Source Code for Module roslaunch.child

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 33  # Revision $Id$ 
 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 traceback 
 48   
 49  import roslaunch.core 
 50  import roslaunch.pmon 
 51  import roslaunch.server 
 52   
 53 -class ROSLaunchChild(object): 
 54      """ 
 55      ROSLaunchChild infrastructure. 
 56   
 57      This must be called from the Python Main thread due to signal registration. 
 58      """ 
 59   
 60 -    def __init__(self, run_id, name, server_uri): 
 61          """ 
 62          Startup roslaunch remote client XML-RPC services. Blocks until shutdown 
 63          @param run_id: UUID of roslaunch session 
 64          @type  run_id: str 
 65          @param name: name of remote client 
 66          @type  name: str 
 67          @param server_uri: XML-RPC URI of roslaunch server 
 68          @type  server_uri: str 
 69          @return: XML-RPC URI 
 70          @rtype:  str 
 71          """ 
 72          roslaunch.core.set_child_mode(True) 
 73           
 74          self.logger = logging.getLogger("roslaunch.child") 
 75          self.run_id = run_id 
 76          self.name = name 
 77          self.server_uri = server_uri 
 78          self.child_server = None 
 79          self.pm = None 
 80   
 81          roslaunch.pmon._init_signal_handlers() 
 82   
 83 -    def _start_pm(self): 
 84          """ 
 85          Start process monitor for child roslaunch 
 86          """ 
 87          # start process monitor 
 88          #  - this test is mainly here so that testing logic can 
 89          #    override process monitor with a mock 
 90          if self.pm is None: 
 91              self.pm = roslaunch.pmon.start_process_monitor() 
 92          if self.pm is None: 
 93              # this should only happen if a shutdown signal is received during startup 
 94              raise roslaunch.core.RLException("cannot startup remote child: unable to start process monitor.") 
 95          self.logger.debug("started process monitor") 
 96           
 97 -    def run(self): 
 98          """ 
 99          Runs child. Blocks until child processes exit. 
100          """ 
101          try: 
102              try: 
103                  self.logger.info("starting roslaunch child process [%s], server URI is [%s]", self.name, self.server_uri) 
104                  self._start_pm() 
105                  self.child_server = roslaunch.server.ROSLaunchChildNode(self.run_id, self.name, self.server_uri, self.pm) 
106                  self.logger.info("... creating XMLRPC server for child") 
107                  self.child_server.start() 
108                  self.logger.info("... started XMLRPC server for child") 
109                  # block until process monitor is shutdown 
110                  self.pm.mainthread_spin() 
111                  self.logger.info("... process monitor is done spinning") 
112              except: 
113                  self.logger.error(traceback.format_exc()) 
114                  raise 
115          finally: 
116              if self.pm: 
117                  self.pm.shutdown() 
118                  self.pm.join() 
119              if self.child_server: 
120                  self.child_server.shutdown('roslaunch child complete') 
121   
122 -    def shutdown(self): 
123          if self.pm: 
124              self.pm.shutdown() 
125              self.pm.join() 
126