EmptyStackException with multi-instance task & CDI

[naag]

Hi all,

I've just run into an EmptyStackException with Activiti 5.10. I've got an multi-instance user task where each task is finished via BusinessProcess.completeTask(). After finishing the last task instance, Activiti calls the end listeners in MultiInstanceActivityBehavior.callActivityEndListeners(), and because I've setup the CdiExecutionListener, this will also be called.

CdiExecutionListener will use Context.getExecutionContext(), but it seems the context is no longer available, that's why there will be the EmptyStackException.

Am I misusing the API here? It's a little bit difficult to provide a meaningful code sample here, but I believe this should work. Before I open a JIRA, I would like to get some confirmation that this should work.

Any pointers are greatly appreciated 🙂
Peter

[naag]

I'm adding a unit test that runs with Arquillian. There are two test classes, one uses activiti.cfg.xml with CdiExecutionListener, and one does not. Hopefully this can help, I can also create a JIRA if you think it's a bug and not API misuse 🙂

[bernd_ruecker]

Hi Naag.
Thanks, I will try to have a look into this later today. Posting the stacktrace is also a good idea by the way, but an arquillian test is nice as well.
Cheers
Bernd

[naag]

Great support as usual 😄 Here comes the stacktrace from the test execution:


——————————————————————————-
Test set: foo.WithCdiExecutionListenerTest
——————————————————————————-
Tests run: 2, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 33.484 sec <<< FAILURE!
testMultiInstanceTask(foo.WithCdiExecutionListenerTest)  Time elapsed: 2.631 sec  <<< ERROR!
org.activiti.engine.ActivitiException: Couldn't execute end listener
at org.activiti.engine.impl.bpmn.behavior.MultiInstanceActivityBehavior.callActivityEndListeners(MultiInstanceActivityBehavior.java:239)
at org.activiti.engine.impl.bpmn.behavior.SequentialMultiInstanceBehavior.leave(SequentialMultiInstanceBehavior.java:58)
at org.activiti.engine.impl.bpmn.behavior.AbstractBpmnActivityBehavior.leave(AbstractBpmnActivityBehavior.java:49)
at org.activiti.engine.impl.bpmn.behavior.UserTaskActivityBehavior.signal(UserTaskActivityBehavior.java:92)
at org.activiti.engine.impl.bpmn.behavior.MultiInstanceActivityBehavior.signal(MultiInstanceActivityBehavior.java:101)
at org.activiti.engine.impl.persistence.entity.ExecutionEntity.signal(ExecutionEntity.java:364)
at org.activiti.engine.impl.persistence.entity.TaskEntity.complete(TaskEntity.java:156)
at org.activiti.engine.impl.cmd.CompleteTaskCmd.completeTask(CompleteTaskCmd.java:63)
at org.activiti.engine.impl.cmd.CompleteTaskCmd.execute(CompleteTaskCmd.java:57)
at org.activiti.engine.impl.cmd.CompleteTaskCmd.execute(CompleteTaskCmd.java:28)
at org.activiti.engine.impl.interceptor.CommandExecutorImpl.execute(CommandExecutorImpl.java:24)
at org.activiti.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:42)
at org.activiti.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:33)
at org.activiti.engine.impl.TaskServiceImpl.complete(TaskServiceImpl.java:144)
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 org.jboss.weld.bean.proxy.AbstractBeanInstance.invoke(AbstractBeanInstance.java:44)
at org.jboss.weld.bean.proxy.ProxyMethodHandler.invoke(ProxyMethodHandler.java:105)
at org.jboss.weld.proxies.TaskService$-663006443$Proxy$_$$_WeldClientProxy.complete(TaskService$-663006443$Proxy$_$$_WeldClientProxy.java)
at foo.WithCdiExecutionListenerTest.testMultiInstanceTask(WithCdiExecutionListenerTest.java:81)
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 org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
at org.jboss.arquillian.junit.Arquillian$6$1.invoke(Arquillian.java:270)
at org.jboss.arquillian.container.test.impl.execution.LocalTestExecuter.execute(LocalTestExecuter.java:60)
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 org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.invokeObservers(EventContextImpl.java:99)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:81)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:135)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:115)
at org.jboss.arquillian.core.impl.EventImpl.fire(EventImpl.java:67)
at org.jboss.arquillian.container.test.impl.execution.ContainerTestExecuter.execute(ContainerTestExecuter.java:38)
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 org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.invokeObservers(EventContextImpl.java:99)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:81)
at org.jboss.arquillian.test.impl.TestContextHandler.createTestContext(TestContextHandler.java:89)
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 org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createClassContext(TestContextHandler.java:75)
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 org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.test.impl.TestContextHandler.createSuiteContext(TestContextHandler.java:60)
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 org.jboss.arquillian.core.impl.ObserverImpl.invoke(ObserverImpl.java:94)
at org.jboss.arquillian.core.impl.EventContextImpl.proceed(EventContextImpl.java:88)
at org.jboss.arquillian.core.impl.ManagerImpl.fire(ManagerImpl.java:135)
at org.jboss.arquillian.test.impl.EventTestRunnerAdaptor.test(EventTestRunnerAdaptor.java:111)
at org.jboss.arquillian.junit.Arquillian$6.evaluate(Arquillian.java:263)
at org.jboss.arquillian.junit.Arquillian$4.evaluate(Arquillian.java:226)
at org.jboss.arquillian.junit.Arquillian.multiExecute(Arquillian.java:314)
at org.jboss.arquillian.junit.Arquillian.access$100(Arquillian.java:46)
at org.jboss.arquillian.junit.Arquillian$5.evaluate(Arquillian.java:240)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
at org.jboss.arquillian.junit.Arquillian$2.evaluate(Arquillian.java:185)
at org.jboss.arquillian.junit.Arquillian.multiExecute(Arquillian.java:314)
at org.jboss.arquillian.junit.Arquillian.access$100(Arquillian.java:46)
at org.jboss.arquillian.junit.Arquillian$3.evaluate(Arquillian.java:199)
at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
at org.jboss.arquillian.junit.Arquillian.run(Arquillian.java:147)
at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
at org.junit.runner.JUnitCore.run(JUnitCore.java:136)
at org.jboss.arquillian.junit.container.JUnitTestRunner.execute(JUnitTestRunner.java:65)
at org.jboss.arquillian.protocol.jmx.JMXTestRunner.runTestMethodInternal(JMXTestRunner.java:129)
at org.jboss.arquillian.protocol.jmx.JMXTestRunner.runTestMethod(JMXTestRunner.java:108)
at org.jboss.as.arquillian.service.ArquillianService$ExtendedJMXTestRunner.runTestMethod(ArquillianService.java:226)
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 com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:93)
at com.sun.jmx.mbeanserver.StandardMBeanIntrospector.invokeM2(StandardMBeanIntrospector.java:27)
at com.sun.jmx.mbeanserver.MBeanIntrospector.invokeM(MBeanIntrospector.java:208)
at com.sun.jmx.mbeanserver.PerInterface.invoke(PerInterface.java:120)
at com.sun.jmx.mbeanserver.MBeanSupport.invoke(MBeanSupport.java:262)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:836)
at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:761)
at org.jboss.as.jmx.PluggableMBeanServerImpl$TcclMBeanServer.invoke(PluggableMBeanServerImpl.java:498)
at org.jboss.as.jmx.PluggableMBeanServerImpl.invoke(PluggableMBeanServerImpl.java:246)
at org.jboss.remotingjmx.protocol.v1.ServerProxy$InvokeHandler.handle(ServerProxy.java:1034)
at org.jboss.remotingjmx.protocol.v1.ServerProxy$MessageReciever$1.run(ServerProxy.java:215)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:662)
Caused by: java.util.EmptyStackException
at java.util.Stack.peek(Stack.java:85)
at org.activiti.engine.impl.context.Context.getExecutionContext(Context.java:68)
at org.activiti.cdi.impl.event.CdiExecutionListener.createEvent(CdiExecutionListener.java:77)
at org.activiti.cdi.impl.event.CdiExecutionListener.notify(CdiExecutionListener.java:71)
at org.activiti.engine.impl.delegate.ExecutionListenerInvocation.invoke(ExecutionListenerInvocation.java:34)
at org.activiti.engine.impl.delegate.DelegateInvocation.proceed(DelegateInvocation.java:37)
at org.activiti.engine.impl.delegate.DefaultDelegateInterceptor.handleInvocation(DefaultDelegateInterceptor.java:25)
at org.activiti.engine.impl.bpmn.behavior.MultiInstanceActivityBehavior.callActivityEndListeners(MultiInstanceActivityBehavior.java:235)
… 114 more


[bernd_ruecker]

Hi Peter.

I can actually confirm this issue, this is a bug. It is actually not related to CDI but to the engine for MultipleInstance's. I created this JIRA issue: http://jira.codehaus.org/browse/ACT-1339. Thanks for the perfect bug report!

Cheers
Bernd

[bernd_ruecker]

P.S: If it is really urgent for you you could think about a support subscription and we could fix it for you in 6.1 😉 Otherwise I would propose to extend the CdiEventListener and check for the empty stack and not send the event in that case if possible for your use case.

[naag]

Thanks for creating the JIRA and the support offer 🙂 Actually we're not yet using CDI events, but we still had the CdiExecutionListener in place. So for now we removed it and everything's fine!

[bernd_ruecker]

Perfect. Would not be a show stopper for not providing support for us 😉