bpo-1596321: Fix threading._shutdown() for the main thread (GH-28549)
Fix the threading._shutdown() function when the threading module was
imported first from a thread different than the main thread: no
longer log an error at Python exit.
(cherry picked from commit 95d31370829b7d729667588e0a9943217401ea5b)
Co-authored-by: Victor Stinner <vstinner@python.org>
diff --git a/Lib/threading.py b/Lib/threading.py
index f39da14..c7f7d5f 100644
--- a/Lib/threading.py
+++ b/Lib/threading.py
@@ -1523,20 +1523,29 @@ def _shutdown():
global _SHUTTING_DOWN
_SHUTTING_DOWN = True
- # Main thread
- tlock = _main_thread._tstate_lock
- # The main thread isn't finished yet, so its thread state lock can't have
- # been released.
- assert tlock is not None
- assert tlock.locked()
- tlock.release()
- _main_thread._stop()
# Call registered threading atexit functions before threads are joined.
# Order is reversed, similar to atexit.
for atexit_call in reversed(_threading_atexits):
atexit_call()
+ # Main thread
+ if _main_thread.ident == get_ident():
+ tlock = _main_thread._tstate_lock
+ # The main thread isn't finished yet, so its thread state lock can't
+ # have been released.
+ assert tlock is not None
+ assert tlock.locked()
+ tlock.release()
+ _main_thread._stop()
+ else:
+ # bpo-1596321: _shutdown() must be called in the main thread.
+ # If the threading module was not imported by the main thread,
+ # _main_thread is the thread which imported the threading module.
+ # In this case, ignore _main_thread, similar behavior than for threads
+ # spawned by C libraries or using _thread.start_new_thread().
+ pass
+
# Join all non-deamon threads
while True:
with _shutdown_locks_lock: