src/java.base/share/classes/jdk/internal/ref/Cleaner.java

@@ -56,11 +56,10 @@
  * @author Mark Reinhold
  */
 
 public class Cleaner
     extends PhantomReference<Object>
-    implements Runnable
 {
 
     // Dummy reference queue, needed because the PhantomReference constructor
     // insists that we pass a queue.  Nothing will ever be placed on this queue
     // since the reference handler invokes cleaners explicitly.

@@ -151,14 +150,6 @@
                         System.exit(1);
                         return null;
                     }});
         }
     }
-
-    @Override public void run() {
-        SecurityManager security = System.getSecurityManager();
-        if (security != null)
-            security.checkPackageAccess("jdk.internal.ref");
-        this.clean();
-    }
-
 }