--- /dev/null	2019-01-28 17:48:29.000000000 +0800
+++ new/src/share/vm/jfr/writers/jfrJavaEventWriter.hpp	2019-01-28 17:48:29.000000000 +0800
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2016, 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_WRITERS_JFRJAVAEVENTWRITER_HPP
+#define SHARE_VM_JFR_WRITERS_JFRJAVAEVENTWRITER_HPP
+
+#include "jni.h"
+#include "memory/allocation.hpp"
+
+class JavaThread;
+class Thread;
+
+class JfrJavaEventWriter : AllStatic {
+  friend class JfrCheckpointThreadClosure;
+  friend class JfrJavaEventWriterNotifyOperation;
+  friend class JfrJavaEventWriterNotificationClosure;
+ private:
+  static void notify(JavaThread* jt);
+
+ public:
+  static bool initialize();
+  static void notify();
+  static jobject event_writer(Thread* t);
+  static jobject new_event_writer(TRAPS);
+  static jboolean flush(jobject writer, jint used, jint requested, JavaThread* jt);
+};
+
+#endif // SHARE_VM_JFR_WRITERS_JFRJAVAEVENTWRITER_HPP