forked from s_ranjbar/city_retrofit
121 lines
4.1 KiB
Python
121 lines
4.1 KiB
Python
"""The client and server for a basic ping-pong style heartbeat.
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"""
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#-----------------------------------------------------------------------------
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# Copyright (C) 2008-2011 The IPython Development Team
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#
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# Distributed under the terms of the BSD License. The full license is in
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# the file COPYING, distributed as part of this software.
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#-----------------------------------------------------------------------------
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#-----------------------------------------------------------------------------
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# Imports
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#-----------------------------------------------------------------------------
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import errno
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import os
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import socket
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from threading import Thread
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import zmq
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from jupyter_client.localinterfaces import localhost
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#-----------------------------------------------------------------------------
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# Code
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#-----------------------------------------------------------------------------
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class Heartbeat(Thread):
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"A simple ping-pong style heartbeat that runs in a thread."
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def __init__(self, context, addr=None):
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if addr is None:
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addr = ('tcp', localhost(), 0)
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Thread.__init__(self)
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self.context = context
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self.transport, self.ip, self.port = addr
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self.original_port = self.port
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if self.original_port == 0:
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self.pick_port()
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self.addr = (self.ip, self.port)
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self.daemon = True
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def pick_port(self):
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if self.transport == 'tcp':
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s = socket.socket()
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# '*' means all interfaces to 0MQ, which is '' to socket.socket
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s.bind(('' if self.ip == '*' else self.ip, 0))
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self.port = s.getsockname()[1]
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s.close()
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elif self.transport == 'ipc':
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self.port = 1
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while os.path.exists("%s-%s" % (self.ip, self.port)):
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self.port = self.port + 1
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else:
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raise ValueError("Unrecognized zmq transport: %s" % self.transport)
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return self.port
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def _try_bind_socket(self):
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c = ':' if self.transport == 'tcp' else '-'
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return self.socket.bind('%s://%s' % (self.transport, self.ip) + c + str(self.port))
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def _bind_socket(self):
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try:
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win_in_use = errno.WSAEADDRINUSE
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except AttributeError:
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win_in_use = None
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# Try up to 100 times to bind a port when in conflict to avoid
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# infinite attempts in bad setups
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max_attempts = 1 if self.original_port else 100
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for attempt in range(max_attempts):
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try:
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self._try_bind_socket()
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except zmq.ZMQError as ze:
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if attempt == max_attempts - 1:
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raise
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# Raise if we have any error not related to socket binding
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if ze.errno != errno.EADDRINUSE and ze.errno != win_in_use:
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raise
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# Raise if we have any error not related to socket binding
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if self.original_port == 0:
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self.pick_port()
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else:
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raise
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else:
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return
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def run(self):
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self.socket = self.context.socket(zmq.ROUTER)
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self.socket.linger = 1000
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try:
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self._bind_socket()
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except Exception:
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self.socket.close()
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raise
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while True:
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try:
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zmq.device(zmq.QUEUE, self.socket, self.socket)
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except zmq.ZMQError as e:
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if e.errno == errno.EINTR:
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# signal interrupt, resume heartbeat
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continue
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elif e.errno == zmq.ETERM:
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# context terminated, close socket and exit
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try:
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self.socket.close()
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except zmq.ZMQError:
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# suppress further errors during cleanup
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# this shouldn't happen, though
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pass
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break
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elif e.errno == zmq.ENOTSOCK:
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# socket closed elsewhere, exit
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break
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else:
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raise
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else:
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break
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