diff -r 2173b8120b13 -r 2836ee97ee27 jdk/src/share/classes/java/dyn/InvokeGeneric.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/dyn/InvokeGeneric.java	Fri Mar 18 00:03:24 2011 -0700
@@ -0,0 +1,151 @@
+/*
+ * Copyright (c) 2009, 2011, 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.dyn;
+
+import sun.dyn.util.*;
+import static java.dyn.MethodHandles.Lookup.IMPL_LOOKUP;
+
+/**
+ * Adapters which manage MethodHandle.invokeGeneric calls.
+ * The JVM calls one of these when the exact type match fails.
+ * @author jrose
+ */
+class InvokeGeneric {
+    // erased type for the call, which originates from an invokeGeneric site
+    private final MethodType erasedCallerType;
+    // an invoker of type (MT, MH; A...) -> R
+    private final MethodHandle initialInvoker;
+
+    /** Compute and cache information for this adapter, so that it can
+     *  call out to targets of the erasure-family of the given erased type.
+     */
+    /*non-public*/ InvokeGeneric(MethodType erasedCallerType) throws ReflectiveOperationException {
+        assert(erasedCallerType.equals(erasedCallerType.erase()));
+        this.erasedCallerType = erasedCallerType;
+        this.initialInvoker = makeInitialInvoker();
+        assert initialInvoker.type().equals(erasedCallerType
+                                            .insertParameterTypes(0, MethodType.class, MethodHandle.class))
+            : initialInvoker.type();
+    }
+
+    private static MethodHandles.Lookup lookup() {
+        return IMPL_LOOKUP;
+    }
+
+    /** Return the adapter information for this type's erasure. */
+    /*non-public*/ static MethodHandle genericInvokerOf(MethodType erasedCallerType) throws ReflectiveOperationException {
+        InvokeGeneric gen = new InvokeGeneric(erasedCallerType);
+        return gen.initialInvoker;
+    }
+
+    private MethodHandle makeInitialInvoker() throws ReflectiveOperationException {
+        // postDispatch = #(MH'; MT, MH; A...){MH'(MT, MH; A)}
+        MethodHandle postDispatch = makePostDispatchInvoker();
+        MethodHandle invoker;
+        if (returnConversionPossible()) {
+            invoker = MethodHandles.foldArguments(postDispatch,
+                                                  dispatcher("dispatchWithConversion"));
+        } else {
+            invoker = MethodHandles.foldArguments(postDispatch, dispatcher("dispatch"));
+        }
+        return invoker;
+    }
+
+    private static final Class<?>[] EXTRA_ARGS = { MethodType.class, MethodHandle.class };
+    private MethodHandle makePostDispatchInvoker() {
+        // Take (MH'; MT, MH; A...) and run MH'(MT, MH; A...).
+        MethodType invokerType = erasedCallerType.insertParameterTypes(0, EXTRA_ARGS);
+        return invokerType.invokers().exactInvoker();
+    }
+    private MethodHandle dropDispatchArguments(MethodHandle targetInvoker) {
+        assert(targetInvoker.type().parameterType(0) == MethodHandle.class);
+        return MethodHandles.dropArguments(targetInvoker, 1, EXTRA_ARGS);
+    }
+
+    private MethodHandle dispatcher(String dispatchName) throws ReflectiveOperationException {
+        return lookup().bind(this, dispatchName,
+                             MethodType.methodType(MethodHandle.class,
+                                                   MethodType.class, MethodHandle.class));
+    }
+
+    static final boolean USE_AS_TYPE_PATH = true;
+
+    /** Return a method handle to invoke on the callerType, target, and remaining arguments.
+     *  The method handle must finish the call.
+     *  This is the first look at the caller type and target.
+     */
+    private MethodHandle dispatch(MethodType callerType, MethodHandle target) {
+        MethodType targetType = target.type();
+        if (USE_AS_TYPE_PATH || target.isVarargsCollector()) {
+            MethodHandle newTarget = target.asType(callerType);
+            targetType = callerType;
+            Invokers invokers = targetType.invokers();
+            MethodHandle invoker = invokers.erasedInvokerWithDrops;
+            if (invoker == null) {
+                invokers.erasedInvokerWithDrops = invoker =
+                    dropDispatchArguments(invokers.erasedInvoker());
+            }
+            return invoker.bindTo(newTarget);
+        }
+        throw new RuntimeException("NYI");
+    }
+
+    private MethodHandle dispatchWithConversion(MethodType callerType, MethodHandle target) {
+        MethodHandle finisher = dispatch(callerType, target);
+        if (returnConversionNeeded(callerType, target))
+            finisher = addReturnConversion(finisher, callerType.returnType());  //FIXME: slow
+        return finisher;
+    }
+
+    private boolean returnConversionPossible() {
+        Class<?> needType = erasedCallerType.returnType();
+        return !needType.isPrimitive();
+    }
+    private boolean returnConversionNeeded(MethodType callerType, MethodHandle target) {
+        Class<?> needType = callerType.returnType();
+        if (needType == erasedCallerType.returnType())
+            return false;  // no conversions possible, since must be primitive or Object
+        Class<?> haveType = target.type().returnType();
+        if (VerifyType.isNullConversion(haveType, needType))
+            return false;
+        return true;
+    }
+    private MethodHandle addReturnConversion(MethodHandle target, Class<?> type) {
+        if (true) throw new RuntimeException("NYI");
+        // FIXME: This is slow because it creates a closure node on every call that requires a return cast.
+        MethodType targetType = target.type();
+        MethodHandle caster = ValueConversions.identity(type);
+        caster = caster.asType(MethodType.methodType(type, targetType.returnType()));
+        // Drop irrelevant arguments, because we only care about the return value:
+        caster = MethodHandles.dropArguments(caster, 1, targetType.parameterList());
+        MethodHandle result = MethodHandles.foldArguments(caster, target);
+        return result.asType(target.type());
+    }
+
+    public String toString() {
+        return "InvokeGeneric"+erasedCallerType;
+    }
+}