Getting an error while deploying an agent in a node

Question

I have written an agent to calculate the distance between two nodes,but when deploying the agent on one of the nodes, following error occurred :

BUG! exception in phase 'semantic analysis' in source unit 'Script26.groovy' The lookup for node_agent caused a failed compilation. There should not have been any compilation from this call.

I have used the command container.add 'myagent' , new node_agent()

Following are the code snippets.

//! Simulation: Simple 3-node network
import org.arl.fjage.*

println '''
3-node network
--------------
'''

platform = RealTimePlatform

// run the simulation forever
simulate {
  
  node '1', address: 101, location: [ 0.km, 0.km, -15.m], web:8081,api: 1101, shell: true, stack: "$home/etc/setup"
  node '2', address: 102, location: [ 0.km, 1.km, -15.m], web:8082,api: 1102, shell: 5101, stack: "$home/etc/setup"
  node '3', address: 103, location: [-1.km, 0.km, -15.m], web:8083,api: 1103, shell: 5102, stack: "$home/etc/setup"
  
  node 'B', address: 104, location: [ 1.km, 0.km, -15.m], web:8084,api: 1104, shell: 5103, stack: "$home/etc/setup"

}

node_agent.groovy placed in the classes folder

import org.arl.fjage.Message
import org.arl.unet.*
import org.arl.unet.net.Router
import org.arl.unet.phy.*
import org.arl.unet.mac.*
import org.arl.fjage.RealTimePlatform
import org.arl.unet.nodeinfo.NodeInfo
import org.arl.fjage.*
import org.arl.unet.phy.Ranging.*
import org.arl.unet.phy.RangeNtf.*
import org.arl.unet.phy.RangeReq 


class node_agent extends UnetAgent {
  int addr;
    float neighbor_distance;

    void startup() 
    {

      def phy = agentForService Services.PHYSICAL;
      subscribe topic(phy);

      def ranging = agentForService Services.RANGING;
      subscribe topic(ranging);

      def nodeInfo = agentForService Services.NODE_INFO;
      addr = nodeInfo.address;
      
      ranging<< new RangeReq(to: host('3')); 
      
    }

    void processMessage(Message msg) {

    if (msg instanceof RangeNtf )
    {   
        float neighbor_distance = msg.getRange();
        println " Distance between node "+addr + " and neighbor 3 is" + neighbor_distance;
    }  
   }  
}

Answer 1

In UnetStack 3.2.0, the RangeNtf class (and other ranging related classes) has moved to the org.arl.unet.localization package. See https://unetstack.net/javadoc/3.2/org/arl/unet/localization/RangeNtf.html. So your imports are incorrect.

In general, as described in this post (as pointed out by Jay Patel in the comment above), the way to find such problems is to manually compile the Groovy agent:

$ groovy -cp lib/unet-framework-3.2.0.jar:lib/fjage-1.8.0.jar:lib/unet-basic-3.2.0.jar classes/node_agent.groovy
org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
unet/classes/node_agent.groovy: 11: unable to resolve class org.arl.unet.phy.RangeReq
 @ line 11, column 1.
   import org.arl.unet.phy.RangeReq
   ^

/Users/mandar/Projects/unet/node_agent.groovy: 36: unable to resolve class RangeNtf
 @ line 36, column 24.
       if (msg instanceof RangeNtf )
                          ^

2 errors