gh-119525: Fix deadlock with _PyType_Lookup and the GIL
#119527
Merged
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The deadlock only affected the free-threaded build and only occurred when the GIL was enabled at runtime. The `Py_DECREF(old_name)` call might temporarily release the GIL while holding the type seqlock. Another thread may spin trying to acquire the seqlock while holding the GIL. The deadlock occurred roughly 1 in ~1,000 runs of `pool_in_threads.py` from `test_multiprocessing_pool_circular_import`.
|
Thanks @colesbury for the PR 🌮🎉.. I'm working now to backport this PR to: 3.13. |
miss-islington
pushed a commit
to miss-islington/cpython
that referenced
this pull request
May 29, 2024
…onGH-119527) The deadlock only affected the free-threaded build and only occurred when the GIL was enabled at runtime. The `Py_DECREF(old_name)` call might temporarily release the GIL while holding the type seqlock. Another thread may spin trying to acquire the seqlock while holding the GIL. The deadlock occurred roughly 1 in ~1,000 runs of `pool_in_threads.py` from `test_multiprocessing_pool_circular_import`. (cherry picked from commit c22323c) Co-authored-by: Sam Gross <colesbury@gmail.com>
|
GH-119746 is a backport of this pull request to the 3.13 branch. |
colesbury
added a commit
that referenced
this pull request
May 29, 2024
…119527) (#119746) The deadlock only affected the free-threaded build and only occurred when the GIL was enabled at runtime. The `Py_DECREF(old_name)` call might temporarily release the GIL while holding the type seqlock. Another thread may spin trying to acquire the seqlock while holding the GIL. The deadlock occurred roughly 1 in ~1,000 runs of `pool_in_threads.py` from `test_multiprocessing_pool_circular_import`. (cherry picked from commit c22323c) Co-authored-by: Sam Gross <colesbury@gmail.com>
noahbkim
pushed a commit
to hudson-trading/cpython
that referenced
this pull request
Jul 11, 2024
…on#119527) The deadlock only affected the free-threaded build and only occurred when the GIL was enabled at runtime. The `Py_DECREF(old_name)` call might temporarily release the GIL while holding the type seqlock. Another thread may spin trying to acquire the seqlock while holding the GIL. The deadlock occurred roughly 1 in ~1,000 runs of `pool_in_threads.py` from `test_multiprocessing_pool_circular_import`.
estyxx
pushed a commit
to estyxx/cpython
that referenced
this pull request
Jul 17, 2024
…on#119527) The deadlock only affected the free-threaded build and only occurred when the GIL was enabled at runtime. The `Py_DECREF(old_name)` call might temporarily release the GIL while holding the type seqlock. Another thread may spin trying to acquire the seqlock while holding the GIL. The deadlock occurred roughly 1 in ~1,000 runs of `pool_in_threads.py` from `test_multiprocessing_pool_circular_import`.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The deadlock only affected the free-threaded build and only occurred when the GIL was enabled at runtime. The
Py_DECREF(old_name)call might temporarily release the GIL while holding the type seqlock. Another thread may spin trying to acquire the seqlock while holding the GIL.The deadlock occurred roughly 1 in ~1,000 runs of
pool_in_threads.pyfromtest_multiprocessing_pool_circular_import.