1786309 - Simplify representation of zones set

Status: RESOLVED FIXED

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

Description

[Jon Coppeard (:jonco)]

The GC iterates over zones in many places. Currently the set of zones is represented by a single atoms zone and a vector of non-atoms zones. Iterators such as AllZonesIter exist to hide this distinction.

It would be simpler to represent this as a single vector with the invariant that the atoms zone is always the first element. Then iteration is just vector iteration, optionally starting at the second element if you don't want the atoms zone.

Comment 1

[Jon Coppeard (:jonco)]

Attachment: Bug 1786309 - Part 1: Remove unused methods to get the atoms zone r?sfink

Comment 2

[Jon Coppeard (:jonco)]

Attachment: Bug 1786309 - Part 2: Move creation of the atoms zone into GCRuntime::init r?sfink

Creation of non-atoms zones already happens in GC.cpp, in js::NewRealm.
Arguably creation of zones should be split between the GC and the VM. Zones are
a GC concept, but much of their contents are VM specific.

Depends on D155224

Comment 3

[Jon Coppeard (:jonco)]

Attachment: Bug 1786309 - Part 3: Store the atoms zone at the start of the zones vector r?sfink

Depends on D155225

Comment 4

[Jon Coppeard (:jonco)]

Attachment: Bug 1786309 - Part 4: Simplify zone iteration r?sfink

Depends on D155226

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c54c096740d9
Part 1: Remove unused methods to get the atoms zone r=sfink
https://hg.mozilla.org/integration/autoland/rev/4a3ba646d292
Part 2: Move creation of the atoms zone into GCRuntime::init r=sfink
https://hg.mozilla.org/integration/autoland/rev/0db63b7bac22
Part 3: Store the atoms zone at the start of the zones vector r=sfink
https://hg.mozilla.org/integration/autoland/rev/c1884222a881
Part 4: Simplify zone iteration r=sfink

Comment 6

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/c54c096740d9
https://hg.mozilla.org/mozilla-central/rev/4a3ba646d292
https://hg.mozilla.org/mozilla-central/rev/0db63b7bac22
https://hg.mozilla.org/mozilla-central/rev/c1884222a881