city.isDestroyed

src/engine/objects/City.java

@@ -41,6 +41,7 @@ import java.util.HashSet;
 import java.util.Iterator;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 
 public class City extends AbstractWorldObject {
@@ -80,6 +81,7 @@ public class City extends AbstractWorldObject {
     private String hash;
     public Warehouse warehouse;
     public Realm realm;
+    public AtomicBoolean isDestroyed = new AtomicBoolean(false);
 
     /**
      * ResultSet Constructor
@@ -1102,10 +1104,14 @@ public class City extends AbstractWorldObject {
 
     public final void destroy() {
 
-        Thread destroyCityThread = new Thread(new DestroyCityThread(this));
+        if (this.isDestroyed.compareAndSet(false, true)) {
 
-        destroyCityThread.setName("destroyCity:" + this.getParent().zoneName);
-        destroyCityThread.start();
+            Thread destroyCityThread = new Thread(new DestroyCityThread(this));
+
+            destroyCityThread.setName("destroyCity:" + this.getParent().zoneName);
+            destroyCityThread.start();
+        } else
+            Logger.error("Attempt to destroy destroyed city");
     }
 
     public final void transfer(AbstractCharacter newOwner) {