Contact emails

v...@chromium.org cl...@chromium.org

Explainer

https://docs.google.com/document/d/1zDlfvfTJ_9e8Jdc8ehuV4zMEu9ySMCiTGMS9y0GU92k

Specification

https://tc39.github.io/ecma262/#sec-sharedarraybuffer-objects

Design docs Including the new security requirements

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer

Discussion how and what to gate

https://github.com/whatwg/html/issues/4732

Summary

‘SharedArrayBuffers’ (SABs) on desktop platforms are restricted to
cross-origin isolated environments, matching the behavior we've recently
shipped on Android and Firefox. We've performed that change in Chrome 92. A
reverse OT was started to give developers the option to use SABs in case
they are not able to adopt cross origin isolation yet.

We’ve worked with multiple internal and external users of the OT to
understand their use cases and why they can’t adopt yet. With
COEP:credentialless and iframes credentialless now available, the SAB non
COI usage went further down.

Unfortunately, the cascading requirements of COEP are still a blocker for
COI adoption. Some of the users of the OT rely heavily on credentialled
cross-origin subresources, so credentialless modes are not an option for
them. And their apps are complex enough that they are still blocked on
child iframes supporting COEP.

To address this, we’re exploring ways of enabling COI that would take
advantage of process isolation in order to waive requirements on child
frames to enforce COEP. However, this is still at an exploratory stage. So
we would like to request a 3 milestones extension (until M124) to this
deprecation trial. This will give us enough time to propose a solution and
discuss it with the standards community and users of the reverse OT. We
will then come back with a proposed solution to finally end the OT and get
the remaining users of the reverse OT, as well as a timeline for the OT
ending.
Blink component

Blink>JavaScript
<https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EJavaScript>

Search tags

SharedArrayBuffer <https://chromestatus.com/features#tags:SharedArrayBuffer>
, SAB <https://chromestatus.com/features#tags:SAB>

TAG reviewhttps://github.com/w3ctag/design-reviews/issues/471
TAG review statusClosed
RisksInteroperability and Compatibility

We expect this change to negatively impact developers using
`SharedArrayBuffer` today. Chrome was the only platform where SABs have
been available without COOP/COEP. Therefore we need to give developers the
right capabilities and a clear path forward to ensure they’ve enough time
to adopt. We aim to mitigate these risks by adopting a longer-than-usual
depreciation period with console warnings/issues and a reverse origin
trial.

Good news is usage is down to ~0.0209%
<https://chromestatus.com/metrics/feature/popularity#V8SharedArrayBufferConstructedWithoutIsolation>
page loads and that other browsers have or are shipping SABs again gated
behind COOP/COEP. Bad news is that Chromium was the only browser that
supported SABs without COI, therefore we need to provide a migration path
to not break existing sites.

Gecko: Shipped/Shipping (
https://bugzilla.mozilla.org/show_bug.cgi?id=1312446)

WebKit: Added COOP/COEP and SAB support recently gated behind COOP/COEP

Will this feature be supported on all six Blink platforms (Windows, Mac,
Linux, Chrome OS, Android, and Android WebView)?

No - This OT is only for desktop, as this was the only platform where SABs
have been available without COOP/COEP.

Android re-enabled SABs gated behind COOP/COEP:
https://chromestatus.com/feature/5171863141482496

Tracking bug

https://bugs.chromium.org/p/chromium/issues/detail?id=1144104

Launch bug

https://bugs.chromium.org/p/chromium/issues/detail?id=1138860

Blink-dev Thread

Planning isolation requirements (COOP/COEP) for SharedArrayBuffer
<https://groups.google.com/a/chromium.org/g/blink-dev/c/_0MEXs6TJhg/m/QzWOGv7pAQAJ>

I2S
<https://groups.google.com/a/chromium.org/g/blink-dev/c/1NKvbIj3dq4/m/nLcgUst-BQAJ>

Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/4570991992766464

-- 
You received this message because you are subscribed to the Google Groups 
"blink-dev" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to blink-dev+unsubscr...@chromium.org.
To view this discussion on the web visit 
https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAMKsNvqRwzmSs2%3DPEEhze175Sf7wm6S_AnGuAOnrcZ0mmA1gYw%40mail.gmail.com.

Reply via email to