From 163b1e32f24cefb4fe6663244404c5e60716245a Mon Sep 17 00:00:00 2001
From: Victor Stinner <vstinner@python.org>
Date: Fri, 27 Mar 2020 18:01:47 +0100
Subject: [PATCH] bpo-40091: Fix a crash in logging after fork

Fix a crash in the logging module after fork in the process process:
reset the main logging lock.
---
 Lib/logging/__init__.py                                         | 2 +-
 .../next/Library/2020-03-27-18-03-12.bpo-40091.ZIh4oL.rst       | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)
 create mode 100644 Misc/NEWS.d/next/Library/2020-03-27-18-03-12.bpo-40091.ZIh4oL.rst

diff --git a/Lib/logging/__init__.py b/Lib/logging/__init__.py
index 59d5fa5b64d2232..9ea2a19667cb9bb 100644
--- a/Lib/logging/__init__.py
+++ b/Lib/logging/__init__.py
@@ -257,8 +257,8 @@ def _after_at_fork_child_reinit_locks():
                 # Similar to what PyErr_WriteUnraisable does.
                 print("Ignoring exception from logging atfork", instance,
                       "._reinit_lock() method:", err, file=sys.stderr)
-        _releaseLock()  # Acquired by os.register_at_fork(before=.
 
+        _lock = threading.RLock()
 
     os.register_at_fork(before=_acquireLock,
                         after_in_child=_after_at_fork_child_reinit_locks,
diff --git a/Misc/NEWS.d/next/Library/2020-03-27-18-03-12.bpo-40091.ZIh4oL.rst b/Misc/NEWS.d/next/Library/2020-03-27-18-03-12.bpo-40091.ZIh4oL.rst
new file mode 100644
index 000000000000000..2177e6e9c3fadf2
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-03-27-18-03-12.bpo-40091.ZIh4oL.rst
@@ -0,0 +1,2 @@
+Fix a crash in the :mod:`logging` module after fork in the process process:
+reset the main logging lock.