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dart / sdk.git / db0fa84d5991334be7e7858c4640762371fe89e1
commitdb0fa84d5991334be7e7858c4640762371fe89e1[log] [tgz]
authorCorey Tabaka <eieio@google.com>Wed Mar 31 20:51:32 2021 +0000
committercommit-bot@chromium.org <commit-bot@chromium.org>Wed Mar 31 20:51:32 2021 +0000
treeacd311ffe25e6952e34397c98257a385200c9e05
parentbddded13aad0ee8b1bff7f235a548df5228e5df6 [diff]
[vm] Optimize get current thread id in Fuchsia.

OSThread::GetCurrentThreadId() is used in many places throughout
the vm, particularly in facilities that are used heavily, such as
SafepointRwLock. The high frequency of invocations means that the
runtime overhead of getting the current thread id has a significant
impact on the overall performance of the vm.

The current Fuchsia implemention of OSThread::GetCurrentThreadId()
makes a syscall to get the koid of the current thread's handle,
resulting in hundreds of nanoseconds of unnecessary overhead per
invocation.

This patch changes to using the thread's handle as the id, which is
guaranteed to be unique for the lifetime of the thread, unless it
is closed prematurely (nothing in the vm does this). This approach
is similar to what MUSL libc (the libc used by Fuchsia) does for
the same purpose and has significant mileage.

Bug: b/182183059
TEST=existing ci test suite; manually deployed into Fuchsia build.

Change-Id: I274a793a823a717c8dd206b396001c6acb897b9a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/193643
Reviewed-by: Chase Latta <chaselatta@google.com>
Commit-Queue: Chase Latta <chaselatta@google.com>
2 files changed
tree: acd311ffe25e6952e34397c98257a385200c9e05
  1. .dart_tool/
  2. .github/
  3. benchmarks/
  4. build/
  5. client/
  6. docs/
  7. pkg/
  8. runtime/
  9. samples/
  10. samples-dev/
  11. samples_2/
  12. sdk/
  13. tests/
  14. third_party/
  15. tools/
  16. utils/
  17. .clang-format
  18. .gitattributes
  19. .gitconfig
  20. .gitignore
  21. .gn
  22. .mailmap
  23. .packages
  24. .style.yapf
  25. .vpython
  26. AUTHORS
  27. BUILD.gn
  28. CHANGELOG.md
  29. codereview.settings
  30. CONTRIBUTING.md
  31. DEPS
  32. LICENSE
  33. PATENT_GRANT
  34. PRESUBMIT.py
  35. README.dart-sdk
  36. README.md
  37. sdk_args.gni
  38. WATCHLISTS
README.md

Dart

A client-optimized language for fast apps on any platform

Dart is:

  • Optimized for UI: Develop with a programming language specialized around the needs of user interface creation.

  • Productive: Make changes iteratively: use hot reload to see the result instantly in your running app.

  • Fast on all platforms: Compile to ARM & x64 machine code for mobile, desktop, and backend. Or compile to JavaScript for the web.

Dart's flexible compiler technology lets you run Dart code in different ways, depending on your target platform and goals:

  • Dart Native: For programs targeting devices (mobile, desktop, server, and more), Dart Native includes both a Dart VM with JIT (just-in-time) compilation and an AOT (ahead-of-time) compiler for producing machine code.

  • Dart Web: For programs targeting the web, Dart Web includes both a development time compiler (dartdevc) and a production time compiler (dart2js).

Dart platforms illustration

License & patents

Dart is free and open source.

See LICENSE and PATENT_GRANT.

Using Dart

Visit dart.dev to learn more about the language, tools, and to find codelabs.

Browse pub.dev for more packages and libraries contributed by the community and the Dart team.

Our API reference documentation is published at api.dart.dev, based on the stable release. (We also publish docs from our beta and dev channels, as well as from the primary development branch).

Building Dart

If you want to build Dart yourself, here is a guide to getting the source, preparing your machine to build the SDK, and building.

There are more documents on our wiki.

Contributing to Dart

The easiest way to contribute to Dart is to file issues.

You can also contribute patches, as described in Contributing.