--- /dev/null	2019-12-04 18:44:18.020007537 +0000
+++ new/src/java.base/share/classes/java/lang/invoke/AddressVarHandleGenerator.java	2019-12-09 18:15:20.091822985 +0000
@@ -0,0 +1,494 @@
+/*
+ * Copyright (c) 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 java.lang.invoke;
+
+import jdk.internal.access.foreign.MemoryAddressProxy;
+import jdk.internal.misc.Unsafe;
+import jdk.internal.org.objectweb.asm.ClassReader;
+import jdk.internal.org.objectweb.asm.ClassWriter;
+import jdk.internal.org.objectweb.asm.MethodVisitor;
+import jdk.internal.org.objectweb.asm.Opcodes;
+import jdk.internal.org.objectweb.asm.Type;
+import jdk.internal.org.objectweb.asm.util.TraceClassVisitor;
+import jdk.internal.vm.annotation.ForceInline;
+import sun.security.action.GetBooleanAction;
+import sun.security.action.GetPropertyAction;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+
+import static jdk.internal.org.objectweb.asm.Opcodes.ACC_FINAL;
+import static jdk.internal.org.objectweb.asm.Opcodes.ACC_PRIVATE;
+import static jdk.internal.org.objectweb.asm.Opcodes.ACC_PUBLIC;
+import static jdk.internal.org.objectweb.asm.Opcodes.ACC_STATIC;
+import static jdk.internal.org.objectweb.asm.Opcodes.ACC_SUPER;
+import static jdk.internal.org.objectweb.asm.Opcodes.ALOAD;
+import static jdk.internal.org.objectweb.asm.Opcodes.ARETURN;
+import static jdk.internal.org.objectweb.asm.Opcodes.BIPUSH;
+import static jdk.internal.org.objectweb.asm.Opcodes.CHECKCAST;
+import static jdk.internal.org.objectweb.asm.Opcodes.GETFIELD;
+import static jdk.internal.org.objectweb.asm.Opcodes.ICONST_0;
+import static jdk.internal.org.objectweb.asm.Opcodes.ICONST_1;
+import static jdk.internal.org.objectweb.asm.Opcodes.ICONST_2;
+import static jdk.internal.org.objectweb.asm.Opcodes.ICONST_3;
+import static jdk.internal.org.objectweb.asm.Opcodes.ICONST_4;
+import static jdk.internal.org.objectweb.asm.Opcodes.ICONST_5;
+import static jdk.internal.org.objectweb.asm.Opcodes.ICONST_M1;
+import static jdk.internal.org.objectweb.asm.Opcodes.ILOAD;
+import static jdk.internal.org.objectweb.asm.Opcodes.INVOKESPECIAL;
+import static jdk.internal.org.objectweb.asm.Opcodes.INVOKESTATIC;
+import static jdk.internal.org.objectweb.asm.Opcodes.INVOKEVIRTUAL;
+import static jdk.internal.org.objectweb.asm.Opcodes.LADD;
+import static jdk.internal.org.objectweb.asm.Opcodes.LALOAD;
+import static jdk.internal.org.objectweb.asm.Opcodes.LASTORE;
+import static jdk.internal.org.objectweb.asm.Opcodes.LLOAD;
+import static jdk.internal.org.objectweb.asm.Opcodes.LMUL;
+import static jdk.internal.org.objectweb.asm.Opcodes.NEWARRAY;
+import static jdk.internal.org.objectweb.asm.Opcodes.PUTFIELD;
+import static jdk.internal.org.objectweb.asm.Opcodes.RETURN;
+import static jdk.internal.org.objectweb.asm.Opcodes.DUP;
+import static jdk.internal.org.objectweb.asm.Opcodes.SIPUSH;
+import static jdk.internal.org.objectweb.asm.Opcodes.T_LONG;
+
+class AddressVarHandleGenerator {
+    private static final String DEBUG_DUMP_CLASSES_DIR_PROPERTY = "jdk.internal.foreign.ClassGenerator.DEBUG_DUMP_CLASSES_DIR";
+
+    private static final boolean DEBUG =
+        GetBooleanAction.privilegedGetProperty("jdk.internal.foreign.ClassGenerator.DEBUG");
+
+    private static final Class<?> BASE_CLASS = VarHandleMemoryAddressBase.class;
+
+    private static final HashMap<Class<?>, Class<?>> helperClassCache;
+
+    static {
+        helperClassCache = new HashMap<>();
+        helperClassCache.put(byte.class, VarHandleMemoryAddressAsBytes.class);
+        helperClassCache.put(short.class, VarHandleMemoryAddressAsShorts.class);
+        helperClassCache.put(char.class, VarHandleMemoryAddressAsChars.class);
+        helperClassCache.put(int.class, VarHandleMemoryAddressAsInts.class);
+        helperClassCache.put(long.class, VarHandleMemoryAddressAsLongs.class);
+        helperClassCache.put(float.class, VarHandleMemoryAddressAsFloats.class);
+        helperClassCache.put(double.class, VarHandleMemoryAddressAsDoubles.class);
+    }
+
+    private static final File DEBUG_DUMP_CLASSES_DIR;
+
+    static {
+        String path = GetPropertyAction.privilegedGetProperty(DEBUG_DUMP_CLASSES_DIR_PROPERTY);
+        if (path == null) {
+            DEBUG_DUMP_CLASSES_DIR = null;
+        } else {
+            DEBUG_DUMP_CLASSES_DIR = new File(path);
+        }
+    }
+
+    private static final Unsafe U = Unsafe.getUnsafe();
+
+    private final String implClassName;
+    private final int dimensions;
+    private final Class<?> carrier;
+    private final Class<?> helperClass;
+    private final VarForm form;
+
+    AddressVarHandleGenerator(Class<?> carrier, int dims) {
+        this.dimensions = dims;
+        this.carrier = carrier;
+        Class<?>[] components = new Class<?>[dimensions];
+        Arrays.fill(components, long.class);
+        this.form = new VarForm(BASE_CLASS, MemoryAddressProxy.class, carrier, components);
+        this.helperClass = helperClassCache.get(carrier);
+        this.implClassName = helperClass.getName().replace('.', '/') + dimensions;
+    }
+
+    /*
+     * Generate a VarHandle memory access factory.
+     * The factory has type (ZJJ[J)VarHandle.
+     */
+    MethodHandle generateHandleFactory() {
+        Class<?> implCls = generateClass();
+        try {
+            Class<?>[] components = new Class<?>[dimensions];
+            Arrays.fill(components, long.class);
+
+            VarForm form = new VarForm(implCls, MemoryAddressProxy.class, carrier, components);
+
+            MethodType constrType = MethodType.methodType(void.class, VarForm.class, boolean.class, long.class, long.class, long.class, long[].class);
+            MethodHandle constr = MethodHandles.Lookup.IMPL_LOOKUP.findConstructor(implCls, constrType);
+            constr = MethodHandles.insertArguments(constr, 0, form);
+            return constr;
+        } catch (Throwable ex) {
+            throw new AssertionError(ex);
+        }
+    }
+
+    /*
+     * Generate a specialized VarHandle class for given carrier
+     * and access coordinates.
+     */
+    Class<?> generateClass() {
+        BinderClassWriter cw = new BinderClassWriter();
+
+        if (DEBUG) {
+            System.out.println("Generating header implementation class");
+        }
+
+        cw.visit(52, ACC_PUBLIC | ACC_SUPER, implClassName, null, Type.getInternalName(BASE_CLASS), null);
+
+        //add dimension fields
+        for (int i = 0; i < dimensions; i++) {
+            cw.visitField(ACC_PRIVATE | ACC_FINAL, "dim" + i, "J", null, null);
+        }
+
+        addConstructor(cw);
+
+        addAccessModeTypeMethod(cw);
+
+        addStridesAccessor(cw);
+
+        addCarrierAccessor(cw);
+
+        for (VarHandle.AccessMode mode : VarHandle.AccessMode.values()) {
+            addAccessModeMethodIfNeeded(mode, cw);
+        }
+
+
+        cw.visitEnd();
+        byte[] classBytes = cw.toByteArray();
+        return defineClass(cw, classBytes);
+    }
+
+    void addConstructor(BinderClassWriter cw) {
+        MethodType constrType = MethodType.methodType(void.class, VarForm.class, boolean.class, long.class, long.class, long.class, long[].class);
+        MethodVisitor mv = cw.visitMethod(0, "<init>", constrType.toMethodDescriptorString(), null, null);
+        mv.visitCode();
+        //super call
+        mv.visitVarInsn(ALOAD, 0);
+        mv.visitVarInsn(ALOAD, 1);
+        mv.visitTypeInsn(CHECKCAST, Type.getInternalName(VarForm.class));
+        mv.visitVarInsn(ILOAD, 2);
+        mv.visitVarInsn(LLOAD, 3);
+        mv.visitVarInsn(LLOAD, 5);
+        mv.visitVarInsn(LLOAD, 7);
+        mv.visitMethodInsn(INVOKESPECIAL, Type.getInternalName(BASE_CLASS), "<init>",
+                MethodType.methodType(void.class, VarForm.class, boolean.class, long.class, long.class, long.class).toMethodDescriptorString(), false);
+        //init dimensions
+        for (int i = 0 ; i < dimensions ; i++) {
+            mv.visitVarInsn(ALOAD, 0);
+            mv.visitVarInsn(ALOAD, 9);
+            mv.visitLdcInsn(i);
+            mv.visitInsn(LALOAD);
+            mv.visitFieldInsn(PUTFIELD, implClassName, "dim" + i, "J");
+        }
+        mv.visitInsn(RETURN);
+        mv.visitMaxs(0, 0);
+        mv.visitEnd();
+    }
+
+    void addAccessModeTypeMethod(BinderClassWriter cw) {
+        MethodType modeMethType = MethodType.methodType(MethodType.class, VarHandle.AccessMode.class);
+        MethodVisitor mv = cw.visitMethod(ACC_FINAL, "accessModeTypeUncached", modeMethType.toMethodDescriptorString(), null, null);
+        mv.visitCode();
+        mv.visitVarInsn(ALOAD, 1);
+        mv.visitFieldInsn(GETFIELD, Type.getInternalName(VarHandle.AccessMode.class), "at", Type.getDescriptor(VarHandle.AccessType.class));
+        mv.visitLdcInsn(cw.makeConstantPoolPatch(MemoryAddressProxy.class));
+        mv.visitTypeInsn(CHECKCAST, Type.getInternalName(Class.class));
+        mv.visitLdcInsn(cw.makeConstantPoolPatch(carrier));
+        mv.visitTypeInsn(CHECKCAST, Type.getInternalName(Class.class));
+
+        Class<?>[] dims = new Class<?>[dimensions];
+        Arrays.fill(dims, long.class);
+        mv.visitLdcInsn(cw.makeConstantPoolPatch(dims));
+        mv.visitTypeInsn(CHECKCAST, Type.getInternalName(Class[].class));
+
+        mv.visitMethodInsn(INVOKEVIRTUAL, Type.getInternalName(VarHandle.AccessType.class),
+                "accessModeType", MethodType.methodType(MethodType.class, Class.class, Class.class, Class[].class).toMethodDescriptorString(), false);
+
+        mv.visitInsn(ARETURN);
+
+        mv.visitMaxs(0, 0);
+        mv.visitEnd();
+    }
+
+    void addAccessModeMethodIfNeeded(VarHandle.AccessMode mode, BinderClassWriter cw) {
+        String methName = mode.methodName();
+        MethodType methType = form.getMethodType(mode.at.ordinal())
+                .insertParameterTypes(0, BASE_CLASS);
+
+        try {
+            MethodType helperType = methType.insertParameterTypes(2, long.class);
+            if (dimensions > 0) {
+                helperType = helperType.dropParameterTypes(3, 3 + dimensions);
+            }
+            //try to resolve...
+            String helperMethodName = methName + "0";
+            MethodHandles.Lookup.IMPL_LOOKUP
+                    .findStatic(helperClass,
+                            helperMethodName,
+                            helperType);
+
+
+            MethodVisitor mv = cw.visitMethod(ACC_STATIC, methName, methType.toMethodDescriptorString(), null, null);
+            mv.visitAnnotation(Type.getDescriptor(ForceInline.class), true);
+            mv.visitCode();
+
+            mv.visitVarInsn(ALOAD, 0); // handle impl
+            mv.visitVarInsn(ALOAD, 1); // receiver
+
+            // offset calculation
+            int slot = 2;
+            mv.visitVarInsn(ALOAD, 0); // load recv
+            mv.visitFieldInsn(GETFIELD, Type.getInternalName(BASE_CLASS), "offset", "J");
+            for (int i = 0 ; i < dimensions ; i++) {
+                mv.visitVarInsn(ALOAD, 0); // load recv
+                mv.visitTypeInsn(CHECKCAST, implClassName);
+                mv.visitFieldInsn(GETFIELD, implClassName, "dim" + i, "J");
+                mv.visitVarInsn(LLOAD, slot);
+                mv.visitInsn(LMUL);
+                mv.visitInsn(LADD);
+                slot += 2;
+            }
+
+            for (int i = 2 + dimensions; i < methType.parameterCount() ; i++) {
+                Class<?> param = methType.parameterType(i);
+                mv.visitVarInsn(loadInsn(param), slot); // load index
+                slot += getSlotsForType(param);
+            }
+
+            //call helper
+            mv.visitMethodInsn(INVOKESTATIC, Type.getInternalName(helperClass), helperMethodName,
+                    helperType.toMethodDescriptorString(), false);
+
+            mv.visitInsn(returnInsn(helperType.returnType()));
+
+            mv.visitMaxs(0, 0);
+            mv.visitEnd();
+        } catch (ReflectiveOperationException ex) {
+            //not found, skip
+        }
+    }
+
+    void addStridesAccessor(BinderClassWriter cw) {
+        MethodVisitor mv = cw.visitMethod(ACC_FINAL, "strides", "()[J", null, null);
+        mv.visitCode();
+        iConstInsn(mv, dimensions);
+        mv.visitIntInsn(NEWARRAY, T_LONG);
+
+        for (int i = 0 ; i < dimensions ; i++) {
+            mv.visitInsn(DUP);
+            iConstInsn(mv, i);
+            mv.visitVarInsn(ALOAD, 0);
+            mv.visitFieldInsn(GETFIELD, implClassName, "dim" + i, "J");
+            mv.visitInsn(LASTORE);
+        }
+
+        mv.visitInsn(ARETURN);
+        mv.visitMaxs(0, 0);
+        mv.visitEnd();
+    }
+
+    void addCarrierAccessor(BinderClassWriter cw) {
+        MethodVisitor mv = cw.visitMethod(ACC_FINAL, "carrier", "()Ljava/lang/Class;", null, null);
+        mv.visitCode();
+        mv.visitLdcInsn(cw.makeConstantPoolPatch(carrier));
+        mv.visitTypeInsn(CHECKCAST, Type.getInternalName(Class.class));
+        mv.visitInsn(ARETURN);
+        mv.visitMaxs(0, 0);
+        mv.visitEnd();
+    }
+
+    //where
+    private Class<?> defineClass(BinderClassWriter cw, byte[] classBytes) {
+        try {
+            if (DEBUG_DUMP_CLASSES_DIR != null) {
+                debugWriteClassToFile(classBytes);
+            }
+            Object[] patches = cw.resolvePatches(classBytes);
+            Class<?> c = U.defineAnonymousClass(BASE_CLASS, classBytes, patches);
+            return c;
+        } catch (Throwable e) {
+            debugPrintClass(classBytes);
+            throw e;
+        }
+    }
+
+    // shared code generation helpers
+
+    private static int getSlotsForType(Class<?> c) {
+        if (c == long.class || c == double.class) {
+            return 2;
+        }
+        return 1;
+    }
+
+    /**
+     * Emits an actual return instruction conforming to the given return type.
+     */
+    private int returnInsn(Class<?> type) {
+        return switch (LambdaForm.BasicType.basicType(type)) {
+            case I_TYPE -> Opcodes.IRETURN;
+            case J_TYPE -> Opcodes.LRETURN;
+            case F_TYPE -> Opcodes.FRETURN;
+            case D_TYPE -> Opcodes.DRETURN;
+            case L_TYPE -> Opcodes.ARETURN;
+            case V_TYPE -> RETURN;
+        };
+    }
+
+    private int loadInsn(Class<?> type) {
+        return switch (LambdaForm.BasicType.basicType(type)) {
+            case I_TYPE -> Opcodes.ILOAD;
+            case J_TYPE -> LLOAD;
+            case F_TYPE -> Opcodes.FLOAD;
+            case D_TYPE -> Opcodes.DLOAD;
+            case L_TYPE -> Opcodes.ALOAD;
+            case V_TYPE -> throw new IllegalStateException("Cannot load void");
+        };
+    }
+
+    private static void iConstInsn(MethodVisitor mv, int i) {
+        switch (i) {
+            case -1, 0, 1, 2, 3, 4, 5:
+                mv.visitInsn(ICONST_0 + i);
+                break;
+            default:
+                if(i >= Byte.MIN_VALUE && i <= Byte.MAX_VALUE) {
+                    mv.visitIntInsn(BIPUSH, i);
+                } else if (i >= Short.MIN_VALUE && i <= Short.MAX_VALUE) {
+                    mv.visitIntInsn(SIPUSH, i);
+                } else {
+                    mv.visitLdcInsn(i);
+                }
+        }
+    }
+
+    // debug helpers
+
+    private static String debugPrintClass(byte[] classFile) {
+        ClassReader cr = new ClassReader(classFile);
+        StringWriter sw = new StringWriter();
+        cr.accept(new TraceClassVisitor(new PrintWriter(sw)), 0);
+        return sw.toString();
+    }
+
+    private void debugWriteClassToFile(byte[] classFile) {
+        File file = new File(DEBUG_DUMP_CLASSES_DIR, implClassName + ".class");
+
+        if (DEBUG) {
+            System.err.println("Dumping class " + implClassName + " to " + file);
+        }
+
+        try {
+            debugWriteDataToFile(classFile, file);
+        } catch (Exception e) {
+            throw new RuntimeException("Failed to write class " + implClassName + " to file " + file);
+        }
+    }
+
+    private void debugWriteDataToFile(byte[] data, File file) {
+        if (file.exists()) {
+            file.delete();
+        }
+        if (file.exists()) {
+            throw new RuntimeException("Failed to remove pre-existing file " + file);
+        }
+
+        File parent = file.getParentFile();
+        if (!parent.exists()) {
+            parent.mkdirs();
+        }
+        if (!parent.exists()) {
+            throw new RuntimeException("Failed to create " + parent);
+        }
+        if (!parent.isDirectory()) {
+            throw new RuntimeException(parent + " is not a directory");
+        }
+
+        try (FileOutputStream fos = new FileOutputStream(file)) {
+            fos.write(data);
+        } catch (IOException e) {
+            throw new RuntimeException("Failed to write class " + implClassName + " to file " + file);
+        }
+    }
+
+    static class BinderClassWriter extends ClassWriter {
+
+        private final ArrayList<ConstantPoolPatch> cpPatches = new ArrayList<>();
+        private int curUniquePatchIndex = 0;
+
+        BinderClassWriter() {
+            super(ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS);
+        }
+
+        public String makeConstantPoolPatch(Object o) {
+            int myUniqueIndex = curUniquePatchIndex++;
+            String cpPlaceholder = "CONSTANT_PLACEHOLDER_" + myUniqueIndex;
+            int index = newConst(cpPlaceholder);
+            cpPatches.add(new ConstantPoolPatch(index, cpPlaceholder, o));
+            return cpPlaceholder;
+        }
+
+        public Object[] resolvePatches(byte[] classFile) {
+            if (cpPatches.isEmpty()) {
+                return null;
+            }
+
+            int size = ((classFile[8] & 0xFF) << 8) | (classFile[9] & 0xFF);
+
+            Object[] patches = new Object[size];
+            for (ConstantPoolPatch p : cpPatches) {
+                if (p.index >= size) {
+                    throw new InternalError("Failed to resolve constant pool patch entries");
+                }
+                patches[p.index] = p.value;
+            }
+
+            return patches;
+        }
+
+        static class ConstantPoolPatch {
+            final int index;
+            final String placeholder;
+            final Object value;
+
+            ConstantPoolPatch(int index, String placeholder, Object value) {
+                this.index = index;
+                this.placeholder = placeholder;
+                this.value = value;
+            }
+
+            @Override
+            public String toString() {
+                return "CpPatch/index="+index+",placeholder="+placeholder+",value="+value;
+            }
+        }
+    }
+}