[3.14] gh-137335: Fix unlikely name conflicts for named pipes in multiprocessing and asyncio on Windows (GH-137389)#145170
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serhiy-storchaka merged 1 commit intopython:3.14from Feb 24, 2026
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…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 d6a71f4690c702892644b1fbae90ae9ef733a8ab) Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
This was referenced Feb 24, 2026
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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