1363214 - Split JS::Compartment from JS::Realm

Status: RESOLVED FIXED

(Core :: JavaScript Engine, enhancement, P2)

Description

[Jason Orendorff [:jorendorff]]

To support same-compartment realms, we factor out a Compartment class so
that Compartment and Realm are no longer identical inside js/src.
However, initially there will be no way to create multiple Realms in the
same Compartment, so they'll still be one-to-one.

Each Realm has a pointer to its freshly factored-out Compartment.
All Wrapper stuff moves from JS::Realm to the new JS::Compartment.

Initially, JS::Compartment also contains a pointer to its sole Realm.
(It will be eliminated later.)

To make way for JS::Compartment, js::wasm::Compartment will have to be
renamed to js::wasm::WasmCompartment.

Comment 1

[Jan de Mooij [:jandem]]

Attachment: Remove JS::Realm/JSCompartment inheritance

On top of the other changes, this is now pretty straight-forward.

JS::GetCompartmentForRealm still exists, it uses JS::shadow::Realm that contains just the compartment pointer. Internally, JS::Realm inherits from JS::shadow::Realm.

Memory reporting of a zone now uses a compartments/ subtree for the compartment data (the JSCompartment objects themselves, the wrapper tables, the XPConnect private data).

Comment 2

[Jon Coppeard (:jonco)]

Comment on attachment 8982981 [details] [diff] [review]
Remove JS::Realm/JSCompartment inheritance

Review of attachment 8982981 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/vm/TypeInference.cpp
@@ +4590,1 @@
>  Zone::addSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf,

Huh, why is this defined here?

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/011f238cc9ab
Remove JS::Realm/JSCompartment inheritance. r=jonco

Comment 4

[Jan de Mooij [:jandem]]

(In reply to Jon Coppeard (:jonco) from comment #2)
> ::: js/src/vm/TypeInference.cpp
> @@ +4590,1 @@
> >  Zone::addSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf,
> 
> Huh, why is this defined here?

Looking at the history of this code in searchfox, I think initially the Zone memory reporting code only measured the TI data so that's probably why it's still in TypeInference.cpp ..

Comment 5

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/mozilla-central/rev/011f238cc9ab