--- /dev/null	2019-01-28 17:46:43.000000000 +0800
+++ new/src/share/vm/jfr/recorder/access/jfrEventClass.hpp	2019-01-28 17:46:43.000000000 +0800
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_JFR_RECORDER_ACCESS_JFREVENTCLASS_HPP
+#define SHARE_VM_JFR_RECORDER_ACCESS_JFREVENTCLASS_HPP
+
+#include "jni.h"
+#include "memory/allocation.hpp"
+
+class Klass;
+
+//
+// For convenient access to the jdk.jfr.Event klass hierarchy.
+//
+class JdkJfrEvent : AllStatic {
+ public:
+  // jdk.jfr.Event
+  static bool is(const Klass* k);
+  static bool is(const jclass jc);
+  static void tag_as(const Klass* k);
+
+  // jdk.jfr.Event subklasses
+  static bool is_subklass(const Klass* k);
+  static bool is_subklass(const jclass jc);
+  static void tag_as_subklass(const Klass* k);
+  static void tag_as_subklass(const jclass jc);
+
+  // jdk.jfr.Event hierarchy
+  static bool is_a(const Klass* k);
+  static bool is_a(const jclass jc);
+
+  // klasses that host a jdk.jfr.Event
+  static bool is_host(const Klass* k);
+  static bool is_host(const jclass jc);
+  static void tag_as_host(const Klass* k);
+  static void tag_as_host(const jclass jc);
+
+  // in the set of classes made visible to java
+  static bool is_visible(const Klass* k);
+  static bool is_visible(const jclass jc);
+};
+
+#endif // SHARE_VM_JFR_RECORDER_ACCESS_JFREVENTCLASS_HPP