src/java.base/share/classes/jdk/internal/misc/Unsafe.java

@@ -1332,10 +1332,21 @@
          }
  
          return arrayIndexScale0(arrayClass);
      }
  
+     /**
+      * Return the size of the object in the heap.
+      * @param o an object
+      * @return the objects's size
+      * @since Valhalla
+      */
+     public long getObjectSize(Object o) {
+         if (o == null)
+             throw new NullPointerException();
+         return getObjectSize0(o);
+     }
  
      /** The value of {@code arrayIndexScale(boolean[].class)} */
      public static final int ARRAY_BOOLEAN_INDEX_SCALE
              = theUnsafe.arrayIndexScale(boolean[].class);
  

@@ -4186,10 +4197,11 @@
      private native Object staticFieldBase0(Field f);
      private native boolean shouldBeInitialized0(Class<?> c);
      private native void ensureClassInitialized0(Class<?> c);
      private native int arrayBaseOffset0(Class<?> arrayClass);
      private native int arrayIndexScale0(Class<?> arrayClass);
+     private native long getObjectSize0(Object o);
      private native Class<?> defineAnonymousClass0(Class<?> hostClass, byte[] data, Object[] cpPatches);
      private native int getLoadAverage0(double[] loadavg, int nelems);
  
  
      /**