Update synchronized.

Author: huizhilu

helix-core/src/main/java/org/apache/helix/monitoring/mbeans/dynamicMBeans/DynamicMBeanProvider.java

@@ -120,27 +120,24 @@ protected void updateAttributesInfo(Collection<DynamicMetric<?, ?>> dynamicMetri
           }
         }
       }
-    }
 
-    // SensorName
-    attributeInfoList.add(new MBeanAttributeInfo(SENSOR_NAME_TAG, String.class.getName(),
-        "The name of the metric sensor", true, false, false));
+      // SensorName
+      attributeInfoList.add(new MBeanAttributeInfo(SENSOR_NAME_TAG, String.class.getName(),
+          "The name of the metric sensor", true, false, false));
 
-    MBeanConstructorInfo constructorInfo = new MBeanConstructorInfo(
-        String.format("Default %s Constructor", getClass().getSimpleName()),
-        getClass().getConstructors()[0]);
+      MBeanConstructorInfo constructorInfo = new MBeanConstructorInfo(
+          String.format("Default %s Constructor", getClass().getSimpleName()), getClass().getConstructors()[0]);
 
-    MBeanAttributeInfo[] attributesInfo = new MBeanAttributeInfo[attributeInfoList.size()];
-    attributesInfo = attributeInfoList.toArray(attributesInfo);
+      MBeanAttributeInfo[] attributesInfo = new MBeanAttributeInfo[attributeInfoList.size()];
+      attributesInfo = attributeInfoList.toArray(attributesInfo);
 
-    if (description == null) {
-      description = DEFAULT_DESCRIPTION;
-    }
+      if (description == null) {
+        description = DEFAULT_DESCRIPTION;
+      }
 
-    _mBeanInfo = new MBeanInfo(getClass().getName(), description, attributesInfo,
-        new MBeanConstructorInfo[] {
-            constructorInfo
-        }, new MBeanOperationInfo[0], new MBeanNotificationInfo[0]);
+      _mBeanInfo = new MBeanInfo(getClass().getName(), description, attributesInfo, new MBeanConstructorInfo[]{constructorInfo}, new MBeanOperationInfo[0],
+          new MBeanNotificationInfo[0]);
+    }
   }
 
   /**