"""An Application for launching a kernel
Authors
-------
* MinRK
"""
#-----------------------------------------------------------------------------
# Copyright (C) 2011 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.
#-----------------------------------------------------------------------------
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
# Standard library imports.
import os
import sys
# System library imports.
import zmq
# IPython imports.
from IPython.core.ultratb import FormattedTB
from IPython.core.application import (
BaseIPythonApplication, base_flags, base_aliases
)
from IPython.utils import io
from IPython.utils.localinterfaces import LOCALHOST
from IPython.utils.traitlets import (Any, Instance, Dict, Unicode, Int, Bool,
DottedObjectName)
from IPython.utils.importstring import import_item
# local imports
from IPython.zmq.heartbeat import Heartbeat
from IPython.zmq.parentpoller import ParentPollerUnix, ParentPollerWindows
from IPython.zmq.session import Session
#-----------------------------------------------------------------------------
# Flags and Aliases
#-----------------------------------------------------------------------------
kernel_aliases = dict(base_aliases)
kernel_aliases.update({
'ip' : 'KernelApp.ip',
'hb' : 'KernelApp.hb_port',
'shell' : 'KernelApp.shell_port',
'iopub' : 'KernelApp.iopub_port',
'stdin' : 'KernelApp.stdin_port',
'parent': 'KernelApp.parent',
})
if sys.platform.startswith('win'):
kernel_aliases['interrupt'] = 'KernelApp.interrupt'
kernel_flags = dict(base_flags)
kernel_flags.update({
'no-stdout' : (
{'KernelApp' : {'no_stdout' : True}},
"redirect stdout to the null device"),
'no-stderr' : (
{'KernelApp' : {'no_stderr' : True}},
"redirect stderr to the null device"),
})
#-----------------------------------------------------------------------------
# Application class for starting a Kernel
#-----------------------------------------------------------------------------
class KernelApp(BaseIPythonApplication):
name='pykernel'
aliases = Dict(kernel_aliases)
flags = Dict(kernel_flags)
classes = [Session]
# the kernel class, as an importstring
kernel_class = DottedObjectName('IPython.zmq.pykernel.Kernel')
kernel = Any()
poller = Any() # don't restrict this even though current pollers are all Threads
heartbeat = Instance(Heartbeat)
session = Instance('IPython.zmq.session.Session')
ports = Dict()
# inherit config file name from parent:
parent_appname = Unicode(config=True)
def _parent_appname_changed(self, name, old, new):
if self.config_file_specified:
# it was manually specified, ignore
return
self.config_file_name = new.replace('-','_') + u'_config.py'
# don't let this count as specifying the config file
self.config_file_specified = False
# connection info:
ip = Unicode(LOCALHOST, config=True,
help="Set the IP or interface on which the kernel will listen.")
hb_port = Int(0, config=True, help="set the heartbeat port [default: random]")
shell_port = Int(0, config=True, help="set the shell (XREP) port [default: random]")
iopub_port = Int(0, config=True, help="set the iopub (PUB) port [default: random]")
stdin_port = Int(0, config=True, help="set the stdin (XREQ) port [default: random]")
# streams, etc.
no_stdout = Bool(False, config=True, help="redirect stdout to the null device")
no_stderr = Bool(False, config=True, help="redirect stderr to the null device")
outstream_class = DottedObjectName('IPython.zmq.iostream.OutStream',
config=True, help="The importstring for the OutStream factory")
displayhook_class = DottedObjectName('IPython.zmq.displayhook.ZMQDisplayHook',
config=True, help="The importstring for the DisplayHook factory")
# polling
parent = Int(0, config=True,
help="""kill this process if its parent dies. On Windows, the argument
specifies the HANDLE of the parent process, otherwise it is simply boolean.
""")
interrupt = Int(0, config=True,
help="""ONLY USED ON WINDOWS
Interrupt this process when the parent is signalled.
""")
def init_crash_handler(self):
# Install minimal exception handling
sys.excepthook = FormattedTB(mode='Verbose', color_scheme='NoColor',
ostream=sys.__stdout__)
def init_poller(self):
if sys.platform == 'win32':
if self.interrupt or self.parent:
self.poller = ParentPollerWindows(self.interrupt, self.parent)
elif self.parent:
self.poller = ParentPollerUnix()
def _bind_socket(self, s, port):
iface = 'tcp://%s' % self.ip
if port <= 0:
port = s.bind_to_random_port(iface)
else:
s.bind(iface + ':%i'%port)
return port
def init_sockets(self):
# Create a context, a session, and the kernel sockets.
self.log.info("Starting the kernel at pid: %i", os.getpid())
context = zmq.Context.instance()
# Uncomment this to try closing the context.
# atexit.register(context.term)
self.shell_socket = context.socket(zmq.ROUTER)
self.shell_port = self._bind_socket(self.shell_socket, self.shell_port)
self.log.debug("shell ROUTER Channel on port: %i"%self.shell_port)
self.iopub_socket = context.socket(zmq.PUB)
self.iopub_port = self._bind_socket(self.iopub_socket, self.iopub_port)
self.log.debug("iopub PUB Channel on port: %i"%self.iopub_port)
self.stdin_socket = context.socket(zmq.XREQ)
self.stdin_port = self._bind_socket(self.stdin_socket, self.stdin_port)
self.log.debug("stdin XREQ Channel on port: %i"%self.stdin_port)
self.heartbeat = Heartbeat(context, (self.ip, self.hb_port))
self.hb_port = self.heartbeat.port
self.log.debug("Heartbeat REP Channel on port: %i"%self.hb_port)
# Helper to make it easier to connect to an existing kernel, until we have
# single-port connection negotiation fully implemented.
# set log-level to critical, to make sure it is output
self.log.critical("To connect another client to this kernel, use:")
self.log.critical("--existing --shell={0} --iopub={1} --stdin={2} --hb={3}".format(
self.shell_port, self.iopub_port, self.stdin_port, self.hb_port))
self.ports = dict(shell=self.shell_port, iopub=self.iopub_port,
stdin=self.stdin_port, hb=self.hb_port)
def init_session(self):
"""create our session object"""
self.session = Session(config=self.config, username=u'kernel')
def init_blackhole(self):
"""redirects stdout/stderr to devnull if necessary"""
if self.no_stdout or self.no_stderr:
blackhole = file(os.devnull, 'w')
if self.no_stdout:
sys.stdout = sys.__stdout__ = blackhole
if self.no_stderr:
sys.stderr = sys.__stderr__ = blackhole
def init_io(self):
"""Redirect input streams and set a display hook."""
if self.outstream_class:
outstream_factory = import_item(str(self.outstream_class))
sys.stdout = outstream_factory(self.session, self.iopub_socket, u'stdout')
sys.stderr = outstream_factory(self.session, self.iopub_socket, u'stderr')
if self.displayhook_class:
displayhook_factory = import_item(str(self.displayhook_class))
sys.displayhook = displayhook_factory(self.session, self.iopub_socket)
def init_kernel(self):
"""Create the Kernel object itself"""
kernel_factory = import_item(str(self.kernel_class))
self.kernel = kernel_factory(config=self.config, session=self.session,
shell_socket=self.shell_socket,
iopub_socket=self.iopub_socket,
stdin_socket=self.stdin_socket,
log=self.log
)
self.kernel.record_ports(self.ports)
def initialize(self, argv=None):
super(KernelApp, self).initialize(argv)
self.init_blackhole()
self.init_session()
self.init_poller()
self.init_sockets()
self.init_io()
self.init_kernel()
def start(self):
self.heartbeat.start()
if self.poller is not None:
self.poller.start()
try:
self.kernel.start()
except KeyboardInterrupt:
pass