Collapse ZMQSocketChannel into HBChannel class

IPython/kernel/channels.py

@@ -1,338 +1,259 b''
 """Base classes to manage a Client's interaction with a running kernel"""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 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
 
 from IPython.core.release import kernel_protocol_version_info
 
 from .channelsabc import (
     ShellChannelABC, IOPubChannelABC,
     HBChannelABC, StdInChannelABC,
 )
 from IPython.utils.py3compat import string_types, iteritems
 
 #-----------------------------------------------------------------------------
 # Constants and exceptions
 #-----------------------------------------------------------------------------
 
 major_protocol_version = kernel_protocol_version_info[0]
 
 class InvalidPortNumber(Exception):
     pass
 
 #-----------------------------------------------------------------------------
 # Utility functions
 #-----------------------------------------------------------------------------
 
 # some utilities to validate message structure, these might get moved elsewhere
 # if they prove to have more generic utility
 
 def validate_string_list(lst):
     """Validate that the input is a list of strings.
 
     Raises ValueError if not."""
     if not isinstance(lst, list):
         raise ValueError('input %r must be a list' % lst)
     for x in lst:
         if not isinstance(x, string_types):
             raise ValueError('element %r in list must be a string' % x)
 
 
 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)
 
 
-#-----------------------------------------------------------------------------
-# ZMQ Socket Channel classes
-#-----------------------------------------------------------------------------
-
-class ZMQSocketChannel(Thread):
-    """The base class for the channels that use ZMQ sockets."""
-    context = None
-    session = None
-    socket = None
-    ioloop = None
-    stream = None
-    _address = None
-    _exiting = False
-    proxy_methods = []
-
-    def __init__(self, context, session, address):
-        """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(ZMQSocketChannel, self).__init__()
-        self.daemon = True
-
-        self.context = context
-        self.session = session
-        if isinstance(address, tuple):
-            if address[1] == 0:
-                message = 'The port number for a channel cannot be 0.'
-                raise InvalidPortNumber(message)
-            address = "tcp://%s:%i" % address
-        self._address = address
-        atexit.register(self._notice_exit)
-
-    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 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
-        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 make_shell_socket(context, identity, address):
     socket = context.socket(zmq.DEALER)
     socket.linger = 1000
     socket.setsockopt(zmq.IDENTITY, identity)
     socket.connect(address)
     return socket
 
 def make_iopub_socket(context, identity, address):
     socket = context.socket(zmq.SUB)
     socket.linger = 1000
     socket.setsockopt(zmq.SUBSCRIBE,b'')
     socket.setsockopt(zmq.IDENTITY, identity)
     socket.connect(address)
     return socket
 
 def make_stdin_socket(context, identity, address):
     socket = context.socket(zmq.DEALER)
     socket.linger = 1000
     socket.setsockopt(zmq.IDENTITY, identity)
     socket.connect(address)
     return socket
 
-class HBChannel(ZMQSocketChannel):
+class HBChannel(Thread):
     """The heartbeat channel which monitors the kernel heartbeat.
 
     Note that the heartbeat channel is paused by default. As long as you start
     this channel, the kernel manager will ensure that it is paused and un-paused
     as appropriate.
     """
+    context = None
+    session = None
+    socket = None
+    address = None
+    _exiting = False
 
     time_to_dead = 1.
-    socket = None
     poller = None
     _running = None
     _pause = None
     _beating = None
 
     def __init__(self, context, session, address):
-        super(HBChannel, self).__init__(context, session, address)
+        """Create the heartbeat monitor thread.
+
+        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(HBChannel, self).__init__()
+        self.daemon = True
+
+        self.context = context
+        self.session = session
+        if isinstance(address, tuple):
+            if address[1] == 0:
+                message = 'The port number for a channel cannot be 0.'
+                raise InvalidPortNumber(message)
+            address = "tcp://%s:%i" % address
+        self.address = address
+        atexit.register(self._notice_exit)
+
         self._running = False
         self._pause =True
         self.poller = zmq.Poller()
 
+    def _notice_exit(self):
+        self._exiting = True
+
     def _create_socket(self):
         if self.socket is not None:
             # close previous socket, before opening a new one
             self.poller.unregister(self.socket)
             self.socket.close()
         self.socket = self.context.socket(zmq.REQ)
         self.socket.linger = 1000
         self.socket.connect(self.address)
 
         self.poller.register(self.socket, zmq.POLLIN)
 
     def _poll(self, start_time):
         """poll for heartbeat replies until we reach self.time_to_dead.
 
         Ignores interrupts, and returns the result of poll(), which
         will be an empty list if no messages arrived before the timeout,
         or the event tuple if there is a message to receive.
         """
 
         until_dead = self.time_to_dead - (time.time() - start_time)
         # ensure poll at least once
         until_dead = max(until_dead, 1e-3)
         events = []
         while True:
             try:
                 events = self.poller.poll(1000 * until_dead)
             except ZMQError as e:
                 if e.errno == errno.EINTR:
                     # ignore interrupts during heartbeat
                     # this may never actually happen
                     until_dead = self.time_to_dead - (time.time() - start_time)
                     until_dead = max(until_dead, 1e-3)
                     pass
                 else:
                     raise
             except Exception:
                 if self._exiting:
                     break
                 else:
                     raise
             else:
                 break
         return events
 
     def run(self):
         """The thread's main activity.  Call start() instead."""
         self._create_socket()
         self._running = True
         self._beating = True
 
         while self._running:
             if self._pause:
                 # just sleep, and skip the rest of the loop
                 time.sleep(self.time_to_dead)
                 continue
 
             since_last_heartbeat = 0.0
             # io.rprint('Ping from HB channel') # dbg
             # no need to catch EFSM here, because the previous event was
             # either a recv or connect, which cannot be followed by EFSM
             self.socket.send(b'ping')
             request_time = time.time()
             ready = self._poll(request_time)
             if ready:
                 self._beating = True
                 # the poll above guarantees we have something to recv
                 self.socket.recv()
                 # sleep the remainder of the cycle
                 remainder = self.time_to_dead - (time.time() - request_time)
                 if remainder > 0:
                     time.sleep(remainder)
                 continue
             else:
                 # nothing was received within the time limit, signal heart failure
                 self._beating = False
                 since_last_heartbeat = time.time() - request_time
                 self.call_handlers(since_last_heartbeat)
                 # and close/reopen the socket, because the REQ/REP cycle has been broken
                 self._create_socket()
                 continue
 
     def pause(self):
         """Pause the heartbeat."""
         self._pause = True
 
     def unpause(self):
         """Unpause the heartbeat."""
         self._pause = False
 
     def is_beating(self):
         """Is the heartbeat running and responsive (and not paused)."""
         if self.is_alive() and not self._pause and self._beating:
             return True
         else:
             return False
 
     def stop(self):
         """Stop the channel's event loop and join its thread."""
         self._running = False
-        super(HBChannel, self).stop()
+        self.join()
+        self.close()
+
+    def close(self):
+        if self.socket is not None:
+            try:
+                self.socket.close(linger=0)
+            except Exception:
+                pass
+            self.socket = None
 
     def call_handlers(self, since_last_heartbeat):
         """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
 
 
 HBChannelABC.register(HBChannel)