1032330 - Make it easier to create new GC kinds

Status: NEW

(Core :: JavaScript: GC, defect)

Description

[Terrence Cole [:terrence]]

Creating a new GC think kind is incredibly difficult at the moment: it requires touching random stuff all over the system and detailed knowledge of GC internals. This has lead on multiple occasions to fantastically over-complicated machinery to re-create the effects of GC management without having to actually touch the GC machinery. This is a bad place to be, since GC management of lifetimes is an incredibly handy utility when implementing a GC'd language.

Comment 1

[Terrence Cole [:terrence]]

Reviewing Shu's recent addition of a GC thing for managing bindings, the following places needed to be edited:

* js/public/TraceKind.h
  - forward decl
  - TraceKind enum
  - FOR_EACH_TRACE_KIND
* js/public/TracingAPI.h
  - onFooEdge
  - dispatchToEdge
* js/src/gc/Allocator.cpp
  - checkAllocatorState assertion
* js/src/gc/Barrier.cpp
  - forward decls
  - GCPtr<Foo> typedef
* js/src/gc/GCInternals.h
  - MovingTracer::onFooEdge
* js/src/gc/Heap.h
  - AllocKind enum
  - FOR_EACH_ALLOC_KIND
* js/src/gc/Marking.*
  - eagerlyMarkChildren
  - Foo::trace
* js/src/gc/Staticstics.*
  - PHASE_SWEEP_FOO
* js/src/jsgc.h
  - various tables
  - MightBeForwarded
* js/src/jsgc.cpp
  - FinalizePhases
  - allocKindsToRelocate
  - onFooEdge impl
  - UpdatePhaseMisc

We should be able to expand most of this from one or more simple tables.