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.
diff --git a/Lib/multiprocessing/reduction.py b/Lib/multiprocessing/reduction.py
index 84d2fe9..656fa8f 100644
--- a/Lib/multiprocessing/reduction.py
+++ b/Lib/multiprocessing/reduction.py
@@ -120,16 +120,24 @@
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 57252a7..b70783a 100644
--- a/Lib/test/test_multiprocessing.py
+++ b/Lib/test/test_multiprocessing.py
@@ -2446,8 +2446,6 @@
# 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):