Use workflow init

core/src/main/java/io/temporal/samples/safemessagepassing/ClusterManagerWorkflow.java

@@ -43,7 +43,7 @@ enum ClusterState {
   // In workflows that continue-as-new, it's convenient to store all your state in one serializable
   // structure to make it easier to pass between runs
   class ClusterManagerState {
-    public ClusterState workflowState;
+    public ClusterState workflowState = ClusterState.NOT_STARTED;
     public Map<String, Optional<String>> nodes = new HashMap<>();
     public Set<String> jobAssigned = new HashSet<>();
   }

core/src/main/java/io/temporal/samples/safemessagepassing/ClusterManagerWorkflowImpl.java

@@ -23,23 +23,23 @@
 import io.temporal.common.RetryOptions;
 import io.temporal.failure.ApplicationFailure;
 import io.temporal.workflow.Workflow;
+import io.temporal.workflow.WorkflowInit;
 import io.temporal.workflow.WorkflowLock;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import java.time.Duration;
 import java.util.Collections;
 import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class ClusterManagerWorkflowImpl implements ClusterManagerWorkflow {
 
   private static final Logger logger = LoggerFactory.getLogger(ClusterManagerWorkflowImpl.class);
-  private ClusterManagerState state = new ClusterManagerState();
-  private WorkflowLock nodeLock = Workflow.newWorkflowLock();
-  private Duration sleepInterval = Duration.ofMinutes(10);
-  private int maxHistoryLength = 0;
+  private final ClusterManagerState state;
+  private final WorkflowLock nodeLock;
+  private final Duration sleepInterval;
+  private final int maxHistoryLength;
 
   private ClusterManagerActivities activities =
       Workflow.newActivityStub(
@@ -51,15 +51,25 @@ public class ClusterManagerWorkflowImpl implements ClusterManagerWorkflow {
                   .setRetryOptions(RetryOptions.newBuilder().setMaximumAttempts(1).build())
                   .build()));
 
-  @Override
-  public ClusterManagerResult run(ClusterManagerInput input) {
+  @WorkflowInit
+  public ClusterManagerWorkflowImpl(ClusterManagerInput input) {
+    nodeLock = Workflow.newWorkflowLock();
     if (input.getState().isPresent()) {
       state = input.getState().get();
+    } else {
+      state = new ClusterManagerState();
     }
     if (input.isTestContinueAsNew()) {
       maxHistoryLength = 120;
       sleepInterval = Duration.ofSeconds(1);
+    } else {
+      sleepInterval = Duration.ofSeconds(10);
+      maxHistoryLength = 0;
     }
+  }
+
+  @Override
+  public ClusterManagerResult run(ClusterManagerInput input) {
     Workflow.await(() -> state.workflowState != ClusterState.NOT_STARTED);
     // The cluster manager is a long-running "entity" workflow so we need to periodically checkpoint
     // its state and

core/src/main/java/io/temporal/samples/safemessagepassing/ClusterManagerWorkflowStarter.java

@@ -109,5 +109,6 @@ public static void main(String[] args) {
         "Cluster shut down successfully.  It had "
             + result.getNumCurrentlyAssignedNodes()
             + " nodes assigned at the end.");
+    System.exit(0);
   }
 }