Move kernel_info for adaptation onto KernelClient

IPython/kernel/blocking/channels.py

@@ -1,192 +1,174 b''
 """Blocking channels
 
 Useful for test suites and blocking terminal interfaces.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 try:
     from queue import Queue, Empty  # Py 3
 except ImportError:
     from Queue import Queue, Empty  # Py 2
 
 from IPython.kernel.channelsabc import ShellChannelABC, IOPubChannelABC, \
     StdInChannelABC
 from IPython.kernel.channels import  HBChannel,\
     make_iopub_socket, make_shell_socket, make_stdin_socket,\
     InvalidPortNumber, major_protocol_version
 from IPython.utils.py3compat import string_types, iteritems
 
 # some utilities to validate message structure, these might get moved elsewhere
 # if they prove to have more generic utility
 
 def validate_string_list(lst):
     """Validate that the input is a list of strings.
 
     Raises ValueError if not."""
     if not isinstance(lst, list):
         raise ValueError('input %r must be a list' % lst)
     for x in lst:
         if not isinstance(x, string_types):
             raise ValueError('element %r in list must be a string' % x)
 
 
 def validate_string_dict(dct):
     """Validate that the input is a dict with string keys and values.
 
     Raises ValueError if not."""
     for k,v in iteritems(dct):
         if not isinstance(k, string_types):
             raise ValueError('key %r in dict must be a string' % k)
         if not isinstance(v, string_types):
             raise ValueError('value %r in dict must be a string' % v)
 
 
 class ZMQSocketChannel(object):
     """The base class for the channels that use ZMQ sockets."""
     context = None
     session = None
     socket = None
     ioloop = None
     stream = None
     _address = None
     _exiting = False
     proxy_methods = []
 
     def __init__(self, context, session, address):
         """Create a channel.
 
         Parameters
         ----------
         context : :class:`zmq.Context`
             The ZMQ context to use.
         session : :class:`session.Session`
             The session to use.
         address : zmq url
             Standard (ip, port) tuple that the kernel is listening on.
         """
         super(ZMQSocketChannel, self).__init__()
         self.daemon = True
 
         self.context = context
         self.session = session
         if isinstance(address, tuple):
             if address[1] == 0:
                 message = 'The port number for a channel cannot be 0.'
                 raise InvalidPortNumber(message)
             address = "tcp://%s:%i" % address
         self._address = address
 
     def _recv(self, **kwargs):
         msg = self.socket.recv_multipart(**kwargs)
         ident,smsg = self.session.feed_identities(msg)
         return self.session.deserialize(smsg)
 
     def get_msg(self, block=True, timeout=None):
         """ Gets a message if there is one that is ready. """
         if block:
             if timeout is not None:
                 timeout *= 1000  # seconds to ms
             ready = self.socket.poll(timeout)
         else:
             ready = self.socket.poll(timeout=0)
 
         if ready:
             return self._recv()
         else:
             raise Empty
 
     def get_msgs(self):
         """ Get all messages that are currently ready. """
         msgs = []
         while True:
             try:
                 msgs.append(self.get_msg(block=False))
             except Empty:
                 break
         return msgs
 
     def msg_ready(self):
         """ Is there a message that has been received? """
         return bool(self.socket.poll(timeout=0))
 
     def close(self):
         if self.socket is not None:
             try:
                 self.socket.close(linger=0)
             except Exception:
                 pass
             self.socket = None
     stop =  close
 
     def is_alive(self):
         return (self.socket is not None)
 
     @property
     def address(self):
         """Get the channel's address as a zmq url string.
 
         These URLS have the form: 'tcp://127.0.0.1:5555'.
         """
         return self._address
 
     def _queue_send(self, msg):
         """Pass a message to the ZMQ socket to send
         """
         self.session.send(self.socket, msg)
 
 
 class BlockingShellChannel(ZMQSocketChannel):
     """The shell channel for issuing request/replies to the kernel."""
 
     def start(self):
         self.socket = make_stdin_socket(self.context, self.session.bsession, self.address)
 
-    def _handle_kernel_info_reply(self, msg):
-        """handle kernel info reply
-
-        sets protocol adaptation version
-        """
-        adapt_version = int(msg['content']['protocol_version'].split('.')[0])
-        if adapt_version != major_protocol_version:
-            self.session.adapt_version = adapt_version
-
-    def _recv(self, **kwargs):
-        # Listen for kernel_info_reply message to do protocol adaptation
-        msg = ZMQSocketChannel._recv(self, **kwargs)
-        if msg['msg_type'] == 'kernel_info_reply':
-            self._handle_kernel_info_reply(msg)
-        return msg
 
 class BlockingIOPubChannel(ZMQSocketChannel):
     """The iopub channel which listens for messages that the kernel publishes.
 
     This channel is where all output is published to frontends.
     """
     def start(self):
         self.socket = make_iopub_socket(self.context, self.session.bsession, self.address)
 
 class BlockingStdInChannel(ZMQSocketChannel):
     """The stdin channel to handle raw_input requests that the kernel makes."""
-    msg_queue = None
-    proxy_methods = ['input']
-
     def start(self):
         self.socket = make_stdin_socket(self.context, self.session.bsession, self.address)
 
 ShellChannelABC.register(BlockingShellChannel)
 IOPubChannelABC.register(BlockingIOPubChannel)
 StdInChannelABC.register(BlockingStdInChannel)
 
 
 class BlockingHBChannel(HBChannel):
 
     # This kernel needs quicker monitoring, shorten to 1 sec.
     # less than 0.5s is unreliable, and will get occasional
     # false reports of missed beats.
     time_to_dead = 1.
 
     def call_handlers(self, since_last_heartbeat):
         """ Pause beating on missed heartbeat. """
         pass

IPython/kernel/blocking/client.py

@@ -1,33 +1,41 b''
 """Implements a fully blocking kernel client.
 
 Useful for test suites and blocking terminal interfaces.
 """
-#-----------------------------------------------------------------------------
-#  Copyright (C) 2013 The IPython Development Team
-#
-#  Distributed under the terms of the BSD License.  The full license is in
-#  the file COPYING.txt, distributed as part of this software.
-#-----------------------------------------------------------------------------
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
 
-#-----------------------------------------------------------------------------
-# Imports
-#-----------------------------------------------------------------------------
+try:
+    from queue import Empty  # Python 3
+except ImportError:
+    from Queue import Empty  # Python 2
 
 from IPython.utils.traitlets import Type
 from IPython.kernel.client import KernelClient
 from .channels import (
     BlockingIOPubChannel, BlockingHBChannel,
     BlockingShellChannel, BlockingStdInChannel
 )
 
-#-----------------------------------------------------------------------------
-# Blocking kernel manager
-#-----------------------------------------------------------------------------
-
 class BlockingKernelClient(KernelClient):
+    def wait_for_ready(self):
+        # Wait for kernel info reply on shell channel
+        while True:
+            msg = self.shell_channel.get_msg(block=True)
+            if msg['msg_type'] == 'kernel_info_reply':
+                self._handle_kernel_info_reply(msg)
+                break
+
+        # Flush IOPub channel
+        while True:
+            try:
+                msg = self.iopub_channel.get_msg(block=True, timeout=0.2)
+                print(msg['msg_type'])
+            except Empty:
+                break
 
     # The classes to use for the various channels
     shell_channel_class = Type(BlockingShellChannel)
     iopub_channel_class = Type(BlockingIOPubChannel)
     stdin_channel_class = Type(BlockingStdInChannel)
     hb_channel_class = Type(BlockingHBChannel)

IPython/kernel/client.py

@@ -1,359 +1,369 b''
 """Base class to manage the interaction with a running kernel"""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import absolute_import
-from IPython.kernel.channels import validate_string_dict
+from IPython.kernel.channels import validate_string_dict, major_protocol_version
 from IPython.utils.py3compat import string_types
 
 import zmq
 
 from IPython.utils.traitlets import (
     Any, Instance, Type,
 )
 
 from .channelsabc import (
     ShellChannelABC, IOPubChannelABC, HBChannelABC, StdInChannelABC
 )
 from .clientabc import KernelClientABC
 from .connect import ConnectionFileMixin
 
 
 class KernelClient(ConnectionFileMixin):
     """Communicates with a single kernel on any host via zmq channels.
 
     There are four channels associated with each kernel:
 
     * shell: for request/reply calls to the kernel.
     * iopub: for the kernel to publish results to frontends.
     * hb: for monitoring the kernel's heartbeat.
     * stdin: for frontends to reply to raw_input calls in the kernel.
 
     The methods of the channels are exposed as methods of the client itself
     (KernelClient.execute, complete, history, etc.).
     See the channels themselves for documentation of these methods.
 
     """
 
     # The PyZMQ Context to use for communication with the kernel.
     context = Instance(zmq.Context)
     def _context_default(self):
         return zmq.Context.instance()
 
     # The classes to use for the various channels
     shell_channel_class = Type(ShellChannelABC)
     iopub_channel_class = Type(IOPubChannelABC)
     stdin_channel_class = Type(StdInChannelABC)
     hb_channel_class = Type(HBChannelABC)
 
     # Protected traits
     _shell_channel = Any
     _iopub_channel = Any
     _stdin_channel = Any
     _hb_channel = Any
 
     # flag for whether execute requests should be allowed to call raw_input:
     allow_stdin = True
 
     #--------------------------------------------------------------------------
     # Channel proxy methods
     #--------------------------------------------------------------------------
 
     def _get_msg(channel, *args, **kwargs):
         return channel.get_msg(*args, **kwargs)
 
     def get_shell_msg(self, *args, **kwargs):
         """Get a message from the shell channel"""
         return self.shell_channel.get_msg(*args, **kwargs)
 
     def get_iopub_msg(self, *args, **kwargs):
         """Get a message from the iopub channel"""
         return self.iopub_channel.get_msg(*args, **kwargs)
 
     def get_stdin_msg(self, *args, **kwargs):
         """Get a message from the stdin channel"""
         return self.stdin_channel.get_msg(*args, **kwargs)
 
     #--------------------------------------------------------------------------
     # Channel management methods
     #--------------------------------------------------------------------------
 
     def start_channels(self, shell=True, iopub=True, stdin=True, hb=True):
         """Starts the channels for this kernel.
 
         This will create the channels if they do not exist and then start
         them (their activity runs in a thread). If port numbers of 0 are
         being used (random ports) then you must first call
         :meth:`start_kernel`. If the channels have been stopped and you
         call this, :class:`RuntimeError` will be raised.
         """
         if shell:
             self.shell_channel.start()
+            self.kernel_info()
         if iopub:
             self.iopub_channel.start()
         if stdin:
             self.stdin_channel.start()
             self.allow_stdin = True
         else:
             self.allow_stdin = False
         if hb:
             self.hb_channel.start()
 
     def stop_channels(self):
         """Stops all the running channels for this kernel.
 
         This stops their event loops and joins their threads.
         """
         if self.shell_channel.is_alive():
             self.shell_channel.stop()
         if self.iopub_channel.is_alive():
             self.iopub_channel.stop()
         if self.stdin_channel.is_alive():
             self.stdin_channel.stop()
         if self.hb_channel.is_alive():
             self.hb_channel.stop()
 
     @property
     def channels_running(self):
         """Are any of the channels created and running?"""
         return (self.shell_channel.is_alive() or self.iopub_channel.is_alive() or
                 self.stdin_channel.is_alive() or self.hb_channel.is_alive())
 
     @property
     def shell_channel(self):
         """Get the shell channel object for this kernel."""
         if self._shell_channel is None:
             url = self._make_url('shell')
             self.log.debug("connecting shell channel to %s", url)
             self._shell_channel = self.shell_channel_class(
                 self.context, self.session, url
             )
         return self._shell_channel
 
     @property
     def iopub_channel(self):
         """Get the iopub channel object for this kernel."""
         if self._iopub_channel is None:
             url = self._make_url('iopub')
             self.log.debug("connecting iopub channel to %s", url)
             self._iopub_channel = self.iopub_channel_class(
                 self.context, self.session, url
             )
         return self._iopub_channel
 
     @property
     def stdin_channel(self):
         """Get the stdin channel object for this kernel."""
         if self._stdin_channel is None:
             url = self._make_url('stdin')
             self.log.debug("connecting stdin channel to %s", url)
             self._stdin_channel = self.stdin_channel_class(
                 self.context, self.session, url
             )
         return self._stdin_channel
 
     @property
     def hb_channel(self):
         """Get the hb channel object for this kernel."""
         if self._hb_channel is None:
             url = self._make_url('hb')
             self.log.debug("connecting heartbeat channel to %s", url)
             self._hb_channel = self.hb_channel_class(
                 self.context, self.session, url
             )
         return self._hb_channel
 
     def is_alive(self):
         """Is the kernel process still running?"""
         if self._hb_channel is not None:
             # We didn't start the kernel with this KernelManager so we
             # use the heartbeat.
             return self._hb_channel.is_beating()
         else:
             # no heartbeat and not local, we can't tell if it's running,
             # so naively return True
             return True
 
 
     # Methods to send specific messages on channels
     def execute(self, code, silent=False, store_history=True,
                 user_expressions=None, allow_stdin=None):
         """Execute code in the kernel.
 
         Parameters
         ----------
         code : str
             A string of Python code.
 
         silent : bool, optional (default False)
             If set, the kernel will execute the code as quietly possible, and
             will force store_history to be False.
 
         store_history : bool, optional (default True)
             If set, the kernel will store command history.  This is forced
             to be False if silent is True.
 
         user_expressions : dict, optional
             A dict mapping names to expressions to be evaluated in the user's
             dict. The expression values are returned as strings formatted using
             :func:`repr`.
 
         allow_stdin : bool, optional (default self.allow_stdin)
             Flag for whether the kernel can send stdin requests to frontends.
 
             Some frontends (e.g. the Notebook) do not support stdin requests.
             If raw_input is called from code executed from such a frontend, a
             StdinNotImplementedError will be raised.
 
         Returns
         -------
         The msg_id of the message sent.
         """
         if user_expressions is None:
             user_expressions = {}
         if allow_stdin is None:
             allow_stdin = self.allow_stdin
 
 
         # Don't waste network traffic if inputs are invalid
         if not isinstance(code, string_types):
             raise ValueError('code %r must be a string' % code)
         validate_string_dict(user_expressions)
 
         # Create class for content/msg creation. Related to, but possibly
         # not in Session.
         content = dict(code=code, silent=silent, store_history=store_history,
                        user_expressions=user_expressions,
                        allow_stdin=allow_stdin,
                        )
         msg = self.session.msg('execute_request', content)
         self.shell_channel._queue_send(msg)
         return msg['header']['msg_id']
 
     def complete(self, code, cursor_pos=None):
         """Tab complete text in the kernel's namespace.
 
         Parameters
         ----------
         code : str
             The context in which completion is requested.
             Can be anything between a variable name and an entire cell.
         cursor_pos : int, optional
             The position of the cursor in the block of code where the completion was requested.
             Default: ``len(code)``
 
         Returns
         -------
         The msg_id of the message sent.
         """
         if cursor_pos is None:
             cursor_pos = len(code)
         content = dict(code=code, cursor_pos=cursor_pos)
         msg = self.session.msg('complete_request', content)
         self.shell_channel._queue_send(msg)
         return msg['header']['msg_id']
 
     def inspect(self, code, cursor_pos=None, detail_level=0):
         """Get metadata information about an object in the kernel's namespace.
 
         It is up to the kernel to determine the appropriate object to inspect.
 
         Parameters
         ----------
         code : str
             The context in which info is requested.
             Can be anything between a variable name and an entire cell.
         cursor_pos : int, optional
             The position of the cursor in the block of code where the info was requested.
             Default: ``len(code)``
         detail_level : int, optional
             The level of detail for the introspection (0-2)
 
         Returns
         -------
         The msg_id of the message sent.
         """
         if cursor_pos is None:
             cursor_pos = len(code)
         content = dict(code=code, cursor_pos=cursor_pos,
             detail_level=detail_level,
         )
         msg = self.session.msg('inspect_request', content)
         self.shell_channel._queue_send(msg)
         return msg['header']['msg_id']
 
     def history(self, raw=True, output=False, hist_access_type='range', **kwargs):
         """Get entries from the kernel's history list.
 
         Parameters
         ----------
         raw : bool
             If True, return the raw input.
         output : bool
             If True, then return the output as well.
         hist_access_type : str
             'range' (fill in session, start and stop params), 'tail' (fill in n)
              or 'search' (fill in pattern param).
 
         session : int
             For a range request, the session from which to get lines. Session
             numbers are positive integers; negative ones count back from the
             current session.
         start : int
             The first line number of a history range.
         stop : int
             The final (excluded) line number of a history range.
 
         n : int
             The number of lines of history to get for a tail request.
 
         pattern : str
             The glob-syntax pattern for a search request.
 
         Returns
         -------
         The msg_id of the message sent.
         """
         content = dict(raw=raw, output=output, hist_access_type=hist_access_type,
                                                                     **kwargs)
         msg = self.session.msg('history_request', content)
         self.shell_channel._queue_send(msg)
         return msg['header']['msg_id']
 
     def kernel_info(self):
         """Request kernel info."""
         msg = self.session.msg('kernel_info_request')
         self.shell_channel._queue_send(msg)
         return msg['header']['msg_id']
 
+    def _handle_kernel_info_reply(self, msg):
+        """handle kernel info reply
+
+        sets protocol adaptation version
+        """
+        adapt_version = int(msg['content']['protocol_version'].split('.')[0])
+        if adapt_version != major_protocol_version:
+            self.session.adapt_version = adapt_version
+
     def shutdown(self, restart=False):
         """Request an immediate kernel shutdown.
 
         Upon receipt of the (empty) reply, client code can safely assume that
         the kernel has shut down and it's safe to forcefully terminate it if
         it's still alive.
 
         The kernel will send the reply via a function registered with Python's
         atexit module, ensuring it's truly done as the kernel is done with all
         normal operation.
         """
         # Send quit message to kernel. Once we implement kernel-side setattr,
         # this should probably be done that way, but for now this will do.
         msg = self.session.msg('shutdown_request', {'restart':restart})
         self.shell_channel._queue_send(msg)
         return msg['header']['msg_id']
 
     def is_complete(self, code):
         msg = self.session.msg('is_complete_request', {'code': code})
         self.shell_channel._queue_send(msg)
         return msg['header']['msg_id']
 
     def input(self, string):
         """Send a string of raw input to the kernel."""
         content = dict(value=string)
         msg = self.session.msg('input_reply', content)
         self.stdin_channel._queue_send(msg)
 
 
 KernelClientABC.register(KernelClient)

IPython/kernel/manager.py

@@ -1,452 +1,443 b''
 """Base class to manage a running kernel"""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import absolute_import
 
 from contextlib import contextmanager
 import os
 import re
 import signal
 import sys
 import time
 import warnings
 try:
     from queue import Empty  # Py 3
 except ImportError:
     from Queue import Empty  # Py 2
 
 import zmq
 
 from IPython.utils.importstring import import_item
 from IPython.utils.localinterfaces import is_local_ip, local_ips
 from IPython.utils.path import get_ipython_dir
 from IPython.utils.traitlets import (
     Any, Instance, Unicode, List, Bool, Type, DottedObjectName
 )
 from IPython.kernel import (
     launch_kernel,
     kernelspec,
 )
 from .connect import ConnectionFileMixin
 from .zmq.session import Session
 from .managerabc import (
     KernelManagerABC
 )
 
 
 class KernelManager(ConnectionFileMixin):
     """Manages a single kernel in a subprocess on this host.
 
     This version starts kernels with Popen.
     """
 
     # The PyZMQ Context to use for communication with the kernel.
     context = Instance(zmq.Context)
     def _context_default(self):
         return zmq.Context.instance()
 
     # the class to create with our `client` method
     client_class = DottedObjectName('IPython.kernel.blocking.BlockingKernelClient')
     client_factory = Type()
     def _client_class_changed(self, name, old, new):
         self.client_factory = import_item(str(new))
 
     # The kernel process with which the KernelManager is communicating.
     # generally a Popen instance
     kernel = Any()
     
     kernel_spec_manager = Instance(kernelspec.KernelSpecManager)
     
     def _kernel_spec_manager_default(self):
         return kernelspec.KernelSpecManager(ipython_dir=self.ipython_dir)
     
     kernel_name = Unicode(kernelspec.NATIVE_KERNEL_NAME)
     
     kernel_spec = Instance(kernelspec.KernelSpec)
     
     def _kernel_spec_default(self):
         return self.kernel_spec_manager.get_kernel_spec(self.kernel_name)
     
     def _kernel_name_changed(self, name, old, new):
         if new == 'python':
             self.kernel_name = kernelspec.NATIVE_KERNEL_NAME
             # This triggered another run of this function, so we can exit now
             return
         self.kernel_spec = self.kernel_spec_manager.get_kernel_spec(new)
         self.ipython_kernel = new in {'python', 'python2', 'python3'}
 
     kernel_cmd = List(Unicode, config=True,
         help="""DEPRECATED: Use kernel_name instead.
         
         The Popen Command to launch the kernel.
         Override this if you have a custom kernel.
         If kernel_cmd is specified in a configuration file,
         IPython does not pass any arguments to the kernel,
         because it cannot make any assumptions about the 
         arguments that the kernel understands. In particular,
         this means that the kernel does not receive the
         option --debug if it given on the IPython command line.
         """
     )
 
     def _kernel_cmd_changed(self, name, old, new):
         warnings.warn("Setting kernel_cmd is deprecated, use kernel_spec to "
                       "start different kernels.")
         self.ipython_kernel = False
 
     ipython_kernel = Bool(True)
     
     ipython_dir = Unicode()
     def _ipython_dir_default(self):
         return get_ipython_dir()
 
     # Protected traits
     _launch_args = Any()
     _control_socket = Any()
 
     _restarter = Any()
 
     autorestart = Bool(False, config=True,
         help="""Should we autorestart the kernel if it dies."""
     )
 
     def __del__(self):
         self._close_control_socket()
         self.cleanup_connection_file()
 
     #--------------------------------------------------------------------------
     # Kernel restarter
     #--------------------------------------------------------------------------
 
     def start_restarter(self):
         pass
 
     def stop_restarter(self):
         pass
 
     def add_restart_callback(self, callback, event='restart'):
         """register a callback to be called when a kernel is restarted"""
         if self._restarter is None:
             return
         self._restarter.add_callback(callback, event)
 
     def remove_restart_callback(self, callback, event='restart'):
         """unregister a callback to be called when a kernel is restarted"""
         if self._restarter is None:
             return
         self._restarter.remove_callback(callback, event)
 
     #--------------------------------------------------------------------------
     # create a Client connected to our Kernel
     #--------------------------------------------------------------------------
 
     def client(self, **kwargs):
         """Create a client configured to connect to our kernel"""
         if self.client_factory is None:
             self.client_factory = import_item(self.client_class)
 
         kw = {}
         kw.update(self.get_connection_info())
         kw.update(dict(
             connection_file=self.connection_file,
             session=self.session,
             parent=self,
         ))
 
         # add kwargs last, for manual overrides
         kw.update(kwargs)
         return self.client_factory(**kw)
 
     #--------------------------------------------------------------------------
     # Kernel management
     #--------------------------------------------------------------------------
 
     def format_kernel_cmd(self, extra_arguments=None):
         """replace templated args (e.g. {connection_file})"""
         extra_arguments = extra_arguments or []
         if self.kernel_cmd:
             cmd = self.kernel_cmd + extra_arguments
         else:
             cmd = self.kernel_spec.argv + extra_arguments
 
         ns = dict(connection_file=self.connection_file)
         ns.update(self._launch_args)
         
         pat = re.compile(r'\{([A-Za-z0-9_]+)\}')
         def from_ns(match):
             """Get the key out of ns if it's there, otherwise no change."""
             return ns.get(match.group(1), match.group())
         
         return [ pat.sub(from_ns, arg) for arg in cmd ]
 
     def _launch_kernel(self, kernel_cmd, **kw):
         """actually launch the kernel
 
         override in a subclass to launch kernel subprocesses differently
         """
         return launch_kernel(kernel_cmd, **kw)
 
     # Control socket used for polite kernel shutdown
 
     def _connect_control_socket(self):
         if self._control_socket is None:
             self._control_socket = self.connect_control()
             self._control_socket.linger = 100
 
     def _close_control_socket(self):
         if self._control_socket is None:
             return
         self._control_socket.close()
         self._control_socket = None
 
     def start_kernel(self, **kw):
         """Starts a kernel on this host in a separate process.
 
         If random ports (port=0) are being used, this method must be called
         before the channels are created.
 
         Parameters
         ----------
         **kw : optional
              keyword arguments that are passed down to build the kernel_cmd
              and launching the kernel (e.g. Popen kwargs).
         """
         if self.transport == 'tcp' and not is_local_ip(self.ip):
             raise RuntimeError("Can only launch a kernel on a local interface. "
                                "Make sure that the '*_address' attributes are "
                                "configured properly. "
                                "Currently valid addresses are: %s" % local_ips()
                                )
 
         # write connection file / get default ports
         self.write_connection_file()
 
         # save kwargs for use in restart
         self._launch_args = kw.copy()
         # build the Popen cmd
         extra_arguments = kw.pop('extra_arguments', [])
         kernel_cmd = self.format_kernel_cmd(extra_arguments=extra_arguments)
         if self.kernel_cmd:
             # If kernel_cmd has been set manually, don't refer to a kernel spec
             env = os.environ
         else:
             # Environment variables from kernel spec are added to os.environ
             env = os.environ.copy()
             env.update(self.kernel_spec.env or {})
         # launch the kernel subprocess
         self.kernel = self._launch_kernel(kernel_cmd, env=env,
                                     ipython_kernel=self.ipython_kernel,
                                     **kw)
         self.start_restarter()
         self._connect_control_socket()
 
     def request_shutdown(self, restart=False):
         """Send a shutdown request via control channel
         
         On Windows, this just kills kernels instead, because the shutdown
         messages don't work.
         """
         content = dict(restart=restart)
         msg = self.session.msg("shutdown_request", content=content)
         self.session.send(self._control_socket, msg)
 
     def finish_shutdown(self, waittime=1, pollinterval=0.1):
         """Wait for kernel shutdown, then kill process if it doesn't shutdown.
         
         This does not send shutdown requests - use :meth:`request_shutdown`
         first.
         """
         for i in range(int(waittime/pollinterval)):
             if self.is_alive():
                 time.sleep(pollinterval)
             else:
                 break
         else:
             # OK, we've waited long enough.
             if self.has_kernel:
                 self._kill_kernel()
 
     def cleanup(self, connection_file=True):
         """Clean up resources when the kernel is shut down"""
         if connection_file:
             self.cleanup_connection_file()
 
         self.cleanup_ipc_files()
         self._close_control_socket()
 
     def shutdown_kernel(self, now=False, restart=False):
         """Attempts to the stop the kernel process cleanly.
 
         This attempts to shutdown the kernels cleanly by:
 
         1. Sending it a shutdown message over the shell channel.
         2. If that fails, the kernel is shutdown forcibly by sending it
            a signal.
 
         Parameters
         ----------
         now : bool
             Should the kernel be forcible killed *now*. This skips the
             first, nice shutdown attempt.
         restart: bool
             Will this kernel be restarted after it is shutdown. When this
             is True, connection files will not be cleaned up.
         """
         # Stop monitoring for restarting while we shutdown.
         self.stop_restarter()
 
         if now:
             self._kill_kernel()
         else:
             self.request_shutdown(restart=restart)
             # Don't send any additional kernel kill messages immediately, to give
             # the kernel a chance to properly execute shutdown actions. Wait for at
             # most 1s, checking every 0.1s.
             self.finish_shutdown()
 
         self.cleanup(connection_file=not restart)
 
     def restart_kernel(self, now=False, **kw):
         """Restarts a kernel with the arguments that were used to launch it.
 
         If the old kernel was launched with random ports, the same ports will be
         used for the new kernel. The same connection file is used again.
 
         Parameters
         ----------
         now : bool, optional
             If True, the kernel is forcefully restarted *immediately*, without
             having a chance to do any cleanup action.  Otherwise the kernel is
             given 1s to clean up before a forceful restart is issued.
 
             In all cases the kernel is restarted, the only difference is whether
             it is given a chance to perform a clean shutdown or not.
 
         **kw : optional
             Any options specified here will overwrite those used to launch the
             kernel.
         """
         if self._launch_args is None:
             raise RuntimeError("Cannot restart the kernel. "
                                "No previous call to 'start_kernel'.")
         else:
             # Stop currently running kernel.
             self.shutdown_kernel(now=now, restart=True)
 
             # Start new kernel.
             self._launch_args.update(kw)
             self.start_kernel(**self._launch_args)
 
     @property
     def has_kernel(self):
         """Has a kernel been started that we are managing."""
         return self.kernel is not None
 
     def _kill_kernel(self):
         """Kill the running kernel.
 
         This is a private method, callers should use shutdown_kernel(now=True).
         """
         if self.has_kernel:
 
             # Signal the kernel to terminate (sends SIGKILL on Unix and calls
             # TerminateProcess() on Win32).
             try:
                 self.kernel.kill()
             except OSError as e:
                 # In Windows, we will get an Access Denied error if the process
                 # has already terminated. Ignore it.
                 if sys.platform == 'win32':
                     if e.winerror != 5:
                         raise
                 # On Unix, we may get an ESRCH error if the process has already
                 # terminated. Ignore it.
                 else:
                     from errno import ESRCH
                     if e.errno != ESRCH:
                         raise
 
             # Block until the kernel terminates.
             self.kernel.wait()
             self.kernel = None
         else:
             raise RuntimeError("Cannot kill kernel. No kernel is running!")
 
     def interrupt_kernel(self):
         """Interrupts the kernel by sending it a signal.
 
         Unlike ``signal_kernel``, this operation is well supported on all
         platforms.
         """
         if self.has_kernel:
             if sys.platform == 'win32':
                 from .zmq.parentpoller import ParentPollerWindows as Poller
                 Poller.send_interrupt(self.kernel.win32_interrupt_event)
             else:
                 self.kernel.send_signal(signal.SIGINT)
         else:
             raise RuntimeError("Cannot interrupt kernel. No kernel is running!")
 
     def signal_kernel(self, signum):
         """Sends a signal to the kernel.
 
         Note that since only SIGTERM is supported on Windows, this function is
         only useful on Unix systems.
         """
         if self.has_kernel:
             self.kernel.send_signal(signum)
         else:
             raise RuntimeError("Cannot signal kernel. No kernel is running!")
 
     def is_alive(self):
         """Is the kernel process still running?"""
         if self.has_kernel:
             if self.kernel.poll() is None:
                 return True
             else:
                 return False
         else:
             # we don't have a kernel
             return False
 
 
 KernelManagerABC.register(KernelManager)
 
 
 def start_new_kernel(startup_timeout=60, kernel_name='python', **kwargs):
     """Start a new kernel, and return its Manager and Client"""
     km = KernelManager(kernel_name=kernel_name)
     km.start_kernel(**kwargs)
     kc = km.client()
     kc.start_channels()
+    kc.wait_for_ready()
 
-    kc.kernel_info()
-    kc.get_shell_msg(block=True, timeout=startup_timeout)
-
-    # Flush channels
-    for channel in (kc.shell_channel, kc.iopub_channel):
-        while True:
-            try:
-                channel.get_msg(block=True, timeout=0.1)
-            except Empty:
-                break
     return km, kc
 
 @contextmanager
 def run_kernel(**kwargs):
     """Context manager to create a kernel in a subprocess.
     
     The kernel is shut down when the context exits.
     
     Returns
     -------
     kernel_client: connected KernelClient instance
     """
     km, kc = start_new_kernel(**kwargs)
     try:
         yield kc
     finally:
         kc.stop_channels()
         km.shutdown_kernel(now=True)

IPython/kernel/zmq/tests/test_embed_kernel.py

@@ -1,198 +1,199 b''
 """test IPython.embed_kernel()"""
 
 #-------------------------------------------------------------------------------
 #  Copyright (C) 2012  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 os
 import shutil
 import sys
 import tempfile
 import time
 
 from contextlib import contextmanager
 from subprocess import Popen, PIPE
 
 import nose.tools as nt
 
 from IPython.kernel import BlockingKernelClient
 from IPython.utils import path, py3compat
 from IPython.utils.py3compat import unicode_type
 
 #-------------------------------------------------------------------------------
 # Tests
 #-------------------------------------------------------------------------------
 
 SETUP_TIMEOUT = 60
 TIMEOUT = 15
 
 def setup():
     """setup temporary IPYTHONDIR for tests"""
     global IPYTHONDIR
     global env
     global save_get_ipython_dir
     
     IPYTHONDIR = tempfile.mkdtemp()
 
     env = os.environ.copy()
     env["IPYTHONDIR"] = IPYTHONDIR
 
     save_get_ipython_dir = path.get_ipython_dir
     path.get_ipython_dir = lambda : IPYTHONDIR
 
 
 def teardown():
     path.get_ipython_dir = save_get_ipython_dir
     
     try:
         shutil.rmtree(IPYTHONDIR)
     except (OSError, IOError):
         # no such file
         pass
 
 
 @contextmanager
 def setup_kernel(cmd):
     """start an embedded kernel in a subprocess, and wait for it to be ready
     
     Returns
     -------
     kernel_manager: connected KernelManager instance
     """
     kernel = Popen([sys.executable, '-c', cmd], stdout=PIPE, stderr=PIPE, env=env)
     connection_file = os.path.join(IPYTHONDIR,
                                     'profile_default',
                                     'security',
                                     'kernel-%i.json' % kernel.pid
     )
     # wait for connection file to exist, timeout after 5s
     tic = time.time()
     while not os.path.exists(connection_file) \
         and kernel.poll() is None \
         and time.time() < tic + SETUP_TIMEOUT:
         time.sleep(0.1)
     
     if kernel.poll() is not None:
         o,e = kernel.communicate()
         e = py3compat.cast_unicode(e)
         raise IOError("Kernel failed to start:\n%s" % e)
     
     if not os.path.exists(connection_file):
         if kernel.poll() is None:
             kernel.terminate()
         raise IOError("Connection file %r never arrived" % connection_file)
     
     client = BlockingKernelClient(connection_file=connection_file)
     client.load_connection_file()
     client.start_channels()
+    client.wait_for_ready()
     
     try:
         yield client
     finally:
         client.stop_channels()
         kernel.terminate()
 
 def test_embed_kernel_basic():
     """IPython.embed_kernel() is basically functional"""
     cmd = '\n'.join([
         'from IPython import embed_kernel',
         'def go():',
         '    a=5',
         '    b="hi there"',
         '    embed_kernel()',
         'go()',
         '',
     ])
     
     with setup_kernel(cmd) as client:
         # oinfo a (int)
         msg_id = client.inspect('a')
         msg = client.get_shell_msg(block=True, timeout=TIMEOUT)
         content = msg['content']
         nt.assert_true(content['found'])
     
         msg_id = client.execute("c=a*2")
         msg = client.get_shell_msg(block=True, timeout=TIMEOUT)
         content = msg['content']
         nt.assert_equal(content['status'], u'ok')
 
         # oinfo c (should be 10)
         msg_id = client.inspect('c')
         msg = client.get_shell_msg(block=True, timeout=TIMEOUT)
         content = msg['content']
         nt.assert_true(content['found'])
         text = content['data']['text/plain']
         nt.assert_in('10', text)
 
 def test_embed_kernel_namespace():
     """IPython.embed_kernel() inherits calling namespace"""
     cmd = '\n'.join([
         'from IPython import embed_kernel',
         'def go():',
         '    a=5',
         '    b="hi there"',
         '    embed_kernel()',
         'go()',
         '',
     ])
     
     with setup_kernel(cmd) as client:
         # oinfo a (int)
         msg_id = client.inspect('a')
         msg = client.get_shell_msg(block=True, timeout=TIMEOUT)
         content = msg['content']
         nt.assert_true(content['found'])
         text = content['data']['text/plain']
         nt.assert_in(u'5', text)
 
         # oinfo b (str)
         msg_id = client.inspect('b')
         msg = client.get_shell_msg(block=True, timeout=TIMEOUT)
         content = msg['content']
         nt.assert_true(content['found'])
         text = content['data']['text/plain']
         nt.assert_in(u'hi there', text)
 
         # oinfo c (undefined)
         msg_id = client.inspect('c')
         msg = client.get_shell_msg(block=True, timeout=TIMEOUT)
         content = msg['content']
         nt.assert_false(content['found'])
 
 def test_embed_kernel_reentrant():
     """IPython.embed_kernel() can be called multiple times"""
     cmd = '\n'.join([
         'from IPython import embed_kernel',
         'count = 0',
         'def go():',
         '    global count',
         '    embed_kernel()',
         '    count = count + 1',
         '',
         'while True:'
         '    go()',
         '',
     ])
     
     with setup_kernel(cmd) as client:
         for i in range(5):
             msg_id = client.inspect('count')
             msg = client.get_shell_msg(block=True, timeout=TIMEOUT)
             content = msg['content']
             nt.assert_true(content['found'])
             text = content['data']['text/plain']
             nt.assert_in(unicode_type(i), text)
             
             # exit from embed_kernel
             client.execute("get_ipython().exit_now = True")
             msg = client.get_shell_msg(block=True, timeout=TIMEOUT)
             time.sleep(0.2)
 
 

IPython/qt/client.py

@@ -1,373 +1,381 b''
 """ Defines a KernelClient that provides signals and slots.
 """
 import atexit
 import errno
 from threading import Thread
 import time
 
 import zmq
 # import ZMQError in top-level namespace, to avoid ugly attribute-error messages
 # during garbage collection of threads at exit:
 from zmq import ZMQError
 from zmq.eventloop import ioloop, zmqstream
 
 from IPython.external.qt import QtCore
 
 # Local imports
 from IPython.utils.traitlets import Type
 from IPython.kernel.channels import HBChannel,\
     make_shell_socket, make_iopub_socket, make_stdin_socket
 from IPython.kernel import KernelClient
 
 from .kernel_mixins import (QtHBChannelMixin, QtKernelClientMixin)
 from .util import SuperQObject
 
 class QtHBChannel(QtHBChannelMixin, HBChannel):
     pass
 
 from IPython.core.release import kernel_protocol_version_info
 
 from IPython.kernel.channelsabc import (
     ShellChannelABC, IOPubChannelABC, StdInChannelABC,
 )
 from IPython.utils.py3compat import string_types, iteritems
 
 major_protocol_version = kernel_protocol_version_info[0]
 
 class InvalidPortNumber(Exception):
     pass
 
 # some utilities to validate message structure, these might get moved elsewhere
 # if they prove to have more generic utility
 
 
 def validate_string_dict(dct):
     """Validate that the input is a dict with string keys and values.
 
     Raises ValueError if not."""
     for k,v in iteritems(dct):
         if not isinstance(k, string_types):
             raise ValueError('key %r in dict must be a string' % k)
         if not isinstance(v, string_types):
             raise ValueError('value %r in dict must be a string' % v)
 
 
 
 class QtZMQSocketChannel(SuperQObject, Thread):
     """The base class for the channels that use ZMQ sockets."""
     context = None
     session = None
     socket = None
     ioloop = None
     stream = None
     _address = None
     _exiting = False
     proxy_methods = []
 
     # Emitted when the channel is started.
     started = QtCore.Signal()
 
     # Emitted when the channel is stopped.
     stopped = QtCore.Signal()
 
     message_received = QtCore.Signal(object)
 
     #---------------------------------------------------------------------------
     # InProcessChannel interface
     #---------------------------------------------------------------------------
 
     def call_handlers_later(self, *args, **kwds):
         """ Call the message handlers later.
         """
         do_later = lambda: self.call_handlers(*args, **kwds)
         QtCore.QTimer.singleShot(0, do_later)
 
     def process_events(self):
         """ Process any pending GUI events.
         """
         QtCore.QCoreApplication.instance().processEvents()
 
     def __init__(self, context, session, address):
         """Create a channel.
 
         Parameters
         ----------
         context : :class:`zmq.Context`
             The ZMQ context to use.
         session : :class:`session.Session`
             The session to use.
         address : zmq url
             Standard (ip, port) tuple that the kernel is listening on.
         """
         super(QtZMQSocketChannel, self).__init__()
         self.daemon = True
 
         self.context = context
         self.session = session
         if isinstance(address, tuple):
             if address[1] == 0:
                 message = 'The port number for a channel cannot be 0.'
                 raise InvalidPortNumber(message)
             address = "tcp://%s:%i" % address
         self._address = address
         atexit.register(self._notice_exit)
 
     def _notice_exit(self):
         self._exiting = True
 
     def _run_loop(self):
         """Run my loop, ignoring EINTR events in the poller"""
         while True:
             try:
                 self.ioloop.start()
             except ZMQError as e:
                 if e.errno == errno.EINTR:
                     continue
                 else:
                     raise
             except Exception:
                 if self._exiting:
                     break
                 else:
                     raise
             else:
                 break
 
     def start(self):
         """ Reimplemented to emit signal.
         """
         super(QtZMQSocketChannel, self).start()
         self.started.emit()
 
     def stop(self):
         """Stop the channel's event loop and join its thread.
 
         This calls :meth:`~threading.Thread.join` and returns when the thread
         terminates. :class:`RuntimeError` will be raised if
         :meth:`~threading.Thread.start` is called again.
         """
         if self.ioloop is not None:
             self.ioloop.stop()
         self.join()
         self.close()
         self.stopped.emit()
 
     def close(self):
         if self.ioloop is not None:
             try:
                 self.ioloop.close(all_fds=True)
             except Exception:
                 pass
         if self.socket is not None:
             try:
                 self.socket.close(linger=0)
             except Exception:
                 pass
             self.socket = None
 
     @property
     def address(self):
         """Get the channel's address as a zmq url string.
 
         These URLS have the form: 'tcp://127.0.0.1:5555'.
         """
         return self._address
 
     def _queue_send(self, msg):
         """Queue a message to be sent from the IOLoop's thread.
 
         Parameters
         ----------
         msg : message to send
 
         This is threadsafe, as it uses IOLoop.add_callback to give the loop's
         thread control of the action.
         """
         def thread_send():
             self.session.send(self.stream, msg)
         self.ioloop.add_callback(thread_send)
 
     def _handle_recv(self, msg):
         """Callback for stream.on_recv.
 
         Unpacks message, and calls handlers with it.
         """
         ident,smsg = self.session.feed_identities(msg)
         msg = self.session.deserialize(smsg)
         self.call_handlers(msg)
 
     def call_handlers(self, msg):
         """This method is called in the ioloop thread when a message arrives.
 
         Subclasses should override this method to handle incoming messages.
         It is important to remember that this method is called in the thread
         so that some logic must be done to ensure that the application level
         handlers are called in the application thread.
         """
         # Emit the generic signal.
         self.message_received.emit(msg)
 
 
 class QtShellChannel(QtZMQSocketChannel):
     """The shell channel for issuing request/replies to the kernel."""
 
     # Emitted when a reply has been received for the corresponding request type.
     execute_reply = QtCore.Signal(object)
     complete_reply = QtCore.Signal(object)
     inspect_reply = QtCore.Signal(object)
     history_reply = QtCore.Signal(object)
     kernel_info_reply = QtCore.Signal(object)
 
     def __init__(self, context, session, address):
         super(QtShellChannel, self).__init__(context, session, address)
         self.ioloop = ioloop.IOLoop()
 
     def run(self):
         """The thread's main activity.  Call start() instead."""
         self.socket = make_shell_socket(self.context, self.session.bsession, self.address)
         self.stream = zmqstream.ZMQStream(self.socket, self.ioloop)
         self.stream.on_recv(self._handle_recv)
         self._run_loop()
 
     def call_handlers(self, msg):
         super(QtShellChannel, self).call_handlers(msg)
 
         # Catch kernel_info_reply for message spec adaptation
         msg_type = msg['header']['msg_type']
         if msg_type == 'kernel_info_reply':
             self._handle_kernel_info_reply(msg)
 
         # Emit specific signals
         signal = getattr(self, msg_type, None)
         if signal:
             signal.emit(msg)
 
     def _handle_kernel_info_reply(self, msg):
         """handle kernel info reply
 
         sets protocol adaptation version
         """
         adapt_version = int(msg['content']['protocol_version'].split('.')[0])
         if adapt_version != major_protocol_version:
             self.session.adapt_version = adapt_version
 
 
 class QtIOPubChannel(QtZMQSocketChannel):
     """The iopub channel which listens for messages that the kernel publishes.
 
     This channel is where all output is published to frontends.
     """
     # Emitted when a message of type 'stream' is received.
     stream_received = QtCore.Signal(object)
 
     # Emitted when a message of type 'execute_input' is received.
     execute_input_received = QtCore.Signal(object)
 
     # Emitted when a message of type 'execute_result' is received.
     execute_result_received = QtCore.Signal(object)
 
     # Emitted when a message of type 'error' is received.
     error_received = QtCore.Signal(object)
 
     # Emitted when a message of type 'display_data' is received
     display_data_received = QtCore.Signal(object)
 
     # Emitted when a crash report message is received from the kernel's
     # last-resort sys.excepthook.
     crash_received = QtCore.Signal(object)
 
     # Emitted when a shutdown is noticed.
     shutdown_reply_received = QtCore.Signal(object)
 
     def __init__(self, context, session, address):
         super(QtIOPubChannel, self).__init__(context, session, address)
         self.ioloop = ioloop.IOLoop()
 
     def run(self):
         """The thread's main activity.  Call start() instead."""
         self.socket = make_iopub_socket(self.context, self.session.bsession, self.address)
         self.stream = zmqstream.ZMQStream(self.socket, self.ioloop)
         self.stream.on_recv(self._handle_recv)
         self._run_loop()
 
     def call_handlers(self, msg):
         super(QtIOPubChannel, self).call_handlers(msg)
 
         # Emit signals for specialized message types.
         msg_type = msg['header']['msg_type']
         signal = getattr(self, msg_type + '_received', None)
         if signal:
             signal.emit(msg)
 
     def flush(self, timeout=1.0):
         """Immediately processes all pending messages on the iopub channel.
 
         Callers should use this method to ensure that :meth:`call_handlers`
         has been called for all messages that have been received on the
         0MQ SUB socket of this channel.
 
         This method is thread safe.
 
         Parameters
         ----------
         timeout : float, optional
             The maximum amount of time to spend flushing, in seconds. The
             default is one second.
         """
         # We do the IOLoop callback process twice to ensure that the IOLoop
         # gets to perform at least one full poll.
         stop_time = time.time() + timeout
         for i in range(2):
             self._flushed = False
             self.ioloop.add_callback(self._flush)
             while not self._flushed and time.time() < stop_time:
                 time.sleep(0.01)
 
     def _flush(self):
         """Callback for :method:`self.flush`."""
         self.stream.flush()
         self._flushed = True
 
 
 class QtStdInChannel(QtZMQSocketChannel):
     """The stdin channel to handle raw_input requests that the kernel makes."""
 
     msg_queue = None
     proxy_methods = ['input']
 
     # Emitted when an input request is received.
     input_requested = QtCore.Signal(object)
 
     def __init__(self, context, session, address):
         super(QtStdInChannel, self).__init__(context, session, address)
         self.ioloop = ioloop.IOLoop()
 
     def run(self):
         """The thread's main activity.  Call start() instead."""
         self.socket = make_stdin_socket(self.context, self.session.bsession, self.address)
         self.stream = zmqstream.ZMQStream(self.socket, self.ioloop)
         self.stream.on_recv(self._handle_recv)
         self._run_loop()
 
     def call_handlers(self, msg):
         super(QtStdInChannel, self).call_handlers(msg)
 
         # Emit signals for specialized message types.
         msg_type = msg['header']['msg_type']
         if msg_type == 'input_request':
             self.input_requested.emit(msg)
 
 
 ShellChannelABC.register(QtShellChannel)
 IOPubChannelABC.register(QtIOPubChannel)
 StdInChannelABC.register(QtStdInChannel)
 
 
 class QtKernelClient(QtKernelClientMixin, KernelClient):
     """ A KernelClient that provides signals and slots.
     """
+    def start_channels(self, shell=True, iopub=True, stdin=True, hb=True):
+        if shell:
+            self.shell_channel.kernel_info_reply.connect(self._handle_kernel_info_reply)
+        super(QtKernelClient, self).start_channels(shell, iopub, stdin, hb)
+
+    def _handle_kernel_info_reply(self, msg):
+        super(QtKernelClient, self)._handle_kernel_info_reply(msg)
+        self.shell_channel.kernel_info_reply.disconnect(self._handle_kernel_info_reply)
 
     iopub_channel_class = Type(QtIOPubChannel)
     shell_channel_class = Type(QtShellChannel)
     stdin_channel_class = Type(QtStdInChannel)
     hb_channel_class = Type(QtHBChannel)