Fix data race (TSan report) on worker thread startup on macOS in `iree_thread_request_affinity` (#15499)

TSan report:

```
WARNING: ThreadSanitizer: data race (pid=45817)
  Read of size 4 at 0x0001084004e0 by thread T2:
    #0 iree_thread_request_affinity threading_darwin.c:230 (local-task_vmvx_semaphore_submission_test:arm64+0x100078f40)
    #1 iree_task_worker_main worker.c:385 (local-task_vmvx_semaphore_submission_test:arm64+0x100071594)
    #2 iree_thread_start_routine threading_darwin.c:72 (local-task_vmvx_semaphore_submission_test:arm64+0x100078e3c)

  Previous write of size 4 at 0x0001084004e0 by main thread:
    #0 iree_thread_create threading_darwin.c:140 (local-task_vmvx_semaphore_submission_test:arm64+0x100078ca4)
    #1 iree_task_worker_initialize worker.c:66 (local-task_vmvx_semaphore_submission_test:arm64+0x1000714f8)
    #2 iree_task_executor_create executor.c:161 (local-task_vmvx_semaphore_submission_test:arm64+0x10006b2b0)
```

The read of `thread->mach_port` at
https://github.com/openxla/iree/blob/ccc4c3719cea467477a783f1c9e9f1fc06b4c508/runtime/src/iree/base/internal/threading_darwin.c#L230

is not ordered relatively to the write of that variable in the parent
thread after `pthread_mach_thread_np` returns:
https://github.com/openxla/iree/blob/ccc4c3719cea467477a783f1c9e9f1fc06b4c508/runtime/src/iree/base/internal/threading_darwin.c#L140

The proposed fix is that the worker thread shouldn't need to access its
own `thread->mach_port`, it can equivalently call `mach_task_self()`.
1 file changed
tree: 1cf6141aad948821819139c75b016b0cb483cec2
  1. .devcontainer/
  2. .github/
  3. build_tools/
  4. compiler/
  5. docs/
  6. experimental/
  7. integrations/
  8. lib/
  9. llvm-external-projects/
  10. runtime/
  11. samples/
  12. tests/
  13. third_party/
  14. tools/
  15. .bazel_to_cmake.cfg.py
  16. .bazelignore
  17. .bazelrc
  18. .bazelversion
  19. .clang-format
  20. .dockerignore
  21. .git-blame-ignore-revs
  22. .gitignore
  23. .gitmodules
  24. .yamllint.yml
  25. AUTHORS
  26. BUILD.bazel
  27. CITATION.cff
  28. CMakeLists.txt
  29. configure_bazel.py
  30. CONTRIBUTING.md
  31. LICENSE
  32. README.md
  33. WORKSPACE
README.md

IREE: Intermediate Representation Execution Environment

IREE (Intermediate Representation Execution Environment, pronounced as “eerie”) is an MLIR-based end-to-end compiler and runtime that lowers Machine Learning (ML) models to a unified IR that scales up to meet the needs of the datacenter and down to satisfy the constraints and special considerations of mobile and edge deployments.

See our website for project details, user guides, and instructions on building from source.

CI Status

Project Status

IREE is still in its early phase. We have settled down on the overarching infrastructure and are actively improving various software components as well as project logistics. It is still quite far from ready for everyday use and is made available without any support at the moment. With that said, we welcome any kind of feedback on any communication channels!

Communication Channels

Related Project Channels

  • MLIR topic within LLVM Discourse: IREE is enabled by and heavily relies on MLIR. IREE sometimes is referred to in certain MLIR discussions. Useful if you are also interested in MLIR evolution.

Architecture Overview

IREE Architecture IREE Architecture

See our website for more information.

Presentations and Talks

License

IREE is licensed under the terms of the Apache 2.0 License with LLVM Exceptions. See LICENSE for more information.