• Michael Lippautz's avatar
    cppgc-js: Concurrently process v8::TracedReference · 1f0d7d20
    Michael Lippautz authored
    Adds concurrent marking for reaching through v8::TracedReference.
    Before this CL, a v8::TracedReference would always be processed on the
    main thread by pushing a callback for each encountered reference.
    
    This CL now wires up concurrent handling for such references. In particular:
    - Global handles are already marked as well and not repurposed during
      the same GC cycle.
    - Since global handles are not repurposed, it is enough to
      double-deref to the V8 object, checking for possible null pointers.
    - The bitmap for global handle flags is mostly non-atomic, with the
      markbit being the exception.
    - Finally, all state is wired up in CppHeap. Concurrent markers keep
      their own local worklist while the mutator marker directly pushes to
      the worklist owned by V8.
    
    Bug: v8:12600
    Change-Id: Ia67dbd18a57dbcccf4dfb9ccfdb9ee438d27fe71
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3516255Reviewed-by: 's avatarOmer Katz <omerkatz@chromium.org>
    Reviewed-by: 's avatarDominik Inführ <dinfuehr@chromium.org>
    Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
    Cr-Commit-Position: refs/heads/main@{#79736}
    1f0d7d20
heap.h 104 KB