diff --git a/Lib/multiprocessing/reduction.py b/Lib/multiprocessing/reduction.py index 84d2fe9ab21..656fa8ff6b0 100644 --- a/Lib/multiprocessing/reduction.py +++ b/Lib/multiprocessing/reduction.py @@ -120,16 +120,24 @@ if sys.platform == 'win32': else: # Unix + + # On MacOSX we should acknowledge receipt of fds -- see Issue14669 + ACKNOWLEDGE = sys.platform == 'darwin' + def send_handle(conn, handle, destination_pid): with socket.fromfd(conn.fileno(), socket.AF_UNIX, socket.SOCK_STREAM) as s: s.sendmsg([b'x'], [(socket.SOL_SOCKET, socket.SCM_RIGHTS, struct.pack("@i", handle))]) + if ACKNOWLEDGE and conn.recv_bytes() != b'ACK': + raise RuntimeError('did not receive acknowledgement of fd') def recv_handle(conn): size = struct.calcsize("@i") with socket.fromfd(conn.fileno(), socket.AF_UNIX, socket.SOCK_STREAM) as s: msg, ancdata, flags, addr = s.recvmsg(1, socket.CMSG_LEN(size)) try: + if ACKNOWLEDGE: + conn.send_bytes(b'ACK') cmsg_level, cmsg_type, cmsg_data = ancdata[0] if (cmsg_level == socket.SOL_SOCKET and cmsg_type == socket.SCM_RIGHTS): diff --git a/Lib/test/test_multiprocessing.py b/Lib/test/test_multiprocessing.py index 57252a7fb08..b70783a1919 100644 --- a/Lib/test/test_multiprocessing.py +++ b/Lib/test/test_multiprocessing.py @@ -2446,8 +2446,6 @@ class _TestPoll(unittest.TestCase): # Test of sending connection and socket objects between processes # -# Intermittent fails on Mac OS X -- see Issue14669 and Issue12958 -@unittest.skipIf(sys.platform == "darwin", "fd passing unreliable on Mac OS X") @unittest.skipUnless(HAS_REDUCTION, "test needs multiprocessing.reduction") class _TestPicklingConnections(BaseTestCase): diff --git a/Misc/NEWS b/Misc/NEWS index a3965c73002..55f99a704a2 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -16,6 +16,10 @@ Core and Builtins Library ------- +- Issue #14669: Fix pickling of connections and sockets on MacOSX + by sending/receiving an acknowledgment after file descriptor transfer. + TestPicklingConnection has been reenabled for MacOSX. + - Issue #11062: Fix adding a message from file to Babyl mailbox. - Issue #15646: Prevent equivalent of a fork bomb when using