Method test_send_signal_race

Lib/test/test_subprocess.py:3511–3531

(self)

        self.assertEqual(returncode, -3)

    def test_send_signal_race(self):
        # bpo-38630: send_signal() must poll the process exit status to reduce
        # the risk of sending the signal to the wrong process.
        proc = subprocess.Popen(ZERO_RETURN_CMD)

        # wait until the process completes without using the Popen APIs.
        support.wait_process(proc.pid, exitcode=0)

        # returncode is still None but the process completed.
        self.assertIsNone(proc.returncode)

        with mock.patch("os.kill") as mock_kill:
            proc.send_signal(signal.SIGTERM)

        # send_signal() didn't call os.kill() since the process already
        # completed.
        mock_kill.assert_not_called()

        # Don't check the returncode value: the test reads the exit status,
        # so Popen failed to read it and uses a default returncode instead.
        self.assertIsNotNone(proc.returncode)

    def test_send_signal_race2(self):
        # bpo-40550: the process might exist between the returncode check and