##// END OF EJS Templates
use pyzmq tools where appropriate...
use pyzmq tools where appropriate ZMQStream is the right object to use for event-driven handling of messages, but instead we chose to rewrite half of it in KernelManager. This removes most of the duplicate code, in favor of using ZMQStream. also use the pyzmq install() function for using pyzmq with tornado, instead of manually pasting its contents in notebook app.

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pykernel.py
282 lines | 10.4 KiB | text/x-python | PythonLexer
#!/usr/bin/env python
"""A simple interactive kernel that talks to a frontend over 0MQ.
Things to do:
* Implement `set_parent` logic. Right before doing exec, the Kernel should
call set_parent on all the PUB objects with the message about to be executed.
* Implement random port and security key logic.
* Implement control messages.
* Implement event loop and poll version.
"""
#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------
# Standard library imports.
import __builtin__
from code import CommandCompiler
import sys
import time
import traceback
# System library imports.
import zmq
# Local imports.
from IPython.utils import py3compat
from IPython.utils.traitlets import HasTraits, Instance, Dict, Float
from completer import KernelCompleter
from entry_point import base_launch_kernel
from session import Session, Message
from kernelapp import KernelApp
#-----------------------------------------------------------------------------
# Main kernel class
#-----------------------------------------------------------------------------
class Kernel(HasTraits):
# Private interface
# Time to sleep after flushing the stdout/err buffers in each execute
# cycle. While this introduces a hard limit on the minimal latency of the
# execute cycle, it helps prevent output synchronization problems for
# clients.
# Units are in seconds. The minimum zmq latency on local host is probably
# ~150 microseconds, set this to 500us for now. We may need to increase it
# a little if it's not enough after more interactive testing.
_execute_sleep = Float(0.0005, config=True)
# This is a dict of port number that the kernel is listening on. It is set
# by record_ports and used by connect_request.
_recorded_ports = Dict()
#---------------------------------------------------------------------------
# Kernel interface
#---------------------------------------------------------------------------
session = Instance(Session)
shell_socket = Instance('zmq.Socket')
iopub_socket = Instance('zmq.Socket')
stdin_socket = Instance('zmq.Socket')
log = Instance('logging.Logger')
def __init__(self, **kwargs):
super(Kernel, self).__init__(**kwargs)
self.user_ns = {}
self.history = []
self.compiler = CommandCompiler()
self.completer = KernelCompleter(self.user_ns)
# Build dict of handlers for message types
msg_types = [ 'execute_request', 'complete_request',
'object_info_request', 'shutdown_request' ]
self.handlers = {}
for msg_type in msg_types:
self.handlers[msg_type] = getattr(self, msg_type)
def start(self):
""" Start the kernel main loop.
"""
while True:
ident,msg = self.session.recv(self.shell_socket,0)
assert ident is not None, "Missing message part."
omsg = Message(msg)
self.log.debug(str(omsg))
handler = self.handlers.get(omsg.msg_type, None)
if handler is None:
self.log.error("UNKNOWN MESSAGE TYPE: %s"%omsg)
else:
handler(ident, omsg)
def record_ports(self, ports):
"""Record the ports that this kernel is using.
The creator of the Kernel instance must call this methods if they
want the :meth:`connect_request` method to return the port numbers.
"""
self._recorded_ports = ports
#---------------------------------------------------------------------------
# Kernel request handlers
#---------------------------------------------------------------------------
def execute_request(self, ident, parent):
try:
code = parent[u'content'][u'code']
except:
self.log.error("Got bad msg: %s"%Message(parent))
return
pyin_msg = self.session.send(self.iopub_socket, u'pyin',{u'code':code}, parent=parent)
try:
comp_code = self.compiler(code, '<zmq-kernel>')
# Replace raw_input. Note that is not sufficient to replace
# raw_input in the user namespace.
raw_input = lambda prompt='': self._raw_input(prompt, ident, parent)
if py3compat.PY3:
__builtin__.input = raw_input
else:
__builtin__.raw_input = raw_input
# Set the parent message of the display hook and out streams.
sys.displayhook.set_parent(parent)
sys.stdout.set_parent(parent)
sys.stderr.set_parent(parent)
exec comp_code in self.user_ns, self.user_ns
except:
etype, evalue, tb = sys.exc_info()
tb = traceback.format_exception(etype, evalue, tb)
exc_content = {
u'status' : u'error',
u'traceback' : tb,
u'ename' : unicode(etype.__name__),
u'evalue' : unicode(evalue)
}
exc_msg = self.session.send(self.iopub_socket, u'pyerr', exc_content, parent)
reply_content = exc_content
else:
reply_content = { 'status' : 'ok', 'payload' : {} }
# Flush output before sending the reply.
sys.stderr.flush()
sys.stdout.flush()
# FIXME: on rare occasions, the flush doesn't seem to make it to the
# clients... This seems to mitigate the problem, but we definitely need
# to better understand what's going on.
if self._execute_sleep:
time.sleep(self._execute_sleep)
# Send the reply.
reply_msg = self.session.send(self.shell_socket, u'execute_reply', reply_content, parent, ident=ident)
self.log.debug(Message(reply_msg))
if reply_msg['content']['status'] == u'error':
self._abort_queue()
def complete_request(self, ident, parent):
matches = {'matches' : self._complete(parent),
'status' : 'ok'}
completion_msg = self.session.send(self.shell_socket, 'complete_reply',
matches, parent, ident)
self.log.debug(completion_msg)
def object_info_request(self, ident, parent):
context = parent['content']['oname'].split('.')
object_info = self._object_info(context)
msg = self.session.send(self.shell_socket, 'object_info_reply',
object_info, parent, ident)
self.log.debug(msg)
def shutdown_request(self, ident, parent):
content = dict(parent['content'])
msg = self.session.send(self.shell_socket, 'shutdown_reply',
content, parent, ident)
msg = self.session.send(self.iopub_socket, 'shutdown_reply',
content, parent, ident)
self.log.debug(msg)
time.sleep(0.1)
sys.exit(0)
#---------------------------------------------------------------------------
# Protected interface
#---------------------------------------------------------------------------
def _abort_queue(self):
while True:
ident,msg = self.session.recv(self.shell_socket, zmq.NOBLOCK)
if msg is None:
# msg=None on EAGAIN
break
else:
assert ident is not None, "Missing message part."
self.log.debug("Aborting: %s"%Message(msg))
msg_type = msg['header']['msg_type']
reply_type = msg_type.split('_')[0] + '_reply'
reply_msg = self.session.send(self.shell_socket, reply_type, {'status':'aborted'}, msg, ident=ident)
self.log.debug(Message(reply_msg))
# We need to wait a bit for requests to come in. This can probably
# be set shorter for true asynchronous clients.
time.sleep(0.1)
def _raw_input(self, prompt, ident, parent):
# Flush output before making the request.
sys.stderr.flush()
sys.stdout.flush()
# Send the input request.
content = dict(prompt=prompt)
msg = self.session.send(self.stdin_socket, u'input_request', content, parent, ident=ident)
# Await a response.
ident,reply = self.session.recv(self.stdin_socket, 0)
try:
value = reply['content']['value']
except:
self.log.error("Got bad raw_input reply: %s"%Message(parent))
value = ''
return value
def _complete(self, msg):
return self.completer.complete(msg.content.line, msg.content.text)
def _object_info(self, context):
symbol, leftover = self._symbol_from_context(context)
if symbol is not None and not leftover:
doc = getattr(symbol, '__doc__', '')
else:
doc = ''
object_info = dict(docstring = doc)
return object_info
def _symbol_from_context(self, context):
if not context:
return None, context
base_symbol_string = context[0]
symbol = self.user_ns.get(base_symbol_string, None)
if symbol is None:
symbol = __builtin__.__dict__.get(base_symbol_string, None)
if symbol is None:
return None, context
context = context[1:]
for i, name in enumerate(context):
new_symbol = getattr(symbol, name, None)
if new_symbol is None:
return symbol, context[i:]
else:
symbol = new_symbol
return symbol, []
#-----------------------------------------------------------------------------
# Kernel main and launch functions
#-----------------------------------------------------------------------------
def launch_kernel(*args, **kwargs):
""" Launches a simple Python kernel, binding to the specified ports.
This function simply calls entry_point.base_launch_kernel with the right first
command to start a pykernel. See base_launch_kernel for arguments.
Returns
-------
A tuple of form:
(kernel_process, xrep_port, pub_port, req_port, hb_port)
where kernel_process is a Popen object and the ports are integers.
"""
return base_launch_kernel('from IPython.zmq.pykernel import main; main()',
*args, **kwargs)
def main():
"""Run a PyKernel as an application"""
app = KernelApp.instance()
app.initialize()
app.start()
if __name__ == '__main__':
main()