diff --git a/Lib/multiprocessing/connection.py b/Lib/multiprocessing/connection.py index 530a8dfe4e5..a02793ff26b 100644 --- a/Lib/multiprocessing/connection.py +++ b/Lib/multiprocessing/connection.py @@ -348,7 +348,10 @@ if sys.platform == 'win32': try: win32.ConnectNamedPipe(handle, win32.NULL) except WindowsError, e: - if e.args[0] != win32.ERROR_PIPE_CONNECTED: + # ERROR_NO_DATA can occur if a client has already connected, + # written data and then disconnected -- see Issue 14725. + if e.args[0] not in (win32.ERROR_PIPE_CONNECTED, + win32.ERROR_NO_DATA): raise return _multiprocessing.PipeConnection(handle) diff --git a/Lib/test/test_multiprocessing.py b/Lib/test/test_multiprocessing.py index eeb768f7d7a..0fe649799a3 100644 --- a/Lib/test/test_multiprocessing.py +++ b/Lib/test/test_multiprocessing.py @@ -1669,6 +1669,23 @@ class _TestListenerClient(BaseTestCase): self.assertEqual(conn.recv(), 'hello') p.join() l.close() + + def test_issue14725(self): + l = self.connection.Listener() + p = self.Process(target=self._test, args=(l.address,)) + p.daemon = True + p.start() + time.sleep(1) + # On Windows the client process should by now have connected, + # written data and closed the pipe handle by now. This causes + # ConnectNamdedPipe() to fail with ERROR_NO_DATA. See Issue + # 14725. + conn = l.accept() + self.assertEqual(conn.recv(), 'hello') + conn.close() + p.join() + l.close() + # # Test of sending connection and socket objects between processes # diff --git a/Modules/_multiprocessing/win32_functions.c b/Modules/_multiprocessing/win32_functions.c index 1666aa9132f..9425929469e 100644 --- a/Modules/_multiprocessing/win32_functions.c +++ b/Modules/_multiprocessing/win32_functions.c @@ -244,6 +244,7 @@ create_win32_namespace(void) Py_INCREF(&Win32Type); WIN32_CONSTANT(F_DWORD, ERROR_ALREADY_EXISTS); + WIN32_CONSTANT(F_DWORD, ERROR_NO_DATA); WIN32_CONSTANT(F_DWORD, ERROR_PIPE_BUSY); WIN32_CONSTANT(F_DWORD, ERROR_PIPE_CONNECTED); WIN32_CONSTANT(F_DWORD, ERROR_SEM_TIMEOUT);