src/java.management/share/classes/sun/management/Sensor.java

8201327: Make Sensor deeply immutably thread safe
Reviewed-by: alanb, chegar, asmundak

@@ -46,25 +46,22 @@
  * @author  Mandy Chung
  * @since   1.5
  */
 
 public abstract class Sensor {
-    private Object  lock;
-    private String  name;
-    private long    count;
-    private boolean on;
+    private final Object lock = new Object();
+    private final String name;
+    private long count;                 // VM-initialized to 0
+    private boolean on;                 // VM-initialized to false
 
     /**
      * Constructs a {@code Sensor} object.
      *
      * @param name The name of this sensor.
      */
     public Sensor(String name) {
         this.name = name;
-        this.count = 0;
-        this.on = false;
-        this.lock = new Object();
     }
 
     /**
      * Returns the name of this sensor.
      *