Contact emails
[email protected], [email protected]

Explainer
No information provided


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


Design docs
No information provided
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer


Summary
Adds the JavaScript type SharedArrayBuffer gated behind COOP/COEP. The concept 
of a SharedArrayBuffer is that a message to a worker, is posted but instead of 
copying the content of the array just a reference to it is shared. The Atomic 
API provides atomic loads and stores and Read/Modify/Write accesses to 
SharedArrayBuffers. The Atomic.wait provides the ability for a worker to wait 
for another worker to signal it, without having to spinlock.


Blink component
Blink>JavaScript


Web Feature ID
No information provided


Search tags
SharedArrayBuffer, SAB


TAG review
https://github.com/w3ctag/design-reviews/issues/471


TAG review status
Pending


Origin Trial Name
SharedArrayBuffers in non-isolated pages on Desktop platforms


Chromium Trial Name
UnrestrictedSharedArrayBuffer


Link to origin trial feedback summary
https://bugs.chromium.org/p/chromium/issues/entry?components=Internals%3ESandbox%3ESiteIsolation


Origin Trial documentation link
https://developer.chrome.com/blog/enabling-shared-array-buffer/


Risks




Interoperability and Compatibility
No information provided

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

WebKit: Shipped/Shipping 
(https://developer.apple.com/library/content/releasenotes/General/WhatsNewInSafari/Articles/Safari_10_1.html)

Web developers: Positive

Other signals:


WebView application risks

Does this intent deprecate or change behavior of existing APIs, such that it 
has potentially high risk for Android WebView-based applications?
No information provided



Goals for experimentation
No information provided


Reason this experiment is being extended
This is a deprecation trial, and we're giving more time to websites to stop 
using the deprecated behavior.


Reason this experiment is being extended
The release of DocumentIsolationPolicy in M137 is helping developers adopt 
crossOriginIsolation as a way out of this reverse Origin Trial. However, it 
will still take time for developers to adopt. We would like to extend the OT as 
the final extension and give developers 6 milestones to get out of this reverse 
Origin Trial. Once this is approved and developers have requested their token, 
we will close this trial so that no further origins adopt the deprecated 
behavior.


Reason this experiment is being extended
We still have one of the historic users of ungated SharedArrayBuffers which has 
not managed to transition to cross-origin isolation (Google Earth). They are in 
the process of deploying COEP and asked us for an extension of the reverse 
origin trial until M146, when they believe they will be done with COEP 
deployment. Once the extension is approved, we'll close the Origin Trial to 
ensure no new users can register.


Ongoing technical constraints
No information provided


Debuggability
DevTools warning in case SAB is used in none COI context is in place


Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, 
ChromeOS, Android, and Android WebView)?
No


Is this feature fully tested by web-platform-tests?
Yes
https://source.chromium.org/chromium/chromium/src/+/master:third_party/blink/web_tests/external/wpt/html/infrastructure/safe-passing-of-structured-data/shared-array-buffers/no-coop-coep.https.any.js
 https://github.com/tc39/test262/tree/master/test/built-ins/SharedArrayBuffer 
https://github.com/tc39/test262/tree/master/test/built-ins/Atomics


Flag name on about://flags
No information provided


Finch feature name
No information provided


Non-finch justification
No information provided


Requires code in //chrome?
False


Tracking bug
https://bugs.chromium.org/p/chromium/issues/detail?id=709179


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


Estimated milestones


Origin trial desktop first 92

Origin trial desktop last 131

Origin trial extension 1 end milestone 109

Origin trial extension 2 end milestone 131

Origin trial extension 3 end milestone 124

Origin trial extension 4 end milestone 136

Origin trial extension 5 end milestone 142

Origin trial extension 6 end milestone 146

DevTrial on desktop 60

DevTrial on Android 88




Link to entry on the Chrome Platform Status
https://chromestatus.com/feature/4570991992766464?gate=5932856039833600


Links to previous Intent discussions
Intent to Experiment: 
https://groups.google.com/a/chromium.org/g/blink-dev/c/1NKvbIj3dq4
Intent to Extend Experiment 1: 
https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAH0ixBN2JhcYtpT4UYKcAfHt1e0Wz_Uxz0CkXcAntguhbmyNCA%40mail.gmail.com
Intent to Extend Experiment 2: 
https://groups.google.com/u/1/a/chromium.org/g/blink-dev/c/4tDmckQLZLQ
Intent to Extend Experiment 3: 
https://groups.google.com/a/chromium.org/g/blink-dev/c/UospzV3lZMk/m/X9K0k8kuAQAJ
Intent to Extend Experiment 4: 
https://groups.google.com/a/chromium.org/g/blink-dev/c/A4CR6MIVzds/m/rpsWnzq6AAAJ?e=48417069
Intent to Extend Experiment 5: 
https://groups.google.com/a/chromium.org/d/msgid/blink-dev/681b67ca.170a0220.4750a.028e.GAE%40google.com
Intent to Ship: 
https://groups.google.com/a/chromium.org/g/blink-dev/c/1NKvbIj3dq4



This intent message was generated by Chrome Platform Status.

-- 
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 [email protected].
To view this discussion visit 
https://groups.google.com/a/chromium.org/d/msgid/blink-dev/68f7ac44.050a0220.39dfc1.0861.GAE%40google.com.

Reply via email to