monitor.py

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#! /usr/bin/env python
# -*- coding: utf-8 -*-
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#            ROBOTICS™
#
#
#  Copyright © 2012 Clearpath Robotics, Inc. 
#  All Rights Reserved
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# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
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#       notice, this list of conditions and the following disclaimer.
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#       documentation and/or other materials provided with the distribution.
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# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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import rospy
import threading


class Monitor(threading.Thread):
  def __init__(self, ports):
    super(Monitor, self).__init__()
    self.ports = ports
    self.finish = threading.Event()

  def run(self):
    while not self.finish:
      rospy.sleep(1.0)
      for name, port in ports.items():
        if not port.is_alive():
          rospy.logerr("Port %s thread died. Signalling node shutdown." % name)
          rospy.signal_shutdown("Node lost thread.")