diff --git a/IPython/html/base/zmqhandlers.py b/IPython/html/base/zmqhandlers.py
index d0b77a1..5635d53 100644
--- a/IPython/html/base/zmqhandlers.py
+++ b/IPython/html/base/zmqhandlers.py
@@ -224,8 +224,7 @@ class AuthenticatedZMQStreamHandler(ZMQStreamHandler, IPythonHandler):
def initialize(self):
self.session = Session(config=self.config)
- def open(self, kernel_id):
- self.kernel_id = cast_unicode(kernel_id, 'ascii')
+ def open(self, *args, **kwargs):
# start the pinging
if self.ping_interval > 0:
diff --git a/IPython/html/services/kernels/handlers.py b/IPython/html/services/kernels/handlers.py
index 6c5f2df..a233fee 100644
--- a/IPython/html/services/kernels/handlers.py
+++ b/IPython/html/services/kernels/handlers.py
@@ -5,10 +5,11 @@
import json
import logging
-from tornado import web
+from tornado import gen, web
+from tornado.concurrent import Future
from IPython.utils.jsonutil import date_default
-from IPython.utils.py3compat import string_types
+from IPython.utils.py3compat import cast_unicode
from IPython.html.utils import url_path_join, url_escape
from ...base.handlers import IPythonHandler, json_errors
@@ -91,17 +92,26 @@ class ZMQChannelHandler(AuthenticatedZMQStreamHandler):
km = self.kernel_manager
meth = getattr(km, 'connect_%s' % self.channel)
self.zmq_stream = meth(self.kernel_id, identity=self.session.bsession)
- # Create a kernel_info channel to query the kernel protocol version.
- # This channel will be closed after the kernel_info reply is received.
- self.kernel_info_channel = None
- self.kernel_info_channel = km.connect_shell(self.kernel_id)
- self.kernel_info_channel.on_recv(self._handle_kernel_info_reply)
- self._request_kernel_info()
- def _request_kernel_info(self):
+ def request_kernel_info(self):
"""send a request for kernel_info"""
- self.log.debug("requesting kernel info")
- self.session.send(self.kernel_info_channel, "kernel_info_request")
+ km = self.kernel_manager
+ kernel = km.get_kernel(self.kernel_id)
+ try:
+ # check for cached value
+ kernel_info = kernel._kernel_info
+ except AttributeError:
+ self.log.debug("Requesting kernel info from %s", self.kernel_id)
+ # Create a kernel_info channel to query the kernel protocol version.
+ # This channel will be closed after the kernel_info reply is received.
+ if self.kernel_info_channel is None:
+ self.kernel_info_channel = km.connect_shell(self.kernel_id)
+ self.kernel_info_channel.on_recv(self._handle_kernel_info_reply)
+ self.session.send(self.kernel_info_channel, "kernel_info_request")
+ else:
+ # use cached value, don't resend request
+ self._finish_kernel_info(kernel_info)
+ return self._kernel_info_future
def _handle_kernel_info_reply(self, msg):
"""process the kernel_info_reply
@@ -113,25 +123,49 @@ class ZMQChannelHandler(AuthenticatedZMQStreamHandler):
msg = self.session.deserialize(msg)
except:
self.log.error("Bad kernel_info reply", exc_info=True)
- self._request_kernel_info()
+ self.request_kernel_info()
return
else:
- if msg['msg_type'] != 'kernel_info_reply' or 'protocol_version' not in msg['content']:
- self.log.error("Kernel info request failed, assuming current %s", msg['content'])
+ info = msg['content']
+ self.log.debug("Received kernel info: %s", info)
+ if msg['msg_type'] != 'kernel_info_reply' or 'protocol_version' not in info:
+ self.log.error("Kernel info request failed, assuming current %s", info)
else:
- protocol_version = msg['content']['protocol_version']
- if protocol_version != kernel_protocol_version:
- self.session.adapt_version = int(protocol_version.split('.')[0])
- self.log.info("adapting kernel to %s" % protocol_version)
- self.kernel_info_channel.close()
+ kernel = self.kernel_manager.get_kernel(self.kernel_id)
+ kernel._kernel_info = info
+ self._finish_kernel_info(info)
+
+ # close the kernel_info channel, we don't need it anymore
+ if self.kernel_info_channel:
+ self.kernel_info_channel.close()
self.kernel_info_channel = None
+ def _finish_kernel_info(self, info):
+ """Finish handling kernel_info reply
+
+ Set up protocol adaptation, if needed,
+ and signal that connection can continue.
+ """
+ protocol_version = info.get('protocol_version', kernel_protocol_version)
+ if protocol_version != kernel_protocol_version:
+ self.session.adapt_version = int(protocol_version.split('.')[0])
+ self.log.info("Kernel %s speaks protocol %s", self.kernel_id, protocol_version)
+ self._kernel_info_future.set_result(info)
+
def initialize(self):
super(ZMQChannelHandler, self).initialize()
self.zmq_stream = None
+ self.kernel_info_channel = None
+ self._kernel_info_future = Future()
+
+ @gen.coroutine
+ def get(self, kernel_id):
+ self.kernel_id = cast_unicode(kernel_id, 'ascii')
+ yield self.request_kernel_info()
+ super(ZMQChannelHandler, self).get(kernel_id)
def open(self, kernel_id):
- super(ZMQChannelHandler, self).open(kernel_id)
+ super(ZMQChannelHandler, self).open()
try:
self.create_stream()
except web.HTTPError: