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DEV: Allow CheckpointManagers to optimize for shared backends....
DEV: Allow CheckpointManagers to optimize for shared backends. On `create_checkpoint` and `restore_checkpoint`, pass a path and a `ContentsManager` to `CheckpointManager` instead of an already-loaded model. The `CheckpointManager` base class provides a correct implementation of these methods that's generic across any ContentsManager, but subclasses are free to specialize when the storage backend of `ContentsManager` is shared.

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threaded.py
230 lines | 6.9 KiB | text/x-python | PythonLexer
""" Defines a KernelClient that provides thread-safe sockets with async callbacks on message replies.
"""
from __future__ import absolute_import
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
# Local imports
from IPython.utils.traitlets import Type, Instance
from IPython.kernel.channels import HBChannel
from IPython.kernel import KernelClient
from IPython.kernel.channels import HBChannel
class ThreadedZMQSocketChannel(object):
"""A ZMQ socket invoking a callback in the ioloop"""
session = None
socket = None
ioloop = None
stream = None
_inspect = None
def __init__(self, socket, session, loop):
"""Create a channel.
Parameters
----------
socket : :class:`zmq.Socket`
The ZMQ socket to use.
session : :class:`session.Session`
The session to use.
loop
A pyzmq ioloop to connect the socket to using a ZMQStream
"""
super(ThreadedZMQSocketChannel, self).__init__()
self.socket = socket
self.session = session
self.ioloop = loop
self.stream = zmqstream.ZMQStream(self.socket, self.ioloop)
self.stream.on_recv(self._handle_recv)
_is_alive = False
def is_alive(self):
return self._is_alive
def start(self):
self._is_alive = True
def stop(self):
self._is_alive = False
def close(self):
if self.socket is not None:
try:
self.socket.close(linger=0)
except Exception:
pass
self.socket = None
def 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)
# let client inspect messages
if self._inspect:
self._inspect(msg)
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.
"""
pass
def process_events(self):
"""Subclasses should override this with a method
processing any pending GUI events.
"""
pass
def flush(self, timeout=1.0):
"""Immediately processes all pending messages on this channel.
This is only used for 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 IOLoopThread(Thread):
"""Run a pyzmq ioloop in a thread to send and receive messages
"""
def __init__(self, loop):
super(IOLoopThread, self).__init__()
self.daemon = True
atexit.register(self._notice_exit)
self.ioloop = loop or ioloop.IOLoop()
def _notice_exit(self):
self._exiting = True
def run(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 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()
def close(self):
if self.ioloop is not None:
try:
self.ioloop.close(all_fds=True)
except Exception:
pass
class ThreadedKernelClient(KernelClient):
""" A KernelClient that provides thread-safe sockets with async callbacks on message replies.
"""
_ioloop = None
@property
def ioloop(self):
if self._ioloop is None:
self._ioloop = ioloop.IOLoop()
return self._ioloop
ioloop_thread = Instance(IOLoopThread)
def start_channels(self, shell=True, iopub=True, stdin=True, hb=True):
if shell:
self.shell_channel._inspect = self._check_kernel_info_reply
self.ioloop_thread = IOLoopThread(self.ioloop)
self.ioloop_thread.start()
super(ThreadedKernelClient, self).start_channels(shell, iopub, stdin, hb)
def _check_kernel_info_reply(self, msg):
"""This is run in the ioloop thread when the kernel info reply is recieved
"""
if msg['msg_type'] == 'kernel_info_reply':
self._handle_kernel_info_reply(msg)
self.shell_channel._inspect = None
def stop_channels(self):
super(ThreadedKernelClient, self).stop_channels()
if self.ioloop_thread.is_alive():
self.ioloop_thread.stop()
iopub_channel_class = Type(ThreadedZMQSocketChannel)
shell_channel_class = Type(ThreadedZMQSocketChannel)
stdin_channel_class = Type(ThreadedZMQSocketChannel)
hb_channel_class = Type(HBChannel)