add the multiprocessing package to fulfill PEP 371
diff --git a/Lib/multiprocessing/reduction.py b/Lib/multiprocessing/reduction.py
new file mode 100644
index 0000000..aa77075
--- /dev/null
+++ b/Lib/multiprocessing/reduction.py
@@ -0,0 +1,190 @@
+#
+# Module to allow connection and socket objects to be transferred
+# between processes
+#
+# multiprocessing/reduction.py
+#
+# Copyright (c) 2006-2008, R Oudkerk --- see COPYING.txt
+#
+
+__all__ = []
+
+import os
+import sys
+import socket
+import threading
+import copy_reg
+
+import _multiprocessing
+from multiprocessing import current_process
+from multiprocessing.forking import Popen, duplicate, close
+from multiprocessing.util import register_after_fork, debug, sub_debug
+from multiprocessing.connection import Client, Listener
+
+
+#
+#
+#
+
+if not(sys.platform == 'win32' or hasattr(_multiprocessing, 'recvfd')):
+ raise ImportError('pickling of connections not supported')
+
+#
+# Platform specific definitions
+#
+
+if sys.platform == 'win32':
+ import _subprocess
+ from ._multiprocessing import win32
+
+ def send_handle(conn, handle, destination_pid):
+ process_handle = win32.OpenProcess(
+ win32.PROCESS_ALL_ACCESS, False, destination_pid
+ )
+ try:
+ new_handle = duplicate(handle, process_handle)
+ conn.send(new_handle)
+ finally:
+ close(process_handle)
+
+ def recv_handle(conn):
+ return conn.recv()
+
+else:
+ def send_handle(conn, handle, destination_pid):
+ _multiprocessing.sendfd(conn.fileno(), handle)
+
+ def recv_handle(conn):
+ return _multiprocessing.recvfd(conn.fileno())
+
+#
+# Support for a per-process server thread which caches pickled handles
+#
+
+_cache = set()
+
+def _reset(obj):
+ global _lock, _listener, _cache
+ for h in _cache:
+ close(h)
+ _cache.clear()
+ _lock = threading.Lock()
+ _listener = None
+
+_reset(None)
+register_after_fork(_reset, _reset)
+
+def _get_listener():
+ global _listener
+
+ if _listener is None:
+ _lock.acquire()
+ try:
+ if _listener is None:
+ debug('starting listener and thread for sending handles')
+ _listener = Listener(authkey=current_process().get_authkey())
+ t = threading.Thread(target=_serve)
+ t.setDaemon(True)
+ t.start()
+ finally:
+ _lock.release()
+
+ return _listener
+
+def _serve():
+ from .util import is_exiting, sub_warning
+
+ while 1:
+ try:
+ conn = _listener.accept()
+ handle_wanted, destination_pid = conn.recv()
+ _cache.remove(handle_wanted)
+ send_handle(conn, handle_wanted, destination_pid)
+ close(handle_wanted)
+ conn.close()
+ except:
+ if not is_exiting():
+ import traceback
+ sub_warning(
+ 'thread for sharing handles raised exception :\n' +
+ '-'*79 + '\n' + traceback.format_exc() + '-'*79
+ )
+
+#
+# Functions to be used for pickling/unpickling objects with handles
+#
+
+def reduce_handle(handle):
+ if Popen.thread_is_spawning():
+ return (None, Popen.duplicate_for_child(handle), True)
+ dup_handle = duplicate(handle)
+ _cache.add(dup_handle)
+ sub_debug('reducing handle %d', handle)
+ return (_get_listener().address, dup_handle, False)
+
+def rebuild_handle(pickled_data):
+ address, handle, inherited = pickled_data
+ if inherited:
+ return handle
+ sub_debug('rebuilding handle %d', handle)
+ conn = Client(address, authkey=current_process().get_authkey())
+ conn.send((handle, os.getpid()))
+ new_handle = recv_handle(conn)
+ conn.close()
+ return new_handle
+
+#
+# Register `_multiprocessing.Connection` with `copy_reg`
+#
+
+def reduce_connection(conn):
+ rh = reduce_handle(conn.fileno())
+ return rebuild_connection, (rh, conn.readable, conn.writable)
+
+def rebuild_connection(reduced_handle, readable, writable):
+ handle = rebuild_handle(reduced_handle)
+ return _multiprocessing.Connection(
+ handle, readable=readable, writable=writable
+ )
+
+copy_reg.pickle(_multiprocessing.Connection, reduce_connection)
+
+#
+# Register `socket.socket` with `copy_reg`
+#
+
+def fromfd(fd, family, type_, proto=0):
+ s = socket.fromfd(fd, family, type_, proto)
+ if s.__class__ is not socket.socket:
+ s = socket.socket(_sock=s)
+ return s
+
+def reduce_socket(s):
+ reduced_handle = reduce_handle(s.fileno())
+ return rebuild_socket, (reduced_handle, s.family, s.type, s.proto)
+
+def rebuild_socket(reduced_handle, family, type_, proto):
+ fd = rebuild_handle(reduced_handle)
+ _sock = fromfd(fd, family, type_, proto)
+ close(fd)
+ return _sock
+
+copy_reg.pickle(socket.socket, reduce_socket)
+
+#
+# Register `_multiprocessing.PipeConnection` with `copy_reg`
+#
+
+if sys.platform == 'win32':
+
+ def reduce_pipe_connection(conn):
+ rh = reduce_handle(conn.fileno())
+ return rebuild_pipe_connection, (rh, conn.readable, conn.writable)
+
+ def rebuild_pipe_connection(reduced_handle, readable, writable):
+ handle = rebuild_handle(reduced_handle)
+ return _multiprocessing.PipeConnection(
+ handle, readable=readable, writable=writable
+ )
+
+ copy_reg.pickle(_multiprocessing.PipeConnection, reduce_pipe_connection)