1066165 - After using accessibility tool FF31 freezes while modifying the DOM with huge elements

Status: RESOLVED WORKSFORME

(Firefox :: Disability Access, defect)

Description

[Sandor]

Attachment: FF31-freeze-test.zip

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Firefox/31.0
Build ID: 20140825060242

Steps to reproduce:

1.
Recognize the "Freeze it now!" link in the attached html page with attached Accessibility-Inspect tool. Don't click, only move into action-area and wait for the yellow highlight! For recognizing you have to switch on the yellow rectangle-button first.
This tool is a part of the Windows SDK. See http://msdn.microsoft.com/en-us/library/windows/desktop/dd318521%28v=vs.85%29.aspx

2.
Switch off the recognizing and close the Accessibility-Inspect tool.

3.
Click the link.



Actual results:

FF31 freezes for more hours.
Earlier FF versions work about 1 minutes.


Expected results:

Modifying the DOM under 2 seconds.
This is the real processing time if you don't use Accessibility earlier.
Same result is with another tool that uses Accessibility functions.

Comment 1

[:Gijs (he/him)]

David, do you know who could look at this?

Comment 2

[alexander :surkov (:asurkov)]

can you run profiler please?

Comment 3

[David Bolter [:davidb] (NeedInfo me for attention)]

The built in gecko profiler will freeze up along with FF. I don't have xperf set up on my windows VM anymore.

I ran this on OSX but it doesn't freeze up like in Windows. The profiling there show most time spent in events.  Inverting the profiled tree shows 3% running time is spent in mozilla::a11y::Accessible::BindToParent.

Comment 4

[Sandor]

Presumably in witch FF version will it fixed?

Comment 5

[alexander :surkov (:asurkov)]

(In reply to David Bolter [:davidb] from comment #3)
> The built in gecko profiler will freeze up along with FF. I don't have xperf
> set up on my windows VM anymore.

I don't have ready-to-go windows machine to try. 

Sandor, maybe you can do that?

> Inverting the profiled tree shows 3%
> running time is spent in mozilla::a11y::Accessible::BindToParent.

maybe it can be fixed in bug 1041070

Comment 6

[Sandor]

No I cannot run profiler.

Comment 7

[James Teh [:Jamie]]

This only takes a few seconds now.