cpython/Lib/test/crashers/warnings_del_crasher.py

30 lines
873 B
Python

"""
Expose a race in the _warnings module, which is the C backend for the
warnings module. The "_warnings" module tries to access attributes of the
"warnings" module (because of the API it has to support), but doing so
during interpreter shutdown is problematic. Specifically, the call to
PyImport_GetModuleDict() in Python/_warnings.c:get_warnings_attr will
abort() if the modules dict has already been cleaned up.
This crasher is timing-dependent, and more threads (NUM_THREADS) may be
necessary to expose it reliably on different systems.
"""
import threading
import warnings
NUM_THREADS = 10
class WarnOnDel(object):
def __del__(self):
warnings.warn("oh no something went wrong", UserWarning)
def do_work():
while True:
w = WarnOnDel()
for i in range(NUM_THREADS):
t = threading.Thread(target=do_work)
t.setDaemon(1)
t.start()