Issue #28053: Applying refactorings, docs and other cleanup to follow.

Lib/multiprocessing/reduction.py

@@ -7,6 +7,7 @@
 # Licensed to PSF under a Contributor Agreement.
 #
 
+from abc import ABCMeta, abstractmethod
 import copyreg
 import functools
 import io
@@ -238,3 +239,36 @@ else:
         fd = df.detach()
         return socket.socket(family, type, proto, fileno=fd)
     register(socket.socket, _reduce_socket)
+
+
+class AbstractReducer(metaclass=ABCMeta):
+    '''Abstract base class for use in implementing a Reduction class
+    suitable for use in replacing the standard reduction mechanism
+    used in multiprocessing.'''
+    ForkingPickler = ForkingPickler
+    register = register
+    dump = dump
+    send_handle = send_handle
+    recv_handle = recv_handle
+
+    if sys.platform == 'win32':
+        steal_handle = steal_handle
+        duplicate = duplicate
+        DupHandle = DupHandle
+    else:
+        sendfds = sendfds
+        recvfds = recvfds
+        DupFd = DupFd
+
+    _reduce_method = _reduce_method
+    _reduce_method_descriptor = _reduce_method_descriptor
+    _rebuild_partial = _rebuild_partial
+    _reduce_socket = _reduce_socket
+    _rebuild_socket = _rebuild_socket
+
+    def __init__(self, *args):
+        register(type(_C().f), _reduce_method)
+        register(type(list.append), _reduce_method_descriptor)
+        register(type(int.__add__), _reduce_method_descriptor)
+        register(functools.partial, _reduce_partial)
+        register(socket.socket, _reduce_socket)