1774918 - Browser stops responding during animation.

Status: NEW

(Core :: Disability Access APIs, defect)

Description

[Alice0775 White]

Attachment: about:support

Browsers often become unresponsive for long periods of time during animation and the animation becomes unresponsive and does not play repeatedly.

Firefox91esr and Google Chrome work fine. The animation played on a loop without this problem..

Steps to Reproduce:

1. Open https://www.jma.go.jp/bosai/map.html#8/34.518/135.544/&elem=temp&contents=amedas&interval=60
2. Click on play button at the bottom left corner.
   Then, when the data loading is complete, the animation begins.

Expected Results:
The animation continues and plays on a loop.

Actual Results:
Browsers often become unresponsive for long periods during animation.

Profile: https://share.firefox.dev/3QHUwJ1

Comment 1

[Olli Pettay [:smaug][[e-mail]]]

Parent process is doing some slow a11y calls.

Everything is very smooth on linux, without a11y.

Comment 2

[James Teh [:Jamie]]

Alice, what a11y client is being used here? I know you've used Atok in the past, but these calls seem to be coming from a different process and I thought Atok calls were injected into Firefox.

It looks like this is either not an installed version of Firefox (e.g. extracted from a zip archive) or your installation is broken. Currently, in order for a11y to function efficiently, a component (AccessibleHandler.dll, identified in about:support as "Accessible Handler Used") needs to be registered with the system. That means you need to use an installed version of Firefox.

If you use an installed version, does this situation improve?

Comment 3

[Alice0775 White]

(In reply to James Teh [:Jamie] from comment #2)

Alice, what a11y client is being used here? I know you've used Atok in the past, but these calls seem to be coming from a different process and I thought Atok calls were injected into Firefox.

Yes, a11y is activated by ATOK2021 insight. And disabling ATOK2021 insight will fix this issue.

It looks like this is either not an installed version of Firefox (e.g. extracted from a zip archive) or your installation is broken. Currently, in order for a11y to function efficiently, a component (AccessibleHandler.dll, identified in about:support as "Accessible Handler Used") needs to be registered with the system. That means you need to use an installed version of Firefox.

If you use an installed version, does this situation improve?

Neither the zip version nor the installer version of Nightly seems to show any significant changes.

Comment 4

[James Teh [:Jamie]]

Does the situation improve if you go to about:config, set accessibility.cache.enabled to true and restart Firefox? Please note that this is still under development, so you probably shouldn't run with it for critical work.

Comment 5

[Alice0775 White]

(In reply to James Teh [:Jamie] from comment #4)

Does the situation improve if you go to about:config, set accessibility.cache.enabled to true and restart Firefox? Please note that this is still under development, so you probably shouldn't run with it for critical work.

Yes, The browser may sometimes become unresponsive and jittery, but the amount of time it is unresponsive has decreased considerably.

Comment 6

[James Teh [:Jamie]]

Would you mind providing a profile of the unresponsiveness/jitteriness with accessibility.cache.enabled set to true? Thanks so much for your help.

Comment 7

[Alice0775 White]

(In reply to James Teh [:Jamie] from comment #6)

Would you mind providing a profile of the unresponsiveness/jitteriness with accessibility.cache.enabled set to true? Thanks so much for your help.

profiler log:
https://share.firefox.dev/3yhrdWs
(Jitter begins to occur more after about 30 seconds.)

Comment 8

[James Teh [:Jamie]]

Thanks. That profile shows a lot of time spent firing a11y events to Windows. I guess we fire a lot of events precisely because of the constant animation. It'd be interesting to figure out whether we can reduce the number of events somehow.

Comment 9

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:Jamie, could you have a look please?

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