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llvm / llvm-project / 186fac33d08b34be494caa58fe63972f69c6d6ab
commit186fac33d08b34be494caa58fe63972f69c6d6ab[log] [tgz]
authorjimingham <jingham@apple.com>Thu Dec 12 12:48:41 2024 -0800
committerGitHub <noreply@github.com>Thu Dec 12 12:48:41 2024 -0800
tree630c67ca9b25293053710aa35ab6581760c6d71a
parent71418379574d2df5e435f67c4b8d7591bd2038e9 [diff]
Convert the StackFrameList mutex to a shared mutex. (#117252)

In fact, there's only one public API in StackFrameList that changes
 the list explicitly.  The rest only change the list if you happen to
ask for more frames than lldb has currently fetched and that 
always adds frames "behind the user's back".  So we were
much more prone to deadlocking than we needed to be.

This patch uses a shared_mutex instead, and when we have to add more
frames (in GetFramesUpTo) we switches to exclusive long enough to add
the frames, then goes back to shared.
    
Most of the work here was actually getting the stack frame list locking
to not
require a recursive mutex (shared mutexes aren't recursive). 
    
I also added a test that has 5 threads progressively asking for more
frames simultaneously to make sure we get back valid frames and don't
deadlock.
6 files changed
tree: 630c67ca9b25293053710aa35ab6581760c6d71a
  1. .ci/
  2. .github/
  3. bolt/
  4. clang/
  5. clang-tools-extra/
  6. cmake/
  7. compiler-rt/
  8. cross-project-tests/
  9. flang/
  10. libc/
  11. libclc/
  12. libcxx/
  13. libcxxabi/
  14. libunwind/
  15. lld/
  16. lldb/
  17. llvm/
  18. llvm-libgcc/
  19. mlir/
  20. offload/
  21. openmp/
  22. polly/
  23. pstl/
  24. runtimes/
  25. third-party/
  26. utils/
  27. .clang-format
  28. .clang-tidy
  29. .git-blame-ignore-revs
  30. .gitattributes
  31. .gitignore
  32. .mailmap
  33. CODE_OF_CONDUCT.md
  34. CONTRIBUTING.md
  35. LICENSE.TXT
  36. pyproject.toml
  37. README.md
  38. SECURITY.md
README.md

The LLVM Compiler Infrastructure

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Welcome to the LLVM project!

This repository contains the source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.

The LLVM project has multiple components. The core of the project is itself called “LLVM”. This contains all of the tools, libraries, and header files needed to process intermediate representations and convert them into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer.

C-like languages use the Clang frontend. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.

Other components include: the libc++ C++ standard library, the LLD linker, and more.

Getting the Source Code and Building LLVM

Consult the Getting Started with LLVM page for information on building and running LLVM.

For information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.

Getting in touch

Join the LLVM Discourse forums, Discord chat, LLVM Office Hours or Regular sync-ups.

The LLVM project has adopted a code of conduct for participants to all modes of communication within the project.