Remove async-send-event attribute from commandContext while sending event (#4123)

* Remove async-send-event attribute from commandContext when sending event

* Only re-add async-send-event attribute if it was there in the first place

Author: BertMatthys

modules/flowable-engine/src/main/java/org/flowable/engine/impl/bpmn/behavior/SendEventTaskActivityBehavior.java

@@ -98,6 +98,8 @@ public void execute(DelegateExecution execution) {
             jobService.scheduleAsyncJob(job);
 
         } else {
+            commandContext.removeAttribute(AsyncSendEventJobHandler.TYPE);
+
             Collection<EventPayloadInstance> eventPayloadInstances = EventInstanceBpmnUtil.createEventPayloadInstances(executionEntity,
                     processEngineConfiguration.getExpressionManager(), execution.getCurrentFlowElement(), eventModel);
 
@@ -112,6 +114,9 @@ public void execute(DelegateExecution execution) {
                 eventRegistry.sendSystemEventOutbound(eventInstance);
             }
 
+            if (executedAsAsyncJob) {
+                commandContext.addAttribute(AsyncSendEventJobHandler.TYPE, true);
+            }
         }
 
         if (sendEventServiceTask.isTriggerable() && !executedAsAsyncJob) {

modules/flowable-engine/src/test/java/org/flowable/engine/test/eventregistry/SendEventTaskTest.java

@@ -188,6 +188,42 @@ public void testSequentialMultiInstanceSendEvent() {
         }
     }
 
+    @Test
+    @Deployment(resources = { "org/flowable/engine/test/eventregistry/SendEventTaskTest.testReceiveAndSendEvent.bpmn20.xml",
+            "org/flowable/engine/test/eventregistry/SendEventTaskTest.testSendEventOnSystemChannel.bpmn20.xml" })
+    public void testSendAsyncAndReceiveOnSystemChannelAndSendAsyncAgain() throws Exception {
+        ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("process");
+        ProcessInstance processInstance2 = runtimeService.startProcessInstanceByKey("sendAndReceiveProcess");
+
+        assertThat(outboundEventChannelAdapter.receivedEvents).isEmpty();
+
+        Task task = taskService.createTaskQuery().processInstanceId(processInstance.getId()).singleResult();
+        assertThat(task).isNotNull();
+
+        taskService.complete(task.getId());
+
+        Job job = managementService.createJobQuery().processInstanceId(processInstance.getId()).singleResult();
+        assertThat(job).isNotNull();
+        assertThat(job.getJobHandlerType()).isEqualTo(AsyncSendEventJobHandler.TYPE);
+        assertThat(job.getElementId()).isEqualTo("sendEventTask");
+
+        assertThat(outboundEventChannelAdapter.receivedEvents).isEmpty();
+
+        managementService.executeJob(job.getId());
+
+        assertThat(outboundEventChannelAdapter.receivedEvents).hasSize(1);
+
+        // Second send event task should also be handled async
+        job = managementService.createJobQuery().processInstanceId(processInstance2.getId()).singleResult();
+        assertThat(job).isNotNull();
+        assertThat(job.getJobHandlerType()).isEqualTo(AsyncSendEventJobHandler.TYPE);
+        assertThat(job.getElementId()).isEqualTo("sendEventTask2");
+
+        JobTestHelper.waitForJobExecutorToProcessAllJobs(processEngineConfiguration, managementService, 5000, 200);
+
+        assertThat(outboundEventChannelAdapter.receivedEvents).hasSize(2);
+    }
+
     @Test
     @Deployment
     public void testSendEventSynchronously() throws Exception {

modules/flowable-engine/src/test/resources/org/flowable/engine/test/eventregistry/SendEventTaskTest.testReceiveAndSendEvent.bpmn20.xml

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<definitions id="definitions" 
+  xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
+  xmlns:flowable="http://flowable.org/bpmn"
+  targetNamespace="Examples"
+  xmlns:tns="Examples">
+  
+  <process id="sendAndReceiveProcess">
+
+    <startEvent id="theStart" />
+  	
+  	<sequenceFlow sourceRef="theStart" targetRef="ReceiveEventTask_1" />
+
+    <receiveTask id="ReceiveEventTask_1" name="Receive event task">
+      <extensionElements>
+          <flowable:eventType><![CDATA[myEvent]]></flowable:eventType>
+      </extensionElements>
+    </receiveTask>
+
+    <sequenceFlow sourceRef="ReceiveEventTask_1" targetRef="sendEventTask2" />
+
+    <serviceTask id="sendEventTask2" flowable:type="send-event">
+      <extensionElements>
+          <flowable:eventType>myEvent</flowable:eventType>
+          <flowable:channelKey>out-channel</flowable:channelKey>
+          <flowable:eventInParameter source="test" target="eventProperty" />
+      </extensionElements>
+    </serviceTask>
+  	
+  	<sequenceFlow sourceRef="sendEventTask2" targetRef="theEnd" />
+    
+    <endEvent id="theEnd" />
+    
+  </process>
+
+</definitions>

modules/flowable-engine/src/test/resources/org/flowable/engine/test/eventregistry/SendEventTaskTest.testSendEventOnSystemChannel.bpmn20.xml

@@ -0,0 +1,37 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<definitions id="definitions" 
+  xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
+  xmlns:flowable="http://flowable.org/bpmn"
+  targetNamespace="Examples"
+  xmlns:tns="Examples">
+  
+  <process id="process">
+  
+    <startEvent id="theStart" />
+    
+    <sequenceFlow sourceRef="theStart" targetRef="task" />
+    
+    <userTask id="task" />
+  	
+  	<sequenceFlow sourceRef="task" targetRef="sendEventTask" />
+  	
+  	<serviceTask id="sendEventTask" flowable:type="send-event">
+        <extensionElements>
+            <flowable:eventType>myEvent</flowable:eventType>
+            <flowable:channelKey>out-channel</flowable:channelKey>
+            <flowable:systemChannel></flowable:systemChannel>
+            <flowable:eventInParameter source="test" target="eventProperty" />
+        </extensionElements>
+    </serviceTask>
+  	
+  	<sequenceFlow sourceRef="sendEventTask" targetRef="taskAfter" />
+  	
+    <userTask id="taskAfter" />
+    
+    <sequenceFlow sourceRef="taskAfter" targetRef="theEnd" />
+    
+    <endEvent id="theEnd" />
+    
+  </process>
+
+</definitions>