1740745 - Runtime check is no longer necessary in barriers

Status: RESOLVED FIXED

(Core :: JavaScript: GC, task, P3)

Description

[Jon Coppeard (:jonco)]

Following on from bug 1734801, we can improve our barriers in a similar way by removing the check we sometimes that the thing we're looking at is not from another runtime. If it is from another runtime it will always be black, so we can remove this check and let the mark check handle it.

Comment 1

[Jon Coppeard (:jonco)]

Attachment: Bug 1740745 - Part 1: Make needs barrier state atomic r?sfink

With the following patches this may be read by other threads so we need to make
it atomic to avoid undefined behaviour. It is only ever written by the main
thread of the runtime that owns the zone.

Comment 2

[Jon Coppeard (:jonco)]

Attachment: Bug 1740745 - Part 2: Remove permanent atom checks from barriers r?sfink

This check is no longer required and can be handled by the mark check.

Depends on D130995

Comment 3

[Jon Coppeard (:jonco)]

Attachment: Bug 1740745 - Part 3: Remove runtime check from JIT code r?jandem

Depends on D130996

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ff8c4f9a99fc
Part 1: Make needs barrier state atomic r=sfink
https://hg.mozilla.org/integration/autoland/rev/0694472ccb3d
Part 2: Remove permanent atom checks from barriers r=sfink
https://hg.mozilla.org/integration/autoland/rev/dc599b0ff23d
Part 3: Remove runtime check from JIT code r=jandem

Comment 5

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/ff8c4f9a99fc
https://hg.mozilla.org/mozilla-central/rev/0694472ccb3d
https://hg.mozilla.org/mozilla-central/rev/dc599b0ff23d