allow connect_multiprocess() and connect_thread() to pickle

Nested Function fails pickle

  File "C:\Python\lib\site-packages\rpyc-4.1.5-py3.8.egg\rpyc\utils\factory.py", line 327, in connect_multiprocess
    t.start()
  File "C:\Python\lib\multiprocessing\process.py", line 121, in start
    self._popen = self._Popen(self)
  File "C:\Python\lib\multiprocessing\context.py", line 224, in _Popen
    return _default_context.get_context().Process._Popen(process_obj)
  File "C:\Python\lib\multiprocessing\context.py", line 327, in _Popen
    return Popen(process_obj)
  File "C:\Python\lib\multiprocessing\popen_spawn_win32.py", line 93, in __init__
    reduction.dump(process_obj, to_child)
  File "C:\Python\lib\multiprocessing\reduction.py", line 60, in dump
    ForkingPickler(file, protocol).dump(obj)
AttributeError: Can't pickle local object 'connect_multiprocess.<locals>.server'

rpyc/utils/factory.py

@@ -264,6 +264,32 @@ def connect_subproc(args, service=VoidService, config={}):
     return conn
 
 
+# callable, picklable functor
+# was un-pickleable nested function
+class _ServerFunctor:
+    """Functor for use in connect calls"""
+
+    def __init__(self, listener, service, config, args=None):
+        """ Holds functor inputs """
+        self.listener = listener
+        self.service = service
+        self.config = config
+        self.args = args
+
+    def __call__(self):
+        """ connects to process/socket """
+        with closing(self.listener):
+            client = self.listener.accept()[0]
+        conn = connect_stream(SocketStream(client), service=self.service, config=self.config)
+        try:
+            if self.args is not None:
+                for k in self.args:
+                    conn._local_root.exposed_namespace[k] = self.args[k]
+            conn.serve_all()
+        except KeyboardInterrupt:
+            interrupt_main()
+
+
 def connect_thread(service=VoidService, config={}, remote_service=VoidService, remote_config={}):
     """starts an rpyc server on a new thread, bound to an arbitrary port,
     and connects to it over a socket.
@@ -277,17 +303,7 @@ def connect_thread(service=VoidService, config={}, remote_service=VoidService, r
     listener.bind(("localhost", 0))
     listener.listen(1)
 
-    def server(listener=listener):
-        with closing(listener):
-            client = listener.accept()[0]
-        conn = connect_stream(SocketStream(client), service=remote_service,
-                              config=remote_config)
-        try:
-            conn.serve_all()
-        except KeyboardInterrupt:
-            interrupt_main()
-
-    spawn(server)
+    spawn(_ServerFunctor(listener, remote_service, remote_config))
     host, port = listener.getsockname()
     return connect(host, port, service=service, config=config)
 
@@ -312,18 +328,7 @@ def connect_multiprocess(service=VoidService, config={}, remote_service=VoidServ
     listener.bind(("localhost", 0))
     listener.listen(1)
 
-    def server(listener=listener, args=args):
-        with closing(listener):
-            client = listener.accept()[0]
-        conn = connect_stream(SocketStream(client), service=remote_service, config=remote_config)
-        try:
-            for k in args:
-                conn._local_root.exposed_namespace[k] = args[k]
-            conn.serve_all()
-        except KeyboardInterrupt:
-            interrupt_main()
-
-    t = Process(target=server)
+    t = Process(target=_ServerFunctor(listener, remote_service, remote_config, args))
     t.start()
     host, port = listener.getsockname()
     return connect(host, port, service=service, config=config)