Prevent potential lookup issue with signals in high concurrent cases

Author: tijsrademakers

modules/flowable-engine/src/main/java/org/flowable/engine/impl/bpmn/parser/handler/SignalEventDefinitionParseHandler.java

@@ -33,10 +33,7 @@ public Class<? extends BaseElement> getHandledType() {
     @Override
     protected void executeParse(BpmnParse bpmnParse, SignalEventDefinition signalDefinition) {
 
-        Signal signal = null;
-        if (bpmnParse.getBpmnModel().containsSignalId(signalDefinition.getSignalRef())) {
-            signal = bpmnParse.getBpmnModel().getSignal(signalDefinition.getSignalRef());
-        }
+        Signal signal = bpmnParse.getBpmnModel().getSignal(signalDefinition.getSignalRef());
 
         if (bpmnParse.getCurrentFlowElement() instanceof IntermediateCatchEvent) {
             IntermediateCatchEvent intermediateCatchEvent = (IntermediateCatchEvent) bpmnParse.getCurrentFlowElement();

modules/flowable-engine/src/main/java/org/flowable/engine/impl/bpmn/parser/handler/StartEventParseHandler.java

@@ -55,10 +55,7 @@ protected void executeParse(BpmnParse bpmnParse, StartEvent element) {
 
                 } else if (eventDefinition instanceof SignalEventDefinition) {
                     SignalEventDefinition signalDefinition = (SignalEventDefinition) eventDefinition;
-                    Signal signal = null;
-                    if (bpmnParse.getBpmnModel().containsSignalId(signalDefinition.getSignalRef())) {
-                        signal = bpmnParse.getBpmnModel().getSignal(signalDefinition.getSignalRef());
-                    }
+                    Signal signal = bpmnParse.getBpmnModel().getSignal(signalDefinition.getSignalRef());
 
                     element.setBehavior(bpmnParse.getActivityBehaviorFactory().createEventSubProcessSignalStartEventActivityBehavior(
                             element, signalDefinition, signal));

modules/flowable-engine/src/main/java/org/flowable/engine/impl/dynamic/AbstractDynamicStateManager.java

@@ -1548,9 +1548,8 @@ protected void processCreatedEventSubProcess(EventSubProcess eventSubProcess, Ex
                     if (eventDefinition instanceof SignalEventDefinition && (eventSubscriptions == null || eventSubscriptions.isEmpty())) {
                         SignalEventDefinition signalEventDefinition = (SignalEventDefinition) eventDefinition;
                         BpmnModel bpmnModel = ProcessDefinitionUtil.getBpmnModel(eventSubProcessExecution.getProcessDefinitionId());
-                        Signal signal = null;
-                        if (bpmnModel.containsSignalId(signalEventDefinition.getSignalRef())) {
-                            signal = bpmnModel.getSignal(signalEventDefinition.getSignalRef());
+                        Signal signal = bpmnModel.getSignal(signalEventDefinition.getSignalRef());
+                        if (signal != null) {
                             signalEventDefinition.setSignalRef(signal.getName());
                         }
 

modules/flowable-engine/src/main/java/org/flowable/engine/impl/util/ProcessInstanceHelper.java

@@ -452,9 +452,8 @@ protected void handleSignalEventSubscription(EventDefinition eventDefinition, St
 
         SignalEventDefinition signalEventDefinition = (SignalEventDefinition) eventDefinition;
         BpmnModel bpmnModel = ProcessDefinitionUtil.getBpmnModel(parentExecution.getProcessDefinitionId());
-        Signal signal = null;
-        if (bpmnModel.containsSignalId(signalEventDefinition.getSignalRef())) {
-            signal = bpmnModel.getSignal(signalEventDefinition.getSignalRef());
+        Signal signal = bpmnModel.getSignal(signalEventDefinition.getSignalRef());
+        if (signal != null) {
             signalEventDefinition.setSignalRef(signal.getName());
         }