cppgc: Establish marking invariants

This is a revival of https://chromium-review.googlesource.com/c/v8/v8/+/2228332

The CL establishes the following:
*) Objects are marked before being pushed to the worklists.
*) Live bytes are always accounted after tracing an object (i.e. move
   from Gray to Black below).
*) Previously not fully constructed objects are traced immediately
   instead of pushed to the marking worklist.

This establishes the following invariants for all marking worklists:
1) White = !object.is_marked() && !worklist.contains(object)
2) Gray = object.is_marked() && worklist.contains(object)
3) Black = object.is_marked() && !worklist.contains(object)

Bug: chromium:1056170
Change-Id: I821573b3fbc057e6ffb836154271ff986ecb4d2b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2336797
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69268}
9 files changed
tree: 24b0f7591b1ed96a3ec5c313c069deb8845bd9d7
  1. .clang-format
  2. .clang-tidy
  3. .editorconfig
  4. .flake8
  5. .git-blame-ignore-revs
  6. .gitattributes
  7. .gitignore
  8. .gn
  9. .vpython
  10. .ycm_extra_conf.py
  11. AUTHORS
  12. BUILD.gn
  13. CODE_OF_CONDUCT.md
  14. COMMON_OWNERS
  15. DEPS
  16. ENG_REVIEW_OWNERS
  17. INFRA_OWNERS
  18. INTL_OWNERS
  19. LICENSE
  20. LICENSE.fdlibm
  21. LICENSE.strongtalk
  22. LICENSE.v8
  23. LICENSE.valgrind
  24. MIPS_OWNERS
  25. OWNERS
  26. PPC_OWNERS
  27. PRESUBMIT.py
  28. README.md
  29. S390_OWNERS
  30. WATCHLISTS
  31. build_overrides/
  32. codereview.settings
  33. custom_deps/
  34. docs/
  35. gni/
  36. include/
  37. infra/
  38. samples/
  39. src/
  40. test/
  41. testing/
  42. third_party/
  43. tools/
README.md

V8 JavaScript Engine

V8 is Google's open source JavaScript engine.

V8 implements ECMAScript as specified in ECMA-262.

V8 is written in C++ and is used in Google Chrome, the open source browser from Google.

V8 can run standalone, or can be embedded into any C++ application.

V8 Project page: https://v8.dev/docs

Getting the Code

Checkout depot tools, and run

    fetch v8

This will checkout V8 into the directory v8 and fetch all of its dependencies. To stay up to date, run

    git pull origin
    gclient sync

For fetching all branches, add the following into your remote configuration in .git/config:

    fetch = +refs/branch-heads/*:refs/remotes/branch-heads/*
    fetch = +refs/tags/*:refs/tags/*

Contributing

Please follow the instructions mentioned at v8.dev/docs/contribute.