--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/sun/reflect/ClassDefiner.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,74 @@
+/*
+ * Copyright 2001 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package sun.reflect;
+
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+import sun.misc.Unsafe;
+
+/** Utility class which assists in calling Unsafe.defineClass() by
+    creating a new class loader which delegates to the one needed in
+    order for proper resolution of the given bytecodes to occur. */
+
+class ClassDefiner {
+    static final Unsafe unsafe = Unsafe.getUnsafe();
+
+    /** <P> We define generated code into a new class loader which
+      delegates to the defining loader of the target class. It is
+      necessary for the VM to be able to resolve references to the
+      target class from the generated bytecodes, which could not occur
+      if the generated code was loaded into the bootstrap class
+      loader. </P>
+
+      <P> There are two primary reasons for creating a new loader
+      instead of defining these bytecodes directly into the defining
+      loader of the target class: first, it avoids any possible
+      security risk of having these bytecodes in the same loader.
+      Second, it allows the generated bytecodes to be unloaded earlier
+      than would otherwise be possible, decreasing run-time
+      footprint. </P>
+    */
+    static Class defineClass(String name, byte[] bytes, int off, int len,
+                             final ClassLoader parentClassLoader)
+    {
+        ClassLoader newLoader = (ClassLoader)
+            AccessController.doPrivileged(new PrivilegedAction() {
+                    public Object run() {
+                        return new DelegatingClassLoader(parentClassLoader);
+                    }
+                });
+        return unsafe.defineClass(name, bytes, off, len, newLoader, null);
+    }
+}
+
+
+// NOTE: this class's name and presence are known to the virtual
+// machine as of the fix for 4474172.
+class DelegatingClassLoader extends ClassLoader {
+    DelegatingClassLoader(ClassLoader parent) {
+        super(parent);
+    }
+}