##// END OF EJS Templates
Updated FrontendWidget to use new 'replace' mode in BlockBreaker.
Updated FrontendWidget to use new 'replace' mode in BlockBreaker.

File last commit:

r2632:deff0b9f
r2638:5e110efd
Show More
kernelmanager.py
403 lines | 12.1 KiB | text/x-python | PythonLexer
"""Kernel frontend classes.
TODO: Create logger to handle debugging and console messages.
"""
# Standard library imports.
from Queue import Queue, Empty
from threading import Thread
import time
import traceback
# System library imports.
import zmq
from zmq import POLLIN, POLLOUT, POLLERR
from zmq.eventloop import ioloop
# Local imports.
from IPython.utils.traitlets import HasTraits, Any, Int, Instance, Str, Type
from session import Session
class MissingHandlerError(Exception):
pass
class ZmqSocketChannel(Thread):
""" The base class for the channels that use ZMQ sockets.
"""
def __init__(self, context, session, address=None):
super(ZmqSocketChannel, self).__init__()
self.daemon = True
self.context = context
self.session = session
self.address = address
self.socket = None
def stop(self):
""" Stop the thread's activity. Returns when the thread terminates.
"""
raise NotImplementedError
def get_address(self):
""" Get the channel's address.
"""
return self._address
def set_adresss(self, address):
""" Set the channel's address. Should be a tuple of form:
(ip address [str], port [int])
or 'None' to indicate that no address has been specified.
"""
# FIXME: Validate address.
if self.is_alive():
raise RuntimeError("Cannot set address on a running channel!")
else:
self._address = address
address = property(get_address, set_adresss)
class SubSocketChannel(ZmqSocketChannel):
handlers = None
_overriden_call_handler = None
def __init__(self, context, session, address=None):
self.handlers = {}
super(SubSocketChannel, self).__init__(context, session, address)
def run(self):
self.socket = self.context.socket(zmq.SUB)
self.socket.setsockopt(zmq.SUBSCRIBE,'')
self.socket.setsockopt(zmq.IDENTITY, self.session.session)
self.socket.connect('tcp://%s:%i' % self.address)
self.ioloop = ioloop.IOLoop()
self.ioloop.add_handler(self.socket, self._handle_events,
POLLIN|POLLERR)
self.ioloop.start()
def stop(self):
self.ioloop.stop()
self.join()
def _handle_events(self, socket, events):
# Turn on and off POLLOUT depending on if we have made a request
if events & POLLERR:
self._handle_err()
if events & POLLIN:
self._handle_recv()
def _handle_err(self):
raise zmq.ZmqError()
def _handle_recv(self):
msg = self.socket.recv_json()
self.call_handlers(msg)
def override_call_handler(self, func):
"""Permanently override the call_handler.
The function func will be called as::
func(handler, msg)
And must call::
handler(msg)
in the main thread.
"""
assert callable(func), "not a callable: %r" % func
self._overriden_call_handler = func
def call_handlers(self, msg):
handler = self.handlers.get(msg['msg_type'], None)
if handler is not None:
try:
self.call_handler(handler, msg)
except:
# XXX: This should be logged at least
traceback.print_last()
def call_handler(self, handler, msg):
if self._overriden_call_handler is not None:
self._overriden_call_handler(handler, msg)
elif hasattr(self, '_call_handler'):
call_handler = getattr(self, '_call_handler')
call_handler(handler, msg)
else:
raise RuntimeError('no handler!')
def add_handler(self, callback, msg_type):
"""Register a callback for msg type."""
self.handlers[msg_type] = callback
def remove_handler(self, msg_type):
"""Remove the callback for msg type."""
self.handlers.pop(msg_type, None)
def flush(self):
"""Immediately processes all pending messages on the SUB channel. This
method is thread safe.
"""
self._flushed = False
self.ioloop.add_callback(self._flush)
while not self._flushed:
time.sleep(0.01)
def _flush(self):
"""Called in this thread by the IOLoop to indicate that all events have
been processed.
"""
self._flushed = True
class XReqSocketChannel(ZmqSocketChannel):
handler_queue = None
command_queue = None
handlers = None
_overriden_call_handler = None
def __init__(self, context, session, address=None):
self.handlers = {}
self.handler_queue = Queue()
self.command_queue = Queue()
super(XReqSocketChannel, self).__init__(context, session, address)
def run(self):
self.socket = self.context.socket(zmq.XREQ)
self.socket.setsockopt(zmq.IDENTITY, self.session.session)
self.socket.connect('tcp://%s:%i' % self.address)
self.ioloop = ioloop.IOLoop()
self.ioloop.add_handler(self.socket, self._handle_events,
POLLIN|POLLOUT|POLLERR)
self.ioloop.start()
def stop(self):
self.ioloop.stop()
self.join()
def _handle_events(self, socket, events):
# Turn on and off POLLOUT depending on if we have made a request
if events & POLLERR:
self._handle_err()
if events & POLLOUT:
self._handle_send()
if events & POLLIN:
self._handle_recv()
def _handle_recv(self):
msg = self.socket.recv_json()
self.call_handlers(msg)
def _handle_send(self):
try:
msg = self.command_queue.get(False)
except Empty:
pass
else:
self.socket.send_json(msg)
def _handle_err(self):
raise zmq.ZmqError()
def _queue_request(self, msg, callback):
handler = self._find_handler(msg['msg_type'], callback)
self.handler_queue.put(handler)
self.command_queue.put(msg)
def execute(self, code, callback=None):
# Create class for content/msg creation. Related to, but possibly
# not in Session.
content = dict(code=code)
msg = self.session.msg('execute_request', content)
self._queue_request(msg, callback)
return msg['header']['msg_id']
def complete(self, text, line, block=None, callback=None):
content = dict(text=text, line=line)
msg = self.session.msg('complete_request', content)
self._queue_request(msg, callback)
return msg['header']['msg_id']
def object_info(self, oname, callback=None):
content = dict(oname=oname)
msg = self.session.msg('object_info_request', content)
self._queue_request(msg, callback)
return msg['header']['msg_id']
def _find_handler(self, name, callback):
if callback is not None:
return callback
handler = self.handlers.get(name)
if handler is None:
raise MissingHandlerError(
'No handler defined for method: %s' % name)
return handler
def override_call_handler(self, func):
"""Permanently override the call_handler.
The function func will be called as::
func(handler, msg)
And must call::
handler(msg)
in the main thread.
"""
assert callable(func), "not a callable: %r" % func
self._overriden_call_handler = func
def call_handlers(self, msg):
try:
handler = self.handler_queue.get(False)
except Empty:
print "Message received with no handler!!!"
print msg
else:
self.call_handler(handler, msg)
def call_handler(self, handler, msg):
if self._overriden_call_handler is not None:
self._overriden_call_handler(handler, msg)
elif hasattr(self, '_call_handler'):
call_handler = getattr(self, '_call_handler')
call_handler(handler, msg)
else:
raise RuntimeError('no handler!')
class RepSocketChannel(ZmqSocketChannel):
def stop(self):
pass
def on_raw_input(self):
pass
class KernelManager(HasTraits):
""" Manages a kernel for a frontend.
The SUB channel is for the frontend to receive messages published by the
kernel.
The REQ channel is for the frontend to make requests of the kernel.
The REP channel is for the kernel to request stdin (raw_input) from the
frontend.
"""
# The PyZMQ Context to use for communication with the kernel.
context = Instance(zmq.Context, ())
# The Session to use for communication with the kernel.
session = Instance(Session, ())
# The classes to use for the various channels.
sub_channel_class = Type(SubSocketChannel)
xreq_channel_class = Type(XReqSocketChannel)
rep_channel_class = Type(RepSocketChannel)
# Protected traits.
_sub_channel = Any
_xreq_channel = Any
_rep_channel = Any
def __init__(self, **traits):
super(KernelManager, self).__init__()
# FIXME: This should be the business of HasTraits. The convention is:
# HasTraits.__init__(self, **traits_to_be_initialized.)
for trait in traits:
setattr(self, trait, traits[trait])
def start_kernel(self):
"""Start a localhost kernel. If ports have been specified, use
them. Otherwise, choose an open port at random.
"""
self.sub_channel.start()
self.xreq_channel.start()
self.rep_channel.start()
def kill_kernel(self):
"""Kill the running kernel.
"""
self.sub_channel.stop()
self.xreq_channel.stop()
self.rep_channel.stop()
def is_alive(self):
"""Is the kernel alive?"""
return True
def signal_kernel(self, signum):
"""Send signum to the kernel."""
#--------------------------------------------------------------------------
# Channels used for communication with the kernel:
#--------------------------------------------------------------------------
@property
def sub_channel(self):
"""Get the SUB socket channel object."""
if self._sub_channel is None:
self._sub_channel = self.sub_channel_class(self.context,
self.session)
return self._sub_channel
@property
def xreq_channel(self):
"""Get the REQ socket channel object to make requests of the kernel."""
if self._xreq_channel is None:
self._xreq_channel = self.xreq_channel_class(self.context,
self.session)
return self._xreq_channel
@property
def rep_channel(self):
"""Get the REP socket channel object to handle stdin (raw_input)."""
if self._rep_channel is None:
self._rep_channel = self.rep_channel_class(self.context,
self.session)
return self._rep_channel
#--------------------------------------------------------------------------
# Channel addresses:
#--------------------------------------------------------------------------
def get_sub_address(self):
return self.sub_channel.address
def set_sub_address(self, address):
self.sub_channel.address = address
sub_address = property(get_sub_address, set_sub_address,
doc="The address used by SUB socket channel.")
def get_xreq_address(self):
return self.xreq_channel.address
def set_xreq_address(self, address):
self.xreq_channel.address = address
xreq_address = property(get_xreq_address, set_xreq_address,
doc="The address used by XREQ socket channel.")
def get_rep_address(self):
return self.rep_channel.address
def set_rep_address(self, address):
self.rep_channel.address = address
rep_address = property(get_rep_address, set_rep_address,
doc="The address used by REP socket channel.")