891869 - Unify thingGCRooters between PerThreadData and ContextFriendFields so ThreadSafeContext can be used to root

Status: RESOLVED INVALID

(Core :: JavaScript Engine, defect)

Description

[Shu-yu Guo [:shu]]

Right now there are thingGCRooters both in ContextFriendFields and in PerThreadData. They should probably be unified into PerThreadData, and the ContextFriendFields field be made into a pointer.

JSContext's thingGCRooters inside ContextFriendFields would be a pointer to &mainThread.thingGCRooters, and ForkJoinSlice's a pointer to perThreadData->thingGCRooters.

This way ThreadSafeContexts can be used to root, as opposed to only JSContext or PerThreadData.

Comment 1

[Shu-yu Guo [:shu]]

Note that what I suggested in the first comment is an additional indirection and will be slower. Should also investigate removing it from PerThreadData.

Comment 2

[Terrence Cole [:terrence]]

I tried this and it doesn't work because the ExclusiveContext in the parsing thread is suddenly racing with main thread uses. I've at least unified the definitions into RootLists.