Don't run call-activities asynchronously

spring-boot/src/main/java/io/vanillabp/camunda7/Camunda7AdapterConfiguration.java

@@ -2,6 +2,7 @@
 
 import io.vanillabp.camunda7.deployment.Camunda7DeploymentAdapter;
 import io.vanillabp.camunda7.service.Camunda7ProcessService;
+import io.vanillabp.camunda7.service.jobs.startprocess.StartProcessJobHandler;
 import io.vanillabp.camunda7.wiring.Camunda7AdapterProperties;
 import io.vanillabp.camunda7.wiring.Camunda7TaskWiring;
 import io.vanillabp.camunda7.wiring.Camunda7TaskWiringPlugin;
@@ -28,11 +29,10 @@
 import org.springframework.context.annotation.Lazy;
 import org.springframework.data.repository.CrudRepository;
 
+import javax.annotation.PostConstruct;
 import java.math.BigInteger;
 import java.util.function.Function;
 
-import javax.annotation.PostConstruct;
-
 @AutoConfigurationPackage(basePackageClasses = Camunda7AdapterConfiguration.class)
 @AutoConfigureBefore(CamundaBpmAutoConfiguration.class)
 @EnableProcessApplication("org.camunda.bpm.spring.boot.starter.SpringBootProcessApplication")
@@ -207,5 +207,11 @@ public <DE> Camunda7ProcessService<?> newProcessServiceImplementation(
         return result;
 
     }
-
+
+    @Bean
+    public StartProcessJobHandler startProcessJobHandler() {
+
+        return new StartProcessJobHandler();
+    }
+
 }

spring-boot/src/main/java/io/vanillabp/camunda7/service/Camunda7ProcessService.java

@@ -1,10 +1,12 @@
 package io.vanillabp.camunda7.service;
 
 import io.vanillabp.camunda7.Camunda7AdapterConfiguration;
+import io.vanillabp.camunda7.service.jobs.startprocess.StartProcessCommand;
 import io.vanillabp.springboot.adapter.AdapterAwareProcessService;
 import io.vanillabp.springboot.adapter.ProcessServiceImplementation;
 import org.camunda.bpm.engine.ProcessEngine;
 import org.camunda.bpm.engine.exception.NullValueException;
+import org.camunda.bpm.engine.impl.cfg.ProcessEngineConfigurationImpl;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.context.ApplicationEventPublisher;
@@ -51,7 +53,7 @@ public Camunda7ProcessService(
         this.isNewEntity = isNewEntity;
         this.getWorkflowAggregateId = getWorkflowAggregateId;
         this.parseWorkflowAggregateIdFromBusinessKey = parseWorkflowAggregateIdFromBusinessKey;
-        
+
     }
 
     @Override
@@ -139,16 +141,20 @@ public DE startWorkflow(
                 .toString();
 
         wakeupJobExecutorOnActivity();
-
-        processEngine
-                .getRuntimeService()
-                .createProcessInstanceByKey(parent.getPrimaryBpmnProcessId())
-                .businessKey(id)
-                .processDefinitionTenantId(parent.getWorkflowModuleId())
-                .execute();
-
-        return workflowAggregateRepository
-                .save(attachedAggregate);
+
+        // Start workflow asynchronously by Camunda's job-executor
+        // Hint: this is not done by setting "async-before" on the start-event
+        // since we don't know which process is used as a call-activity which
+        // has to be started synchronously.
+        ((ProcessEngineConfigurationImpl) processEngine
+                .getProcessEngineConfiguration())
+                .getCommandExecutorTxRequired()
+                .execute(new StartProcessCommand(
+                        parent.getWorkflowModuleId(),
+                        parent.getPrimaryBpmnProcessId(),
+                        id));
+
+        return attachedAggregate;
 
     }
 

spring-boot/src/main/java/io/vanillabp/camunda7/service/jobs/startprocess/StartProcessCommand.java

@@ -0,0 +1,41 @@
+package io.vanillabp.camunda7.service.jobs.startprocess;
+
+import org.camunda.bpm.engine.impl.interceptor.Command;
+import org.camunda.bpm.engine.impl.interceptor.CommandContext;
+import org.camunda.bpm.engine.impl.persistence.entity.MessageEntity;
+
+public class StartProcessCommand implements Command<String> {
+
+    static final String TYPE = "VBP_StartProcess";
+
+    private final StartProcessJobHandlerConfiguration configuration;
+
+    public StartProcessCommand(
+            final String workflowModuleId,
+            final String bpmnProcessId,
+            final String businessKey) {
+
+        this.configuration = new StartProcessJobHandlerConfiguration(
+                workflowModuleId,
+                bpmnProcessId,
+                businessKey);
+
+    }
+
+    @Override
+    public String execute(
+            final CommandContext commandContext) {
+
+        final var entity = new MessageEntity();
+
+        entity.init(commandContext);
+        entity.setJobHandlerType(TYPE);
+        entity.setJobHandlerConfiguration(configuration);
+
+        commandContext.getJobManager().send(entity);
+
+        return entity.getId();
+
+    }
+
+}

spring-boot/src/main/java/io/vanillabp/camunda7/service/jobs/startprocess/StartProcessJobHandler.java

@@ -0,0 +1,63 @@
+package io.vanillabp.camunda7.service.jobs.startprocess;
+
+import org.camunda.bpm.engine.impl.interceptor.CommandContext;
+import org.camunda.bpm.engine.impl.jobexecutor.JobHandler;
+import org.camunda.bpm.engine.impl.persistence.entity.ExecutionEntity;
+import org.camunda.bpm.engine.impl.persistence.entity.JobEntity;
+
+import java.util.regex.Pattern;
+
+public class StartProcessJobHandler implements JobHandler<StartProcessJobHandlerConfiguration> {
+
+    private static final Pattern SPLITTER = Pattern.compile("([^\n]+)\n([^\n]+)\n(.*)");
+
+    @Override
+    public String getType() {
+        return StartProcessCommand.TYPE;
+    }
+
+    @Override
+    public void execute(
+            final StartProcessJobHandlerConfiguration configuration,
+            final ExecutionEntity execution,
+            final CommandContext commandContext,
+            final String tenantId) {
+
+        commandContext
+                .getProcessEngineConfiguration()
+                .getProcessEngine()
+                .getRuntimeService()
+                .createProcessInstanceByKey(configuration.getBpmnProcessId())
+                .businessKey(configuration.getBusinessKey())
+                .processDefinitionTenantId(configuration.getWorkflowModuleId())
+                .execute();
+
+    }
+
+    @Override
+    public StartProcessJobHandlerConfiguration newConfiguration(
+            final String canonicalString) {
+
+        if (canonicalString == null) {
+            return null;
+        }
+
+        final var splitter = SPLITTER.matcher(canonicalString);
+        if (!splitter.matches()) {
+            return null;
+        }
+
+        return new StartProcessJobHandlerConfiguration(
+                splitter.group(1),
+                splitter.group(2),
+                splitter.group(3));
+
+    }
+
+    @Override
+    public void onDelete(
+            final StartProcessJobHandlerConfiguration configuration,
+            final JobEntity jobEntity) {
+        // nothing to do
+    }
+}

spring-boot/src/main/java/io/vanillabp/camunda7/service/jobs/startprocess/StartProcessJobHandlerConfiguration.java

@@ -0,0 +1,43 @@
+package io.vanillabp.camunda7.service.jobs.startprocess;
+
+import org.camunda.bpm.engine.impl.jobexecutor.JobHandlerConfiguration;
+
+public class StartProcessJobHandlerConfiguration implements JobHandlerConfiguration {
+
+    private final String businessKey;
+
+    private final String workflowModuleId;
+
+    private final String bpmnProcessId;
+
+    public StartProcessJobHandlerConfiguration(
+            final String workflowModuleId,
+            final String bpmnProcessId,
+            final String businessKey) {
+
+        this.businessKey = businessKey;
+        this.workflowModuleId = workflowModuleId;
+        this.bpmnProcessId = bpmnProcessId;
+
+    }
+
+    @Override
+    public String toCanonicalString() {
+
+        return workflowModuleId + "\n" + bpmnProcessId + "\n" + businessKey;
+
+    }
+
+    public String getWorkflowModuleId() {
+        return workflowModuleId;
+    }
+
+    public String getBpmnProcessId() {
+        return bpmnProcessId;
+    }
+
+    public String getBusinessKey() {
+        return businessKey;
+    }
+
+}

spring-boot/src/main/java/io/vanillabp/camunda7/wiring/TaskWiringBpmnParseListener.java

@@ -465,12 +465,20 @@ private void resetAsyncBeforeAndAsyncAfter(
 
     @Override
     public void parseStartEvent(
-            final Element element,
+            final Element startElement,
             final ScopeImpl scope,
             final ActivityImpl activity) {
-
-        resetAsyncBeforeAndAsyncAfter(element, activity, Async.SET_ASYNC_BEFORE_ONLY);
-
+
+        final var isEventBasedStartEvent = startElement.element("messageEventDefinition") != null;
+        if (isEventBasedStartEvent) {
+            resetAsyncBeforeAndAsyncAfter(startElement, activity, Async.SET_ASYNC_BEFORE_ONLY);
+        } else  {
+            // plain start events need to be handled synchronously in cases of call-activities.
+            // in cases of starting an independent process the Camunda7ProcessService is
+            // responsible for running this asynchronously.
+            removeAsyncBeforeAndAsyncAfter(startElement, activity);
+        }
+
     }
 
     @Override