[ORC] Fix Task cleanup during DynamicThreadPoolTaskDispatcher::shutdown.

Threads created by DynamicThreadPoolTaskDispatcher::dispatch had been holding a
unique_ptr to the most recent Task, meaning that the Task would be destroyed
when the thread object was destroyed, but this would happen *after* the thread
signaled the Dispatcher that it was finished. This could cause
DynamicThreadPoolTaskDispatcher::shutdown to return (and consequently
ExecutionSession to be destroyed) before all Tasks were destroyed, with Task
destructors accessing ExecutionSession and related objects after they were
freed.

The fix is to reset the Task pointer immediately after it is run to trigger
cleanup, *then* (if there are no other tasks to run) signal the Dispatcher that
the thread is finished.

This patch also updates DynamicThreadPoolTaskDispatcher::dispatch to reject any
new Tasks dispatched after DynamicThreadPoolTaskDispatcher::shutdown is called.
2 files changed
tree: c3062debee27fef9c05afbc48e7ca2f02ced820c
  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.

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