[rules-users] order of injected events

[Chris Richmond]

I am running a simple test like so:

package com.sample;

import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderError;
import org.drools.builder.KnowledgeBuilderErrors;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.io.ResourceFactory;
import org.drools.logger.KnowledgeRuntimeLogger;
import org.drools.logger.KnowledgeRuntimeLoggerFactory;
import org.drools.runtime.KnowledgeSessionConfiguration;
import org.drools.runtime.StatefulKnowledgeSession;
import org.drools.runtime.conf.ClockTypeOption;
import org.drools.runtime.rule.WorkingMemoryEntryPoint;

import com.sample.DroolsTest.Message;

public class FusionMain {

   public static final void main(String[] args) {




     try {

       KnowledgeSessionConfiguration config = 
KnowledgeBaseFactory.newKnowledgeSessionConfiguration();
       config.setOption( ClockTypeOption.get("realtime") );
       KnowledgeBase kbase;
       kbase = readKnowledgeBase();
       final StatefulKnowledgeSession ksession = 
kbase.newStatefulKnowledgeSession();

       WorkingMemoryEntryPoint myStream = 
ksession.getWorkingMemoryEntryPoint("My Stream");

       Thread t = new Thread(new Runnable(){

         @Override
         public void run() {
           ksession.fireUntilHalt();

         }

       });

       t.start();

       for (float x = 0.0f; x < 20.0f; x++){
         DataReading dr = new DataReading("Reading " + x, x);
         myStream.insert(dr);
       }


     } catch (Exception e) {
       // TODO Auto-generated catch block
       e.printStackTrace();
     }

   }

   private static KnowledgeBase readKnowledgeBase() throws Exception {
     KnowledgeBuilder kbuilder = 
KnowledgeBuilderFactory.newKnowledgeBuilder();
     kbuilder.add(ResourceFactory.newClassPathResource("Sample.drl"), 
ResourceType.DRL);
     KnowledgeBuilderErrors errors = kbuilder.getErrors();
     if (errors.size() > 0) {
       for (KnowledgeBuilderError error: errors) {
         System.err.println(error);
       }
       throw new IllegalArgumentException("Could not parse knowledge.");
     }
     KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
     kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
     return kbase;
   }


}

With the following rule in the sample.drl file:

package com.sample
import com.sample.DroolsTest.Message;
import java.util.Date;

declare DataReading
     @role( event )

end

rule "MyGuidedRule"
     dialect "mvel"
     when
         $dr: DataReading( reading > "10.0" ) from entry-point "My Stream"
     then
         System.err.println("Reading: " +  $dr.name + " > 10.0 " + 
System.currentTimeMillis());
end

know I am running fireUntilHalt on a seperate thread as you can see, but 
events injected fire rules out of order...in fact almost the exact 
opposite order in which they were inserted to the stream every time:

Reading: Reading 19.0 > 10.0 1311325346490
Reading: Reading 18.0 > 10.0 1311325346491
Reading: Reading 17.0 > 10.0 1311325346491
Reading: Reading 16.0 > 10.0 1311325346491
Reading: Reading 15.0 > 10.0 1311325346491
Reading: Reading 14.0 > 10.0 1311325346491
Reading: Reading 13.0 > 10.0 1311325346491
Reading: Reading 12.0 > 10.0 1311325346491
Reading: Reading 11.0 > 10.0 1311325346491

I want to eventually perform temporal reasoning, but how can I expect 
that to work if events are not evaluated in the order they were inserted.

Perhaps I am setting up my session/kb improperly?

Thanks,
Chris