https://github.com/python/cpython/commit/7b7c6dcfff6a35333988a3c74c895ed19df... commit: 7b7c6dcfff6a35333988a3c74c895ed19dff2e09 branch: master author: Victor Stinner <victor.stinner@gmail.com> committer: GitHub <noreply@github.com> date: 2017-08-10T12:37:39+02:00 summary: bpo-31173: Rewrite WSTOPSIG test of test_subprocess (#3055) The current test_child_terminated_in_stopped_state() function test creates a child process which calls ptrace(PTRACE_TRACEME, 0, 0) and then crash (SIGSEGV). The problem is that calling os.waitpid() in the parent process is not enough to close the process: the child process remains alive and so the unit test leaks a child process in a strange state. Closing the child process requires non-trivial code, maybe platform specific. Remove the functional test and replaces it with an unit test which mocks os.waitpid() using a new _testcapi.W_STOPCODE() function to test the WIFSTOPPED() path. files: M Lib/test/test_subprocess.py M Modules/_testcapimodule.c diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py index d152826213e..1d2d15c7a24 100644 --- a/Lib/test/test_subprocess.py +++ b/Lib/test/test_subprocess.py @@ -29,6 +29,11 @@ except ImportError: threading = None +try: + import _testcapi +except ImportError: + _testcapi = None + if support.PGO: raise unittest.SkipTest("test is not helpful for PGO") @@ -2565,42 +2570,24 @@ def test_communicate_BrokenPipeError_stdin_close_with_timeout(self): proc.communicate(timeout=999) mock_proc_stdin.close.assert_called_once_with() - @unittest.skipIf(not ctypes, 'ctypes module required') - @unittest.skipIf(not sys.executable, 'Test requires sys.executable') - def test_child_terminated_in_stopped_state(self): + @unittest.skipUnless(_testcapi is not None + and hasattr(_testcapi, 'W_STOPCODE'), + 'need _testcapi.W_STOPCODE') + def test_stopped(self): """Test wait() behavior when waitpid returns WIFSTOPPED; issue29335.""" - PTRACE_TRACEME = 0 # From glibc and MacOS (PT_TRACE_ME). - libc_name = ctypes.util.find_library('c') - libc = ctypes.CDLL(libc_name) - if not hasattr(libc, 'ptrace'): - raise unittest.SkipTest('ptrace() required') - - code = textwrap.dedent(f""" - import ctypes - import faulthandler - from test.support import SuppressCrashReport - - libc = ctypes.CDLL({libc_name!r}) - libc.ptrace({PTRACE_TRACEME}, 0, 0) - """) - - child = subprocess.Popen([sys.executable, '-c', code]) - if child.wait() != 0: - raise unittest.SkipTest('ptrace() failed - unable to test') - - code += textwrap.dedent(f""" - with SuppressCrashReport(): - # Crash the process - faulthandler._sigsegv() - """) - child = subprocess.Popen([sys.executable, '-c', code]) - try: - returncode = child.wait() - except: - child.kill() # Clean up the hung stopped process. - raise - self.assertNotEqual(0, returncode) - self.assertLess(returncode, 0) # signal death, likely SIGSEGV. + args = [sys.executable, '-c', 'pass'] + proc = subprocess.Popen(args) + + # Wait until the real process completes to avoid zombie process + pid = proc.pid + pid, status = os.waitpid(pid, 0) + self.assertEqual(status, 0) + + status = _testcapi.W_STOPCODE(3) + with mock.patch('subprocess.os.waitpid', return_value=(pid, status)): + returncode = proc.wait() + + self.assertEqual(returncode, -3) @unittest.skipUnless(mswindows, "Windows specific tests") diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c index 655669050dd..95c10184159 100644 --- a/Modules/_testcapimodule.c +++ b/Modules/_testcapimodule.c @@ -18,6 +18,10 @@ # include <winsock2.h> /* struct timeval */ #endif +#ifdef HAVE_SYS_WAIT_H +#include <sys/wait.h> /* For W_STOPCODE */ +#endif + #ifdef WITH_THREAD #include "pythread.h" #endif /* WITH_THREAD */ @@ -4272,6 +4276,7 @@ test_pyobject_fastcallkeywords(PyObject *self, PyObject *args) return _PyObject_FastCallKeywords(func, stack, nargs, kwnames); } + static PyObject* stack_pointer(PyObject *self, PyObject *args) { @@ -4280,6 +4285,20 @@ stack_pointer(PyObject *self, PyObject *args) } +#ifdef W_STOPCODE +static PyObject* +py_w_stopcode(PyObject *self, PyObject *args) +{ + int sig, status; + if (!PyArg_ParseTuple(args, "i", &sig)) { + return NULL; + } + status = W_STOPCODE(sig); + return PyLong_FromLong(status); +} +#endif + + static PyMethodDef TestMethods[] = { {"raise_exception", raise_exception, METH_VARARGS}, {"raise_memoryerror", (PyCFunction)raise_memoryerror, METH_NOARGS}, @@ -4493,6 +4512,9 @@ static PyMethodDef TestMethods[] = { {"pyobject_fastcalldict", test_pyobject_fastcalldict, METH_VARARGS}, {"pyobject_fastcallkeywords", test_pyobject_fastcallkeywords, METH_VARARGS}, {"stack_pointer", stack_pointer, METH_NOARGS}, +#ifdef W_STOPCODE + {"W_STOPCODE", py_w_stopcode, METH_VARARGS}, +#endif {NULL, NULL} /* sentinel */ };