Issue #12981: rewrite multiprocessing_{sendfd,recvfd} in Python.
diff --git a/Lib/multiprocessing/reduction.py b/Lib/multiprocessing/reduction.py
index b32c725..042a136 100644
--- a/Lib/multiprocessing/reduction.py
+++ b/Lib/multiprocessing/reduction.py
@@ -39,6 +39,7 @@
import sys
import socket
import threading
+import struct
import _multiprocessing
from multiprocessing import current_process
@@ -51,7 +52,8 @@
#
#
-if not(sys.platform == 'win32' or hasattr(_multiprocessing, 'recvfd')):
+if not(sys.platform == 'win32' or (hasattr(socket, 'CMSG_LEN') and
+ hasattr(socket, 'SCM_RIGHTS'))):
raise ImportError('pickling of connections not supported')
#
@@ -77,10 +79,23 @@
else:
def send_handle(conn, handle, destination_pid):
- _multiprocessing.sendfd(conn.fileno(), handle)
+ 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))])
def recv_handle(conn):
- return _multiprocessing.recvfd(conn.fileno())
+ 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:
+ cmsg_level, cmsg_type, cmsg_data = ancdata[0]
+ if (cmsg_level == socket.SOL_SOCKET and
+ cmsg_type == socket.SCM_RIGHTS):
+ return struct.unpack("@i", cmsg_data[:size])[0]
+ except (ValueError, IndexError, struct.error):
+ pass
+ raise RuntimeError('Invalid data received')
+
#
# Support for a per-process server thread which caches pickled handles