https://github.com/python/cpython/commit/e833f57383546a02d61028aa87194aa65d5a92a3
commit: e833f57383546a02d61028aa87194aa65d5a92a3
branch: main
author: Bernát Gábor <[email protected]>
committer: vsajip <[email protected]>
date: 2026-06-04T17:15:12+01:00
summary:
gh-150818: Speed up logging.getLogger() for existing loggers (GH-150825)
files:
A Misc/NEWS.d/next/Library/2026-06-02-15-44-58.gh-issue-150818.Orcefu.rst
M Lib/logging/__init__.py
diff --git a/Lib/logging/__init__.py b/Lib/logging/__init__.py
index 6eef90ae5cd914..9febc50b1264ef 100644
--- a/Lib/logging/__init__.py
+++ b/Lib/logging/__init__.py
@@ -1373,9 +1373,16 @@ def getLogger(self, name):
logger and fix up the parent/child references which pointed to the
placeholder to now point to the logger.
"""
- rv = None
if not isinstance(name, str):
raise TypeError('A logger name must be a string')
+ # Fast path: an already-registered, non-placeholder logger can be
+ # returned without taking the lock. dict.get() is atomic under both
+ # the GIL and free threading, and a Logger is fully initialised before
+ # being inserted into loggerDict under the lock, so this never sees a
+ # partially-constructed object.
+ rv = self.loggerDict.get(name)
+ if rv is not None and not isinstance(rv, PlaceHolder):
+ return rv
with _lock:
if name in self.loggerDict:
rv = self.loggerDict[name]
diff --git
a/Misc/NEWS.d/next/Library/2026-06-02-15-44-58.gh-issue-150818.Orcefu.rst
b/Misc/NEWS.d/next/Library/2026-06-02-15-44-58.gh-issue-150818.Orcefu.rst
new file mode 100644
index 00000000000000..3bb16001cc0bb4
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-06-02-15-44-58.gh-issue-150818.Orcefu.rst
@@ -0,0 +1,3 @@
+Speed up :func:`logging.getLogger` with a lock-free fast path that returns an
+already-registered logger without acquiring the logging lock. Patch by Bernát
+Gábor.
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