
Here is this leak in details using this unit test:
With 200 instances
 before: 45231876
 after : 49095036

Comment 3

[Alexandre Poirot [:ochameau]]

Attachment: Fix this leak.

And now, with this patch, we have:
 before: 45426972
 after : 44792644
(memory used before and after changing 200 times widget.content attribute)

This leak was due to document-element-inserted/DOMContentLoaded/load listeners not unregistered when you change Symbiont contentURL *and* because we do not destroy the Symbiont before creating a new one in Widget.setContent.

Comment 4

[Irakli Gozalishvili [:irakli] [:gozala] [@gozala]]

Comment on attachment 531726 [details] [diff] [review]
Fix this leak.

Review of attachment 531726 [details] [diff] [review]:
-----------------------------------------------------------------

Looks good, thanks Alex.

Comment 5

[Alexandre Poirot [:ochameau]]

https://github.com/mozilla/addon-sdk/commit/2b6480335bf92419610f452421f511aa41e329d0