param_updater.py

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# Copyright (c) 2012, Willow Garage, Inc.
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# Author: Isaac Saito, Ze'ev Klapow
 
import threading
import time
 
from rospy import ServiceException
 
from rqt_reconfigure import logging
 
 
class ParamUpdater(threading.Thread):
    """
    Using dynamic_reconfigure that is passed in __init__, this thread updates
    the Dynamic Reconfigure server's value.
 
    This class works for a single element in a single parameter.
    """
 
    # TODO: Modify variable names to the ones that's more intuitive.
 
    def __init__(self, reconf):
        """
        :type reconf: dynamic_reconfigure
        """
        super(ParamUpdater, self).__init__()
        self.setDaemon(True)
 
        self._reconf = reconf
        self._condition_variable = threading.Condition()
        self._configs_pending = {}
        self._timestamp_last_pending = None
        self._stop_flag = False
 
    def run(self):
        _timestamp_last_commit = None
 
        logging.debug(' ParamUpdater started')
 
        while not self._stop_flag:
            if self._timestamp_last_pending is None or _timestamp_last_commit >= self._timestamp_last_pending:
                with self._condition_variable:
                    logging.debug(' ParamUpdater loop 1.1')
                    self._condition_variable.wait()
                    logging.debug(' ParamUpdater loop 1.2')
            logging.debug(' ParamUpdater loop 2')
 
            if self._stop_flag:
                return
 
            _timestamp_last_commit = time.time()
            configs_tobe_updated = self._configs_pending.copy()
            self._configs_pending = {}
 
            logging.debug('  run last_commit={}, last_pend={}'.format(
                _timestamp_last_commit, self._timestamp_last_pending))
 
            try:
                self._reconf.update_configuration(configs_tobe_updated)
            except ServiceException as ex:
                logging.debug('Could not update configs due to {}'.format(
                    ex.value))
            except Exception as exc:
                raise exc
 
    def update(self, config):
        with self._condition_variable:
            for name, value in config.items():
                self._configs_pending[name] = value
 
            self._timestamp_last_pending = time.time()
 
            self._condition_variable.notify()
 
    def stop(self):
        self._stop_flag = True
        with self._condition_variable:
            self._condition_variable.notify()