final Version

pp.A4-HandOverHandLocking/src/main/java/pp/ThreadsafeSimplifiedList.java

@@ -113,9 +113,12 @@ public class ThreadsafeSimplifiedList<T>
                 throw new IndexOutOfBoundsException(index + " out of bounds");           
            
         }
-        ptr.element = element;
-        ptr.nodeLock.unlock();
-        return element;
+        try {
+            ptr.element = element;
+            return element;
+        } finally {
+            ptr.nodeLock.unlock();
+        }
     }
 
     /**