[3.13] gh-137335: Fix unlikely name conflicts for named pipes in multiprocessing and asyncio on Windows (GH-137389)#145171
Merged
serhiy-storchaka merged 1 commit intopython:3.13from Feb 24, 2026
Conversation
…processing and asyncio on Windows (pythonGH-137389) Since os.stat() raises an OSError for existing named pipe "\\.\pipe\...", os.path.exists() always returns False for it, and tempfile.mktemp() can return a name that matches an existing named pipe. So, tempfile.mktemp() cannot be used to generate unique names for named pipes. Instead, CreateNamedPipe() should be called in a loop with different names until it completes successfully. (cherry picked from commit d6a71f4) Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
miss-islington
requested review from
1st1,
asvetlov,
gpshead,
gvanrossum,
kumaraditya303 and
willingc
as code owners
This was referenced Feb 24, 2026
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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Since os.stat() raises an OSError for existing named pipe "\.\pipe...",
os.path.exists() always returns False for it, and tempfile.mktemp() can
return a name that matches an existing named pipe.
So, tempfile.mktemp() cannot be used to generate unique names for named
pipes. Instead, CreateNamedPipe() should be called in a loop with
different names until it completes successfully.
(cherry picked from commit d6a71f4)
Co-authored-by: Serhiy Storchaka storchaka@gmail.com
tempfile.mktemp()for creating named pipes on Windows #137335