use Context.instance() for default in SessionFactory

IPython/parallel/factory.py

@@ -1,95 +1,99 b''
 """Base config factories."""
 
 #-----------------------------------------------------------------------------
 #  Copyright (C) 2008-2009  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-----------------------------------------------------------------------------
 
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
 
 
 import logging
 import os
 
+import zmq
 from zmq.eventloop.ioloop import IOLoop
 
 from IPython.config.configurable import Configurable
 from IPython.utils.traitlets import Int, Instance, Unicode
 
 import IPython.parallel.streamsession as ss
 from IPython.parallel.util import select_random_ports
 
 #-----------------------------------------------------------------------------
 # Classes
 #-----------------------------------------------------------------------------
 class LoggingFactory(Configurable):
     """A most basic class, that has a `log` (type:`Logger`) attribute, set via a `logname` Trait."""
     log = Instance('logging.Logger', ('ZMQ', logging.WARN))
     logname = Unicode('ZMQ')
     def _logname_changed(self, name, old, new):
         self.log = logging.getLogger(new)
     
 
 class SessionFactory(LoggingFactory):
     """The Base factory from which every factory in IPython.parallel inherits"""
     
     # not configurable:
-    context = Instance('zmq.Context', (), {})
+    context = Instance('zmq.Context')
+    def _context_default(self):
+        return zmq.Context.instance()
+    
     session = Instance('IPython.parallel.streamsession.StreamSession')
     loop = Instance('zmq.eventloop.ioloop.IOLoop', allow_none=False)
     def _loop_default(self):
         return IOLoop.instance()
     
     
     def __init__(self, **kwargs):
         super(SessionFactory, self).__init__(**kwargs)
         
         # construct the session
         self.session = ss.StreamSession(**kwargs)
     
 
 class RegistrationFactory(SessionFactory):
     """The Base Configurable for objects that involve registration."""
     
     url = Unicode('', config=True,
         help="""The 0MQ url used for registration. This sets transport, ip, and port
         in one variable. For example: url='tcp://127.0.0.1:12345' or
         url='epgm://*:90210'""") # url takes precedence over ip,regport,transport
     transport = Unicode('tcp', config=True,
         help="""The 0MQ transport for communications.  This will likely be
         the default of 'tcp', but other values include 'ipc', 'epgm', 'inproc'.""")
     ip = Unicode('127.0.0.1', config=True,
         help="""The IP address for registration.  This is generally either
         '127.0.0.1' for loopback only or '*' for all interfaces.
         [default: '127.0.0.1']""")
     regport = Int(config=True,
         help="""The port on which the Hub listens for registration.""")
     def _regport_default(self):
         return select_random_ports(1)[0]
     
     def __init__(self, **kwargs):
         super(RegistrationFactory, self).__init__(**kwargs)
         self._propagate_url()
         self._rebuild_url()
         self.on_trait_change(self._propagate_url, 'url')
         self.on_trait_change(self._rebuild_url, 'ip')
         self.on_trait_change(self._rebuild_url, 'transport')
         self.on_trait_change(self._rebuild_url, 'regport')
     
     def _rebuild_url(self):
         self.url = "%s://%s:%i"%(self.transport, self.ip, self.regport)
         
     def _propagate_url(self):
         """Ensure self.url contains full transport://interface:port"""
         if self.url:
             iface = self.url.split('://',1)
             if len(iface) == 2:
                 self.transport,iface = iface
             iface = iface.split(':')
             self.ip = iface[0]
             if iface[1]:
                 self.regport = int(iface[1])