Class _OurHandler

Lib/test/test_logging.py:755–763

    def test_post_fork_child_no_deadlock(self):
        """Ensure child logging locks are not held; bpo-6721 & bpo-36533."""
        class _OurHandler(logging.Handler):
            def __init__(self):
                super().__init__()
                self.sub_handler = logging.StreamHandler(
                    stream=open('/dev/null', 'wt', encoding='utf-8'))

            def emit(self, record):
                with self.sub_handler.lock:
                    self.sub_handler.emit(record)

        self.assertEqual(len(logging._handlers), 0)
        refed_h = _OurHandler()