bpo-42350: Fix Thread._reset_internal_locks() (GH-23268)
Fix the threading.Thread class at fork: do nothing if the thread is
already stopped (ex: fork called at Python exit). Previously, an
error was logged in the child process.
(cherry picked from commit 5909a494cd3ba43143b28bd439773ed85a485dfc)
Co-authored-by: Victor Stinner <vstinner@python.org>
diff --git a/Lib/test/test_threading.py b/Lib/test/test_threading.py
index 81e5f70..c21cdf8 100644
--- a/Lib/test/test_threading.py
+++ b/Lib/test/test_threading.py
@@ -439,6 +439,35 @@
t = threading.Thread(daemon=True)
self.assertTrue(t.daemon)
+ @unittest.skipUnless(hasattr(os, 'fork'), 'needs os.fork()')
+ def test_fork_at_exit(self):
+ # bpo-42350: Calling os.fork() after threading._shutdown() must
+ # not log an error.
+ code = textwrap.dedent("""
+ import atexit
+ import os
+ import sys
+ from test.support import wait_process
+
+ # Import the threading module to register its "at fork" callback
+ import threading
+
+ def exit_handler():
+ pid = os.fork()
+ if not pid:
+ print("child process ok", file=sys.stderr, flush=True)
+ # child process
+ sys.exit()
+ else:
+ wait_process(pid, exitcode=0)
+
+ # exit_handler() will be called after threading._shutdown()
+ atexit.register(exit_handler)
+ """)
+ _, out, err = assert_python_ok("-c", code)
+ self.assertEqual(out, b'')
+ self.assertEqual(err.rstrip(), b'child process ok')
+
@unittest.skipUnless(hasattr(os, 'fork'), 'test needs fork()')
def test_dummy_thread_after_fork(self):
# Issue #14308: a dummy thread in the active list doesn't mess up