BUG: avoid thread-unsafe refcount check in temp elision #29649
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
|
Thanks Nathan. |
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Outdated suggestions cannot be applied.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.
Checking
Py_REFCNT == 1is thread-unsafe on the free-threaded build, since refcounts are stored and loaded in free-threading using atomic operations.Python 3.14 added
PyUnstable_Object_IsUniquelyReferencedto replace static refcount checks. I added a backport to pythoncapi-compat in python/pythoncapi-compat#149, which allows me to use the function unconditionally and get correct behavior on 3.13t as well. This relies on some private implementation details on 3.13t, but all that is done in the compat header.