ConcurrentModification issue when using PooledStreamingProcessor #63

java.util.ConcurrentModificationException: null at java.base/java.util.HashMap.computeIfAbsent(HashMap.java:1221) at com.insidion.axon.openadmin.insights.InsightRegistrationService.reportHandlerMessagesPublished(InsightRegistrationService.kt:28) at com.insidion.axon.openadmin.insights.InsightDispatchInterceptor$handle$1$1.accept(InsightDispatchInterceptor.kt:41) at com.insidion.axon.openadmin.insights.InsightDispatchInterceptor$handle$1$1.accept(InsightDispatchInterceptor.kt:40) at org.axonframework.messaging.unitofwork.MessageProcessingContext.notifyHandlers(MessageProcessingContext.java:72) at org.axonframework.messaging.unitofwork.BatchingUnitOfWork.lambda$notifyHandlers$2(BatchingUnitOfWork.java:161) at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133) at org.axonframework.messaging.unitofwork.BatchingUnitOfWork.notifyHandlers(BatchingUnitOfWork.java:161) at org.axonframework.messaging.unitofwork.AbstractUnitOfWork.changePhase(AbstractUnitOfWork.java:236) at org.axonframework.messaging.unitofwork.AbstractUnitOfWork.commitAsRoot(AbstractUnitOfWork.java:87) at org.axonframework.messaging.unitofwork.AbstractUnitOfWork.commit(AbstractUnitOfWork.java:75) at org.axonframework.messaging.unitofwork.BatchingUnitOfWork.executeWithResult(BatchingUnitOfWork.java:117) at org.axonframework.eventhandling.AbstractEventProcessor.processInUnitOfWork(AbstractEventProcessor.java:165) at org.axonframework.eventhandling.pooled.WorkPackage.processEvents(WorkPackage.java:320) at org.axonframework.eventhandling.pooled.WorkPackage.lambda$scheduleWorker$5(WorkPackage.java:281) at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) at java.base/java.lang.Thread.run(Thread.java:833)

Probably because class "HandlerStats" defines a HashMap instead of ConcurrentHashMap. Also the Int usage instead of AtomicInt could lead to wrong stats.