1599936 - Cleanup JSFunction non-lazy <-> lazy transistions

Status: RESOLVED FIXED

(Core :: JavaScript Engine, task, P2)

Description

[Ted Campbell [:tcampbell]]

Cleanup code around JSFunction changing which union arms are initialized. This should make the manual gc barriers easier to understand. Add a JSFunction::isIncomplete() accessor that defines the reset state of a JSFunction (INTERPRETED flag + nullptr script). Transitions should generally go through this state to make sure barriers are fired when old pointers are cleared.

Comment 1

[Ted Campbell [:tcampbell]]

Attachment: Bug 1599936 - Cleanups in AutoAssertFunctionDelazificationCompletion. r?jandem

Refactor slightly for readability and cleanup the conditions on function that
are checked.

Comment 2

[Ted Campbell [:tcampbell]]

Attachment: Bug 1599936 - Rename JSFunction::initSelfHostLazyScript. r?jandem

This should have been 'initSelfHostedLazyScript' all along for consistency
with other method names.

Depends on D55053

Comment 3

[Ted Campbell [:tcampbell]]

Attachment: Bug 1599936 - Add JSFunction::isIncomplete(). r?jandem

This replaces the 'hasUncompletedScript' accessor and removes the requirement
that 'hasScript' is already true. In general, if function is found by
scanning the GC arenas, one should check for the isIncomplete() state.

Depends on D55054

Comment 4

[Ted Campbell [:tcampbell]]

Attachment: Bug 1599936 - Add JSFunction::clearLazyScript() method. r?jandem

Ensure we avoid clobbering live GC pointers in JSFunction by using helper
methods to clear to the isIncomplete state and trigger write barriers.

Depends on D55055

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f17bcf3a751d
Cleanups in AutoAssertFunctionDelazificationCompletion. r=jandem
https://hg.mozilla.org/integration/autoland/rev/229082dcd5ac
Rename JSFunction::initSelfHostLazyScript. r=jandem
https://hg.mozilla.org/integration/autoland/rev/882eb2df7604
Add JSFunction::isIncomplete(). r=jandem
https://hg.mozilla.org/integration/autoland/rev/fdc09794f265
Add JSFunction::clearLazyScript() method. r=jandem

Comment 6

[Raul Gurzau (:RaulG)]

https://hg.mozilla.org/mozilla-central/rev/f17bcf3a751d
https://hg.mozilla.org/mozilla-central/rev/229082dcd5ac
https://hg.mozilla.org/mozilla-central/rev/882eb2df7604
https://hg.mozilla.org/mozilla-central/rev/fdc09794f265