--- /dev/null	2018-06-17 23:18:20.806999507 +0800
+++ new/test/lib/testlibrary/jdk/testlibrary/jfr/oldobject/TestClassLoader.java	2019-01-29 11:06:18.975899285 +0800
@@ -0,0 +1,122 @@
+/*
+ * Copyright (c) 2018, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+
+package jdk.testlibrary.jfr.oldobject;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.List;
+
+/*
+ * A special class loader that will, for our test class, make sure that each
+ * load will become a unique class
+ */
+public final class TestClassLoader extends ClassLoader {
+
+    public static final class TestClass0000000 {
+        public static final byte[] oneByte = new byte[1];
+    }
+
+    static byte[] classByteCode = readTestClassBytes();
+    private static int classIdCounter;
+
+    public TestClassLoader() {
+        super(TestClassLoader.class.getClassLoader());
+    }
+
+    public List<Class<?>> loadClasses(int count) throws Exception {
+        List<Class<?>> classes = new ArrayList<>();
+        for (int i = 0; i < count; i++) {
+            String className = "jdk.testlibrary.jfr.oldobject.TestClassLoader$";
+            className += "TestClass" + String.format("%07d", classIdCounter++);
+            Class<?> clazz = Class.forName(className, true, this);
+            classes.add(clazz);
+        }
+        return classes;
+    }
+
+    @Override
+    protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
+        // If not loading the test class, just go on with the normal class loader
+        if (!name.contains("TestClass")) {
+            return super.loadClass(name, resolve);
+        }
+        String[] classNameParts = name.split("\\$");
+        String newName = classNameParts[1];
+        String oldName = "TestClass0000000";
+        if (oldName.length() != newName.length()) {
+            throw new AssertionError("String lengths don't match. Unable to replace class name");
+        }
+        byte[] newBytes = classByteCode.clone();
+        replaceBytes(newBytes, oldName.getBytes(), newName.getBytes());
+        Class<?> c = defineClass(name, newBytes, 0, newBytes.length);
+        if (resolve) {
+            resolveClass(c);
+        }
+        return c;
+    }
+
+    static void replaceBytes(byte[] bytes, byte[] find, byte[] replacement) {
+        for (int index = 0; index < bytes.length - find.length; index++) {
+            if (matches(bytes, index, find)) {
+                replace(bytes, index, replacement);
+            }
+        }
+    }
+
+    private static void replace(byte[] bytes, int startIndex, byte[] replacement) {
+        for (int index = 0; index < replacement.length; index++) {
+            bytes[startIndex + index] = replacement[index];
+        }
+    }
+
+    private static boolean matches(byte[] bytes, int startIndex, byte[] matching) {
+        for (int i = 0; i < matching.length; i++) {
+            if (bytes[startIndex + i] != matching[i]) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private static byte[] readTestClassBytes() {
+        try {
+            String classFileName = "jdk/testlibrary/jfr/oldobject/TestClassLoader$TestClass0000000.class";
+            InputStream is = TestClassLoader.class.getClassLoader().getResourceAsStream(classFileName);
+            if (is == null) {
+                throw new RuntimeException("Culd not find class file " + classFileName);
+            }
+            byte[] b = new byte[is.available()];
+            is.read(b);
+            is.close();
+            return b;
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+            throw new RuntimeException(ioe);
+        }
+    }
+}
+