diff options
Diffstat (limited to 'Lib/test')
| -rw-r--r-- | Lib/test/test_subprocess.py | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py index 2073fd1461..f1fb93455d 100644 --- a/Lib/test/test_subprocess.py +++ b/Lib/test/test_subprocess.py @@ -3120,6 +3120,31 @@ class POSIXProcessTestCase(BaseTestCase): 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. + pid, status = os.waitpid(proc.pid, 0) + self.assertEqual(pid, proc.pid) + self.assertTrue(os.WIFEXITED(status), status) + self.assertEqual(os.WEXITSTATUS(status), 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) + @unittest.skipUnless(mswindows, "Windows specific tests") class Win32ProcessTestCase(BaseTestCase): |