1843030 - Provide a public API to allocate the underlying buffer for InstantiationStorage off-main-thread

Status: RESOLVED FIXED

(Core :: JavaScript Engine, task)

Description

[Tooru Fujisawa [:arai]]

The current off-thread API allocates vectors in CompilationGCOutput (JS::InstantiationStorage) and passes it to the main-thread via JS::FinishOffThreadStencil out-parameter.

The equivalent needs to be supported for JS::FrontendContext API, but without requiring tracing.
Possible solution would be the following:

• Add Vector::reserve variant that receives raw buffer and use it if it needs to allocate memory
• Add a struct that holds the raw buffers
• Add public API that returns the new struct, reserved for the script data and scope data
• Add public API that moves the new struct's buffer to JS::InstantiationStorage

Comment 1

[Tooru Fujisawa [:arai]]

actually, we don't need to use Vector.
in all cases, the size of the collection is known at the beginning of the instantiation, and it doesn't change.
we can use raw buffer instead.

Comment 2

[Tooru Fujisawa [:arai]]

Also, JS::InstantiationStorage doesn't have to wrap CompilationGCOutput, but it need to wrap the underlying buffer by the new struct.

Comment 3

[Tooru Fujisawa [:arai]]

Attachment: Bug 1843030 - Part 1: Cleanup include in HelperThreadState.h. r?nbp!

Comment 4

[Tooru Fujisawa [:arai]]

Attachment: Bug 1843030 - Part 2: Cleanup include in CompilationStencil.h. r?nbp!

Depends on D183459

Comment 5

[Tooru Fujisawa [:arai]]

Attachment: Bug 1843030 - Part 3: Add PreAllocateableGCArray and use it in CompilationGCOutput. r?nbp!

Depends on D183460

Comment 6

[Tooru Fujisawa [:arai]]

Attachment: Bug 1843030 - Part 4: Add PreallocatedCompilationGCOutput. r?nbp!

Depends on D183461

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/aed4882e9850
Part 1: Cleanup include in HelperThreadState.h. r=nbp
https://hg.mozilla.org/integration/autoland/rev/8cece5c78d43
Part 2: Cleanup include in CompilationStencil.h. r=nbp
https://hg.mozilla.org/integration/autoland/rev/b836986e6f89
Part 3: Add PreAllocateableGCArray and use it in CompilationGCOutput. r=nbp
https://hg.mozilla.org/integration/autoland/rev/65de67ceb4f8
Part 4: Add PreallocatedCompilationGCOutput. r=nbp

Comment 8

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/aed4882e9850
https://hg.mozilla.org/mozilla-central/rev/8cece5c78d43
https://hg.mozilla.org/mozilla-central/rev/b836986e6f89
https://hg.mozilla.org/mozilla-central/rev/65de67ceb4f8