1f8dcc5d2e
The idea here is that in case the `thenable` is a JSPromise and `then` is the initial `Promise.prototype.then` method, and the @@species lookup chain is intact, we can skip creating the temporary promise and the closures (with the shared context), and instead directly call into our PerformPromiseThen. This is sound since - given above mentioned conditions - our short-cut PerformPromiseThen(thenable, undefined, undefined, promise_to_resolve) is not observably different from the actual resolve, reject = CreateResolvingFunctions(promise_to_resolve) result_capability = NewPromiseCapability(%Promise%) PerformPromiseThen(thenable, resolve, reject, result_capability) except through PromiseHooks (and potentially via the async stack traces). So we disable the fast-path if either promise hooks are enabled or the debugger is active for now. This improves the performance on the wikipedia benchmark by 20-25% and the bluebird-doxbee benchmark by around 20%. Bug: v8:7253 Change-Id: I23c92ad365c2b71d65057573f2d8febe2afe00b0 Reviewed-on: https://chromium-review.googlesource.com/911800 Commit-Queue: Benedikt Meurer <bmeurer@chromium.org> Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org> Cr-Commit-Position: refs/heads/master@{#51261} |
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benchmarks | ||
build_overrides | ||
docs | ||
gni | ||
include | ||
infra | ||
samples | ||
src | ||
test | ||
testing | ||
third_party | ||
tools | ||
.clang-format | ||
.editorconfig | ||
.git-blame-ignore-revs | ||
.gitignore | ||
.gn | ||
.vpython | ||
.ycm_extra_conf.py | ||
AUTHORS | ||
BUILD.gn | ||
ChangeLog | ||
CODE_OF_CONDUCT.md | ||
codereview.settings | ||
DEPS | ||
LICENSE | ||
LICENSE.fdlibm | ||
LICENSE.strongtalk | ||
LICENSE.v8 | ||
LICENSE.valgrind | ||
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.