cpython/Misc
Miss Islington (bot) 7d074702eb
[3.14] gh-143650: Fix importlib race condition on import failure (GH-143651) (#144662)
gh-143650: Fix importlib race condition on import failure (GH-143651)

Fix a race condition where a thread could receive a partially-initialized
module when another thread's import fails. The race occurs when:

1. Thread 1 starts importing, adds module to sys.modules
2. Thread 2 sees the module in sys.modules via the fast path
3. Thread 1's import fails, removes module from sys.modules
4. Thread 2 returns a stale module reference not in sys.modules

The fix adds verification after the "skip lock" optimization in both Python
and C code paths to check if the module is still in sys.modules. If the
module was removed (due to import failure), we retry the import so the
caller receives the actual exception from the import failure rather than
a stale module reference.
(cherry picked from commit ac8b5b6890)

Co-authored-by: Gregory P. Smith <68491+gpshead@users.noreply.github.com>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
2026-02-11 06:06:51 +00:00
..
mypy gh-131507: Add support for syntax highlighting in PyREPL (GH-133247) 2025-05-02 20:22:31 +02:00
NEWS.d [3.14] gh-143650: Fix importlib race condition on import failure (GH-143651) (#144662) 2026-02-11 06:06:51 +00:00
rhel7 gh-95957: Add instructions for Tcl/Tk and OpenSSL on RHEL/CentOS 7 (#95964) 2022-08-16 13:44:02 +02:00
ACKS [3.14] gh-128067: Fix pyrepl overriding printed output without newlines (GH-138732) (GH-143350) 2026-01-02 16:12:02 +01:00
externals.spdx.json [3.14] gh-139573: Update Windows builds to use OpenSSL 3.0.18 (GH-139574) (#139586) 2025-10-05 08:00:29 +03:00
HISTORY gh-123492: Remove unnecessary :func: parentheses (#123493) 2024-08-30 14:34:09 +03:00
indent.pro
platform_triplet.c gh-132026: Ensure _MIPS_SIM has defined _ABI identifiers for comparison (GH-132027) 2025-04-27 21:56:00 +00:00
Porting
python-config.in bpo-45101: Add consistency in usage message IO between 2 versions of python-config (GH-28162) 2024-02-26 22:04:44 +02:00
python-config.sh.in gh-116622: Rename build variable MODULE_LDFLAGS back to LIBPYTHON (#122764) 2024-08-09 00:00:55 +02:00
python-embed.pc.in
python.man [3.14] Manpage: -X gil is not related to PYTHON_HISTORY (GH-133753) (#133758) 2025-05-09 14:17:33 +00:00
python.pc.in gh-116622: Rename build variable MODULE_LDFLAGS back to LIBPYTHON (#122764) 2024-08-09 00:00:55 +02:00
README gh-124457: Remove coverity from CPython repo (GH-124460) 2024-09-27 13:42:32 -07:00
README.AIX
README.valgrind
sbom.spdx.json [3.14] gh-144363: Update bundled libexpat to 2.7.4 (GH-144365) (GH-144499) 2026-02-09 14:21:54 +01:00
SpecialBuilds.txt GH-129763: Remove the LLTRACE macro (GH-129764) 2025-02-07 08:49:51 -08:00
stable_abi.toml [3.14] gh-141909: Add PyModuleDef_Slot and earlier Py_mod_* constants to stable ABI manifest (#141910) (GH-141978) 2025-11-26 15:35:04 +01:00
svnmap.txt
valgrind-python.supp gh-121096: Ignore dlopen() leaks in Valgrind suppression file (#121097) 2024-06-28 13:10:11 +02:00
vgrindefs

Python Misc subdirectory
========================

This directory contains files that wouldn't fit in elsewhere.  Some
documents are only of historic importance.

Files found here
----------------

ACKS                    Acknowledgements
HISTORY                 News from previous releases -- oldest last
indent.pro              GNU indent profile approximating my C style
NEWS                    News for this release (for some meaning of "this")
Porting                 Mini-FAQ on porting to new platforms
python-config.in        Python script template for python-config
python.man              UNIX man page for the python interpreter
python.pc.in            Package configuration info template for pkg-config
README                  The file you're reading now
README.AIX              Information about using Python on AIX
README.valgrind         Information for Valgrind users, see valgrind-python.supp
SpecialBuilds.txt       Describes extra symbols you can set for debug builds
svnmap.txt              Map of old SVN revs and branches to hg changeset ids,
                        help history-digging
valgrind-python.supp    Valgrind suppression file, see README.valgrind
vgrindefs               Python configuration for vgrind (a generic pretty printer)