--- old/src/java.base/share/classes/valhalla/shady/MinimalValueTypes_1_0.java	2017-06-20 14:47:36.000000000 -0700
+++ new/src/java.base/share/classes/valhalla/shady/MinimalValueTypes_1_0.java	2017-06-20 14:47:36.000000000 -0700
@@ -28,32 +28,40 @@
 import jdk.internal.misc.Unsafe;
 import sun.security.action.GetPropertyAction;
 
-import java.io.File;
-import java.io.FileOutputStream;
+import java.io.BufferedOutputStream;
 import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.security.ProtectionDomain;
 import java.util.Properties;
 
 import static jdk.internal.org.objectweb.asm.Opcodes.*;
 
+import jdk.internal.misc.JavaLangAccess;
+import jdk.internal.misc.SharedSecrets;
 public class MinimalValueTypes_1_0 {
 
-    public static final int    V53_1                  = 1 << 16 | 53;
-    public static final int    ACC_VALUE              = ACC_NATIVE;
-    public static final String OBJECT_CLASS_DESC      = "java/lang/Object";
-    public static final String VALUE_CLASS_DESC       = "java/lang/__Value";
+    public static final int V53_1 = 1 << 16 | 53;
+    public static final int ACC_VALUE = ACC_NATIVE;
+    public static final String OBJECT_CLASS_DESC = "java/lang/Object";
+    public static final String VALUE_CLASS_DESC = "java/lang/__Value";
 
     public static final String DERIVE_VALUE_TYPE_DESC = "Ljvm/internal/value/DeriveValueType;";
     public static final String DERIVE_VT_CLASSNAME_POSTFIX = "$Value";
     public static final int    DERIVE_VT_CLASS_ACCESS = ACC_PUBLIC|ACC_SUPER|ACC_FINAL|ACC_VALUE|ACC_SYNTHETIC;
 
     public static final boolean DUMP_CLASS_FILES;
+    private static final JavaLangAccess JLA;
 
     static {
         // Use same property as in j.l.invoke.MethodHandleStatics
         Properties props = GetPropertyAction.privilegedGetProperties();
         DUMP_CLASS_FILES = Boolean.parseBoolean(
-                props.getProperty("java.lang.invoke.MethodHandle.DUMP_CLASS_FILES"));
+            props.getProperty("java.lang.invoke.MethodHandle.DUMP_CLASS_FILES"));
+
+        JLA = SharedSecrets.getJavaLangAccess();
     }
 
     public static String getValueTypeClassName(ValueTypeDesc valueTypeDesc) {
@@ -79,11 +87,11 @@
         return Class.forName(getValueCapableClassName(x.getName()), true, x.getClassLoader());
     }
 
-    public static Class<?> getValueTypeClass(Class<?> x)  throws ClassNotFoundException {
+    public static Class<?> getValueTypeClass(Class<?> x) throws ClassNotFoundException {
         if (isValueType(x)) {
             throw new IllegalArgumentException("Expected Value Capable Class");
         }
-        return Class.forName(getValueTypeClassName(x.getName()), true, x.getClassLoader());
+        return loadValueTypeClass(x, getValueTypeClassName(x.getName()));
     }
 
     public static String getValueTypeClassName(Class<?> x) {
@@ -98,18 +106,27 @@
         if (x.getDeclaredAnnotation(jvm.internal.value.DeriveValueType.class) == null) {
             return false;
         }
-        try {
-            Class.forName(getValueTypeClassName(x), true, x.getClassLoader());
-            return true;
+        return loadValueTypeClass(x, getValueTypeClassName(x)) != null;
+    }
+
+    public static Class<?> loadValueTypeClass(Class<?> vcc, String className) {
+        if (isValueType(vcc)) {
+            throw new IllegalArgumentException(vcc.getName() + " already a derived value type");
         }
-        catch (ClassNotFoundException cnfe) {
-            return false;
+        Class<?> c = JLA.loadValueTypeClass(vcc.getModule(), vcc.getClassLoader(), className);
+        if (c == null) {
+            throw new InternalError(className + " not loaded");
         }
+        return c;
     }
 
     // fds   : name/sig pairs
     // fmods : field modifiers
-    public static String createDerivedValueType(String vccInternalClassName, ClassLoader cl, ProtectionDomain pd, String[] fds, int[] fmods) {
+    public static String createDerivedValueType(String vccInternalClassName,
+                                                ClassLoader cl,
+                                                ProtectionDomain pd,
+                                                String[] fds,
+                                                int[] fmods) {
         String vtInternalClassName = getValueTypeClassName(vccInternalClassName);
         ValueTypeDesc valueTypeDesc = new ValueTypeDesc(vccInternalClassName, fds, fmods);
         byte[] valueTypeBytes = createValueType(valueTypeDesc);
@@ -122,8 +139,8 @@
         String valueTypeClassName = getValueTypeClassName(valueTypeDesc);
 
         BasicClassBuilder builder = new BasicClassBuilder(valueTypeClassName, 53, 1)
-                .withFlags(DERIVE_VT_CLASS_ACCESS)
-                .withSuperclass(VALUE_CLASS_DESC);
+            .withFlags(DERIVE_VT_CLASS_ACCESS)
+            .withSuperclass(VALUE_CLASS_DESC);
 
         ValueTypeDesc.Field[] fields = valueTypeDesc.getFields();
         for (ValueTypeDesc.Field field : fields) {
@@ -136,15 +153,13 @@
     }
 
     /** debugging flag for saving generated class files */
-    private static final File DUMP_CLASS_FILES_DIR;
+    private static final Path DUMP_CLASS_FILES_DIR;
 
     static {
         if (DUMP_CLASS_FILES) {
             try {
-                File dumpDir = new File("DUMP_CLASS_FILES");
-                if (!dumpDir.exists()) {
-                    dumpDir.mkdirs();
-                }
+                Path dumpDir = Paths.get("DUMP_CLASS_FILES");
+                Files.createDirectories(dumpDir);
                 DUMP_CLASS_FILES_DIR = dumpDir;
             } catch (Exception e) {
                 throw new InternalError(e);
@@ -155,25 +170,24 @@
     }
 
     public static void maybeDump(final String className, final byte[] classFile) {
-        if (DUMP_CLASS_FILES) {
+        if (DUMP_CLASS_FILES_DIR != null) {
             java.security.AccessController.doPrivileged(
-                    new java.security.PrivilegedAction<>() {
-                        public Void run() {
-                            try {
-                                String dumpName = className;
-                                //dumpName = dumpName.replace('/', '-');
-                                File dumpFile = new File(DUMP_CLASS_FILES_DIR, dumpName+".class");
-                                System.out.println("dump: " + dumpFile);
-                                dumpFile.getParentFile().mkdirs();
-                                FileOutputStream file = new FileOutputStream(dumpFile);
-                                file.write(classFile);
-                                file.close();
-                                return null;
-                            } catch (IOException ex) {
-                                throw new InternalError(ex);
-                            }
+                new java.security.PrivilegedAction<>() {
+                    public Void run() {
+                        String dumpName = className;
+                        //dumpName = dumpName.replace('/', '-');
+                        Path dumpFile = DUMP_CLASS_FILES_DIR.resolve(dumpName + ".class");
+                        System.out.println("dump: " + dumpFile);
+                        try (OutputStream os = Files.newOutputStream(dumpFile);
+                             BufferedOutputStream bos = new BufferedOutputStream(os)) {
+                            bos.write(classFile);
+                        } catch (IOException ex) {
+                            throw new InternalError(ex);
                         }
-                    });
+                        return null;
+                    }
+                });
+
         }
     }