7023639: JSR 292 method handle invocation needs a fast path for compiled code

6984705: JSR 292 method handle creation should not go through JNI
Summary: remove assembly code for JDK 7 chained method handles
Reviewed-by: jrose, twisti, mhaupt, forax
Contributed-by: NJohn Rose &lt;john.r.rose@oracle.com&gt;, Christian Thalinger &lt;christian.thalinger@oracle.com&gt;, Michael Haupt <michael.haupt@oracle.com>

src/share/classes/java/lang/invoke/CallSite.java

@@ -26,7 +26,7 @@
 package java.lang.invoke;
 
 import sun.invoke.empty.Empty;
-import sun.misc.Unsafe;
+import static java.lang.invoke.MethodHandleStatics.*;
 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
 
 /**
@@ -86,13 +86,9 @@ abstract
 public class CallSite {
     static { MethodHandleImpl.initStatics(); }
 
-    // Fields used only by the JVM.  Do not use or change.
-    private MemberName vmmethod; // supplied by the JVM (ref. to calling method)
-    private int        vmindex;  // supplied by the JVM (BCI within calling method)
-
     // The actual payload of this call site:
     /*package-private*/
-    MethodHandle target;
+    MethodHandle target;    // Note: This field is known to the JVM.  Do not change.
 
     /**
      * Make a blank call site object with the given method type.
@@ -151,24 +147,6 @@ public class CallSite {
         return target.type();
     }
 
-    /** Called from JVM (or low-level Java code) after the BSM returns the newly created CallSite.
-     *  The parameters are JVM-specific.
-     */
-    void initializeFromJVM(String name,
-                           MethodType type,
-                           MemberName callerMethod,
-                           int        callerBCI) {
-        if (this.vmmethod != null) {
-            // FIXME
-            throw new BootstrapMethodError("call site has already been linked to an invokedynamic instruction");
-        }
-        if (!this.type().equals(type)) {
-            throw wrongTargetType(target, type);
-        }
-        this.vmindex  = callerBCI;
-        this.vmmethod = callerMethod;
-    }
-
     /**
      * Returns the target method of the call site, according to the
      * behavior defined by this call site's specific class.
@@ -233,7 +211,7 @@ public class CallSite {
     public abstract MethodHandle dynamicInvoker();
 
     /*non-public*/ MethodHandle makeDynamicInvoker() {
-        MethodHandle getTarget = MethodHandleImpl.bindReceiver(GET_TARGET, this);
+        MethodHandle getTarget = GET_TARGET.bindReceiver(this);
         MethodHandle invoker = MethodHandles.exactInvoker(this.type());
         return MethodHandles.foldArguments(invoker, getTarget);
     }
@@ -255,12 +233,10 @@ public class CallSite {
     }
 
     // unsafe stuff:
-    private static final Unsafe unsafe = Unsafe.getUnsafe();
     private static final long TARGET_OFFSET;
-
     static {
         try {
-            TARGET_OFFSET = unsafe.objectFieldOffset(CallSite.class.getDeclaredField("target"));
+            TARGET_OFFSET = UNSAFE.objectFieldOffset(CallSite.class.getDeclaredField("target"));
         } catch (Exception ex) { throw new Error(ex); }
     }
 
@@ -270,7 +246,7 @@ public class CallSite {
     }
     /*package-private*/
     MethodHandle getTargetVolatile() {
-        return (MethodHandle) unsafe.getObjectVolatile(this, TARGET_OFFSET);
+        return (MethodHandle) UNSAFE.getObjectVolatile(this, TARGET_OFFSET);
     }
     /*package-private*/
     void setTargetVolatile(MethodHandle newTarget) {
@@ -284,8 +260,7 @@ public class CallSite {
                              // Extra arguments for BSM, if any:
                              Object info,
                              // Caller information:
-                             MemberName callerMethod, int callerBCI) {
-        Class<?> callerClass = callerMethod.getDeclaringClass();
+                             Class<?> callerClass) {
         Object caller = IMPL_LOOKUP.in(callerClass);
         CallSite site;
         try {

src/share/classes/java/lang/invoke/CountingMethodHandle.java → src/share/classes/java/lang/invoke/DontInline.java

 /*
- * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 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
@@ -25,26 +25,13 @@
 
 package java.lang.invoke;
 
-import static java.lang.invoke.MethodHandleNatives.Constants.*;
+import java.lang.annotation.*;
 
 /**
- * This method handle is used to optionally provide a count of how
- * many times it was invoked.
- *
- * @author never
+ * Internal marker for some methods in the JSR 292 implementation.
  */
-class CountingMethodHandle extends AdapterMethodHandle {
-    private int vmcount;
-
-    private CountingMethodHandle(MethodHandle target) {
-        super(target, target.type(), AdapterMethodHandle.makeConv(OP_RETYPE_ONLY));
-    }
-
-    /** Wrap the incoming MethodHandle in a CountingMethodHandle if they are enabled */
-    static MethodHandle wrap(MethodHandle mh) {
-        if (MethodHandleNatives.COUNT_GWT) {
-            return new CountingMethodHandle(mh);
-        }
-        return mh;
-    }
+/*non-public*/
+@Target({ElementType.METHOD, ElementType.CONSTRUCTOR})
+@Retention(RetentionPolicy.RUNTIME)
+@interface DontInline {
 }

src/share/classes/java/lang/invoke/ForceInline.java

+/*
+ * Copyright (c) 2012, 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 java.lang.annotation.*;
+
+/**
+ * Internal marker for some methods in the JSR 292 implementation.
+ */
+/*non-public*/
+@Target({ElementType.METHOD, ElementType.CONSTRUCTOR})
+@Retention(RetentionPolicy.RUNTIME)
+@interface ForceInline {
+}

src/share/classes/java/lang/invoke/Invokers.java

@@ -25,8 +25,11 @@
 
 package java.lang.invoke;
 
+import java.util.Arrays;
 import sun.invoke.empty.Empty;
+import static java.lang.invoke.MethodHandleNatives.Constants.*;
 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
+import static java.lang.invoke.LambdaForm.*;
 
 /**
  * Construction and caching of often-used invokers.
@@ -36,11 +39,15 @@ class Invokers {
     // exact type (sans leading taget MH) for the outgoing call
     private final MethodType targetType;
 
+    // FIXME: Get rid of the invokers that are not useful.
+
     // exact invoker for the outgoing call
     private /*lazy*/ MethodHandle exactInvoker;
 
     // erased (partially untyped but with primitives) invoker for the outgoing call
+    // FIXME: get rid of
     private /*lazy*/ MethodHandle erasedInvoker;
+    // FIXME: get rid of
     /*lazy*/ MethodHandle erasedInvokerWithDrops;  // for InvokeGeneric
 
     // general invoker for the outgoing call
@@ -63,14 +70,13 @@ class Invokers {
         this.spreadInvokers = new MethodHandle[targetType.parameterCount()+1];
     }
 
-    /*non-public*/ static MethodType invokerType(MethodType targetType) {
-        return targetType.insertParameterTypes(0, MethodHandle.class);
-    }
-
     /*non-public*/ MethodHandle exactInvoker() {
         MethodHandle invoker = exactInvoker;
         if (invoker != null)  return invoker;
-        invoker = lookupInvoker("invokeExact");
+        MethodType mtype = targetType;
+        LambdaForm lform = invokeForm(mtype, MethodTypeForm.LF_EX_INVOKER);
+        invoker = BoundMethodHandle.bindSingle(mtype.invokerType(), lform, mtype);
+        assert(checkInvoker(invoker));
         exactInvoker = invoker;
         return invoker;
     }
@@ -78,29 +84,50 @@ class Invokers {
     /*non-public*/ MethodHandle generalInvoker() {
         MethodHandle invoker = generalInvoker;
         if (invoker != null)  return invoker;
-        invoker = lookupInvoker("invoke");
+        MethodType mtype = targetType;
+        prepareForGenericCall(mtype);
+        LambdaForm lform = invokeForm(mtype, MethodTypeForm.LF_GEN_INVOKER);
+        invoker = BoundMethodHandle.bindSingle(mtype.invokerType(), lform, mtype);
+        assert(checkInvoker(invoker));
         generalInvoker = invoker;
         return invoker;
     }
 
-    private MethodHandle lookupInvoker(String name) {
-        MethodHandle invoker;
+    /*non-public*/ MethodHandle makeBasicInvoker() {
+        MethodHandle invoker = DirectMethodHandle.make(invokeBasicMethod(targetType));
+        assert(targetType == targetType.basicType());
+        // Note:  This is not cached here.  It is cached by the calling MethodTypeForm.
+        assert(checkInvoker(invoker));
+        return invoker;
+    }
+
+    static MemberName invokeBasicMethod(MethodType type) {
+        String name = "invokeBasic";
         try {
-            invoker = IMPL_LOOKUP.findVirtual(MethodHandle.class, name, targetType);
+            //Lookup.findVirtual(MethodHandle.class, name, type);
+            return IMPL_LOOKUP.resolveOrFail(REF_invokeVirtual, MethodHandle.class, name, type);
+
         } catch (ReflectiveOperationException ex) {
-            throw new InternalError("JVM cannot find invoker for "+targetType, ex);
+            throw new InternalError("JVM cannot find invoker for "+type, ex);
         }
-        assert(invokerType(targetType) == invoker.type());
+    }
+
+    private boolean checkInvoker(MethodHandle invoker) {
+        assert(targetType.invokerType().equals(invoker.type()))
+                : java.util.Arrays.asList(targetType, targetType.invokerType(), invoker);
+        assert(invoker.internalMemberName() == null ||
+               invoker.internalMemberName().getMethodType().equals(targetType));
         assert(!invoker.isVarargsCollector());
-        return invoker;
+        return true;
     }
 
+    // FIXME: get rid of
     /*non-public*/ MethodHandle erasedInvoker() {
         MethodHandle xinvoker = exactInvoker();
         MethodHandle invoker = erasedInvoker;
         if (invoker != null)  return invoker;
         MethodType erasedType = targetType.erase();
-        invoker = xinvoker.asType(invokerType(erasedType));
+        invoker = xinvoker.asType(erasedType.invokerType());
         erasedInvoker = invoker;
         return invoker;
     }
@@ -118,7 +145,7 @@ class Invokers {
     /*non-public*/ MethodHandle varargsInvoker() {
         MethodHandle vaInvoker = varargsInvoker;
         if (vaInvoker != null)  return vaInvoker;
-        vaInvoker = spreadInvoker(0).asType(invokerType(MethodType.genericMethodType(0, true)));
+        vaInvoker = spreadInvoker(0).asType(MethodType.genericMethodType(0, true).invokerType());
         varargsInvoker = vaInvoker;
         return vaInvoker;
     }
@@ -137,16 +164,18 @@ class Invokers {
             uninitializedCallSite = invoker;
             return invoker;
         }
-        if (THROW_UCS == null) {
+        invoker = THROW_UCS;
+        if (invoker == null) {
             try {
-                THROW_UCS = IMPL_LOOKUP
+                THROW_UCS = invoker = IMPL_LOOKUP
                     .findStatic(CallSite.class, "uninitializedCallSite",
                                 MethodType.methodType(Empty.class));
             } catch (ReflectiveOperationException ex) {
                 throw new RuntimeException(ex);
             }
         }
-        invoker = AdapterMethodHandle.makeRetypeRaw(targetType, THROW_UCS);
+        invoker = MethodHandles.explicitCastArguments(invoker, MethodType.methodType(targetType.returnType()));
+        invoker = invoker.dropArguments(targetType, 0, targetType.parameterCount());
         assert(invoker.type().equals(targetType));
         uninitializedCallSite = invoker;
         return invoker;
@@ -155,4 +184,208 @@ class Invokers {
     public String toString() {
         return "Invokers"+targetType;
     }
+
+    private static MethodType fixMethodType(Class<?> callerClass, Object type) {
+        if (type instanceof MethodType)
+            return (MethodType) type;
+        else
+            return MethodType.fromMethodDescriptorString((String)type, callerClass.getClassLoader());
+    }
+
+    static MemberName exactInvokerMethod(Class<?> callerClass, Object type, Object[] appendixResult) {
+        MethodType mtype = fixMethodType(callerClass, type);
+        LambdaForm lform = invokeForm(mtype, MethodTypeForm.LF_EX_LINKER);
+        appendixResult[0] = mtype;
+        return lform.vmentry;
+    }
+
+    static MemberName genericInvokerMethod(Class<?> callerClass, Object type, Object[] appendixResult) {
+        MethodType mtype = fixMethodType(callerClass, type);
+        LambdaForm lform = invokeForm(mtype, MethodTypeForm.LF_GEN_LINKER);
+        prepareForGenericCall(mtype);
+        appendixResult[0] = mtype;
+        return lform.vmentry;
+    }
+
+    private static LambdaForm invokeForm(MethodType mtype, int which) {
+        mtype = mtype.basicType();  // normalize Z to I, String to Object, etc.
+        boolean isLinker, isGeneric;
+        String debugName;
+        switch (which) {
+        case MethodTypeForm.LF_EX_LINKER:   isLinker = true;  isGeneric = false; debugName = "invokeExact_MT"; break;
+        case MethodTypeForm.LF_EX_INVOKER:  isLinker = false; isGeneric = false; debugName = "exactInvoker"; break;
+        case MethodTypeForm.LF_GEN_LINKER:  isLinker = true;  isGeneric = true;  debugName = "invoke_MT"; break;
+        case MethodTypeForm.LF_GEN_INVOKER: isLinker = false; isGeneric = true;  debugName = "invoker"; break;
+        default: throw new InternalError();
+        }
+        LambdaForm lform = mtype.form().cachedLambdaForm(which);
+        if (lform != null)  return lform;
+        // exactInvokerForm (Object,Object)Object
+        //   link with java.lang.invoke.MethodHandle.invokeBasic(MethodHandle,Object,Object)Object/invokeSpecial
+        final int THIS_MH      = 0;
+        final int CALL_MH      = THIS_MH + (isLinker ? 0 : 1);
+        final int ARG_BASE     = CALL_MH + 1;
+        final int OUTARG_LIMIT = ARG_BASE + mtype.parameterCount();
+        final int INARG_LIMIT  = OUTARG_LIMIT + (isLinker ? 1 : 0);
+        int nameCursor = OUTARG_LIMIT;
+        final int MTYPE_ARG    = nameCursor++;  // might be last in-argument
+        final int CHECK_TYPE   = nameCursor++;
+        final int LINKER_CALL  = nameCursor++;
+        MethodType invokerFormType = mtype.invokerType();
+        if (isLinker) {
+            invokerFormType = invokerFormType.appendParameterTypes(MemberName.class);
+        } else {
+            invokerFormType = invokerFormType.invokerType();
+        }
+        Name[] names = arguments(nameCursor - INARG_LIMIT, invokerFormType);
+        assert(names.length == nameCursor);
+        if (MTYPE_ARG >= INARG_LIMIT) {
+            assert(names[MTYPE_ARG] == null);
+            names[MTYPE_ARG] = BoundMethodHandle.getSpeciesData("L").getterName(names[THIS_MH], 0);
+            // else if isLinker, then MTYPE is passed in from the caller (e.g., the JVM)
+        }
+
+        // Make the final call.  If isGeneric, then prepend the result of type checking.
+        MethodType outCallType;
+        Object[] outArgs;
+        if (!isGeneric) {
+            names[CHECK_TYPE] = new Name(NF_checkExactType, names[CALL_MH], names[MTYPE_ARG]);
+            // mh.invokeExact(a*):R => checkExactType(mh, TYPEOF(a*:R)); mh.invokeBasic(a*)
+            outArgs = Arrays.copyOfRange(names, CALL_MH, OUTARG_LIMIT, Object[].class);
+            outCallType = mtype;
+        } else {
+            names[CHECK_TYPE] = new Name(NF_checkGenericType, names[CALL_MH], names[MTYPE_ARG]);
+            // mh.invokeGeneric(a*):R =>
+            //  let mt=TYPEOF(a*:R), gamh=checkGenericType(mh, mt);
+            //    gamh.invokeBasic(mt, mh, a*)
+            final int PREPEND_GAMH = 0, PREPEND_MT = 1, PREPEND_COUNT = 2;
+            outArgs = Arrays.copyOfRange(names, CALL_MH, OUTARG_LIMIT + PREPEND_COUNT, Object[].class);
+            // prepend arguments:
+            System.arraycopy(outArgs, 0, outArgs, PREPEND_COUNT, outArgs.length - PREPEND_COUNT);
+            outArgs[PREPEND_GAMH] = names[CHECK_TYPE];
+            outArgs[PREPEND_MT] = names[MTYPE_ARG];
+            outCallType = mtype.insertParameterTypes(0, MethodType.class, MethodHandle.class);
+        }
+        names[LINKER_CALL] = new Name(invokeBasicMethod(outCallType), outArgs);
+        lform = new LambdaForm(debugName, INARG_LIMIT, names);
+        if (isLinker)
+            lform.compileToBytecode();  // JVM needs a real methodOop
+        lform = mtype.form().setCachedLambdaForm(which, lform);
+        return lform;
+    }
+
+    /*non-public*/ static
+    WrongMethodTypeException newWrongMethodTypeException(MethodType actual, MethodType expected) {
+        // FIXME: merge with JVM logic for throwing WMTE
+        return new WrongMethodTypeException("expected "+expected+" but found "+actual);
+    }
+
+    /** Static definition of MethodHandle.invokeExact checking code. */
+    /*non-public*/ static
+    @ForceInline
+    void checkExactType(Object mhObj, Object expectedObj) {
+        MethodHandle mh = (MethodHandle) mhObj;
+        MethodType expected = (MethodType) expectedObj;
+        MethodType actual = mh.type();
+        if (actual != expected)
+            throw newWrongMethodTypeException(expected, actual);
+    }
+
+    /** Static definition of MethodHandle.invokeGeneric checking code. */
+    /*non-public*/ static
+    @ForceInline
+    Object checkGenericType(Object mhObj, Object expectedObj) {
+        MethodHandle mh = (MethodHandle) mhObj;
+        MethodType expected = (MethodType) expectedObj;
+        //MethodType actual = mh.type();
+        MethodHandle gamh = expected.form().genericInvoker;
+        if (gamh != null)  return gamh;
+        return prepareForGenericCall(expected);
+    }
+
+    /**
+     * Returns an adapter GA for invoking a MH with type adjustments.
+     * The MethodType of the generic invocation site is prepended to MH
+     * and its arguments as follows:
+     * {@code (R)MH.invoke(A*) => GA.invokeBasic(TYPEOF<A*,R>, MH, A*)}
+     */
+    /*non-public*/ static MethodHandle prepareForGenericCall(MethodType mtype) {
+        // force any needed adapters to be preconstructed
+        MethodTypeForm form = mtype.form();
+        MethodHandle gamh = form.genericInvoker;
+        if (gamh != null)  return gamh;
+        try {
+            // Trigger adapter creation.
+            gamh = InvokeGeneric.generalInvokerOf(form.erasedType);
+            form.genericInvoker = gamh;
+            return gamh;
+        } catch (Exception ex) {
+            throw new InternalError("Exception while resolving inexact invoke", ex);
+        }
+    }
+
+    static MemberName linkToCallSiteMethod(MethodType mtype) {
+        LambdaForm lform = callSiteForm(mtype);
+        return lform.vmentry;
+    }
+
+    private static LambdaForm callSiteForm(MethodType mtype) {
+        mtype = mtype.basicType();  // normalize Z to I, String to Object, etc.
+        LambdaForm lform = mtype.form().cachedLambdaForm(MethodTypeForm.LF_CS_LINKER);
+        if (lform != null)  return lform;
+        // exactInvokerForm (Object,Object)Object
+        //   link with java.lang.invoke.MethodHandle.invokeBasic(MethodHandle,Object,Object)Object/invokeSpecial
+        final int ARG_BASE     = 0;
+        final int OUTARG_LIMIT = ARG_BASE + mtype.parameterCount();
+        final int INARG_LIMIT  = OUTARG_LIMIT + 1;
+        int nameCursor = OUTARG_LIMIT;
+        final int CSITE_ARG    = nameCursor++;  // the last in-argument
+        final int CALL_MH      = nameCursor++;  // result of getTarget
+        final int LINKER_CALL  = nameCursor++;
+        MethodType invokerFormType = mtype.appendParameterTypes(CallSite.class);
+        Name[] names = arguments(nameCursor - INARG_LIMIT, invokerFormType);
+        assert(names.length == nameCursor);
+        assert(names[CSITE_ARG] != null);
+        names[CALL_MH] = new Name(NF_getCallSiteTarget, names[CSITE_ARG]);
+        // (site.)invokedynamic(a*):R => mh = site.getTarget(); mh.invokeBasic(a*)
+        final int PREPEND_MH = 0, PREPEND_COUNT = 1;
+        Object[] outArgs = Arrays.copyOfRange(names, ARG_BASE, OUTARG_LIMIT + PREPEND_COUNT, Object[].class);
+        // prepend MH argument:
+        System.arraycopy(outArgs, 0, outArgs, PREPEND_COUNT, outArgs.length - PREPEND_COUNT);
+        outArgs[PREPEND_MH] = names[CALL_MH];
+        names[LINKER_CALL] = new Name(invokeBasicMethod(mtype), outArgs);
+        lform = new LambdaForm("linkToCallSite", INARG_LIMIT, names);
+        lform.compileToBytecode();  // JVM needs a real methodOop
+        lform = mtype.form().setCachedLambdaForm(MethodTypeForm.LF_CS_LINKER, lform);
+        return lform;
+    }
+
+    /** Static definition of MethodHandle.invokeGeneric checking code. */
+    /*non-public*/ static
+    @ForceInline
+    Object getCallSiteTarget(Object site) {
+        return ((CallSite)site).getTarget();
+    }
+
+    // Local constant functions:
+    private static final NamedFunction NF_checkExactType;
+    private static final NamedFunction NF_checkGenericType;
+    private static final NamedFunction NF_getCallSiteTarget;
+    static {
+        try {
+            NF_checkExactType = new NamedFunction(Invokers.class
+                    .getDeclaredMethod("checkExactType", Object.class, Object.class));
+            NF_checkGenericType = new NamedFunction(Invokers.class
+                    .getDeclaredMethod("checkGenericType", Object.class, Object.class));
+            NF_getCallSiteTarget = new NamedFunction(Invokers.class
+                    .getDeclaredMethod("getCallSiteTarget", Object.class));
+            NF_checkExactType.resolve();
+            NF_checkGenericType.resolve();
+            NF_getCallSiteTarget.resolve();
+            // bound
+        } catch (ReflectiveOperationException ex) {
+            throw new InternalError(ex);
+        }
+    }
+
 }

src/share/classes/java/lang/invoke/MethodHandle.java

@@ -26,9 +26,13 @@
 package java.lang.invoke;
 
 
-import java.util.ArrayList;
-import sun.invoke.util.ValueConversions;
+import java.util.*;
+import sun.invoke.util.*;
+import sun.misc.Unsafe;
+
 import static java.lang.invoke.MethodHandleStatics.*;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 /**
  * A method handle is a typed, directly executable reference to an underlying method,
@@ -208,8 +212,8 @@ import static java.lang.invoke.MethodHandleStatics.*;
  * refers directly to an associated {@code CONSTANT_Methodref},
  * {@code CONSTANT_InterfaceMethodref}, or {@code CONSTANT_Fieldref}
  * constant pool entry.
- * (For more details on method handle constants,
- * see the <a href="package-summary.html#mhcon">package summary</a>.)
+ * (For full details on method handle constants,
+ * see sections 4.4.8 and 5.4.3.5 of the Java Virtual Machine Specification.)
  * <p>
  * Method handles produced by lookups or constant loads from methods or
  * constructors with the variable arity modifier bit ({@code 0x0080})
@@ -224,6 +228,19 @@ import static java.lang.invoke.MethodHandleStatics.*;
  * (E.g., if a non-static method handle is obtained via {@code ldc},
  * the type of the receiver is the class named in the constant pool entry.)
  * <p>
+ * Method handle constants are subject to the same link-time access checks
+ * their corresponding bytecode instructions, and the {@code ldc} instruction
+ * will throw corresponding linkage errors if the bytecode behaviors would
+ * throw such errors.
+ * <p>
+ * As a corollary of this, access to protected members is restricted
+ * to receivers only of the accessing class, or one of its subclasses,
+ * and the accessing class must in turn be a subclass (or package sibling)
+ * of the protected member's defining class.
+ * If a method reference refers to a protected non-static method or field
+ * of a class outside the current package, the receiver argument will
+ * be narrowed to the type of the accessing class.
+ * <p>
  * When a method handle to a virtual method is invoked, the method is
  * always looked up in the receiver (that is, the first argument).
  * <p>
@@ -390,39 +407,8 @@ mh.invokeExact(System.out, "Hello, world.");
  * @author John Rose, JSR 292 EG
  */
 public abstract class MethodHandle {
-    // { JVM internals:
-
-    private byte       vmentry;    // adapter stub or method entry point
-    //private int      vmslots;    // optionally, hoist type.form.vmslots
-    /*non-public*/ Object vmtarget;   // VM-specific, class-specific target value
-
-    // TO DO:  vmtarget should be invisible to Java, since the JVM puts internal
-    // managed pointers into it.  Making it visible exposes it to debuggers,
-    // which can cause errors when they treat the pointer as an Object.
-
-    // These two dummy fields are present to force 'I' and 'J' signatures
-    // into this class's constant pool, so they can be transferred
-    // to vmentry when this class is loaded.
-    static final int  INT_FIELD = 0;
-    static final long LONG_FIELD = 0;
-
-    // vmentry (a void* field) is used *only* by the JVM.
-    // The JVM adjusts its type to int or long depending on system wordsize.
-    // Since it is statically typed as neither int nor long, it is impossible
-    // to use this field from Java bytecode.  (Please don't try to, either.)
-
-    // The vmentry is an assembly-language stub which is jumped to
-    // immediately after the method type is verified.
-    // For a direct MH, this stub loads the vmtarget's entry point
-    // and jumps to it.
-
-    // } End of JVM internals.
-
     static { MethodHandleImpl.initStatics(); }
 
-    // interface MethodHandle<R throws X extends Exception,A...>
-    // { MethodType<R throws X,A...> type(); public R invokeExact(A...) throws X; }
-
     /**
      * Internal marker interface which distinguishes (to the Java compiler)
      * those methods which are <a href="MethodHandle.html#sigpoly">signature polymorphic</a>.
@@ -431,7 +417,9 @@ public abstract class MethodHandle {
     @java.lang.annotation.Retention(java.lang.annotation.RetentionPolicy.RUNTIME)
     @interface PolymorphicSignature { }
 
-    private MethodType type;
+    private final MethodType type;
+    /*private*/ final LambdaForm form;
+    // form is not private so that invokers can easily fetch it
 
     /**
      * Reports the type of this method handle.
@@ -448,9 +436,13 @@ public abstract class MethodHandle {
      * the {@code java.lang.invoke} package.
      */
     // @param type type (permanently assigned) of the new method handle
-    /*non-public*/ MethodHandle(MethodType type) {
-        type.getClass();  // elicit NPE
+    /*non-public*/ MethodHandle(MethodType type, LambdaForm form) {
+        type.getClass();  // explicit NPE
+        form.getClass();  // explicit NPE
         this.type = type;
+        this.form = form;
+
+        form.prepare();  // TO DO:  Try to delay this step until just before invocation.
     }
 
     /**
@@ -505,6 +497,46 @@ public abstract class MethodHandle {
      */
     public final native @PolymorphicSignature Object invoke(Object... args) throws Throwable;
 
+    /**
+     * Private method for trusted invocation of a method handle respecting simplified signatures.
+     * Type mismatches will not throw {@code WrongMethodTypeException}, but could crash the JVM.
+     * <p>
+     * The caller signature is restricted to the following basic types:
+     * Object, int, long, float, double, and void return.
+     * <p>
+     * The caller is responsible for maintaining type correctness by ensuring
+     * that the each outgoing argument value is a member of the range of the corresponding
+     * callee argument type.
+     * (The caller should therefore issue appropriate casts and integer narrowing
+     * operations on outgoing argument values.)
+     * The caller can assume that the incoming result value is part of the range
+     * of the callee's return type.
+     */
+    /*non-public*/ final native @PolymorphicSignature Object invokeBasic(Object... args) throws Throwable;
+
+    /*non-public*/ static native @PolymorphicSignature Object linkToVirtual(Object... args) throws Throwable;
+
+    /**
+     * Private method for trusted invocation of a MemberName of kind {@code REF_invokeStatic}.
+     * The caller signature is restricted to basic types as with {@code invokeBasic}.
+     * The trailing (not leading) argument must be a MemberName.
+     */
+    /*non-public*/ static native @PolymorphicSignature Object linkToStatic(Object... args) throws Throwable;
+
+    /**
+     * Private method for trusted invocation of a MemberName of kind {@code REF_invokeSpecial}.
+     * The caller signature is restricted to basic types as with {@code invokeBasic}.
+     * The trailing (not leading) argument must be a MemberName.
+     */
+    /*non-public*/ static native @PolymorphicSignature Object linkToSpecial(Object... args) throws Throwable;
+
+    /**
+     * Private method for trusted invocation of a MemberName of kind {@code REF_invokeInterface}.
+     * The caller signature is restricted to basic types as with {@code invokeBasic}.
+     * The trailing (not leading) argument must be a MemberName.
+     */
+    /*non-public*/ static native @PolymorphicSignature Object linkToInterface(Object... args) throws Throwable;
+
     /**
      * Performs a variable arity invocation, passing the arguments in the given array
      * to the method handle, as if via an inexact {@link #invoke invoke} from a call site
@@ -557,6 +589,7 @@ public abstract class MethodHandle {
      */
     public Object invokeWithArguments(Object... arguments) throws Throwable {
         int argc = arguments == null ? 0 : arguments.length;
+        @SuppressWarnings("LocalVariableHidesMemberVariable")
         MethodType type = type();
         if (type.parameterCount() != argc || isVarargsCollector()) {
             // simulate invoke
@@ -690,7 +723,7 @@ public abstract class MethodHandle {
         if (!type.isConvertibleTo(newType)) {
             throw new WrongMethodTypeException("cannot convert "+this+" to "+newType);
         }
-        return MethodHandleImpl.convertArguments(this, newType, 1);
+        return convertArguments(newType);
     }
 
     /**
@@ -772,7 +805,8 @@ assertEquals("[A, B, C]", (String) caToString2.invokeExact('A', "BC".toCharArray
      */
     public MethodHandle asSpreader(Class<?> arrayType, int arrayLength) {
         asSpreaderChecks(arrayType, arrayLength);
-        return MethodHandleImpl.spreadArguments(this, arrayType, arrayLength);
+        int spreadArgPos = type.parameterCount() - arrayLength;
+        return MethodHandleImpl.makeSpreadArguments(this, arrayType, spreadArgPos, arrayLength);
     }
 
     private void asSpreaderChecks(Class<?> arrayType, int arrayLength) {
@@ -790,7 +824,7 @@ assertEquals("[A, B, C]", (String) caToString2.invokeExact('A', "BC".toCharArray
                 }
             }
             if (sawProblem) {
-                ArrayList<Class<?>> ptypes = new ArrayList<Class<?>>(type().parameterList());
+                ArrayList<Class<?>> ptypes = new ArrayList<>(type().parameterList());
                 for (int i = nargs - arrayLength; i < nargs; i++) {
                     ptypes.set(i, arrayElement);
                 }
@@ -885,8 +919,12 @@ assertEquals("[123]", (String) longsToString.invokeExact((long)123));
      */
     public MethodHandle asCollector(Class<?> arrayType, int arrayLength) {
         asCollectorChecks(arrayType, arrayLength);
+        int collectArgPos = type().parameterCount()-1;
+        MethodHandle target = this;
+        if (arrayType != type().parameterType(collectArgPos))
+            target = convertArguments(type().changeParameterType(collectArgPos, arrayType));
         MethodHandle collector = ValueConversions.varargsArray(arrayType, arrayLength);
-        return MethodHandleImpl.collectArguments(this, type.parameterCount()-1, collector);
+        return MethodHandleImpl.makeCollectArguments(target, collector, collectArgPos, false);
     }
 
     // private API: return true if last param exactly matches arrayType
@@ -1056,7 +1094,7 @@ assertEquals("[three, thee, tee]", Arrays.toString((Object[])ls.get(0)));
         boolean lastMatch = asCollectorChecks(arrayType, 0);
         if (isVarargsCollector() && lastMatch)
             return this;
-        return AdapterMethodHandle.makeVarargsCollector(this, arrayType);
+        return MethodHandleImpl.makeVarargsCollector(this, arrayType);
     }
 
     /**
@@ -1155,14 +1193,13 @@ assertEquals("[three, thee, tee]", asListFix.invoke((Object)argv).toString());
      */
     public MethodHandle bindTo(Object x) {
         Class<?> ptype;
-        if (type().parameterCount() == 0 ||
-            (ptype = type().parameterType(0)).isPrimitive())
+        @SuppressWarnings("LocalVariableHidesMemberVariable")
+        MethodType type = type();
+        if (type.parameterCount() == 0 ||
+            (ptype = type.parameterType(0)).isPrimitive())
             throw newIllegalArgumentException("no leading reference parameter", x);
-        x = MethodHandles.checkValue(ptype, x);
-        // Cf. MethodHandles.insertArguments for the following logic:
-        MethodHandle bmh = MethodHandleImpl.bindReceiver(this, x);
-        if (bmh != null)  return bmh;
-        return MethodHandleImpl.bindArgument(this, 0, x);
+        x = ptype.cast(x);  // throw CCE if needed
+        return bindReceiver(x);
     }
 
     /**
@@ -1183,11 +1220,178 @@ assertEquals("[three, thee, tee]", asListFix.invoke((Object)argv).toString());
     @Override
     public String toString() {
         if (DEBUG_METHOD_HANDLE_NAMES)  return debugString();
+        return standardString();
+    }
+    String standardString() {
         return "MethodHandle"+type;
     }
+    String debugString() {
+        return standardString()+"="+internalForm()+internalValues();
+    }
+
+    //// Implementation methods.
+    //// Sub-classes can override these default implementations.
+    //// All these methods assume arguments are already validated.
+
+    // Other transforms to do:  convert, explicitCast, permute, drop, filter, fold, GWT, catch
 
     /*non-public*/
-    String debugString() {
-        return getNameString(this);
+    MethodHandle setVarargs(MemberName member) throws IllegalAccessException {
+        if (!member.isVarargs())  return this;
+        int argc = type().parameterCount();
+        if (argc != 0) {
+            Class<?> arrayType = type().parameterType(argc-1);
+            if (arrayType.isArray()) {
+                return MethodHandleImpl.makeVarargsCollector(this, arrayType);
+            }
+        }
+        throw member.makeAccessException("cannot make variable arity", null);
+    }
+    /*non-public*/
+    MethodHandle viewAsType(MethodType newType) {
+        // No actual conversions, just a new view of the same method.
+        if (!type.isViewableAs(newType))
+            throw new InternalError();
+        return MethodHandleImpl.makePairwiseConvert(this, newType, 0);
+    }
+
+    // Decoding
+
+    /*non-public*/
+    LambdaForm internalForm() {
+        return form;
+    }
+
+    /*non-public*/
+    MemberName internalMemberName() {
+        return null;  // DMH returns DMH.member
+    }
+
+    /*non-public*/
+    Object internalValues() {
+        return "";
+    }
+
+    //// Method handle implementation methods.
+    //// Sub-classes can override these default implementations.
+    //// All these methods assume arguments are already validated.
+
+    /*non-public*/ MethodHandle convertArguments(MethodType newType) {
+        // Override this if it can be improved.
+        return MethodHandleImpl.makePairwiseConvert(this, newType, 1);
+    }
+
+    /*non-public*/
+    MethodHandle bindArgument(int pos, char basicType, Object value) {
+        // Override this if it can be improved.
+        return rebind().bindArgument(pos, basicType, value);
+    }
+
+    /*non-public*/
+    MethodHandle bindReceiver(Object receiver) {
+        // Override this if it can be improved.
+        return bindArgument(0, 'L', receiver);
+    }
+
+    /*non-public*/
+    MethodHandle bindImmediate(int pos, char basicType, Object value) {
+        // Bind an immediate value to a position in the arguments.
+        // This means, elide the respective argument,
+        // and replace all references to it in NamedFunction args with the specified value.
+
+        // CURRENT RESTRICTIONS
+        // * only for pos 0 and UNSAFE (position is adjusted in MHImpl to make API usable for others)
+        assert pos == 0 && basicType == 'L' && value instanceof Unsafe;
+        MethodType type2 = type.dropParameterTypes(pos, pos + 1); // adjustment: ignore receiver!
+        LambdaForm form2 = form.bindImmediate(pos + 1, basicType, value); // adjust pos to form-relative pos
+        return copyWith(type2, form2);
+    }
+
+    /*non-public*/
+    MethodHandle copyWith(MethodType mt, LambdaForm lf) {
+        throw new InternalError("copyWith: " + this.getClass());
+    }
+
+    /*non-public*/
+    MethodHandle dropArguments(MethodType srcType, int pos, int drops) {
+        // Override this if it can be improved.
+        return rebind().dropArguments(srcType, pos, drops);
+    }
+
+    /*non-public*/
+    MethodHandle permuteArguments(MethodType newType, int[] reorder) {
+        // Override this if it can be improved.
+        return rebind().permuteArguments(newType, reorder);
+    }
+
+    /*non-public*/
+    MethodHandle rebind() {
+        // Bind 'this' into a new invoker, of the known class BMH.
+        MethodType type2 = type();
+        LambdaForm form2 = reinvokerForm(type2.basicType());
+        // form2 = lambda (bmh, arg*) { thismh = bmh[0]; invokeBasic(thismh, arg*) }
+        return BoundMethodHandle.bindSingle(type2, form2, this);
+    }
+
+    /*non-public*/
+    MethodHandle reinvokerTarget() {
+        throw new InternalError("not a reinvoker MH: "+this.getClass().getName()+": "+this);
+    }
+
+    /** Create a LF which simply reinvokes a target of the given basic type.
+     *  The target MH must override {@link #reinvokerTarget} to provide the target.
+     */
+    static LambdaForm reinvokerForm(MethodType mtype) {
+        mtype = mtype.basicType();
+        LambdaForm reinvoker = mtype.form().cachedLambdaForm(MethodTypeForm.LF_REINVOKE);
+        if (reinvoker != null)  return reinvoker;
+        MethodHandle MH_invokeBasic = MethodHandles.basicInvoker(mtype);
+        final int THIS_BMH    = 0;
+        final int ARG_BASE    = 1;
+        final int ARG_LIMIT   = ARG_BASE + mtype.parameterCount();
+        int nameCursor = ARG_LIMIT;
+        final int NEXT_MH     = nameCursor++;
+        final int REINVOKE    = nameCursor++;
+        LambdaForm.Name[] names = LambdaForm.arguments(nameCursor - ARG_LIMIT, mtype.invokerType());
+        names[NEXT_MH] = new LambdaForm.Name(NF_reinvokerTarget, names[THIS_BMH]);
+        Object[] targetArgs = Arrays.copyOfRange(names, THIS_BMH, ARG_LIMIT, Object[].class);
+        targetArgs[0] = names[NEXT_MH];  // overwrite this MH with next MH
+        names[REINVOKE] = new LambdaForm.Name(MH_invokeBasic, targetArgs);
+        return mtype.form().setCachedLambdaForm(MethodTypeForm.LF_REINVOKE, new LambdaForm("BMH.reinvoke", ARG_LIMIT, names));
+    }
+
+    private static final LambdaForm.NamedFunction NF_reinvokerTarget;
+    static {
+        try {
+            NF_reinvokerTarget = new LambdaForm.NamedFunction(MethodHandle.class
+                .getDeclaredMethod("reinvokerTarget"));
+        } catch (ReflectiveOperationException ex) {
+            throw new InternalError(ex);
+        }
+    }
+
+    /**
+     * Replace the old lambda form of this method handle with a new one.
+     * The new one must be functionally equivalent to the old one.
+     * Threads may continue running the old form indefinitely,
+     * but it is likely that the new one will be preferred for new executions.
+     * Use with discretion.
+     * @param newForm
+     */
+    /*non-public*/
+    void updateForm(LambdaForm newForm) {
+        if (form == newForm)  return;
+        // ISSUE: Should we have a memory fence here?
+        UNSAFE.putObject(this, FORM_OFFSET, newForm);
+        this.form.prepare();  // as in MethodHandle.<init>
+    }
+
+    private static final long FORM_OFFSET;
+    static {
+        try {
+            FORM_OFFSET = UNSAFE.objectFieldOffset(MethodHandle.class.getDeclaredField("form"));
+        } catch (ReflectiveOperationException ex) {
+            throw new InternalError(ex);
+        }
     }
 }

src/share/classes/java/lang/invoke/MethodHandleInfo.java

+/*
+ * Copyright (c) 2012, 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 java.lang.invoke.MethodHandleNatives.Constants;
+
+//Not yet public: public
+class MethodHandleInfo {
+   public static final int
+       REF_NONE                    = Constants.REF_NONE,
+       REF_getField                = Constants.REF_getField,
+       REF_getStatic               = Constants.REF_getStatic,
+       REF_putField                = Constants.REF_putField,
+       REF_putStatic               = Constants.REF_putStatic,
+       REF_invokeVirtual           = Constants.REF_invokeVirtual,
+       REF_invokeStatic            = Constants.REF_invokeStatic,
+       REF_invokeSpecial           = Constants.REF_invokeSpecial,
+       REF_newInvokeSpecial        = Constants.REF_newInvokeSpecial,
+       REF_invokeInterface         = Constants.REF_invokeInterface;
+
+   private final Class<?> declaringClass;
+   private final String name;
+   private final MethodType methodType;
+   private final int referenceKind;
+
+   public MethodHandleInfo(MethodHandle mh) throws ReflectiveOperationException {
+       MemberName mn = mh.internalMemberName();
+       this.declaringClass = mn.getDeclaringClass();
+       this.name = mn.getName();
+       this.methodType = mn.getMethodType();
+       this.referenceKind = mn.getReferenceKind();
+   }
+
+   public Class<?> getDeclaringClass() {
+       return declaringClass;
+   }
+
+   public String getName() {
+       return name;
+   }
+
+   public MethodType getMethodType() {
+       return methodType;
+   }
+
+   public int getReferenceKind() {
+       return referenceKind;
+   }
+}

src/share/classes/java/lang/invoke/MethodHandleStatics.java

@@ -27,6 +27,7 @@ package java.lang.invoke;
 
 import java.security.AccessController;
 import java.security.PrivilegedAction;
+import sun.misc.Unsafe;
 
 /**
  * This class consists exclusively of static names internal to the
@@ -38,16 +39,30 @@ import java.security.PrivilegedAction;
 
     private MethodHandleStatics() { }  // do not instantiate
 
+    static final Unsafe UNSAFE = Unsafe.getUnsafe();
+
     static final boolean DEBUG_METHOD_HANDLE_NAMES;
+    static final boolean DUMP_CLASS_FILES;
+    static final boolean TRACE_INTERPRETER;
+    static final boolean TRACE_METHOD_LINKAGE;
+    static final Integer COMPILE_THRESHOLD;
     static {
-        final Object[] values = { false };
+        final Object[] values = { false, false, false, false, null };
         AccessController.doPrivileged(new PrivilegedAction<Void>() {
                 public Void run() {
                     values[0] = Boolean.getBoolean("java.lang.invoke.MethodHandle.DEBUG_NAMES");
+                    values[1] = Boolean.getBoolean("java.lang.invoke.MethodHandle.DUMP_CLASS_FILES");
+                    values[2] = Boolean.getBoolean("java.lang.invoke.MethodHandle.TRACE_INTERPRETER");
+                    values[3] = Boolean.getBoolean("java.lang.invoke.MethodHandle.TRACE_METHOD_LINKAGE");
+                    values[4] = Integer.getInteger("java.lang.invoke.MethodHandle.COMPILE_THRESHOLD");
                     return null;
                 }
             });
         DEBUG_METHOD_HANDLE_NAMES = (Boolean) values[0];
+        DUMP_CLASS_FILES          = (Boolean) values[1];
+        TRACE_INTERPRETER         = (Boolean) values[2];
+        TRACE_METHOD_LINKAGE      = (Boolean) values[3];
+        COMPILE_THRESHOLD         = (Integer) values[4];
     }
 
     /*non-public*/ static String getNameString(MethodHandle target, MethodType type) {
@@ -55,7 +70,7 @@ import java.security.PrivilegedAction;
             type = target.type();
         MemberName name = null;
         if (target != null)
-            name = MethodHandleNatives.getMethodName(target);
+            name = target.internalMemberName();
         if (name == null)
             return "invoke" + type;
         return name.getName() + type;
@@ -77,20 +92,6 @@ import java.security.PrivilegedAction;
         return str + target.type();
     }
 
-    static void checkSpreadArgument(Object av, int n) {
-        if (av == null) {
-            if (n == 0)  return;
-        } else if (av instanceof Object[]) {
-            int len = ((Object[])av).length;
-            if (len == n)  return;
-        } else {
-            int len = java.lang.reflect.Array.getLength(av);
-            if (len == n)  return;
-        }
-        // fall through to error:
-        throw newIllegalArgumentException("Array is not of length "+n);
-    }
-
     // handy shared exception makers (they simplify the common case code)
     /*non-public*/ static RuntimeException newIllegalStateException(String message) {
         return new IllegalStateException(message);
@@ -110,6 +111,9 @@ import java.security.PrivilegedAction;
     /*non-public*/ static Error uncaughtException(Exception ex) {
         throw new InternalError("uncaught exception", ex);
     }
+    static Error NYI() {
+        throw new AssertionError("NYI");
+    }
     private static String message(String message, Object obj) {
         if (obj != null)  message = message + ": " + obj;
         return message;

src/share/classes/java/lang/invoke/SimpleMethodHandle.java

+/*
+ * Copyright (c) 2008, 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.lang.invoke;
+
+import static java.lang.invoke.LambdaForm.*;
+import static java.lang.invoke.MethodHandleNatives.Constants.*;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * A method handle whose behavior is determined only by its LambdaForm.
+ * @author jrose
+ */
+final class SimpleMethodHandle extends MethodHandle {
+    SimpleMethodHandle(MethodType type, LambdaForm form) {
+        super(type, form);
+    }
+
+    @Override
+    MethodHandle bindArgument(int pos, char basicType, Object value) {
+        MethodType type2 = type().dropParameterTypes(pos, pos+1);
+        LambdaForm form2 = internalForm().bind(1+pos, BoundMethodHandle.SpeciesData.EMPTY);
+        return BoundMethodHandle.bindSingle(type2, form2, basicType, value);
+    }
+
+    @Override
+    MethodHandle dropArguments(MethodType srcType, int pos, int drops) {
+        LambdaForm newForm = internalForm().addArguments(pos, srcType.parameterList().subList(pos, pos+drops));
+        return new SimpleMethodHandle(srcType, newForm);
+    }
+
+    @Override
+    MethodHandle permuteArguments(MethodType newType, int[] reorder) {
+        LambdaForm form2 = internalForm().permuteArguments(1, reorder, basicTypes(newType.parameterList()));
+        return new SimpleMethodHandle(newType, form2);
+    }
+
+    @Override
+    MethodHandle copyWith(MethodType mt, LambdaForm lf) {
+        return new SimpleMethodHandle(mt, lf);
+    }
+
+}