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

Lib/multiprocessing/context.py

@@ -3,6 +3,7 @@ import sys
 import threading
 
 from . import process
+from . import reduction
 
 __all__ = []            # things are copied from here to __init__.py
 
@@ -198,6 +199,16 @@ class BaseContext(object):
     def set_start_method(self, method=None):
         raise ValueError('cannot set start method of concrete context')
 
+    @property
+    def reducer(self):
+        '''Controls how objects will be reduced to a form that can be
+        shared with other processes.'''
+        return globals().get('reduction')
+
+    @reducer.setter
+    def reducer(self, reduction):
+        globals()['reduction'] = reduction
+
     def _check_available(self):
         pass
 
@@ -245,7 +256,6 @@ class DefaultContext(BaseContext):
         if sys.platform == 'win32':
             return ['spawn']
         else:
-            from . import reduction
             if reduction.HAVE_SEND_HANDLE:
                 return ['fork', 'spawn', 'forkserver']
             else:
@@ -292,7 +302,6 @@ if sys.platform != 'win32':
         _name = 'forkserver'
         Process = ForkServerProcess
         def _check_available(self):
-            from . import reduction
             if not reduction.HAVE_SEND_HANDLE:
                 raise ValueError('forkserver start method not available')