""" Defines a KernelClient that provides signals and slots. """ 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 from IPython.external.qt import QtCore # Local imports from IPython.utils.traitlets import Type from IPython.kernel.channels import HBChannel,\ make_shell_socket, make_iopub_socket, make_stdin_socket from IPython.kernel import KernelClient from .kernel_mixins import (QtHBChannelMixin, QtKernelClientMixin) from .util import SuperQObject class QtHBChannel(QtHBChannelMixin, HBChannel): pass from IPython.core.release import kernel_protocol_version_info from IPython.kernel.channelsabc import ( ShellChannelABC, IOPubChannelABC, StdInChannelABC, ) from IPython.utils.py3compat import string_types, iteritems major_protocol_version = kernel_protocol_version_info[0] class InvalidPortNumber(Exception): pass # some utilities to validate message structure, these might get moved elsewhere # if they prove to have more generic utility def validate_string_dict(dct): """Validate that the input is a dict with string keys and values. Raises ValueError if not.""" for k,v in iteritems(dct): if not isinstance(k, string_types): raise ValueError('key %r in dict must be a string' % k) if not isinstance(v, string_types): raise ValueError('value %r in dict must be a string' % v) class QtZMQSocketChannel(SuperQObject, Thread): """The base class for the channels that use ZMQ sockets.""" session = None socket = None ioloop = None stream = None _exiting = False proxy_methods = [] # Emitted when the channel is started. started = QtCore.Signal() # Emitted when the channel is stopped. stopped = QtCore.Signal() message_received = QtCore.Signal(object) #--------------------------------------------------------------------------- # InProcessChannel interface #--------------------------------------------------------------------------- def call_handlers_later(self, *args, **kwds): """ Call the message handlers later. """ do_later = lambda: self.call_handlers(*args, **kwds) QtCore.QTimer.singleShot(0, do_later) def process_events(self): """ Process any pending GUI events. """ QtCore.QCoreApplication.instance().processEvents() def __init__(self, socket, session): """Create a channel. Parameters ---------- context : :class:`zmq.Context` The ZMQ context to use. session : :class:`session.Session` The session to use. address : zmq url Standard (ip, port) tuple that the kernel is listening on. """ super(QtZMQSocketChannel, self).__init__() self.daemon = True self.socket = socket self.session = session atexit.register(self._notice_exit) self.ioloop = ioloop.IOLoop() def _notice_exit(self): self._exiting = True def _run_loop(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 start(self): """ Reimplemented to emit signal. """ super(QtZMQSocketChannel, self).start() self.started.emit() def run(self): """The thread's main activity. Call start() instead.""" self.stream = zmqstream.ZMQStream(self.socket, self.ioloop) self.stream.on_recv(self._handle_recv) self._run_loop() 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() self.stopped.emit() def close(self): if self.ioloop is not None: try: self.ioloop.close(all_fds=True) except Exception: pass if self.socket is not None: try: self.socket.close(linger=0) except Exception: pass self.socket = None @property def address(self): """Get the channel's address as a zmq url string. These URLS have the form: 'tcp://127.0.0.1:5555'. """ return self._address def _queue_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) 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. """ # Emit the generic signal. self.message_received.emit(msg) 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 QtKernelClient(QtKernelClientMixin, KernelClient): """ A KernelClient that provides signals and slots. """ def start_channels(self, shell=True, iopub=True, stdin=True, hb=True): if shell: self.shell_channel.message_received.connect(self._check_kernel_info_reply) super(QtKernelClient, self).start_channels(shell, iopub, stdin, hb) def _check_kernel_info_reply(self, msg): if msg['msg_type'] == 'kernel_info_reply': self._handle_kernel_info_reply(msg) self.shell_channel.message_received.disconnect(self._check_kernel_info_reply) iopub_channel_class = Type(QtZMQSocketChannel) shell_channel_class = Type(QtZMQSocketChannel) stdin_channel_class = Type(QtZMQSocketChannel) hb_channel_class = Type(QtHBChannel)