File size: 11,283 Bytes
d1ceb73 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 |
""" Defines a KernelClient that provides thread-safe sockets with async callbacks on message
replies.
"""
import asyncio
import atexit
import time
from concurrent.futures import Future
from functools import partial
from threading import Thread
from typing import Any, Dict, List, Optional
import zmq
from tornado.ioloop import IOLoop
from traitlets import Instance, Type
from traitlets.log import get_logger
from zmq.eventloop import zmqstream
from .channels import HBChannel
from .client import KernelClient
from .session import Session
# Local imports
# import ZMQError in top-level namespace, to avoid ugly attribute-error messages
# during garbage collection of threads at exit
class ThreadedZMQSocketChannel:
"""A ZMQ socket invoking a callback in the ioloop"""
session = None
socket = None
ioloop = None
stream = None
_inspect = None
def __init__(
self,
socket: Optional[zmq.Socket],
session: Optional[Session],
loop: Optional[IOLoop],
) -> None:
"""Create a channel.
Parameters
----------
socket : :class:`zmq.Socket`
The ZMQ socket to use.
session : :class:`session.Session`
The session to use.
loop
A tornado ioloop to connect the socket to using a ZMQStream
"""
super().__init__()
self.socket = socket
self.session = session
self.ioloop = loop
f: Future = Future()
def setup_stream() -> None:
try:
assert self.socket is not None
self.stream = zmqstream.ZMQStream(self.socket, self.ioloop)
self.stream.on_recv(self._handle_recv)
except Exception as e:
f.set_exception(e)
else:
f.set_result(None)
assert self.ioloop is not None
self.ioloop.add_callback(setup_stream)
# don't wait forever, raise any errors
f.result(timeout=10)
_is_alive = False
def is_alive(self) -> bool:
"""Whether the channel is alive."""
return self._is_alive
def start(self) -> None:
"""Start the channel."""
self._is_alive = True
def stop(self) -> None:
"""Stop the channel."""
self._is_alive = False
def close(self) -> None:
"""Close the channel."""
if self.stream is not None and self.ioloop is not None:
# c.f.Future for threadsafe results
f: Future = Future()
def close_stream() -> None:
try:
if self.stream is not None:
self.stream.close(linger=0)
self.stream = None
except Exception as e:
f.set_exception(e)
else:
f.set_result(None)
self.ioloop.add_callback(close_stream)
# wait for result
try:
f.result(timeout=5)
except Exception as e:
log = get_logger()
msg = f"Error closing stream {self.stream}: {e}"
log.warning(msg, RuntimeWarning, stacklevel=2)
if self.socket is not None:
try:
self.socket.close(linger=0)
except Exception:
pass
self.socket = None
def send(self, msg: Dict[str, Any]) -> None:
"""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() -> None:
assert self.session is not None
self.session.send(self.stream, msg)
assert self.ioloop is not None
self.ioloop.add_callback(thread_send)
def _handle_recv(self, msg_list: List) -> None:
"""Callback for stream.on_recv.
Unpacks message, and calls handlers with it.
"""
assert self.ioloop is not None
assert self.session is not None
ident, smsg = self.session.feed_identities(msg_list)
msg = self.session.deserialize(smsg)
# let client inspect messages
if self._inspect:
self._inspect(msg) # type:ignore[unreachable]
self.call_handlers(msg)
def call_handlers(self, msg: Dict[str, Any]) -> None:
"""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) -> None:
"""Subclasses should override this with a method
processing any pending GUI events.
"""
pass
def flush(self, timeout: float = 1.0) -> None:
"""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.monotonic() + timeout
assert self.ioloop is not None
if self.stream is None or self.stream.closed():
# don't bother scheduling flush on a thread if we're closed
_msg = "Attempt to flush closed stream"
raise OSError(_msg)
def flush(f: Any) -> None:
try:
self._flush()
except Exception as e:
f.set_exception(e)
else:
f.set_result(None)
for _ in range(2):
f: Future = Future()
self.ioloop.add_callback(partial(flush, f))
# wait for async flush, re-raise any errors
timeout = max(stop_time - time.monotonic(), 0)
try:
f.result(max(stop_time - time.monotonic(), 0))
except TimeoutError:
# flush with a timeout means stop waiting, not raise
return
def _flush(self) -> None:
"""Callback for :method:`self.flush`."""
assert self.stream is not None
self.stream.flush()
self._flushed = True
class IOLoopThread(Thread):
"""Run a pyzmq ioloop in a thread to send and receive messages"""
_exiting = False
ioloop = None
def __init__(self) -> None:
"""Initialize an io loop thread."""
super().__init__()
self.daemon = True
@staticmethod
@atexit.register
def _notice_exit() -> None:
# Class definitions can be torn down during interpreter shutdown.
# We only need to set _exiting flag if this hasn't happened.
if IOLoopThread is not None:
IOLoopThread._exiting = True
def start(self) -> None:
"""Start the IOLoop thread
Don't return until self.ioloop is defined,
which is created in the thread
"""
self._start_future: Future = Future()
Thread.start(self)
# wait for start, re-raise any errors
self._start_future.result(timeout=10)
def run(self) -> None:
"""Run my loop, ignoring EINTR events in the poller"""
try:
loop = asyncio.new_event_loop()
asyncio.set_event_loop(loop)
async def assign_ioloop() -> None:
self.ioloop = IOLoop.current()
loop.run_until_complete(assign_ioloop())
except Exception as e:
self._start_future.set_exception(e)
else:
self._start_future.set_result(None)
loop.run_until_complete(self._async_run())
async def _async_run(self) -> None:
"""Run forever (until self._exiting is set)"""
while not self._exiting:
await asyncio.sleep(1)
def stop(self) -> None:
"""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.
"""
self._exiting = True
self.join()
self.close()
self.ioloop = None
def __del__(self) -> None:
self.close()
def close(self) -> None:
"""Close the io loop thread."""
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."""
@property
def ioloop(self) -> Optional[IOLoop]: # type:ignore[override]
if self.ioloop_thread:
return self.ioloop_thread.ioloop
return None
ioloop_thread = Instance(IOLoopThread, allow_none=True)
def start_channels(
self,
shell: bool = True,
iopub: bool = True,
stdin: bool = True,
hb: bool = True,
control: bool = True,
) -> None:
"""Start the channels on the client."""
self.ioloop_thread = IOLoopThread()
self.ioloop_thread.start()
if shell:
self.shell_channel._inspect = self._check_kernel_info_reply
super().start_channels(shell, iopub, stdin, hb, control)
def _check_kernel_info_reply(self, msg: Dict[str, Any]) -> None:
"""This is run in the ioloop thread when the kernel info reply is received"""
if msg["msg_type"] == "kernel_info_reply":
self._handle_kernel_info_reply(msg)
self.shell_channel._inspect = None
def stop_channels(self) -> None:
"""Stop the channels on the client."""
super().stop_channels()
if self.ioloop_thread and self.ioloop_thread.is_alive():
self.ioloop_thread.stop()
iopub_channel_class = Type(ThreadedZMQSocketChannel) # type:ignore[arg-type]
shell_channel_class = Type(ThreadedZMQSocketChannel) # type:ignore[arg-type]
stdin_channel_class = Type(ThreadedZMQSocketChannel) # type:ignore[arg-type]
hb_channel_class = Type(HBChannel) # type:ignore[arg-type]
control_channel_class = Type(ThreadedZMQSocketChannel) # type:ignore[arg-type]
def is_alive(self) -> bool:
"""Is the kernel process still running?"""
if self._hb_channel is not None:
# We don't have access to the KernelManager,
# so we use the heartbeat.
return self._hb_channel.is_beating()
# no heartbeat and not local, we can't tell if it's running,
# so naively return True
return True
|