Add custom initializer argument to multiprocess.Manager*, courtesy of lekma

2 files changed, 13 insertions, 3 deletions

diff --git a/Lib/multiprocessing/managers.py b/Lib/multiprocessing/managers.py
index 02e96b9..fde0e40 100644
--- a/Lib/multiprocessing/managers.py
+++ b/Lib/multiprocessing/managers.py
@@ -475,12 +475,15 @@ class BaseManager(object):
         dispatch(conn, None, 'dummy')
         self._state.value = State.STARTED
 
-    def start(self):
+    def start(self, initializer=None, initargs=()):
         '''
         Spawn a server process for this manager object
         '''
         assert self._state.value == State.INITIAL
 
+        if initializer is not None and not hasattr(initializer, '__call__'):
+            raise TypeError('initializer must be a callable')
+
         # pipe over which we will retrieve address of server
         reader, writer = connection.Pipe(duplex=False)
 
@@ -488,7 +491,7 @@ class BaseManager(object):
         self._process = Process(
             target=type(self)._run_server,
             args=(self._registry, self._address, self._authkey,
-                  self._serializer, writer),
+                  self._serializer, writer, initializer, initargs),
             )
         ident = ':'.join(str(i) for i in self._process._identity)
         self._process.name = type(self).__name__  + '-' + ident
@@ -509,10 +512,14 @@ class BaseManager(object):
             )
 
     @classmethod
-    def _run_server(cls, registry, address, authkey, serializer, writer):
+    def _run_server(cls, registry, address, authkey, serializer, writer,
+                    initializer=None, initargs=()):
         '''
         Create a server, report its address and run it
         '''
+        if initializer is not None:
+            initializer(*initargs)
+
         # create server
         server = cls._Server(registry, address, authkey, serializer)
 
diff --git a/Lib/multiprocessing/pool.py b/Lib/multiprocessing/pool.py
index 9da27d4..bc7e8f1 100644
--- a/Lib/multiprocessing/pool.py
+++ b/Lib/multiprocessing/pool.py
@@ -92,6 +92,9 @@ class Pool(object):
             except NotImplementedError:
                 processes = 1
 
+        if initializer is not None and not hasattr(initializer, '__call__'):
+            raise TypeError('initializer must be a callable')
+
         self._pool = []
         for i in range(processes):
             w = self.Process(