From 243fd01047ddce1a7eb0f99a49732d123e942c63 Mon Sep 17 00:00:00 2001 From: Victor Stinner Date: Tue, 15 Jun 2021 16:14:24 +0200 Subject: bpo-44422: Fix threading.enumerate() reentrant call (GH-26727) The threading.enumerate() function now uses a reentrant lock to prevent a hang on reentrant call. --- Lib/threading.py | 9 ++++++--- .../NEWS.d/next/Library/2021-06-14-23-28-17.bpo-44422.BlWOgv.rst | 3 +++ 2 files changed, 9 insertions(+), 3 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2021-06-14-23-28-17.bpo-44422.BlWOgv.rst diff --git a/Lib/threading.py b/Lib/threading.py index 6c3d49c..766011f 100644 --- a/Lib/threading.py +++ b/Lib/threading.py @@ -775,8 +775,11 @@ _counter = _count(1).__next__ def _newname(name_template): return name_template % _counter() -# Active thread administration -_active_limbo_lock = _allocate_lock() +# Active thread administration. +# +# bpo-44422: Use a reentrant lock to allow reentrant calls to functions like +# threading.enumerate(). +_active_limbo_lock = RLock() _active = {} # maps thread id to Thread object _limbo = {} _dangling = WeakSet() @@ -1564,7 +1567,7 @@ def _after_fork(): # by another (non-forked) thread. http://bugs.python.org/issue874900 global _active_limbo_lock, _main_thread global _shutdown_locks_lock, _shutdown_locks - _active_limbo_lock = _allocate_lock() + _active_limbo_lock = RLock() # fork() only copied the current thread; clear references to others. new_active = {} diff --git a/Misc/NEWS.d/next/Library/2021-06-14-23-28-17.bpo-44422.BlWOgv.rst b/Misc/NEWS.d/next/Library/2021-06-14-23-28-17.bpo-44422.BlWOgv.rst new file mode 100644 index 0000000..09bace0 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2021-06-14-23-28-17.bpo-44422.BlWOgv.rst @@ -0,0 +1,3 @@ +The :func:`threading.enumerate` function now uses a reentrant lock to +prevent a hang on reentrant call. +Patch by Victor Stinner. -- cgit v0.12