RequestPolicy/tractest — Issue #133: Facebook Translate application high CPU
Author: jsamuel
Created: 2011-12-22 02:42:01+00:00
State: open
Labels: extension

Archaeopteryx reports:

using Facebook Translate and RequestPolicy I noticed the following problem: When FT tries to add something to the page, the CPU activity will be higher than normal and stay there (in my test profil above 50%, in my default profile the whole Firefox processes freezes and it can take up to a minute to do something in the UI. Switching the tab or closing it fixes it.

I tried signing up as a Kiswahili translator and clicking around through the translation site, including the area that lists the phrases to be translated (though I didn't submit any translations). I was not able to repeat this problem (RP 0.5.15, Fx 3.6.10pre).

If I had to guess, there's an onerror handler of an img or other external file that doesn't remove itself when it fires and then results in the onerror handler being called again when the handler itself tries to load a blocked image. This scenario has been reported twice in very small websites with poor code, one of which fixed their code independently of it being reported by me. Note that this is not an RP bug. The same situation can be triggered by the websites being down that the remote resources is being loaded from.

I'll need more info to be able to look into this further.