Source Code for Module roslaunch.child

  1  # Software License Agreement (BSD License) 
  2  # 
  3  # Copyright (c) 2008, Willow Garage, Inc. 
  4  # All rights reserved. 
  5  # 
  6  # Redistribution and use in source and binary forms, with or without 
  7  # modification, are permitted provided that the following conditions 
  8  # are met: 
  9  # 
 10  #  * Redistributions of source code must retain the above copyright 
 11  #    notice, this list of conditions and the following disclaimer. 
 12  #  * Redistributions in binary form must reproduce the above 
 13  #    copyright notice, this list of conditions and the following 
 14  #    disclaimer in the documentation and/or other materials provided 
 15  #    with the distribution. 
 16  #  * Neither the name of Willow Garage, Inc. nor the names of its 
 17  #    contributors may be used to endorse or promote products derived 
 18  #    from this software without specific prior written permission. 
 19  # 
 20  # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
 21  # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
 22  # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
 23  # FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
 24  # COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
 25  # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
 26  # BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
 27  # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
 28  # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
 29  # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 
 30  # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 31  # POSSIBILITY OF SUCH DAMAGE. 
 32  # 
 33  # Revision $Id: child.py 9195 2010-04-19 18:25:24Z kwc $ 
 34   
 35  """ 
 36  ROSLaunch child server. 
 37   
 38  ROSLaunch has a client/server architecture for running remote 
 39  processes. When a user runs roslaunch, this creates a "parent" 
 40  roslaunch process. This parent process will then start "child" 
 41  processes on remote machines. The parent can then invoke methods on 
 42  this child process to launch remote processes, and the child can 
 43  invoke methods on the parent to provide feedback. 
 44  """ 
 45   
 46  import logging 
 47  import sys 
 48  import time 
 49  import traceback 
 50   
 51  import roslaunch.core  
 52  import roslaunch.pmon 
 53  import roslaunch.server 
 54   
 55 -class ROSLaunchChild(object): 
 56      """ 
 57      ROSLaunchChild infrastructure. 
 58   
 59      This must be called from the Python Main thread due to signal registration. 
 60      """ 
 61   
 62 -    def __init__(self, run_id, name, server_uri): 
 63          """ 
 64          Startup roslaunch remote client XML-RPC services. Blocks until shutdown 
 65          @param run_id: UUID of roslaunch session 
 66          @type  run_id: str 
 67          @param name: name of remote client 
 68          @type  name: str 
 69          @param server_uri: XML-RPC URI of roslaunch server 
 70          @type  server_uri: str 
 71          @return: XML-RPC URI 
 72          @rtype:  str 
 73          """ 
 74          roslaunch.core.set_child_mode(True) 
 75           
 76          self.logger = logging.getLogger("roslaunch.child") 
 77          self.run_id = run_id 
 78          self.name = name 
 79          self.server_uri = server_uri 
 80          self.child_server = None 
 81          self.pm = None 
 82   
 83          roslaunch.pmon._init_signal_handlers() 
 84   
 85 -    def _start_pm(self): 
 86          """ 
 87          Start process monitor for child roslaunch 
 88          """ 
 89          # start process monitor 
 90          #  - this test is mainly here so that testing logic can 
 91          #    override process monitor with a mock 
 92          if self.pm is None: 
 93              self.pm = roslaunch.pmon.start_process_monitor() 
 94          if self.pm is None: 
 95              # this should only happen if a shutdown signal is received during startup 
 96              raise roslaunch.core.RLException("cannot startup remote child: unable to start process monitor.") 
 97          self.logger.debug("started process monitor") 
 98           
 99 -    def run(self): 
100          """ 
101          Runs child. Blocks until child processes exit. 
102          """ 
103          try: 
104              try: 
105                  self.logger.info("starting roslaunch child process [%s], server URI is [%s]", self.name, self.server_uri) 
106                  self._start_pm() 
107                  self.child_server = roslaunch.server.ROSLaunchChildNode(self.run_id, self.name, self.server_uri, self.pm) 
108                  self.logger.info("... creating XMLRPC server for child") 
109                  self.child_server.start() 
110                  self.logger.info("... started XMLRPC server for child") 
111                  # block until process monitor is shutdown 
112                  self.pm.mainthread_spin() 
113                  self.logger.info("... process monitor is done spinning") 
114              except: 
115                  self.logger.error(traceback.format_exc()) 
116                  raise 
117          finally: 
118              if self.pm: 
119                  self.pm.shutdown() 
120                  self.pm.join() 
121              if self.child_server: 
122                  self.child_server.shutdown('roslaunch child complete') 
123   
124 -    def shutdown(self): 
125          if self.pm: 
126              self.pm.shutdown() 
127              self.pm.join() 
128