"""A kernel manager for multiple kernels"""
# Copyright (c) Jupyter Development Team.
# Distributed under the terms of the Modified BSD License.
from __future__ import absolute_import
import os
import uuid
import zmq
from traitlets.config.configurable import LoggingConfigurable
from ipython_genutils.importstring import import_item
from traitlets import (
Instance, Dict, List, Unicode, Any, DottedObjectName
)
from ipython_genutils.py3compat import unicode_type
from .kernelspec import NATIVE_KERNEL_NAME, KernelSpecManager
class DuplicateKernelError(Exception):
pass
def kernel_method(f):
"""decorator for proxying MKM.method(kernel_id) to individual KMs by ID"""
def wrapped(self, kernel_id, *args, **kwargs):
# get the kernel
km = self.get_kernel(kernel_id)
method = getattr(km, f.__name__)
# call the kernel's method
r = method(*args, **kwargs)
# last thing, call anything defined in the actual class method
# such as logging messages
f(self, kernel_id, *args, **kwargs)
# return the method result
return r
return wrapped
class MultiKernelManager(LoggingConfigurable):
"""A class for managing multiple kernels."""
default_kernel_name = Unicode(NATIVE_KERNEL_NAME, config=True,
help="The name of the default kernel to start"
)
kernel_spec_manager = Instance(KernelSpecManager, allow_none=True)
kernel_manager_class = DottedObjectName(
"jupyter_client.ioloop.IOLoopKernelManager", config=True,
help="""The kernel manager class. This is configurable to allow
subclassing of the KernelManager for customized behavior.
"""
)
def _kernel_manager_class_changed(self, name, old, new):
self.kernel_manager_factory = import_item(new)
kernel_manager_factory = Any(help="this is kernel_manager_class after import")
def _kernel_manager_factory_default(self):
return import_item(self.kernel_manager_class)
context = Instance('zmq.Context')
def _context_default(self):
return zmq.Context.instance()
connection_dir = Unicode('')
_kernels = Dict()
def list_kernel_ids(self):
"""Return a list of the kernel ids of the active kernels."""
# Create a copy so we can iterate over kernels in operations
# that delete keys.
return list(self._kernels.keys())
def __len__(self):
"""Return the number of running kernels."""
return len(self.list_kernel_ids())
def __contains__(self, kernel_id):
return kernel_id in self._kernels
def start_kernel(self, kernel_name=None, **kwargs):
"""Start a new kernel.
The caller can pick a kernel_id by passing one in as a keyword arg,
otherwise one will be picked using a uuid.
The kernel ID for the newly started kernel is returned.
"""
kernel_id = kwargs.pop('kernel_id', unicode_type(uuid.uuid4()))
if kernel_id in self:
raise DuplicateKernelError('Kernel already exists: %s' % kernel_id)
if kernel_name is None:
kernel_name = self.default_kernel_name
# kernel_manager_factory is the constructor for the KernelManager
# subclass we are using. It can be configured as any Configurable,
# including things like its transport and ip.
constructor_kwargs = {}
if self.kernel_spec_manager:
constructor_kwargs['kernel_spec_manager'] = self.kernel_spec_manager
km = self.kernel_manager_factory(connection_file=os.path.join(
self.connection_dir, "kernel-%s.json" % kernel_id),
parent=self, log=self.log, kernel_name=kernel_name,
**constructor_kwargs
)
km.start_kernel(**kwargs)
self._kernels[kernel_id] = km
return kernel_id
@kernel_method
def shutdown_kernel(self, kernel_id, now=False, restart=False):
"""Shutdown a kernel by its kernel uuid.
Parameters
==========
kernel_id : uuid
The id of the kernel to shutdown.
now : bool
Should the kernel be shutdown forcibly using a signal.
restart : bool
Will the kernel be restarted?
"""
self.log.info("Kernel shutdown: %s" % kernel_id)
self.remove_kernel(kernel_id)
@kernel_method
def request_shutdown(self, kernel_id, restart=False):
"""Ask a kernel to shut down by its kernel uuid"""
@kernel_method
def finish_shutdown(self, kernel_id, waittime=None, pollinterval=0.1):
"""Wait for a kernel to finish shutting down, and kill it if it doesn't
"""
self.log.info("Kernel shutdown: %s" % kernel_id)
@kernel_method
def cleanup(self, kernel_id, connection_file=True):
"""Clean up a kernel's resources"""
def remove_kernel(self, kernel_id):
"""remove a kernel from our mapping.
Mainly so that a kernel can be removed if it is already dead,
without having to call shutdown_kernel.
The kernel object is returned.
"""
return self._kernels.pop(kernel_id)
def shutdown_all(self, now=False):
"""Shutdown all kernels."""
kids = self.list_kernel_ids()
for kid in kids:
self.request_shutdown(kid)
for kid in kids:
self.finish_shutdown(kid)
self.cleanup(kid)
self.remove_kernel(kid)
@kernel_method
def interrupt_kernel(self, kernel_id):
"""Interrupt (SIGINT) the kernel by its uuid.
Parameters
==========
kernel_id : uuid
The id of the kernel to interrupt.
"""
self.log.info("Kernel interrupted: %s" % kernel_id)
@kernel_method
def signal_kernel(self, kernel_id, signum):
"""Sends a signal to the kernel by its uuid.
Note that since only SIGTERM is supported on Windows, this function
is only useful on Unix systems.
Parameters
==========
kernel_id : uuid
The id of the kernel to signal.
"""
self.log.info("Signaled Kernel %s with %s" % (kernel_id, signum))
@kernel_method
def restart_kernel(self, kernel_id, now=False):
"""Restart a kernel by its uuid, keeping the same ports.
Parameters
==========
kernel_id : uuid
The id of the kernel to interrupt.
"""
self.log.info("Kernel restarted: %s" % kernel_id)
@kernel_method
def is_alive(self, kernel_id):
"""Is the kernel alive.
This calls KernelManager.is_alive() which calls Popen.poll on the
actual kernel subprocess.
Parameters
==========
kernel_id : uuid
The id of the kernel.
"""
def _check_kernel_id(self, kernel_id):
"""check that a kernel id is valid"""
if kernel_id not in self:
raise KeyError("Kernel with id not found: %s" % kernel_id)
def get_kernel(self, kernel_id):
"""Get the single KernelManager object for a kernel by its uuid.
Parameters
==========
kernel_id : uuid
The id of the kernel.
"""
self._check_kernel_id(kernel_id)
return self._kernels[kernel_id]
@kernel_method
def add_restart_callback(self, kernel_id, callback, event='restart'):
"""add a callback for the KernelRestarter"""
@kernel_method
def remove_restart_callback(self, kernel_id, callback, event='restart'):
"""remove a callback for the KernelRestarter"""
@kernel_method
def get_connection_info(self, kernel_id):
"""Return a dictionary of connection data for a kernel.
Parameters
==========
kernel_id : uuid
The id of the kernel.
Returns
=======
connection_dict : dict
A dict of the information needed to connect to a kernel.
This includes the ip address and the integer port
numbers of the different channels (stdin_port, iopub_port,
shell_port, hb_port).
"""
@kernel_method
def connect_iopub(self, kernel_id, identity=None):
"""Return a zmq Socket connected to the iopub channel.
Parameters
==========
kernel_id : uuid
The id of the kernel
identity : bytes (optional)
The zmq identity of the socket
Returns
=======
stream : zmq Socket or ZMQStream
"""
@kernel_method
def connect_shell(self, kernel_id, identity=None):
"""Return a zmq Socket connected to the shell channel.
Parameters
==========
kernel_id : uuid
The id of the kernel
identity : bytes (optional)
The zmq identity of the socket
Returns
=======
stream : zmq Socket or ZMQStream
"""
@kernel_method
def connect_stdin(self, kernel_id, identity=None):
"""Return a zmq Socket connected to the stdin channel.
Parameters
==========
kernel_id : uuid
The id of the kernel
identity : bytes (optional)
The zmq identity of the socket
Returns
=======
stream : zmq Socket or ZMQStream
"""
@kernel_method
def connect_hb(self, kernel_id, identity=None):
"""Return a zmq Socket connected to the hb channel.
Parameters
==========
kernel_id : uuid
The id of the kernel
identity : bytes (optional)
The zmq identity of the socket
Returns
=======
stream : zmq Socket or ZMQStream
"""