dfc6b4ddaa
This patch changes how space size and capacity are updated in GC:
- space capacity changes only when a page added/removed from the space.
- space size is reset to zero before sweeping and incremented by
page->live_bytes_count_ for each to-be-swept page.
- space size is refined after sweeping using the accurate
page->allocated_bytes counter produces by the sweeper.
Invariants:
1. space.capacity = sum [page.size | for page in space].
2. After marking, before sweeping:
a) space.size = sum [page.live_bytes_count | for page in space].
3. After sweeping, before marking ends:
a) space.size = sum [page.allocated_bytes | for page in space].
b) page.allocated_bytes >= (sum [object.size | for object in page] +
page.linear_allocation_area).
c) page.area_size = (page.allocated_bytes + page.wasted_memory +
sum [free_list_entry.size | for free_list_entry in page].
3.b becomes equality if the mutator is not doing array trimming,
object slack tracking during sweeping.
Bug: chromium:694255
Change-Id: Ic8d16a8171187a113fee2df8bf3c2a4c5e77bc08
Reviewed-on: https://chromium-review.googlesource.com/618889
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47409}
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| benchmarks | ||
| build_overrides | ||
| docs | ||
| gni | ||
| gypfiles | ||
| include | ||
| infra | ||
| samples | ||
| src | ||
| test | ||
| testing | ||
| third_party | ||
| tools | ||
| .clang-format | ||
| .editorconfig | ||
| .gitignore | ||
| .gn | ||
| .ycm_extra_conf.py | ||
| AUTHORS | ||
| BUILD.gn | ||
| ChangeLog | ||
| CODE_OF_CONDUCT.md | ||
| codereview.settings | ||
| DEPS | ||
| LICENSE | ||
| LICENSE.fdlibm | ||
| LICENSE.strongtalk | ||
| LICENSE.v8 | ||
| LICENSE.valgrind | ||
| Makefile | ||
| Makefile.android | ||
| OWNERS | ||
| PRESUBMIT.py | ||
| README.md | ||
| snapshot_toolchain.gni | ||
| WATCHLISTS | ||
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://github.com/v8/v8/wiki
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 on the V8 wiki.