Regarding multi instance behaviour

[vram]

Hello,

I am trying to run a multi instance sequential behaviour for my service task. I have set the loop counter to 5.

My listener receives a start event from  activiti for each iteration i.e, in this case it receives 5 start events.

But , I get only one end event . Does this single end event mark the completion of all the iterations ?

Also, in the case of failure in any one of the iteration ,  how will this end happen?

It would be great if someone could clarify on this.


Thanks

[frederikherema1]

An error in a multi-instance is handled the same way as it would occur in a simple service-task: transaction is rolled back and process is back in the state it first was.

I assume you're referring to an "execution-listener" on the multi-instance serviceTask? AFAIK, there are called for every execution of the loop:

Take for example org.activiti.engine.impl.bpmn.behavior.SequentialMultiInstanceBehavior

/**
   * Called when the wrapped {@link ActivityBehavior} calls the
   * {@link AbstractBpmnActivityBehavior#leave(ActivityExecution)} method.
   * Handles the completion of one instance, and executes the logic for the sequential behavior.   
   */
  public void leave(ActivityExecution execution) {
    callActivityEndListeners(execution);

If you are indeed referring to a execution-listener on the service-task, and you only see the end-execution-listeners executed once, please comment and perhaps include the bpmn20.xml file.

[vram]

I am referring to the execution listener and the end execution listener is executed only once ( after the completion of all the iterations).I have attached my xml herewith

<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:activiti="http://activiti.org/bpmn" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlnsmgdc="http://www.omg.org/spec/DD/20100524/DC" xmlnsmgdi="http://www.omg.org/spec/DD/20100524/DI" typeLanguage="http://www.w3.org/2001/XMLSchema" expressionLanguage="http://www.w3.org/1999/XPath" targetNamespace="http://www.activiti.org/test">
  <process id="Dia1" name="dia1">
    <documentation>Place documentation for the 'dia1' process here.</documentation>
    <startEvent id="startevent1" name="Start"></startEvent>
    <endEvent id="endevent1" name="End"></endEvent>
    <serviceTask id="servicetask1" name="Service Task" activiti:class="com.mikewidgets.helloWorld.HelloWorldTask">
      <multiInstanceLoopCharacteristics isSequential="true">
        <loopCardinality>8</loopCardinality>
      </multiInstanceLoopCharacteristics>
    </serviceTask>
    <sequenceFlow id="flow1" name="" sourceRef="startevent1" targetRef="servicetask1"></sequenceFlow>
    <sequenceFlow id="flow2" name="" sourceRef="servicetask1" targetRef="endevent1"></sequenceFlow>
  </process>
  <bpmndi:BPMNDiagram id="BPMNDiagram_Dia1">
    <bpmndi:BPMNPlane bpmnElement="Dia1" id="BPMNPlane_Dia1">
      <bpmndi:BPMNShape bpmnElement="startevent1" id="BPMNShape_startevent1">
        <omgdc:Bounds height="35" width="35" x="90" y="150"></omgdc:Bounds>
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape bpmnElement="endevent1" id="BPMNShape_endevent1">
        <omgdc:Bounds height="35" width="35" x="430" y="300"></omgdc:Bounds>
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape bpmnElement="servicetask1" id="BPMNShape_servicetask1">
        <omgdc:Bounds height="55" width="105" x="240" y="160"></omgdc:Bounds>
      </bpmndi:BPMNShape>
      <bpmndi:BPMNEdge bpmnElement="flow1" id="BPMNEdge_flow1">
        <omgdi:waypoint x="125" y="167"></omgdi:waypoint>
        <omgdi:waypoint x="240" y="187"></omgdi:waypoint>
      </bpmndi:BPMNEdge>
      <bpmndi:BPMNEdge bpmnElement="flow2" id="BPMNEdge_flow2">
        <omgdi:waypoint x="345" y="187"></omgdi:waypoint>
        <omgdi:waypoint x="447" y="187"></omgdi:waypoint>
        <omgdi:waypoint x="447" y="300"></omgdi:waypoint>
      </bpmndi:BPMNEdge>
    </bpmndi:BPMNPlane>
  </bpmndi:BPMNDiagram>
</definitions>

[frederikherema1]

Seems like there is NO execution-listener defined in your process, am I right? Or are they added through a BPMNParseListener?

Anyway, I double-checked and I'm seeing different behavior. In my unit-test, the end-listener is called (loopCount +1) times instead of just once:

Code added to MultiInstanceTest

@Deployment(resources = {"org/activiti/engine/test/bpmn/multiinstance/MultiInstanceTest.sequentialServiceTasksWithListeners.bpmn20.xml"})
  public void testSequentialServiceTasksWithListeners() {
   
    HashMap<String, Object> variables = new HashMap<String, Object>();
    variables.put("nrOfLoops", 3);
    variables.put("startCount", 0L);
    variables.put("runCount", 0L);
    variables.put("endCount", 0L);
   
    // Start process
    String procId = runtimeService.startProcessInstanceByKey("miSequentialServiceTasks", variables).getId();
   
    Map<String, Object> variablesAfterRun = runtimeService.getVariables(procId);
    assertEquals(3L, variablesAfterRun.get("startCount"));
    assertEquals(3L, variablesAfterRun.get("runCount"));
    assertEquals(3L, variablesAfterRun.get("endCount"));
  }

<?xml version="1.0" encoding="UTF-8"?>
<definitions id="definition"
  xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:activiti="http://activiti.org/bpmn"
  targetNamespace="Examples">
 
  <process id="miSequentialServiceTasks">
 
    <startEvent id="theStart" />
    <sequenceFlow id="flow1" sourceRef="theStart" targetRef="serviceTask" />
   
    <serviceTask id="serviceTask" name="Do stuff" activiti:expression="${execution.setVariable('runCount', execution.getVariable('runCount') + 1)}">
      <extensionElements>
         <activiti:executionListener expression="${execution.setVariable('endCount', execution.getVariable('endCount') + 1)}" event="end" />
         <activiti:executionListener expression="${execution.setVariable('startCount', execution.getVariable('startCount') + 1)}" event="start" />
      </extensionElements>
      <multiInstanceLoopCharacteristics isSequential="true">
        <loopCardinality>${nrOfLoops}</loopCardinality>
        <completionCondition>${nrOfCompletedInstances == 3}</completionCondition>
      </multiInstanceLoopCharacteristics>
    </serviceTask>
   
    <sequenceFlow id="flow3" sourceRef="serviceTask" targetRef="userTask" />
    <userTask id="userTask" />
   
    <sequenceFlow id="flow4" sourceRef="userTask" targetRef="theEnd" />
    <endEvent id="theEnd" />
   
  </process>

</definitions>


junit.framework.AssertionFailedError: expected:<3> but was:<4>
at junit.framework.Assert.fail(Assert.java:47)
at junit.framework.Assert.failNotEquals(Assert.java:283)
at junit.framework.Assert.assertEquals(Assert.java:64)
at junit.framework.Assert.assertEquals(Assert.java:71)
at org.activiti.engine.test.bpmn.multiinstance.MultiInstanceTest.testSequentialServiceTasksWithListeners(MultiInstanceTest.java:82)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at junit.framework.TestCase.runTest(TestCase.java:168)
at org.activiti.engine.impl.test.PvmTestCase.runTest(PvmTestCase.java:75)
at junit.framework.TestCase.runBare(TestCase.java:134)
at org.activiti.engine.impl.test.AbstractActivitiTestCase.runBare(AbstractActivitiTestCase.java:90)
at junit.framework.TestResult$1.protect(TestResult.java:110)
at junit.framework.TestResult.runProtected(TestResult.java:128)
at junit.framework.TestResult.run(TestResult.java:113)
at junit.framework.TestCase.run(TestCase.java:124)
at junit.framework.TestSuite.runTest(TestSuite.java:232)
at junit.framework.TestSuite.run(TestSuite.java:227)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:83)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:49)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

I've created https://jira.codehaus.org/browse/ACT-1271

[vram]

My execution listener is added through the BPMNParseListener. Though, I see the variable values correctly, the end event is received by my listener only once after all the iterations.The  end event is not received after each iteration.

[frederikherema1]

Okay… Probabily the way the listener is added makes a difference. I looked into the behavior and will take this into account when fixing the related issue. Because listeners added in the process-definition do get fired x+1 times..