1718481 - Rewrite nsXULPrototypeScript / nsXULPrototypeCache with stencil

Status: RESOLVED FIXED

(Core :: JavaScript Engine, task, P3)

Description

[Tooru Fujisawa [:arai]]

nsXULPrototypeScript / nsXULPrototypeCache uses JSScript as a cache for JS::CompileOffThread/JS::Compile result.
they holds the result both on memory and in file (nsIXPConnect::{ReadScript,WriteScript})

rewriting them with stencil removes JS::CloneAndExecuteScript call in PrototypeDocumentContentSink::ExecuteScript and partially unblocks bug 1662152.

JS::CloneAndExecuteScript in PrototypeDocumentContentSink::ExecuteScript always clones, so using stencil instead and instantiating there won't regress much.

Comment 1

[Tooru Fujisawa [:arai]]

Attachment: Bug 1718481 - Use stencil in nsXULPrototypeCache. r?tcampbell!

Depends on D118832

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/1cd8bdf1fc92
Use stencil in nsXULPrototypeCache. r=tcampbell,kmag

Comment 3

[Atila Butkovits]

Backed out for causing leaks.

Backout link: https://hg.mozilla.org/integration/autoland/rev/67b1f53e79bbd755fb285606dcd246b5ae131295

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&selectedTaskRun=cm4Ib7QxR1SVp5Lp0SBCVQ.0&resultStatus=testfailed%2Cbusted%2Cexception%2Cretry%2Cusercancel&revision=1cd8bdf1fc92414f6e3a0784ac37e8fe31a64771

Failure log: https://treeherder.mozilla.org/logviewer?job_id=351989321&repo=autoland&lineNumber=3022

Comment 4

[Andreea Pavel [:apavel]]

Backout merged to central: https://hg.mozilla.org/mozilla-central/rev/67b1f53e79bbd755fb285606dcd246b5ae131295

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/559a943daf25
Use stencil in nsXULPrototypeCache. r=tcampbell,kmag

Comment 6

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/559a943daf25

Comment 7

[Acasandrei Beatrice (needinfo me)]

== Change summary for alert #31422 (as of Tue, 21 Sep 2021 12:28:43 GMT) ==

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
5%	JS	windows10-64-2004-shippable-qr	fission tp6	244,981,923.50 -> 233,097,527.06

For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=31422

Comment 8

[John Bieling (:TbSync)]

Attachment: test.xpi

The changes introduced in this bug cause Firefox to crash, if WebExtension Experiments flush the cash using:

Services.obs.notifyObservers(null, "startupcache-invalidate", null);

This method has been working before and is the only supported and "preferred" way to do it. See instructions given in https://bugzilla.mozilla.org/show_bug.cgi?id=703720#c0

Crash observed on Windows 10.

Steps to reproduce:

• Set xpinstall.signatures.required to false
• Set extensions.experiments.enabled to true
• Restart Firefox (to make sure the changed config is picked up)
• Install the attached add-on
• Wait 10 seconds
• Disable the add-on in Add-ons Manager
• Wait 10 seconds (until the add-on is moved to the "Disabled" section)
• Open Hamburger Menu -> Settings/Preferences
• Observe Firefox crash.

Comment 9

[Tooru Fujisawa [:arai]]

copied it to bug 1736039