1309861 - Enable SharedArrayBuffer and Atomics by default on Developer Edition

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect, P1)

Description

[Lars T Hansen [:lth]]

Enabling on Dev Edition is a reasonable first step to test webcompat concerns created by introducing two new top-level names ('Atomics' and 'SharedArrayBuffer').  No problems are expected, and none have been reported in the many months it's been enabled by default on Nightly.

Comment 1

[Lars T Hansen [:lth]]

Attachment: bug1309861-sab-enable-on-deved.patch

Switch the default setting for SAB+Atomics enablement from false to true for DevEd / Aurora (as well as for Nightly, where that was already the case).

Comment 2

[Lars T Hansen [:lth]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/22293babd8a6e8a50a196e264e0b271ad242a038
Bug 1309861 - enable SAB+Atomics by default on DevEd.  r=jorendorff

Comment 3

[Lars T Hansen [:lth]]

Comment on attachment 8800616 [details] [diff] [review]
bug1309861-sab-enable-on-deved.patch

Approval Request Comment

[Feature/regressing bug #]:
Shared memory feature will be enabled by default in FF51 (pending final security review) and we would like to enable it by default for Aurora right now, this should have happened months ago but was overlooked.

[User impact if declined]:
Feature must be enabled manually in about config; content will not work automatically.

[Describe test coverage new/current, TreeHerder]:
Has been enabled on Nightly for a long time and many tests exist already in the repo.

[Risks and why]: 
Low risk resulting from introducing two new top-level names in the JS globals, "Atomics" and "SharedArrayBuffer".  No problems have been discovered after having these names in nightly for over a year.

[String/UUID change made/needed]:
None, I think; this just flips a pref default from false to true on Aurora.

Comment 4

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/22293babd8a6

Comment 5

[Gerry Chang [:gchang]]

Comment on attachment 8800616 [details] [diff] [review]
bug1309861-sab-enable-on-deved.patch

Enable shared memory feature in 51 aurora by default. Aurora 51+.

Comment 6

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/d4fda3ccf384

Comment 7

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

I had to back this out from aurora in https://hg.mozilla.org/releases/mozilla-aurora/rev/f4283f32adb12d2bc35d055fccabd737b90feba6 because tests are failing due to the apparent lack of dom peer review on enabling a new interface:
https://treeherder.mozilla.org/logviewer.html#?job_id=3951991&repo=mozilla-aurora

Comment 8

[Lars T Hansen [:lth]]

OK, will attend to this ASAP and offer a modified patch for uplift.

Comment 9

[Lars T Hansen [:lth]]

Attachment: bug1309861-whitelist-sab-atomics.patch

Whitelist SharedArrayBuffer and Atomics APIs for aurora in Mochitests.

According to the file, this requires JS peer review, not DOM peer review.

Comment 10

[Lars T Hansen [:lth]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/d41feccb93b2e1dd2cb4248ae275e447be5a06f6
Bug 1309861 - new APIs whitelisted for Aurora. r=h4writer

Comment 11

[Lars T Hansen [:lth]]

Comment on attachment 8804170 [details] [diff] [review]
bug1309861-whitelist-sab-atomics.patch

Approval Request Comment

See Comment #3 for justification.  This patch contains additional functionality that is needed to pass the test suite, which guards against new APIs being introduced accidentally.

Note that the other patch also has to be relanded since it was backed out.

Comment 12

[Carsten Book [:Tomcat]]

(In reply to Lars T Hansen [:lth] from comment #11)
> Comment on attachment 8804170 [details] [diff] [review]
> bug1309861-whitelist-sab-atomics.patch
> 
> Approval Request Comment
> 
> See Comment #3 for justification.  This patch contains additional
> functionality that is needed to pass the test suite, which guards against
> new APIs being introduced accidentally.
> 
> Note that the other patch also has to be relanded since it was backed out.

note: we need this also since this will cause otherwise issues on merge day like bug 1312757

Comment 13

[Lars T Hansen [:lth]]

(In reply to Carsten Book [:Tomcat] from comment #12)
> (In reply to Lars T Hansen [:lth] from comment #11)
> > Comment on attachment 8804170 [details] [diff] [review]
> > bug1309861-whitelist-sab-atomics.patch
> > 
> > Approval Request Comment
> > 
> > See Comment #3 for justification.  This patch contains additional
> > functionality that is needed to pass the test suite, which guards against
> > new APIs being introduced accidentally.
> > 
> > Note that the other patch also has to be relanded since it was backed out.
> 
> note: we need this also since this will cause otherwise issues on merge day
> like bug 1312757

Right.  Note this has landed on m-i already I figured it would just get merged with the pref change, on branch day.

Comment 14

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/d41feccb93b2

Comment 15

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/6cf0ec3c4fbb

Comment 16

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/3dfa3b1c70d5

Comment 17

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/76d7f4eb6100
Update the dom/workers interfaces test expectations as well. r=bz

Comment 18

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/52d62548a29d97d03e2e11ecd16db7602eb93ee7

Comment 19

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/76d7f4eb6100

Comment 20

[Florian Scholz (Open Web Docs)]

Marked as enabled in DevEdition 51 on https://developer.mozilla.org/en-US/Firefox/Experimental_features#JavaScript