jdk8-mips64-public/nashorn: src/jdk/nashorn/internal/runtime/ScriptObject.java@a2065f67857c (annotated)

src/jdk/nashorn/internal/runtime/ScriptObject.java@a2065f67857c (annotated)

src/jdk/nashorn/internal/runtime/ScriptObject.java

Thu, 17 Oct 2013 17:33:16 +0200

author: hannesw
date: Thu, 17 Oct 2013 17:33:16 +0200
changeset 633: a2065f67857c
parent 620: 8c617a092d68
child 636: d8aa87d292eb
permissions: -rw-r--r--

8026701: Array.prototype.splice is slow on dense arrays
Reviewed-by: lagergren, sundar, jlaskey

 /*
  * Copyright (c) 2010, 2013, 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 jdk.nashorn.internal.runtime;
 import static jdk.nashorn.internal.codegen.CompilerConstants.virtualCall;
 import static jdk.nashorn.internal.codegen.CompilerConstants.virtualCallNoLookup;
 import static jdk.nashorn.internal.lookup.Lookup.MH;
 import static jdk.nashorn.internal.runtime.ECMAErrors.referenceError;
 import static jdk.nashorn.internal.runtime.ECMAErrors.typeError;
 import static jdk.nashorn.internal.runtime.PropertyDescriptor.CONFIGURABLE;
 import static jdk.nashorn.internal.runtime.PropertyDescriptor.ENUMERABLE;
 import static jdk.nashorn.internal.runtime.PropertyDescriptor.GET;
 import static jdk.nashorn.internal.runtime.PropertyDescriptor.SET;
 import static jdk.nashorn.internal.runtime.PropertyDescriptor.VALUE;
 import static jdk.nashorn.internal.runtime.PropertyDescriptor.WRITABLE;
 import static jdk.nashorn.internal.runtime.ScriptRuntime.UNDEFINED;
 import static jdk.nashorn.internal.runtime.arrays.ArrayIndex.getArrayIndex;
 import static jdk.nashorn.internal.runtime.arrays.ArrayIndex.isValidArrayIndex;
 import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.MethodType;
 import java.util.AbstractMap;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import jdk.internal.dynalink.CallSiteDescriptor;
 import jdk.internal.dynalink.linker.GuardedInvocation;
 import jdk.internal.dynalink.linker.LinkRequest;
 import jdk.internal.dynalink.support.CallSiteDescriptorFactory;
 import jdk.nashorn.internal.codegen.CompilerConstants.Call;
 import jdk.nashorn.internal.codegen.ObjectClassGenerator;
 import jdk.nashorn.internal.lookup.Lookup;
 import jdk.nashorn.internal.lookup.MethodHandleFactory;
 import jdk.nashorn.internal.objects.AccessorPropertyDescriptor;
 import jdk.nashorn.internal.objects.DataPropertyDescriptor;
 import jdk.nashorn.internal.runtime.arrays.ArrayData;
 import jdk.nashorn.internal.runtime.arrays.ArrayIndex;
 import jdk.nashorn.internal.runtime.linker.Bootstrap;
 import jdk.nashorn.internal.runtime.linker.LinkerCallSite;
 import jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor;
 import jdk.nashorn.internal.runtime.linker.NashornGuards;
 /**
  * Base class for generic JavaScript objects.
  * <p>
  * Notes:
  * <ul>
  * <li>The map is used to identify properties in the object.</li>
  * <li>If the map is modified then it must be cloned and replaced.  This notifies
  *     any code that made assumptions about the object that things have changed.
  *     Ex. CallSites that have been validated must check to see if the map has
  *     changed (or a map from a different object type) and hence relink the method
  *     to call.</li>
  * <li>Modifications of the map include adding/deleting attributes or changing a
  *     function field value.</li>
  * </ul>
  */
 public abstract class ScriptObject extends PropertyListenerManager implements PropertyAccess {
     /** __proto__ special property name */
     public static final String PROTO_PROPERTY_NAME   = "__proto__";
     /** Search fall back routine name for "no such method" */
     static final String NO_SUCH_METHOD_NAME   = "__noSuchMethod__";
     /** Search fall back routine name for "no such property" */
     static final String NO_SUCH_PROPERTY_NAME = "__noSuchProperty__";
     /** Per ScriptObject flag - is this a scope object? */
     public static final int IS_SCOPE       = 0b0000_0001;
     /** Per ScriptObject flag - is this an array object? */
     public static final int IS_ARRAY       = 0b0000_0010;
     /** Per ScriptObject flag - is this an arguments object? */
     public static final int IS_ARGUMENTS   = 0b0000_0100;
     /** Is this a prototype PropertyMap? */
     public static final int IS_PROTOTYPE   = 0b0000_1000;
     /** Is length property not-writable? */
     public static final int IS_LENGTH_NOT_WRITABLE = 0b0001_0000;
     /** Spill growth rate - by how many elements does {@link ScriptObject#spill} when full */
     public static final int SPILL_RATE = 8;
     /** Map to property information and accessor functions. Ordered by insertion. */
     private PropertyMap map;
     /** objects proto. */
     private ScriptObject proto;
     /** Object flags. */
     private int flags;
     /** Area for properties added to object after instantiation, see {@link AccessorProperty} */
     public Object[] spill;
     /** Indexed array data. */
     private ArrayData arrayData;
     static final MethodHandle GETPROTO           = findOwnMH("getProto", ScriptObject.class);
     static final MethodHandle SETPROTOCHECK      = findOwnMH("setProtoCheck", void.class, Object.class);
     static final MethodHandle MEGAMORPHIC_GET    = findOwnMH("megamorphicGet", Object.class, String.class, boolean.class);
     static final MethodHandle SETFIELD           = findOwnMH("setField",         void.class, CallSiteDescriptor.class, PropertyMap.class, PropertyMap.class, MethodHandle.class, Object.class, Object.class);
     static final MethodHandle SETSPILL           = findOwnMH("setSpill",         void.class, CallSiteDescriptor.class, PropertyMap.class, PropertyMap.class, int.class, Object.class, Object.class);
     static final MethodHandle SETSPILLWITHNEW    = findOwnMH("setSpillWithNew",  void.class, CallSiteDescriptor.class, PropertyMap.class, PropertyMap.class, int.class, Object.class, Object.class);
     static final MethodHandle SETSPILLWITHGROW   = findOwnMH("setSpillWithGrow", void.class, CallSiteDescriptor.class, PropertyMap.class, PropertyMap.class, int.class, int.class, Object.class, Object.class);
     private static final MethodHandle TRUNCATINGFILTER   = findOwnMH("truncatingFilter", Object[].class, int.class, Object[].class);
     private static final MethodHandle KNOWNFUNCPROPGUARD = findOwnMH("knownFunctionPropertyGuard", boolean.class, Object.class, PropertyMap.class, MethodHandle.class, Object.class, ScriptFunction.class);
     /** Method handle for getting a function argument at a given index. Used from MapCreator */
     public static final Call GET_ARGUMENT       = virtualCall(MethodHandles.lookup(), ScriptObject.class, "getArgument", Object.class, int.class);
     /** Method handle for setting a function argument at a given index. Used from MapCreator */
     public static final Call SET_ARGUMENT       = virtualCall(MethodHandles.lookup(), ScriptObject.class, "setArgument", void.class, int.class, Object.class);
     /** Method handle for getting the proto of a ScriptObject */
     public static final Call GET_PROTO          = virtualCallNoLookup(ScriptObject.class, "getProto", ScriptObject.class);
     /** Method handle for setting the proto of a ScriptObject */
     public static final Call SET_PROTO          = virtualCallNoLookup(ScriptObject.class, "setProto", void.class, ScriptObject.class);
     /** Method handle for setting the proto of a ScriptObject after checking argument */
     public static final Call SET_PROTO_CHECK    = virtualCallNoLookup(ScriptObject.class, "setProtoCheck", void.class, Object.class);
     /** Method handle for setting the user accessors of a ScriptObject */
     public static final Call SET_USER_ACCESSORS = virtualCall(MethodHandles.lookup(), ScriptObject.class, "setUserAccessors", void.class, String.class, ScriptFunction.class, ScriptFunction.class);
     /**
      * Constructor
      */
     public ScriptObject() {
         this(null);
     }
     /**
     * Constructor
     *
     * @param map {@link PropertyMap} used to create the initial object
     */
     public ScriptObject(final PropertyMap map) {
         if (Context.DEBUG) {
             ScriptObject.count++;
         }
         this.arrayData = ArrayData.EMPTY_ARRAY;
         this.setMap(map == null ? PropertyMap.newMap() : map);
     }
     /**
      * Constructor that directly sets the prototype to {@code proto} and property map to
      * {@code map} without invalidating the map as calling {@link #setProto(ScriptObject)}
      * would do. This should only be used for objects that are always constructed with the
      * same combination of prototype and property map.
      *
      * @param proto the prototype object
      * @param map intial {@link PropertyMap}
      */
     protected ScriptObject(final ScriptObject proto, final PropertyMap map) {
         if (Context.DEBUG) {
             ScriptObject.count++;
         }
         this.arrayData = ArrayData.EMPTY_ARRAY;
         this.setMap(map == null ? PropertyMap.newMap() : map);
         this.proto = proto;
         if (proto != null) {
             proto.setIsPrototype();
         }
     }
     /**
      * Copy all properties from the source object with their receiver bound to the source.
      * This function was known as mergeMap
      *
      * @param source The source object to copy from.
      */
     public void addBoundProperties(final ScriptObject source) {
         addBoundProperties(source, source.getMap().getProperties());
     }
     /**
      * Copy all properties from the array with their receiver bound to the source.
      *
      * @param source The source object to copy from.
      * @param properties The array of properties to copy.
      */
     public void addBoundProperties(final ScriptObject source, final Property[] properties) {
         PropertyMap newMap = this.getMap();
         for (final Property property : properties) {
             final String key = property.getKey();
             if (newMap.findProperty(key) == null) {
                 if (property instanceof UserAccessorProperty) {
                     final UserAccessorProperty prop = this.newUserAccessors(key, property.getFlags(), property.getGetterFunction(source), property.getSetterFunction(source));
                     newMap = newMap.addProperty(prop);
                 } else {
                     newMap = newMap.addPropertyBind((AccessorProperty)property, source);
                 }
             }
         }
         this.setMap(newMap);
     }
     /**
      * Copy all properties from the array with their receiver bound to the source.
      *
      * @param source The source object to copy from.
      * @param properties The collection of accessor properties to copy.
      */
     public void addBoundProperties(final Object source, final AccessorProperty[] properties) {
         PropertyMap newMap = this.getMap();
         for (final AccessorProperty property : properties) {
             final String key = property.getKey();
             if (newMap.findProperty(key) == null) {
                 newMap = newMap.addPropertyBind(property, source);
             }
         }
         this.setMap(newMap);
     }
     /**
      * Bind the method handle to the specified receiver, while preserving its original type (it will just ignore the
      * first argument in lieu of the bound argument).
      * @param methodHandle Method handle to bind to.
      * @param receiver     Object to bind.
      * @return Bound method handle.
      */
     static MethodHandle bindTo(final MethodHandle methodHandle, final Object receiver) {
         return MH.dropArguments(MH.bindTo(methodHandle, receiver), 0, methodHandle.type().parameterType(0));
     }
     /**
      * Return a property iterator.
      * @return Property iterator.
      */
     public Iterator<String> propertyIterator() {
         return new KeyIterator(this);
     }
     /**
      * Return a property value iterator.
      * @return Property value iterator.
      */
     public Iterator<Object> valueIterator() {
         return new ValueIterator(this);
     }
     /**
      * ECMA 8.10.1 IsAccessorDescriptor ( Desc )
      * @return true if this has a {@link AccessorPropertyDescriptor} with a getter or a setter
      */
     public final boolean isAccessorDescriptor() {
         return has(GET) || has(SET);
     }
     /**
      * ECMA 8.10.2 IsDataDescriptor ( Desc )
      * @return true if this has a {@link DataPropertyDescriptor}, i.e. the object has a property value and is writable
      */
     public final boolean isDataDescriptor() {
         return has(VALUE) || has(WRITABLE);
     }
     /**
      * ECMA 8.10.3 IsGenericDescriptor ( Desc )
      * @return true if this has a descriptor describing an {@link AccessorPropertyDescriptor} or {@link DataPropertyDescriptor}
      */
     public final boolean isGenericDescriptor() {
         return isAccessorDescriptor() || isDataDescriptor();
     }
     /**
       * ECMA 8.10.5 ToPropertyDescriptor ( Obj )
       *
       * @return property descriptor
       */
     public final PropertyDescriptor toPropertyDescriptor() {
         final GlobalObject global = (GlobalObject) Context.getGlobalTrusted();
         final PropertyDescriptor desc;
         if (isDataDescriptor()) {
             if (has(SET) || has(GET)) {
                 throw typeError((ScriptObject)global, "inconsistent.property.descriptor");
             }
             desc = global.newDataDescriptor(UNDEFINED, false, false, false);
         } else if (isAccessorDescriptor()) {
             if (has(VALUE) || has(WRITABLE)) {
                 throw typeError((ScriptObject)global, "inconsistent.property.descriptor");
             }
             desc = global.newAccessorDescriptor(UNDEFINED, UNDEFINED, false, false);
         } else {
             desc = global.newGenericDescriptor(false, false);
         }
         return desc.fillFrom(this);
     }
     /**
      * ECMA 8.10.5 ToPropertyDescriptor ( Obj )
      *
      * @param global  global scope object
      * @param obj object to create property descriptor from
      *
      * @return property descriptor
      */
     public static PropertyDescriptor toPropertyDescriptor(final ScriptObject global, final Object obj) {
         if (obj instanceof ScriptObject) {
             return ((ScriptObject)obj).toPropertyDescriptor();
         }
         throw typeError(global, "not.an.object", ScriptRuntime.safeToString(obj));
     }
     /**
      * ECMA 8.12.1 [[GetOwnProperty]] (P)
      *
      * @param key property key
      *
      * @return Returns the Property Descriptor of the named own property of this
      * object, or undefined if absent.
      */
     public Object getOwnPropertyDescriptor(final String key) {
         final Property property = getMap().findProperty(key);
         final GlobalObject global = (GlobalObject)Context.getGlobalTrusted();
         if (property != null) {
             final ScriptFunction get   = property.getGetterFunction(this);
             final ScriptFunction set   = property.getSetterFunction(this);
             final boolean configurable = property.isConfigurable();
             final boolean enumerable   = property.isEnumerable();
             final boolean writable     = property.isWritable();
             if (property instanceof UserAccessorProperty) {
                 return global.newAccessorDescriptor(
                     (get != null) ?
                         get :
                         UNDEFINED,
                     (set != null) ?
                         set :
                         UNDEFINED,
                     configurable,
                     enumerable);
             }
             return global.newDataDescriptor(getWithProperty(property), configurable, enumerable, writable);
         }
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getDescriptor(global, index);
         }
         return UNDEFINED;
     }
     /**
      * ECMA 8.12.2 [[GetProperty]] (P)
      *
      * @param key property key
      *
      * @return Returns the fully populated Property Descriptor of the named property
      * of this object, or undefined if absent.
      */
     public Object getPropertyDescriptor(final String key) {
         final Object res = getOwnPropertyDescriptor(key);
         if (res != UNDEFINED) {
             return res;
         } else if (getProto() != null) {
             return getProto().getOwnPropertyDescriptor(key);
         } else {
             return UNDEFINED;
         }
     }
     /**
      * ECMA 8.12.9 [[DefineOwnProperty]] (P, Desc, Throw)
      *
      * @param key the property key
      * @param propertyDesc the property descriptor
      * @param reject is the property extensible - true means new definitions are rejected
      *
      * @return true if property was successfully defined
      */
     public boolean defineOwnProperty(final String key, final Object propertyDesc, final boolean reject) {
         final ScriptObject       global  = Context.getGlobalTrusted();
         final PropertyDescriptor desc    = toPropertyDescriptor(global, propertyDesc);
         final Object             current = getOwnPropertyDescriptor(key);
         final String             name    = JSType.toString(key);
         if (current == UNDEFINED) {
             if (isExtensible()) {
                 // add a new own property
                 addOwnProperty(key, desc);
                 return true;
             }
             // new property added to non-extensible object
             if (reject) {
                 throw typeError(global, "object.non.extensible", name, ScriptRuntime.safeToString(this));
             }
             return false;
         }
         // modifying an existing property
         final PropertyDescriptor currentDesc = (PropertyDescriptor) current;
         final PropertyDescriptor newDesc     = desc;
         if (newDesc.type() == PropertyDescriptor.GENERIC &&
             ! newDesc.has(CONFIGURABLE) && ! newDesc.has(ENUMERABLE)) {
             // every descriptor field is absent
             return true;
         }
         if (currentDesc.equals(newDesc)) {
             // every descriptor field of the new is same as the current
             return true;
         }
         if (! currentDesc.isConfigurable()) {
             if (newDesc.has(CONFIGURABLE) && newDesc.isConfigurable()) {
                 // not configurable can not be made configurable
                 if (reject) {
                     throw typeError(global, "cant.redefine.property", name, ScriptRuntime.safeToString(this));
                 }
                 return false;
             }
             if (newDesc.has(ENUMERABLE) &&
                 currentDesc.isEnumerable() != newDesc.isEnumerable()) {
                 // cannot make non-enumerable as enumerable or vice-versa
                 if (reject) {
                     throw typeError(global, "cant.redefine.property", name, ScriptRuntime.safeToString(this));
                 }
                 return false;
             }
         }
         int propFlags = Property.mergeFlags(currentDesc, newDesc);
         Property property = getMap().findProperty(key);
         if (currentDesc.type() == PropertyDescriptor.DATA &&
             (newDesc.type() == PropertyDescriptor.DATA || newDesc.type() == PropertyDescriptor.GENERIC)) {
             if (! currentDesc.isConfigurable() && ! currentDesc.isWritable()) {
                 if (newDesc.has(WRITABLE) && newDesc.isWritable() ||
                     newDesc.has(VALUE) && ! ScriptRuntime.sameValue(currentDesc.getValue(), newDesc.getValue())) {
                     if (reject) {
                         throw typeError(global, "cant.redefine.property", name, ScriptRuntime.safeToString(this));
                     }
                     return false;
                 }
             }
             final boolean newValue = newDesc.has(VALUE);
             final Object value     = newValue? newDesc.getValue() : currentDesc.getValue();
             if (newValue && property != null) {
                 // Temporarily clear flags.
                 property = modifyOwnProperty(property, 0);
                 set(key, value, false);
             }
             if (property == null) {
                 // promoting an arrayData value to actual property
                 addOwnProperty(key, propFlags, value);
                 removeArraySlot(key);
             } else {
                 // Now set the new flags
                 modifyOwnProperty(property, propFlags);
             }
         } else if (currentDesc.type() == PropertyDescriptor.ACCESSOR &&
                    (newDesc.type() == PropertyDescriptor.ACCESSOR ||
                     newDesc.type() == PropertyDescriptor.GENERIC)) {
             if (! currentDesc.isConfigurable()) {
                 if (newDesc.has(PropertyDescriptor.GET) && ! ScriptRuntime.sameValue(currentDesc.getGetter(), newDesc.getGetter()) ||
                     newDesc.has(PropertyDescriptor.SET) && ! ScriptRuntime.sameValue(currentDesc.getSetter(), newDesc.getSetter())) {
                     if (reject) {
                         throw typeError(global, "cant.redefine.property", name, ScriptRuntime.safeToString(this));
                     }
                     return false;
                 }
             }
             // New set the new features.
             modifyOwnProperty(property, propFlags,
                                       newDesc.has(GET) ? newDesc.getGetter() : currentDesc.getGetter(),
                                       newDesc.has(SET) ? newDesc.getSetter() : currentDesc.getSetter());
         } else {
             // changing descriptor type
             if (! currentDesc.isConfigurable()) {
                 // not configurable can not be made configurable
                 if (reject) {
                     throw typeError(global, "cant.redefine.property", name, ScriptRuntime.safeToString(this));
                 }
                 return false;
             }
             propFlags = 0;
             // Preserve only configurable and enumerable from current desc
             // if those are not overridden in the new property descriptor.
             boolean value = newDesc.has(CONFIGURABLE)? newDesc.isConfigurable() : currentDesc.isConfigurable();
             if (!value) {
                 propFlags |= Property.NOT_CONFIGURABLE;
             }
             value = newDesc.has(ENUMERABLE)? newDesc.isEnumerable() : currentDesc.isEnumerable();
             if (!value) {
                 propFlags |= Property.NOT_ENUMERABLE;
             }
             final int type = newDesc.type();
             if (type == PropertyDescriptor.DATA) {
                 // get writable from the new descriptor
                 value = newDesc.has(WRITABLE) && newDesc.isWritable();
                 if (! value) {
                     propFlags |= Property.NOT_WRITABLE;
                 }
                 // delete the old property
                 deleteOwnProperty(property);
                 // add new data property
                 addOwnProperty(key, propFlags, newDesc.getValue());
             } else if (type == PropertyDescriptor.ACCESSOR) {
                 if (property == null) {
                     addOwnProperty(key, propFlags,
                                      newDesc.has(GET) ? newDesc.getGetter() : null,
                                      newDesc.has(SET) ? newDesc.getSetter() : null);
                 } else {
                     // Modify old property with the new features.
                     modifyOwnProperty(property, propFlags,
                                         newDesc.has(GET) ? newDesc.getGetter() : null,
                                         newDesc.has(SET) ? newDesc.getSetter() : null);
                 }
             }
         }
         checkIntegerKey(key);
         return true;
     }
     /**
      * Spec. mentions use of [[DefineOwnProperty]] for indexed properties in
      * certain places (eg. Array.prototype.map, filter). We can not use ScriptObject.set
      * method in such cases. This is because set method uses inherited setters (if any)
      * from any object in proto chain such as Array.prototype, Object.prototype.
      * This method directly sets a particular element value in the current object.
      *
      * @param index key for property
      * @param value value to define
      */
     public final void defineOwnProperty(final int index, final Object value) {
         assert isValidArrayIndex(index) : "invalid array index";
         final long longIndex = ArrayIndex.toLongIndex(index);
         if (longIndex >= getArray().length()) {
             // make array big enough to hold..
             setArray(getArray().ensure(longIndex));
         }
         setArray(getArray().set(index, value, false));
     }
     private void checkIntegerKey(final String key) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             final ArrayData data = getArray();
             if (data.has(index)) {
                 setArray(data.delete(index));
             }
         }
     }
     private void removeArraySlot(final String key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             setArray(array.delete(index));
         }
     }
     /**
       * Add a new property to the object.
       *
       * @param key          property key
       * @param propertyDesc property descriptor for property
       */
     public final void addOwnProperty(final String key, final PropertyDescriptor propertyDesc) {
         // Already checked that there is no own property with that key.
         PropertyDescriptor pdesc = propertyDesc;
         final int propFlags = Property.toFlags(pdesc);
         if (pdesc.type() == PropertyDescriptor.GENERIC) {
             final GlobalObject global = (GlobalObject) Context.getGlobalTrusted();
             final PropertyDescriptor dDesc = global.newDataDescriptor(UNDEFINED, false, false, false);
             dDesc.fillFrom((ScriptObject)pdesc);
             pdesc = dDesc;
         }
         final int type = pdesc.type();
         if (type == PropertyDescriptor.DATA) {
             addOwnProperty(key, propFlags, pdesc.getValue());
         } else if (type == PropertyDescriptor.ACCESSOR) {
             addOwnProperty(key, propFlags,
                     pdesc.has(GET) ? pdesc.getGetter() : null,
                     pdesc.has(SET) ? pdesc.getSetter() : null);
         }
         checkIntegerKey(key);
     }
     /**
      * Low level property API (not using property descriptors)
      * <p>
      * Find a property in the prototype hierarchy. Note: this is final and not
      * a good idea to override. If you have to, use
      * {jdk.nashorn.internal.objects.NativeArray{@link #getProperty(String)} or
      * {jdk.nashorn.internal.objects.NativeArray{@link #getPropertyDescriptor(String)} as the
      * overriding way to find array properties
      *
      * @see jdk.nashorn.internal.objects.NativeArray
      *
      * @param key  Property key.
      * @param deep Whether the search should look up proto chain.
      *
      * @return FindPropertyData or null if not found.
      */
     public final FindProperty findProperty(final String key, final boolean deep) {
         return findProperty(key, deep, false, this);
     }
     /**
      * Low level property API (not using property descriptors)
      * <p>
      * Find a property in the prototype hierarchy. Note: this is not a good idea
      * to override except as it was done in {@link WithObject}.
      * If you have to, use
      * {jdk.nashorn.internal.objects.NativeArray{@link #getProperty(String)} or
      * {jdk.nashorn.internal.objects.NativeArray{@link #getPropertyDescriptor(String)} as the
      * overriding way to find array properties
      *
      * @see jdk.nashorn.internal.objects.NativeArray
      *
      * @param key  Property key.
      * @param deep Whether the search should look up proto chain.
      * @param stopOnNonScope should a deep search stop on the first non-scope object?
      * @param start the object on which the lookup was originally initiated
      *
      * @return FindPropertyData or null if not found.
      */
     FindProperty findProperty(final String key, final boolean deep, final boolean stopOnNonScope, final ScriptObject start) {
         // if doing deep search, stop search on the first non-scope object if asked to do so
         if (stopOnNonScope && start != this && !isScope()) {
             return null;
         }
         final PropertyMap selfMap  = getMap();
         final Property    property = selfMap.findProperty(key);
         if (property != null) {
             return new FindProperty(start, this, property);
         }
         if (deep) {
             final ScriptObject myProto = getProto();
             if (myProto != null) {
                 return myProto.findProperty(key, deep, stopOnNonScope, start);
             }
         }
         return null;
     }
     /**
      * Low level property API. This is similar to {@link #findProperty(String, boolean)} but returns a
      * {@code boolean} value instead of a {@link FindProperty} object.
      * @param key  Property key.
      * @param deep Whether the search should look up proto chain.
      * @return true if the property was found.
      */
     boolean hasProperty(final String key, final boolean deep) {
         if (getMap().findProperty(key) != null) {
             return true;
         }
         if (deep) {
             final ScriptObject myProto = getProto();
             if (myProto != null) {
                 return myProto.hasProperty(key, deep);
             }
         }
         return false;
     }
     /**
      * Add a new property to the object.
      * <p>
      * This a more "low level" way that doesn't involve {@link PropertyDescriptor}s
      *
      * @param key             Property key.
      * @param propertyFlags   Property flags.
      * @param getter          Property getter, or null if not defined
      * @param setter          Property setter, or null if not defined
      *
      * @return New property.
      */
     public final Property addOwnProperty(final String key, final int propertyFlags, final ScriptFunction getter, final ScriptFunction setter) {
         return addOwnProperty(newUserAccessors(key, propertyFlags, getter, setter));
     }
     /**
      * Add a new property to the object.
      * <p>
      * This a more "low level" way that doesn't involve {@link PropertyDescriptor}s
      *
      * @param key             Property key.
      * @param propertyFlags   Property flags.
      * @param value           Value of property
      *
      * @return New property.
      */
     public final Property addOwnProperty(final String key, final int propertyFlags, final Object value) {
         final Property property = addSpillProperty(key, propertyFlags);
         property.setObjectValue(this, this, value, false);
         return property;
     }
     /**
      * Add a new property to the object.
      * <p>
      * This a more "low level" way that doesn't involve {@link PropertyDescriptor}s
      *
      * @param newProperty property to add
      *
      * @return New property.
      */
     public final Property addOwnProperty(final Property newProperty) {
         PropertyMap oldMap = getMap();
         while (true) {
             final PropertyMap newMap = oldMap.addProperty(newProperty);
             if (!compareAndSetMap(oldMap, newMap)) {
                 oldMap = getMap();
                 final Property oldProperty = oldMap.findProperty(newProperty.getKey());
                 if (oldProperty != null) {
                     return oldProperty;
                 }
             } else {
                 return newProperty;
             }
         }
     }
     private void erasePropertyValue(final Property property) {
         // Erase the property field value with undefined. If the property is defined
         // by user-defined accessors, we don't want to call the setter!!
         if (!(property instanceof UserAccessorProperty)) {
             property.setObjectValue(this, this, UNDEFINED, false);
         }
     }
     /**
      * Delete a property from the object.
      *
      * @param property Property to delete.
      *
      * @return true if deleted.
      */
     public final boolean deleteOwnProperty(final Property property) {
         erasePropertyValue(property);
         PropertyMap oldMap = getMap();
         while (true) {
             final PropertyMap newMap = oldMap.deleteProperty(property);
             if (newMap == null) {
                 return false;
             }
             if (!compareAndSetMap(oldMap, newMap)) {
                 oldMap = getMap();
             } else {
                 // delete getter and setter function references so that we don't leak
                 if (property instanceof UserAccessorProperty) {
                     final UserAccessorProperty uc = (UserAccessorProperty) property;
                     setSpill(uc.getGetterSlot(), null);
                     setSpill(uc.getSetterSlot(), null);
                 }
                 return true;
             }
         }
     }
     /**
      * Modify a property in the object
      *
      * @param oldProperty    property to modify
      * @param propertyFlags  new property flags
      * @param getter         getter for {@link UserAccessorProperty}, null if not present or N/A
      * @param setter         setter for {@link UserAccessorProperty}, null if not present or N/A
      *
      * @return new property
      */
     public final Property modifyOwnProperty(final Property oldProperty, final int propertyFlags, final ScriptFunction getter, final ScriptFunction setter) {
         Property newProperty;
         if (oldProperty instanceof UserAccessorProperty) {
             final UserAccessorProperty uc = (UserAccessorProperty) oldProperty;
             final int getterSlot = uc.getGetterSlot();
             final int setterSlot = uc.getSetterSlot();
             setSpill(getterSlot, getter);
             setSpill(setterSlot, setter);
             // if just flipping getter and setter with new functions, no need to change property or map
             if (uc.flags == propertyFlags) {
                 return oldProperty;
             }
             newProperty = new UserAccessorProperty(oldProperty.getKey(), propertyFlags, getterSlot, setterSlot);
         } else {
             // erase old property value and create new user accessor property
             erasePropertyValue(oldProperty);
             newProperty = newUserAccessors(oldProperty.getKey(), propertyFlags, getter, setter);
         }
         notifyPropertyModified(this, oldProperty, newProperty);
         return modifyOwnProperty(oldProperty, newProperty);
     }
     /**
       * Modify a property in the object
       *
       * @param oldProperty    property to modify
       * @param propertyFlags  new property flags
       *
       * @return new property
       */
     public final Property modifyOwnProperty(final Property oldProperty, final int propertyFlags) {
         return modifyOwnProperty(oldProperty, oldProperty.setFlags(propertyFlags));
     }
     /**
      * Modify a property in the object, replacing a property with a new one
      *
      * @param oldProperty   property to replace
      * @param newProperty   property to replace it with
      *
      * @return new property
      */
     private Property modifyOwnProperty(final Property oldProperty, final Property newProperty) {
         assert newProperty.getKey().equals(oldProperty.getKey()) : "replacing property with different key";
         PropertyMap oldMap = getMap();
         while (true) {
             final PropertyMap newMap = oldMap.replaceProperty(oldProperty, newProperty);
             if (!compareAndSetMap(oldMap, newMap)) {
                 oldMap = getMap();
                 final Property oldPropertyLookup = oldMap.findProperty(oldProperty.getKey());
                 if (oldPropertyLookup != null && oldPropertyLookup.equals(newProperty)) {
                     return oldPropertyLookup;
                 }
             } else {
                 return newProperty;
             }
         }
     }
     /**
      * Update getter and setter in an object literal.
      *
      * @param key    Property key.
      * @param getter {@link UserAccessorProperty} defined getter, or null if none
      * @param setter {@link UserAccessorProperty} defined setter, or null if none
      */
     public final void setUserAccessors(final String key, final ScriptFunction getter, final ScriptFunction setter) {
         final Property oldProperty = getMap().findProperty(key);
         if (oldProperty instanceof UserAccessorProperty) {
             modifyOwnProperty(oldProperty, oldProperty.getFlags(), getter, setter);
         } else {
             addOwnProperty(newUserAccessors(key, oldProperty != null ? oldProperty.getFlags() : 0, getter, setter));
         }
     }
     private static int getIntValue(final FindProperty find) {
         final MethodHandle getter = find.getGetter(int.class);
         if (getter != null) {
             try {
                 return (int)getter.invokeExact((Object)find.getGetterReceiver());
             } catch (final Error|RuntimeException e) {
                 throw e;
             } catch (final Throwable e) {
                 throw new RuntimeException(e);
             }
         }
         return ObjectClassGenerator.UNDEFINED_INT;
     }
     private static long getLongValue(final FindProperty find) {
         final MethodHandle getter = find.getGetter(long.class);
         if (getter != null) {
             try {
                 return (long)getter.invokeExact((Object)find.getGetterReceiver());
             } catch (final Error|RuntimeException e) {
                 throw e;
             } catch (final Throwable e) {
                 throw new RuntimeException(e);
             }
         }
         return ObjectClassGenerator.UNDEFINED_LONG;
     }
     private static double getDoubleValue(final FindProperty find) {
         final MethodHandle getter = find.getGetter(double.class);
         if (getter != null) {
             try {
                 return (double)getter.invokeExact((Object)find.getGetterReceiver());
             } catch (final Error|RuntimeException e) {
                 throw e;
             } catch (final Throwable e) {
                 throw new RuntimeException(e);
             }
         }
         return ObjectClassGenerator.UNDEFINED_DOUBLE;
     }
     /**
       * Get the object value of a property
       *
       * @param find {@link FindProperty} lookup result
       *
       * @return the value of the property
       */
     protected static Object getObjectValue(final FindProperty find) {
         return find.getObjectValue();
     }
     /**
      * Return methodHandle of value function for call.
      *
      * @param find      data from find property.
      * @param type      method type of function.
      * @param bindName  null or name to bind to second argument (property not found method.)
      *
      * @return value of property as a MethodHandle or null.
      */
     protected MethodHandle getCallMethodHandle(final FindProperty find, final MethodType type, final String bindName) {
         return getCallMethodHandle(getObjectValue(find), type, bindName);
     }
     /**
      * Return methodHandle of value function for call.
      *
      * @param value     value of receiver, it not a {@link ScriptFunction} this will return null.
      * @param type      method type of function.
      * @param bindName  null or name to bind to second argument (property not found method.)
      *
      * @return value of property as a MethodHandle or null.
      */
     protected static MethodHandle getCallMethodHandle(final Object value, final MethodType type, final String bindName) {
         return value instanceof ScriptFunction ? ((ScriptFunction)value).getCallMethodHandle(type, bindName) : null;
     }
     /**
      * Get value using found property.
      *
      * @param property Found property.
      *
      * @return Value of property.
      */
     public final Object getWithProperty(final Property property) {
         return getObjectValue(new FindProperty(this, this, property));
     }
     /**
      * Get a property given a key
      *
      * @param key property key
      *
      * @return property for key
      */
     public final Property getProperty(final String key) {
         return getMap().findProperty(key);
     }
     /**
      * Overridden by {@link jdk.nashorn.internal.objects.NativeArguments} class (internal use.)
      * Used for argument access in a vararg function using parameter name.
      * Returns the argument at a given key (index)
      *
      * @param key argument index
      *
      * @return the argument at the given position, or undefined if not present
      */
     public Object getArgument(final int key) {
         return get(key);
     }
     /**
      * Overridden by {@link jdk.nashorn.internal.objects.NativeArguments} class (internal use.)
      * Used for argument access in a vararg function using parameter name.
      * Returns the argument at a given key (index)
      *
      * @param key   argument index
      * @param value the value to write at the given index
      */
     public void setArgument(final int key, final Object value) {
         set(key, value, false);
     }
     /**
      * Return the current context from the object's map.
      * @return Current context.
      */
     protected Context getContext() {
         return Context.fromClass(getClass());
     }
     /**
      * Return the map of an object.
      * @return PropertyMap object.
      */
     public final PropertyMap getMap() {
         return map;
     }
     /**
      * Set the initial map.
      * @param map Initial map.
      */
     public final void setMap(final PropertyMap map) {
         this.map = map;
     }
     /**
      * Conditionally set the new map if the old map is the same.
      * @param oldMap Map prior to manipulation.
      * @param newMap Replacement map.
      * @return true if the operation succeeded.
      */
     protected synchronized final boolean compareAndSetMap(final PropertyMap oldMap, final PropertyMap newMap) {
         final boolean update = oldMap == this.map;
         if (update) {
             this.map = newMap;
         }
         return update;
      }
     /**
      * Return the __proto__ of an object.
      * @return __proto__ object.
      */
     public final ScriptObject getProto() {
         return proto;
     }
     /**
      * Set the __proto__ of an object.
      * @param newProto new __proto__ to set.
      */
     public synchronized final void setProto(final ScriptObject newProto) {
         final ScriptObject oldProto = proto;
         map = map.changeProto(oldProto, newProto);
         if (newProto != null) {
             newProto.setIsPrototype();
         }
         proto = newProto;
         if (isPrototype()) {
             // tell listeners that my __proto__ has been changed
             notifyProtoChanged(this, oldProto, newProto);
             if (oldProto != null) {
                 oldProto.removePropertyListener(this);
             }
             if (newProto != null) {
                 newProto.addPropertyListener(this);
             }
         }
     }
     /**
      * Set the __proto__ of an object with checks.
      * @param newProto Prototype to set.
      */
     public final void setProtoCheck(final Object newProto) {
         if (!isExtensible()) {
             throw typeError("__proto__.set.non.extensible", ScriptRuntime.safeToString(this));
         }
         if (newProto == null || newProto instanceof ScriptObject) {
             // check for circularity
             ScriptObject p = (ScriptObject)newProto;
             while (p != null) {
                 if (p == this) {
                     throw typeError("circular.__proto__.set", ScriptRuntime.safeToString(this));
                 }
                 p = p.getProto();
             }
             setProto((ScriptObject)newProto);
         } else {
             final ScriptObject global = Context.getGlobalTrusted();
             final Object  newProtoObject = JSType.toScriptObject(global, newProto);
             if (newProtoObject instanceof ScriptObject) {
                 setProto((ScriptObject)newProtoObject);
             } else {
                 throw typeError(global, "cant.set.proto.to.non.object", ScriptRuntime.safeToString(this), ScriptRuntime.safeToString(newProto));
             }
         }
     }
     /**
      * return an array of own property keys associated with the object.
      *
      * @param all True if to include non-enumerable keys.
      * @return Array of keys.
      */
     public String[] getOwnKeys(final boolean all) {
         final List<Object> keys    = new ArrayList<>();
         final PropertyMap  selfMap = this.getMap();
         final ArrayData array  = getArray();
         final long length      = array.length();
         for (long i = 0; i < length; i = array.nextIndex(i)) {
             if (array.has((int)i)) {
                 keys.add(JSType.toString(i));
             }
         }
         for (final Property property : selfMap.getProperties()) {
             if (all || property.isEnumerable()) {
                 keys.add(property.getKey());
             }
         }
         return keys.toArray(new String[keys.size()]);
     }
     /**
      * Check if this ScriptObject has array entries. This means that someone has
      * set values with numeric keys in the object.
      *
      * Note: this can be O(n) up to the array length
      *
      * @return true if array entries exists.
      */
     public boolean hasArrayEntries() {
         final ArrayData array = getArray();
         final long length = array.length();
         for (long i = 0; i < length; i++) {
             if (array.has((int)i)) {
                 return true;
             }
         }
         return false;
     }
     /**
      * Return the valid JavaScript type name descriptor
      *
      * @return "Object"
      */
     public String getClassName() {
         return "Object";
     }
     /**
      * {@code length} is a well known property. This is its getter.
      * Note that this *may* be optimized by other classes
      *
      * @return length property value for this ScriptObject
      */
     public Object getLength() {
         return get("length");
     }
     /**
      * Stateless toString for ScriptObjects.
      *
      * @return string description of this object, e.g. {@code [object Object]}
      */
     public String safeToString() {
         return "[object " + getClassName() + "]";
     }
     /**
      * Return the default value of the object with a given preferred type hint.
      * The preferred type hints are String.class for type String, Number.class
      * for type Number. <p>
      *
      * A <code>hint</code> of null means "no hint".
      *
      * ECMA 8.12.8 [[DefaultValue]](hint)
      *
      * @param typeHint the preferred type hint
      * @return the default value
      */
     public Object getDefaultValue(final Class<?> typeHint) {
         // We delegate to GlobalObject, as the implementation uses dynamic call sites to invoke object's "toString" and
         // "valueOf" methods, and in order to avoid those call sites from becoming megamorphic when multiple contexts
         // are being executed in a long-running program, we move the code and their associated dynamic call sites
         // (Global.TO_STRING and Global.VALUE_OF) into per-context code.
         return ((GlobalObject)Context.getGlobalTrusted()).getDefaultValue(this, typeHint);
     }
     /**
      * Checking whether a script object is an instance of another. Used
      * in {@link ScriptFunction} for hasInstance implementation, walks
      * the proto chain
      *
      * @param instance instace to check
      * @return true if 'instance' is an instance of this object
      */
     public boolean isInstance(final ScriptObject instance) {
         return false;
     }
     /**
      * Flag this ScriptObject as non extensible
      *
      * @return the object after being made non extensible
      */
     public ScriptObject preventExtensions() {
         PropertyMap oldMap = getMap();
         while (true) {
             final PropertyMap newMap = getMap().preventExtensions();
             if (!compareAndSetMap(oldMap, newMap)) {
                 oldMap = getMap();
             } else {
                 return this;
             }
         }
     }
     /**
      * Check whether if an Object (not just a ScriptObject) represents JavaScript array
      *
      * @param obj object to check
      *
      * @return true if array
      */
     public static boolean isArray(final Object obj) {
         return (obj instanceof ScriptObject) && ((ScriptObject)obj).isArray();
     }
     /**
      * Check if this ScriptObject is an array
      * @return true if array
      */
     public final boolean isArray() {
         return (flags & IS_ARRAY) != 0;
     }
     /**
      * Flag this ScriptObject as being an array
      */
     public final void setIsArray() {
         flags |= IS_ARRAY;
     }
     /**
      * Check if this ScriptObject is an {@code arguments} vector
      * @return true if arguments vector
      */
     public final boolean isArguments() {
         return (flags & IS_ARGUMENTS) != 0;
     }
     /**
      * Flag this ScriptObject as being an {@code arguments} vector
      */
     public final void setIsArguments() {
         flags |= IS_ARGUMENTS;
     }
     /**
      * Check if this object is a prototype
      *
      * @return {@code true} if is prototype
      */
     public final boolean isPrototype() {
         return (flags & IS_PROTOTYPE) != 0;
     }
     /**
      * Flag this object as having a prototype.
      */
     public final void setIsPrototype() {
         if (proto != null && !isPrototype()) {
             proto.addPropertyListener(this);
         }
         flags |= IS_PROTOTYPE;
     }
     /**
      * Check if this object has non-writable length property
      *
      * @return {@code true} if 'length' property is non-writable
      */
     public final boolean isLengthNotWritable() {
         return (flags & IS_LENGTH_NOT_WRITABLE) != 0;
     }
     /**
      * Flag this object as having non-writable length property
      */
     public void setIsLengthNotWritable() {
         flags |= IS_LENGTH_NOT_WRITABLE;
     }
     /**
      * Get the {@link ArrayData} for this ScriptObject if it is an array
      * @return array data
      */
     public final ArrayData getArray() {
         return arrayData;
     }
     /**
      * Set the {@link ArrayData} for this ScriptObject if it is to be an array
      * @param arrayData the array data
      */
     public final void setArray(final ArrayData arrayData) {
         this.arrayData = arrayData;
     }
     /**
      * Check if this ScriptObject is extensible
      * @return true if extensible
      */
     public boolean isExtensible() {
         return getMap().isExtensible();
     }
     /**
      * ECMAScript 15.2.3.8 - seal implementation
      * @return the sealed ScriptObject
      */
     public ScriptObject seal() {
         PropertyMap oldMap = getMap();
         while (true) {
             final PropertyMap newMap = getMap().seal();
             if (!compareAndSetMap(oldMap, newMap)) {
                 oldMap = getMap();
             } else {
                 setArray(ArrayData.seal(getArray()));
                 return this;
             }
         }
     }
     /**
      * Check whether this ScriptObject is sealed
      * @return true if sealed
      */
     public boolean isSealed() {
         return getMap().isSealed();
     }
     /**
      * ECMA 15.2.39 - freeze implementation. Freeze this ScriptObject
      * @return the frozen ScriptObject
      */
     public ScriptObject freeze() {
         PropertyMap oldMap = getMap();
         while (true) {
             final PropertyMap newMap = getMap().freeze();
             if (!compareAndSetMap(oldMap, newMap)) {
                 oldMap = getMap();
             } else {
                 setArray(ArrayData.freeze(getArray()));
                 return this;
             }
         }
     }
     /**
      * Check whether this ScriptObject is frozen
      * @return true if frozen
      */
     public boolean isFrozen() {
         return getMap().isFrozen();
     }
     /**
      * Flag this ScriptObject as scope
      */
     public final void setIsScope() {
         if (Context.DEBUG) {
             scopeCount++;
         }
         flags |= IS_SCOPE;
     }
     /**
      * Check whether this ScriptObject is scope
      * @return true if scope
      */
     public final boolean isScope() {
         return (flags & IS_SCOPE) != 0;
     }
     /**
      * Clears the properties from a ScriptObject
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @param strict strict mode or not
      */
     public void clear(final boolean strict) {
         final Iterator<String> iter = propertyIterator();
         while (iter.hasNext()) {
             delete(iter.next(), strict);
         }
     }
     /**
      * Checks if a property with a given key is present in a ScriptObject
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @param key the key to check for
      * @return true if a property with the given key exists, false otherwise
      */
     public boolean containsKey(final Object key) {
         return has(key);
     }
     /**
      * Checks if a property with a given value is present in a ScriptObject
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @param value value to check for
      * @return true if a property with the given value exists, false otherwise
      */
     public boolean containsValue(final Object value) {
         final Iterator<Object> iter = valueIterator();
         while (iter.hasNext()) {
             if (iter.next().equals(value)) {
                 return true;
             }
         }
         return false;
     }
     /**
      * Returns the set of {@literal <property, value>} entries that make up this
      * ScriptObject's properties
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @return an entry set of all the properties in this object
      */
     public Set<Map.Entry<Object, Object>> entrySet() {
         final Iterator<String> iter = propertyIterator();
         final Set<Map.Entry<Object, Object>> entries = new HashSet<>();
         while (iter.hasNext()) {
             final Object key = iter.next();
             entries.add(new AbstractMap.SimpleImmutableEntry<>(key, get(key)));
         }
         return Collections.unmodifiableSet(entries);
     }
     /**
      * Check whether a ScriptObject contains no properties
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @return true if object has no properties
      */
     public boolean isEmpty() {
         return !propertyIterator().hasNext();
     }
     /**
      * Return the set of keys (property names) for all properties
      * in this ScriptObject
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @return keySet of this ScriptObject
      */
     public Set<Object> keySet() {
         final Iterator<String> iter = propertyIterator();
         final Set<Object> keySet = new HashSet<>();
         while (iter.hasNext()) {
             keySet.add(iter.next());
         }
         return Collections.unmodifiableSet(keySet);
     }
     /**
      * Put a property in the ScriptObject
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @param key property key
      * @param value property value
      * @param strict strict mode or not
      * @return oldValue if property with same key existed already
      */
     public Object put(final Object key, final Object value, final boolean strict) {
         final Object oldValue = get(key);
         set(key, value, strict);
         return oldValue;
     }
     /**
      * Put several properties in the ScriptObject given a mapping
      * of their keys to their values
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @param otherMap a {@literal <key,value>} map of properties to add
      * @param strict strict mode or not
      */
     public void putAll(final Map<?, ?> otherMap, final boolean strict) {
         for (final Map.Entry<?, ?> entry : otherMap.entrySet()) {
             set(entry.getKey(), entry.getValue(), strict);
         }
     }
     /**
      * Remove a property from the ScriptObject.
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @param key the key of the property
      * @param strict strict mode or not
      * @return the oldValue of the removed property
      */
     public Object remove(final Object key, final boolean strict) {
         final Object oldValue = get(key);
         delete(key, strict);
         return oldValue;
     }
     /**
      * Return the size of the ScriptObject - i.e. the number of properties
      * it contains
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @return number of properties in ScriptObject
      */
     public int size() {
         int n = 0;
         for (final Iterator<String> iter = propertyIterator(); iter.hasNext(); iter.next()) {
             n++;
         }
         return n;
     }
     /**
      * Return the values of the properties in the ScriptObject
      * (java.util.Map-like method to help ScriptObjectMirror implementation)
      *
      * @return collection of values for the properties in this ScriptObject
      */
     public Collection<Object> values() {
         final List<Object>     values = new ArrayList<>(size());
         final Iterator<Object> iter   = valueIterator();
         while (iter.hasNext()) {
             values.add(iter.next());
         }
         return Collections.unmodifiableList(values);
     }
     /**
      * Lookup method that, given a CallSiteDescriptor, looks up the target
      * MethodHandle and creates a GuardedInvocation
      * with the appropriate guard(s).
      *
      * @param desc call site descriptor
      * @param request the link request
      *
      * @return GuardedInvocation for the callsite
      */
     public GuardedInvocation lookup(final CallSiteDescriptor desc, final LinkRequest request) {
         final int c = desc.getNameTokenCount();
         // JavaScript is "immune" to all currently defined Dynalink composite operation - getProp is the same as getElem
         // is the same as getMethod as JavaScript objects have a single namespace for all three. Therefore, we don't
         // care about them, and just link to whatever is the first operation.
         final String operator = CallSiteDescriptorFactory.tokenizeOperators(desc).get(0);
         // NOTE: we support getElem and setItem as JavaScript doesn't distinguish items from properties. Nashorn itself
         // emits "dyn:getProp:identifier" for "<expr>.<identifier>" and "dyn:getElem" for "<expr>[<expr>]", but we are
         // more flexible here and dispatch not on operation name (getProp vs. getElem), but rather on whether the
         // operation has an associated name or not.
         switch (operator) {
         case "getProp":
         case "getElem":
         case "getMethod":
             return c > 2 ? findGetMethod(desc, request, operator) : findGetIndexMethod(desc, request);
         case "setProp":
         case "setElem":
             return c > 2 ? findSetMethod(desc, request) : findSetIndexMethod(desc);
         case "call":
             return findCallMethod(desc, request);
         case "new":
             return findNewMethod(desc);
         case "callMethod":
             return findCallMethodMethod(desc, request);
         default:
             return null;
         }
     }
     /**
      * Find the appropriate New method for an invoke dynamic call.
      *
      * @param desc The invoke dynamic call site descriptor.
      *
      * @return GuardedInvocation to be invoked at call site.
      */
     protected GuardedInvocation findNewMethod(final CallSiteDescriptor desc) {
         return notAFunction();
     }
     /**
      * Find the appropriate CALL method for an invoke dynamic call.
      * This generates "not a function" always
      *
      * @param desc    the call site descriptor.
      * @param request the link request
      *
      * @return GuardedInvocation to be invoed at call site.
      */
     protected GuardedInvocation findCallMethod(final CallSiteDescriptor desc, final LinkRequest request) {
         return notAFunction();
     }
     private GuardedInvocation notAFunction() {
         throw typeError("not.a.function", ScriptRuntime.safeToString(this));
     }
     /**
      * Find an implementation for a "dyn:callMethod" operation. Note that Nashorn internally never uses
      * "dyn:callMethod", but instead always emits two call sites in bytecode, one for "dyn:getMethod", and then another
      * one for "dyn:call". Explicit support for "dyn:callMethod" is provided for the benefit of potential external
      * callers. The implementation itself actually folds a "dyn:getMethod" method handle into a "dyn:call" method handle.
      *
      * @param desc    the call site descriptor.
      * @param request the link request
      *
      * @return GuardedInvocation to be invoked at call site.
      */
     protected GuardedInvocation findCallMethodMethod(final CallSiteDescriptor desc, final LinkRequest request) {
         // R(P0, P1, ...)
         final MethodType callType = desc.getMethodType();
         // use type Object(P0) for the getter
         final CallSiteDescriptor getterType = desc.changeMethodType(MethodType.methodType(Object.class, callType.parameterType(0)));
         final GuardedInvocation getter = findGetMethod(getterType, request, "getMethod");
         // Object(P0) => Object(P0, P1, ...)
         final MethodHandle argDroppingGetter = MH.dropArguments(getter.getInvocation(), 1, callType.parameterList().subList(1, callType.parameterCount()));
         // R(Object, P0, P1, ...)
         final MethodHandle invoker = Bootstrap.createDynamicInvoker("dyn:call", callType.insertParameterTypes(0, argDroppingGetter.type().returnType()));
         // Fold Object(P0, P1, ...) into R(Object, P0, P1, ...) => R(P0, P1, ...)
         return getter.replaceMethods(MH.foldArguments(invoker, argDroppingGetter), getter.getGuard());
     }
     /**
      * Find the appropriate GET method for an invoke dynamic call.
      *
      * @param desc     the call site descriptor
      * @param request  the link request
      * @param operator operator for get: getProp, getMethod, getElem etc
      *
      * @return GuardedInvocation to be invoked at call site.
      */
     protected GuardedInvocation findGetMethod(final CallSiteDescriptor desc, final LinkRequest request, final String operator) {
         final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
         if (request.isCallSiteUnstable()) {
             return findMegaMorphicGetMethod(desc, name, "getMethod".equals(operator));
         }
         final FindProperty find = findProperty(name, true);
         MethodHandle methodHandle;
         if (find == null) {
             if (PROTO_PROPERTY_NAME.equals(name)) {
                 return new GuardedInvocation(GETPROTO, NashornGuards.getScriptObjectGuard());
             }
             if ("getProp".equals(operator)) {
                 return noSuchProperty(desc, request);
             } else if ("getMethod".equals(operator)) {
                 return noSuchMethod(desc, request);
             } else if ("getElem".equals(operator)) {
                 return createEmptyGetter(desc, name);
             }
             throw new AssertionError(); // never invoked with any other operation
         }
         final Class<?> returnType = desc.getMethodType().returnType();
         final Property property = find.getProperty();
         methodHandle = find.getGetter(returnType);
         // getMap() is fine as we have the prototype switchpoint depending on where the property was found
         final MethodHandle guard = NashornGuards.getMapGuard(getMap());
         if (methodHandle != null) {
             assert methodHandle.type().returnType().equals(returnType);
             if (find.isSelf()) {
                 return new GuardedInvocation(methodHandle, ObjectClassGenerator.OBJECT_FIELDS_ONLY &&
                         NashornCallSiteDescriptor.isFastScope(desc) && !property.canChangeType() ? null : guard);
             }
             final ScriptObject prototype = find.getOwner();
             if (!property.hasGetterFunction(prototype)) {
                 methodHandle = bindTo(methodHandle, prototype);
             }
             return new GuardedInvocation(methodHandle, getMap().getProtoGetSwitchPoint(proto, name), guard);
         }
         assert !NashornCallSiteDescriptor.isFastScope(desc);
         return new GuardedInvocation(Lookup.emptyGetter(returnType), getMap().getProtoGetSwitchPoint(proto, name), guard);
     }
     private static GuardedInvocation findMegaMorphicGetMethod(final CallSiteDescriptor desc, final String name, final boolean isMethod) {
         final MethodHandle invoker = MH.insertArguments(MEGAMORPHIC_GET, 1, name, isMethod);
         final MethodHandle guard = getScriptObjectGuard(desc.getMethodType());
         return new GuardedInvocation(invoker, guard);
     }
     @SuppressWarnings("unused")
     private Object megamorphicGet(final String key, final boolean isMethod) {
         final FindProperty find = findProperty(key, true);
         if (find != null) {
             return getObjectValue(find);
         }
         return isMethod ? getNoSuchMethod(key) : invokeNoSuchProperty(key);
     }
     /**
      * Find the appropriate GETINDEX method for an invoke dynamic call.
      *
      * @param desc    the call site descriptor
      * @param request the link request
      *
      * @return GuardedInvocation to be invoked at call site.
      */
     protected GuardedInvocation findGetIndexMethod(final CallSiteDescriptor desc, final LinkRequest request) {
         return findGetIndexMethod(desc.getMethodType());
     }
     /**
      * Find the appropriate GETINDEX method for an invoke dynamic call.
      *
      * @param callType the call site method type
      * @return GuardedInvocation to be invoked at call site.
      */
     private static GuardedInvocation findGetIndexMethod(final MethodType callType) {
         final Class<?> returnClass = callType.returnType();
         final Class<?> keyClass    = callType.parameterType(1);
         String name = "get";
         if (returnClass.isPrimitive()) {
             //turn e.g. get with a double into getDouble
             final String returnTypeName = returnClass.getName();
             name += Character.toUpperCase(returnTypeName.charAt(0)) + returnTypeName.substring(1, returnTypeName.length());
         }
         return new GuardedInvocation(findOwnMH(name, returnClass, keyClass), getScriptObjectGuard(callType));
     }
     private static MethodHandle getScriptObjectGuard(final MethodType type) {
         return ScriptObject.class.isAssignableFrom(type.parameterType(0)) ? null : NashornGuards.getScriptObjectGuard();
     }
     /**
      * Find the appropriate SET method for an invoke dynamic call.
      *
      * @param desc    the call site descriptor
      * @param request the link request
      *
      * @return GuardedInvocation to be invoked at call site.
      */
     protected GuardedInvocation findSetMethod(final CallSiteDescriptor desc, final LinkRequest request) {
         final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
         if (request.isCallSiteUnstable()) {
             return findMegaMorphicSetMethod(desc, name);
         }
         final boolean scope = isScope();
         /*
          * If doing property set on a scope object, we should stop proto search on the first
          * non-scope object. Without this, for example, when assigning "toString" on global scope,
          * we'll end up assigning it on it's proto - which is Object.prototype.toString !!
          *
          * toString = function() { print("global toString"); } // don't affect Object.prototype.toString
          */
         FindProperty find = findProperty(name, true, scope, this);
         // If it's not a scope search, then we don't want any inherited properties except those with user defined accessors.
         if (!scope && find != null && find.isInherited() && !(find.getProperty() instanceof UserAccessorProperty)) {
             // We should still check if inherited data property is not writable
             if (isExtensible() && !find.getProperty().isWritable()) {
                 return createEmptySetMethod(desc, "property.not.writable", false);
             }
             // Otherwise, forget the found property
             find = null;
         }
         if (find != null) {
             if(!find.getProperty().isWritable()) {
                 // Existing, non-writable property
                 return createEmptySetMethod(desc, "property.not.writable", true);
             }
         } else {
             if (PROTO_PROPERTY_NAME.equals(name)) {
                 return new GuardedInvocation(SETPROTOCHECK, NashornGuards.getScriptObjectGuard());
             } else if (! isExtensible()) {
                 return createEmptySetMethod(desc, "object.non.extensible", false);
             }
         }
         return new SetMethodCreator(this, find, desc).createGuardedInvocation();
     }
     private GuardedInvocation createEmptySetMethod(final CallSiteDescriptor desc, String strictErrorMessage, boolean canBeFastScope) {
         final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
         if (NashornCallSiteDescriptor.isStrict(desc)) {
                throw typeError(strictErrorMessage, name, ScriptRuntime.safeToString((this)));
            }
            assert canBeFastScope || !NashornCallSiteDescriptor.isFastScope(desc);
            final PropertyMap myMap = getMap();
            return new GuardedInvocation(Lookup.EMPTY_SETTER, myMap.getProtoGetSwitchPoint(proto, name), NashornGuards.getMapGuard(myMap));
     }
     @SuppressWarnings("unused")
     private static void setField(final CallSiteDescriptor desc, final PropertyMap oldMap, final PropertyMap newMap, final MethodHandle setter, final Object self, final Object value) throws Throwable {
         final ScriptObject obj = (ScriptObject)self;
         final boolean isStrict = NashornCallSiteDescriptor.isStrict(desc);
         if (!obj.isExtensible()) {
             throw typeError("object.non.extensible", desc.getNameToken(2), ScriptRuntime.safeToString(obj));
         } else if (obj.compareAndSetMap(oldMap, newMap)) {
             setter.invokeExact(self, value);
         } else {
             obj.set(desc.getNameToken(CallSiteDescriptor.NAME_OPERAND), value, isStrict);
         }
     }
     @SuppressWarnings("unused")
     private static void setSpill(final CallSiteDescriptor desc, final PropertyMap oldMap, final PropertyMap newMap, final int index, final Object self, final Object value) {
         final ScriptObject obj = (ScriptObject)self;
         if (obj.trySetSpill(desc, oldMap, newMap, value)) {
             obj.spill[index] = value;
         }
     }
     private boolean trySetSpill(final CallSiteDescriptor desc, final PropertyMap oldMap, final PropertyMap newMap, final Object value) {
         final boolean isStrict = NashornCallSiteDescriptor.isStrict(desc);
         if (!isExtensible() && isStrict) {
             throw typeError("object.non.extensible", desc.getNameToken(2), ScriptRuntime.safeToString(this));
         } else if (compareAndSetMap(oldMap, newMap)) {
             return true;
         } else {
             set(desc.getNameToken(CallSiteDescriptor.NAME_OPERAND), value, isStrict);
             return false;
         }
     }
     @SuppressWarnings("unused")
     private static void setSpillWithNew(final CallSiteDescriptor desc, final PropertyMap oldMap, final PropertyMap newMap, final int index, final Object self, final Object value) {
         final ScriptObject obj      = (ScriptObject)self;
         final boolean      isStrict = NashornCallSiteDescriptor.isStrict(desc);
         if (!obj.isExtensible()) {
             if (isStrict) {
                 throw typeError("object.non.extensible", desc.getNameToken(2), ScriptRuntime.safeToString(obj));
             }
         } else if (obj.compareAndSetMap(oldMap, newMap)) {
             obj.spill = new Object[SPILL_RATE];
             obj.spill[index] = value;
         } else {
             obj.set(desc.getNameToken(2), value, isStrict);
         }
     }
     @SuppressWarnings("unused")
     private static void setSpillWithGrow(final CallSiteDescriptor desc, final PropertyMap oldMap, final PropertyMap newMap, final int index, final int newLength, final Object self, final Object value) {
         final ScriptObject obj      = (ScriptObject)self;
         final boolean      isStrict = NashornCallSiteDescriptor.isStrict(desc);
         if (!obj.isExtensible()) {
             if (isStrict) {
                 throw typeError("object.non.extensible", desc.getNameToken(2), ScriptRuntime.safeToString(obj));
             }
         } else if (obj.compareAndSetMap(oldMap, newMap)) {
             final int oldLength = obj.spill.length;
             final Object[] newSpill = new Object[newLength];
             System.arraycopy(obj.spill, 0, newSpill, 0, oldLength);
             obj.spill = newSpill;
             obj.spill[index] = value;
         } else {
             obj.set(desc.getNameToken(2), value, isStrict);
         }
     }
     private static GuardedInvocation findMegaMorphicSetMethod(final CallSiteDescriptor desc, final String name) {
         final MethodType type = desc.getMethodType().insertParameterTypes(1, Object.class);
         final GuardedInvocation inv = findSetIndexMethod(type, NashornCallSiteDescriptor.isStrict(desc));
         return inv.replaceMethods(MH.insertArguments(inv.getInvocation(), 1, name), inv.getGuard());
     }
     private static GuardedInvocation findSetIndexMethod(final CallSiteDescriptor desc) { // array, index, value
         return findSetIndexMethod(desc.getMethodType(), NashornCallSiteDescriptor.isStrict(desc));
     }
     /**
      * Find the appropriate SETINDEX method for an invoke dynamic call.
      *
      * @param callType the method type at the call site
      * @param isStrict are we in strict mode?
      *
      * @return GuardedInvocation to be invoked at call site.
      */
     private static GuardedInvocation findSetIndexMethod(final MethodType callType, final boolean isStrict) {
         assert callType.parameterCount() == 3;
         final Class<?>   keyClass   = callType.parameterType(1);
         final Class<?>   valueClass = callType.parameterType(2);
         MethodHandle methodHandle = findOwnMH("set", void.class, keyClass, valueClass, boolean.class);
         methodHandle = MH.insertArguments(methodHandle, 3, isStrict);
         return new GuardedInvocation(methodHandle, getScriptObjectGuard(callType));
     }
     /**
      * Fall back if a function property is not found.
      * @param desc The call site descriptor
      * @param request the link request
      * @return GuardedInvocation to be invoked at call site.
      */
     public GuardedInvocation noSuchMethod(final CallSiteDescriptor desc, final LinkRequest request) {
         final String       name      = desc.getNameToken(2);
         final FindProperty find      = findProperty(NO_SUCH_METHOD_NAME, true);
         final boolean      scopeCall = isScope() && NashornCallSiteDescriptor.isScope(desc);
         if (find == null) {
             return noSuchProperty(desc, request);
         }
         final Object value = getObjectValue(find);
         if (! (value instanceof ScriptFunction)) {
             return createEmptyGetter(desc, name);
         }
         final ScriptFunction func = (ScriptFunction)value;
         final Object thiz = scopeCall && func.isStrict() ? ScriptRuntime.UNDEFINED : this;
         // TODO: It'd be awesome if we could bind "name" without binding "this".
         return new GuardedInvocation(MH.dropArguments(MH.constant(ScriptFunction.class,
                 func.makeBoundFunction(thiz, new Object[] { name })), 0, Object.class),
                 null, NashornGuards.getMapGuard(getMap()));
     }
     /**
      * Fall back if a property is not found.
      * @param desc the call site descriptor.
      * @param request the link request
      * @return GuardedInvocation to be invoked at call site.
      */
     @SuppressWarnings("null")
     public GuardedInvocation noSuchProperty(final CallSiteDescriptor desc, final LinkRequest request) {
         final String name = desc.getNameToken(CallSiteDescriptor.NAME_OPERAND);
         final FindProperty find = findProperty(NO_SUCH_PROPERTY_NAME, true);
         final boolean scopeAccess = isScope() && NashornCallSiteDescriptor.isScope(desc);
         if (find != null) {
             final Object   value        = getObjectValue(find);
             ScriptFunction func         = null;
             MethodHandle   methodHandle = null;
             if (value instanceof ScriptFunction) {
                 func = (ScriptFunction)value;
                 methodHandle = getCallMethodHandle(func, desc.getMethodType(), name);
             }
             if (methodHandle != null) {
                 if (scopeAccess && func.isStrict()) {
                     methodHandle = bindTo(methodHandle, UNDEFINED);
                 }
                 return new GuardedInvocation(methodHandle,
                         find.isInherited()? getMap().getProtoGetSwitchPoint(proto, NO_SUCH_PROPERTY_NAME) : null,
                         getKnownFunctionPropertyGuard(getMap(), find.getGetter(Object.class), find.getOwner(), func));
             }
         }
         if (scopeAccess) {
             throw referenceError("not.defined", name);
         }
         return createEmptyGetter(desc, name);
     }
     /**
      * Invoke fall back if a property is not found.
      * @param name Name of property.
      * @return Result from call.
      */
     private Object invokeNoSuchProperty(final String name) {
         final FindProperty find = findProperty(NO_SUCH_PROPERTY_NAME, true);
         if (find != null) {
             final Object func = getObjectValue(find);
             if (func instanceof ScriptFunction) {
                 return ScriptRuntime.apply((ScriptFunction)func, this, name);
             }
         }
         return UNDEFINED;
     }
     /**
      * Get __noSuchMethod__ as a function bound to this object and {@code name} if it is defined.
      * @param name the method name
      * @return the bound function, or undefined
      */
     private Object getNoSuchMethod(final String name) {
         final FindProperty find = findProperty(NO_SUCH_METHOD_NAME, true);
         if (find == null) {
             return invokeNoSuchProperty(name);
         }
         final Object value = getObjectValue(find);
         if (! (value instanceof ScriptFunction)) {
             return UNDEFINED;
         }
         return ((ScriptFunction)value).makeBoundFunction(this, new Object[] {name});
     }
     private GuardedInvocation createEmptyGetter(final CallSiteDescriptor desc, final String name) {
         return new GuardedInvocation(Lookup.emptyGetter(desc.getMethodType().returnType()), getMap().getProtoGetSwitchPoint(proto, name), NashornGuards.getMapGuard(getMap()));
     }
     private abstract static class ScriptObjectIterator <T extends Object> implements Iterator<T> {
         protected T[] values;
         protected final ScriptObject object;
         private int index;
         ScriptObjectIterator(final ScriptObject object) {
             this.object = object;
         }
         protected abstract void init();
         @Override
         public boolean hasNext() {
             if (values == null) {
                 init();
             }
             return index < values.length;
         }
         @Override
         public T next() {
             if (values == null) {
                 init();
             }
             return values[index++];
         }
         @Override
         public void remove() {
             throw new UnsupportedOperationException();
         }
     }
     private static class KeyIterator extends ScriptObjectIterator<String> {
         KeyIterator(final ScriptObject object) {
             super(object);
         }
         @Override
         protected void init() {
             final Set<String> keys = new LinkedHashSet<>();
             for (ScriptObject self = object; self != null; self = self.getProto()) {
                 keys.addAll(Arrays.asList(self.getOwnKeys(false)));
             }
             this.values = keys.toArray(new String[keys.size()]);
         }
     }
     private static class ValueIterator extends ScriptObjectIterator<Object> {
         ValueIterator(final ScriptObject object) {
             super(object);
         }
         @Override
         protected void init() {
             final ArrayList<Object> valueList = new ArrayList<>();
             for (ScriptObject self = object; self != null; self = self.getProto()) {
                 for (final String key : self.getOwnKeys(false)) {
                     valueList.add(self.get(key));
                 }
             }
             this.values = valueList.toArray(new Object[valueList.size()]);
         }
     }
     /**
      * Add a spill property for the given key.
      * @param key           Property key.
      * @param propertyFlags Property flags.
      * @return Added property.
      */
     private Property addSpillProperty(final String key, final int propertyFlags) {
         int fieldCount   = getMap().getFieldCount();
         int fieldMaximum = getMap().getFieldMaximum();
         Property property;
         if (fieldCount < fieldMaximum) {
             property = new AccessorProperty(key, propertyFlags & ~Property.IS_SPILL, getClass(), fieldCount);
             notifyPropertyAdded(this, property);
             property = addOwnProperty(property);
         } else {
             int i = getMap().getSpillLength();
             property = new AccessorProperty(key, propertyFlags | Property.IS_SPILL, i);
             notifyPropertyAdded(this, property);
             property = addOwnProperty(property);
             i = property.getSlot();
             final int newLength = (i + SPILL_RATE) / SPILL_RATE * SPILL_RATE;
             if (spill == null || newLength > spill.length) {
                 final Object[] newSpill = new Object[newLength];
                 if (spill != null) {
                     System.arraycopy(spill, 0, newSpill, 0, spill.length);
                 }
                 spill = newSpill;
             }
         }
         return property;
     }
     /**
      * Add a spill entry for the given key.
      * @param key Property key.
      * @return Setter method handle.
      */
     MethodHandle addSpill(final String key) {
         final Property spillProperty = addSpillProperty(key, 0);
         final Class<?> type = Object.class;
         return spillProperty.getSetter(type, getMap()); //TODO specfields
     }
     /**
      * Make sure arguments are paired correctly, with respect to more parameters than declared,
      * fewer parameters than declared and other things that JavaScript allows. This might involve
      * creating collectors.
      *
      * @param methodHandle method handle for invoke
      * @param callType     type of the call
      *
      * @return method handle with adjusted arguments
      */
     protected static MethodHandle pairArguments(final MethodHandle methodHandle, final MethodType callType) {
         return pairArguments(methodHandle, callType, null);
     }
     /**
      * Make sure arguments are paired correctly, with respect to more parameters than declared,
      * fewer parameters than declared and other things that JavaScript allows. This might involve
      * creating collectors.
      *
      * Make sure arguments are paired correctly.
      * @param methodHandle MethodHandle to adjust.
      * @param callType     MethodType of the call site.
      * @param callerVarArg true if the caller is vararg, false otherwise, null if it should be inferred from the
      * {@code callType}; basically, if the last parameter type of the call site is an array, it'll be considered a
      * variable arity call site. These are ordinarily rare; Nashorn code generator creates variable arity call sites
      * when the call has more than {@link LinkerCallSite#ARGLIMIT} parameters.
      *
      * @return method handle with adjusted arguments
      */
     public static MethodHandle pairArguments(final MethodHandle methodHandle, final MethodType callType, final Boolean callerVarArg) {
         final MethodType methodType = methodHandle.type();
         if (methodType.equals(callType)) {
             return methodHandle;
         }
         final int parameterCount = methodType.parameterCount();
         final int callCount      = callType.parameterCount();
         final boolean isCalleeVarArg = parameterCount > 0 && methodType.parameterType(parameterCount - 1).isArray();
         final boolean isCallerVarArg = callerVarArg != null ? callerVarArg.booleanValue() : (callCount > 0 &&
                 callType.parameterType(callCount - 1).isArray());
         if (callCount < parameterCount) {
             final int      missingArgs = parameterCount - callCount;
             final Object[] fillers     = new Object[missingArgs];
             Arrays.fill(fillers, UNDEFINED);
             if (isCalleeVarArg) {
                 fillers[missingArgs - 1] = new Object[0];
             }
             return MH.insertArguments(
                 methodHandle,
                 parameterCount - missingArgs,
                 fillers);
         }
         if (isCalleeVarArg) {
             return isCallerVarArg ?
                 methodHandle :
                 MH.asCollector(methodHandle, Object[].class, callCount - parameterCount + 1);
         }
         if (isCallerVarArg) {
             final int spreadArgs = parameterCount - callCount + 1;
             return MH.filterArguments(
                 MH.asSpreader(
                     methodHandle,
                     Object[].class,
                     spreadArgs),
                 callCount - 1,
                 MH.insertArguments(
                     TRUNCATINGFILTER,
 ,
                     spreadArgs)
                 );
         }
         if (callCount > parameterCount) {
             final int discardedArgs = callCount - parameterCount;
             final Class<?>[] discards = new Class<?>[discardedArgs];
             Arrays.fill(discards, Object.class);
             return MH.dropArguments(methodHandle, callCount - discardedArgs, discards);
         }
         return methodHandle;
     }
     @SuppressWarnings("unused")
     private static Object[] truncatingFilter(final int n, final Object[] array) {
         final int length = array == null ? 0 : array.length;
         if (n == length) {
             return array == null ? new Object[0] : array;
         }
         final Object[] newArray = new Object[n];
         if (array != null) {
             for (int i = 0; i < n && i < length; i++) {
                 newArray[i] = array[i];
             }
         }
         if (length < n) {
             final Object fill = UNDEFINED;
             for (int i = length; i < n; i++) {
                 newArray[i] = fill;
             }
         }
         return newArray;
     }
     /**
       * Numeric length setter for length property
       *
       * @param newLength new length to set
       */
     public final void setLength(final long newLength) {
        final long arrayLength = getArray().length();
        if (newLength == arrayLength) {
            return;
        }
        if (newLength > arrayLength) {
            setArray(getArray().ensure(newLength - 1));
             if (getArray().canDelete(arrayLength, (newLength - 1), false)) {
                setArray(getArray().delete(arrayLength, (newLength - 1)));
            }
            return;
        }
        if (newLength < arrayLength) {
            setArray(getArray().shrink(newLength));
            getArray().setLength(newLength);
        }
     }
     private int getInt(final int index, final String key) {
         if (isValidArrayIndex(index)) {
              for (ScriptObject object = this; ; ) {
                 final FindProperty find = object.findProperty(key, false, false, this);
                 if (find != null) {
                     return getIntValue(find);
                 }
                 if ((object = object.getProto()) == null) {
                     break;
                 }
                 final ArrayData array = object.getArray();
                 if (array.has(index)) {
                     return array.getInt(index);
                 }
            }
         } else {
             final FindProperty find = findProperty(key, true);
             if (find != null) {
                 return getIntValue(find);
             }
         }
         return JSType.toInt32(invokeNoSuchProperty(key));
     }
     @Override
     public int getInt(final Object key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getInt(index);
         }
         return getInt(index, JSType.toString(key));
     }
     @Override
     public int getInt(final double key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getInt(index);
         }
         return getInt(index, JSType.toString(key));
     }
     @Override
     public int getInt(final long key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getInt(index);
         }
         return getInt(index, JSType.toString(key));
     }
     @Override
     public int getInt(final int key) {
         final ArrayData array = getArray();
         if (array.has(key)) {
             return array.getInt(key);
         }
         return getInt(key, JSType.toString(key));
     }
     private long getLong(final int index, final String key) {
         if (isValidArrayIndex(index)) {
             for (ScriptObject object = this; ; ) {
                 final FindProperty find = object.findProperty(key, false, false, this);
                 if (find != null) {
                     return getLongValue(find);
                 }
                 if ((object = object.getProto()) == null) {
                     break;
                 }
                 final ArrayData array = object.getArray();
                 if (array.has(index)) {
                     return array.getLong(index);
                 }
            }
         } else {
             final FindProperty find = findProperty(key, true);
             if (find != null) {
                 return getLongValue(find);
             }
         }
         return JSType.toLong(invokeNoSuchProperty(key));
     }
     @Override
     public long getLong(final Object key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getLong(index);
         }
         return getLong(index, JSType.toString(key));
     }
     @Override
     public long getLong(final double key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getLong(index);
         }
         return getLong(index, JSType.toString(key));
     }
     @Override
     public long getLong(final long key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getLong(index);
         }
         return getLong(index, JSType.toString(key));
     }
     @Override
     public long getLong(final int key) {
         final ArrayData array = getArray();
         if (array.has(key)) {
             return array.getLong(key);
         }
         return getLong(key, JSType.toString(key));
     }
     private double getDouble(final int index, final String key) {
         if (isValidArrayIndex(index)) {
             for (ScriptObject object = this; ; ) {
                 final FindProperty find = object.findProperty(key, false, false, this);
                 if (find != null) {
                     return getDoubleValue(find);
                 }
                 if ((object = object.getProto()) == null) {
                     break;
                 }
                 final ArrayData array = object.getArray();
                 if (array.has(index)) {
                     return array.getDouble(index);
                 }
            }
         } else {
             final FindProperty find = findProperty(key, true);
             if (find != null) {
                 return getDoubleValue(find);
             }
         }
         return JSType.toNumber(invokeNoSuchProperty(key));
     }
     @Override
     public double getDouble(final Object key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getDouble(index);
         }
         return getDouble(index, JSType.toString(key));
     }
     @Override
     public double getDouble(final double key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getDouble(index);
         }
         return getDouble(index, JSType.toString(key));
     }
     @Override
     public double getDouble(final long key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getDouble(index);
         }
         return getDouble(index, JSType.toString(key));
     }
     @Override
     public double getDouble(final int key) {
         final ArrayData array = getArray();
         if (array.has(key)) {
             return array.getDouble(key);
         }
         return getDouble(key, JSType.toString(key));
     }
     private Object get(final int index, final String key) {
         if (isValidArrayIndex(index)) {
             for (ScriptObject object = this; ; ) {
                 final FindProperty find = object.findProperty(key, false, false, this);
                 if (find != null) {
                     return getObjectValue(find);
                 }
                 if ((object = object.getProto()) == null) {
                     break;
                 }
                 final ArrayData array = object.getArray();
                 if (array.has(index)) {
                     return array.getObject(index);
                 }
             }
         } else {
             final FindProperty find = findProperty(key, true);
             if (find != null) {
                 return getObjectValue(find);
             }
         }
         return invokeNoSuchProperty(key);
     }
     @Override
     public Object get(final Object key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getObject(index);
         }
         return get(index, JSType.toString(key));
     }
     @Override
     public Object get(final double key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getObject(index);
         }
         return get(index, JSType.toString(key));
     }
     @Override
     public Object get(final long key) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             return array.getObject(index);
         }
         return get(index, JSType.toString(key));
     }
     @Override
     public Object get(final int key) {
         final ArrayData array = getArray();
         if (array.has(key)) {
             return array.getObject(key);
         }
         return get(key, JSType.toString(key));
     }
     /**
      * Handle when an array doesn't have a slot - possibly grow and/or convert array.
      *
      * @param index  key as index
      * @param value  element value
      * @param strict are we in strict mode
      */
     private void doesNotHave(final int index, final Object value, final boolean strict) {
         final long oldLength = getArray().length();
         final long longIndex = index & JSType.MAX_UINT;
         if (!getArray().has(index)) {
             final String key = JSType.toString(longIndex);
             final FindProperty find = findProperty(key, true);
             if (find != null) {
                 setObject(find, strict, key, value);
                 return;
             }
         }
         if (longIndex >= oldLength) {
             if (!isExtensible()) {
                 if (strict) {
                     throw typeError("object.non.extensible", JSType.toString(index), ScriptRuntime.safeToString(this));
                 }
                 return;
             }
             setArray(getArray().ensure(longIndex));
         }
         if (value instanceof Integer) {
             setArray(getArray().set(index, (int)value, strict));
         } else if (value instanceof Long) {
             setArray(getArray().set(index, (long)value, strict));
         } else if (value instanceof Double) {
             setArray(getArray().set(index, (double)value, strict));
         } else {
             setArray(getArray().set(index, value, strict));
         }
         if (longIndex > oldLength) {
             ArrayData array = getArray();
             if (array.canDelete(oldLength, (longIndex - 1), strict)) {
                 array = array.delete(oldLength, (longIndex - 1));
             }
             setArray(array);
         }
     }
     /**
      * This is the most generic of all Object setters. Most of the others use this in some form.
      * TODO: should be further specialized
      *
      * @param find    found property
      * @param strict  are we in strict mode
      * @param key     property key
      * @param value   property value
      */
     public final void setObject(final FindProperty find, final boolean strict, final String key, final Object value) {
         FindProperty f = find;
         if (f != null && f.isInherited() && !(f.getProperty() instanceof UserAccessorProperty)) {
             f = null;
         }
         if (f != null) {
             if (!f.getProperty().isWritable()) {
                 if (strict) {
                     throw typeError("property.not.writable", key, ScriptRuntime.safeToString(this));
                 }
                 return;
             }
             f.setObjectValue(value, strict);
         } else if (!isExtensible()) {
             if (strict) {
                 throw typeError("object.non.extensible", key, ScriptRuntime.safeToString(this));
             }
         } else {
             spill(key, value);
         }
     }
     private void spill(final String key, final Object value) {
         addSpillProperty(key, 0).setObjectValue(this, this, value, false);
     }
     @Override
     public void set(final Object key, final int value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final Object key, final long value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final Object key, final double value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final Object key, final Object value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, value);
     }
     @Override
     public void set(final double key, final int value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final double key, final long value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final double key, final double value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final double key, final Object value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, value);
     }
     @Override
     public void set(final long key, final int value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final long key, final long value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final long key, final double value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final long key, final Object value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, value);
     }
     @Override
     public void set(final int key, final int value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final int key, final long value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final int key, final double value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, JSType.toObject(value));
     }
     @Override
     public void set(final int key, final Object value, final boolean strict) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             if (getArray().has(index)) {
                 setArray(getArray().set(index, value, strict));
             } else {
                 doesNotHave(index, value, strict);
             }
             return;
         }
         final String propName = JSType.toString(key);
         setObject(findProperty(propName, true), strict, propName, value);
     }
     @Override
     public boolean has(final Object key) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             for (ScriptObject self = this; self != null; self = self.getProto()) {
                 if (self.getArray().has(index)) {
                     return true;
                 }
             }
         }
         return hasProperty(JSType.toString(key), true);
     }
     @Override
     public boolean has(final double key) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             for (ScriptObject self = this; self != null; self = self.getProto()) {
                 if (self.getArray().has(index)) {
                     return true;
                 }
             }
         }
         return hasProperty(JSType.toString(key), true);
     }
     @Override
     public boolean has(final long key) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             for (ScriptObject self = this; self != null; self = self.getProto()) {
                 if (self.getArray().has(index)) {
                     return true;
                 }
             }
         }
         return hasProperty(JSType.toString(key), true);
     }
     @Override
     public boolean has(final int key) {
         final int index = getArrayIndex(key);
         if (isValidArrayIndex(index)) {
             for (ScriptObject self = this; self != null; self = self.getProto()) {
                 if (self.getArray().has(index)) {
                     return true;
                 }
             }
         }
         return hasProperty(JSType.toString(key), true);
     }
     @Override
     public boolean hasOwnProperty(final Object key) {
         return getArray().has(getArrayIndex(key)) || hasProperty(JSType.toString(key), false);
     }
     @Override
     public boolean hasOwnProperty(final int key) {
         return getArray().has(getArrayIndex(key)) || hasProperty(JSType.toString(key), false);
     }
     @Override
     public boolean hasOwnProperty(final long key) {
         return getArray().has(getArrayIndex(key)) || hasProperty(JSType.toString(key), false);
     }
     @Override
     public boolean hasOwnProperty(final double key) {
         return getArray().has(getArrayIndex(key)) || hasProperty(JSType.toString(key), false);
     }
     @Override
     public boolean delete(final int key, final boolean strict) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             if (array.canDelete(index, strict)) {
                 setArray(array.delete(index));
                 return true;
             }
             return false;
         }
         return deleteObject(JSType.toObject(key), strict);
     }
     @Override
     public boolean delete(final long key, final boolean strict) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             if (array.canDelete(index, strict)) {
                 setArray(array.delete(index));
                 return true;
             }
             return false;
         }
         return deleteObject(JSType.toObject(key), strict);
     }
     @Override
     public boolean delete(final double key, final boolean strict) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             if (array.canDelete(index, strict)) {
                 setArray(array.delete(index));
                 return true;
             }
             return false;
         }
         return deleteObject(JSType.toObject(key), strict);
     }
     @Override
     public boolean delete(final Object key, final boolean strict) {
         final int index = getArrayIndex(key);
         final ArrayData array = getArray();
         if (array.has(index)) {
             if (array.canDelete(index, strict)) {
                 setArray(array.delete(index));
                 return true;
             }
             return false;
         }
         return deleteObject(key, strict);
     }
     private boolean deleteObject(final Object key, final boolean strict) {
         final String propName = JSType.toString(key);
         final FindProperty find = findProperty(propName, false);
         if (find == null) {
             return true;
         }
         if (!find.getProperty().isConfigurable()) {
             if (strict) {
                 throw typeError("cant.delete.property", propName, ScriptRuntime.safeToString(this));
             }
             return false;
         }
         final Property prop = find.getProperty();
         notifyPropertyDeleted(this, prop);
         deleteOwnProperty(prop);
         return true;
     }
     /**
      * Make a new UserAccessorProperty property. getter and setter functions are stored in
      * this ScriptObject and slot values are used in property object.
      *
      * @param key the property name
      * @param propertyFlags attribute flags of the property
      * @param getter getter function for the property
      * @param setter setter function for the property
      * @return the newly created UserAccessorProperty
      */
     protected final UserAccessorProperty newUserAccessors(final String key, final int propertyFlags, final ScriptFunction getter, final ScriptFunction setter) {
         final UserAccessorProperty property = getMap().newUserAccessors(key, propertyFlags);
         setSpill(property.getGetterSlot(), getter);
         setSpill(property.getSetterSlot(), setter);
         return property;
     }
     /**
      * Write a value to a spill slot
      * @param slot  the slot index
      * @param value the value
      */
     protected final void setSpill(final int slot, final Object value) {
         if (spill == null) {
             // create new spill.
             spill = new Object[Math.max(slot + 1, SPILL_RATE)];
         } else if (slot >= spill.length) {
             // grow spill as needed
             final Object[] newSpill = new Object[slot + 1];
             System.arraycopy(spill, 0, newSpill, 0, spill.length);
             spill = newSpill;
         }
         spill[slot] = value;
     }
     /**
      * Get a value from a spill slot
      * @param slot the slot index
      * @return the value in the spill slot with the given index
      */
     protected Object getSpill(final int slot) {
         return spill != null && slot < spill.length ? spill[slot] : null;
     }
     private static MethodHandle findOwnMH(final String name, final Class<?> rtype, final Class<?>... types) {
         final Class<?>   own = ScriptObject.class;
         final MethodType mt  = MH.type(rtype, types);
         try {
             return MH.findStatic(MethodHandles.lookup(), own, name, mt);
         } catch (final MethodHandleFactory.LookupException e) {
             return MH.findVirtual(MethodHandles.lookup(), own, name, mt);
         }
     }
     private static MethodHandle getKnownFunctionPropertyGuard(final PropertyMap map, final MethodHandle getter, final Object where, final ScriptFunction func) {
         return MH.insertArguments(KNOWNFUNCPROPGUARD, 1, map, getter, where, func);
     }
     @SuppressWarnings("unused")
     private static boolean knownFunctionPropertyGuard(final Object self, final PropertyMap map, final MethodHandle getter, final Object where, final ScriptFunction func) {
         if (self instanceof ScriptObject && ((ScriptObject)self).getMap() == map) {
             try {
                 return getter.invokeExact(where) == func;
             } catch (final RuntimeException | Error e) {
                 throw e;
             } catch (final Throwable t) {
                 throw new RuntimeException(t);
             }
         }
         return false;
     }
     /** This is updated only in debug mode - counts number of {@code ScriptObject} instances created */
     private static int count;
     /** This is updated only in debug mode - counts number of {@code ScriptObject} instances created that are scope */
     private static int scopeCount;
     /**
      * Get number of {@code ScriptObject} instances created. If not running in debug
      * mode this is always 0
      *
      * @return number of ScriptObjects created
      */
     public static int getCount() {
         return count;
     }
     /**
      * Get number of scope {@code ScriptObject} instances created. If not running in debug
      * mode this is always 0
      *
      * @return number of scope ScriptObjects created
      */
     public static int getScopeCount() {
         return scopeCount;
     }
 }

Mercurial > jdk8-mips64-public > nashorn / annotate

src/jdk/nashorn/internal/runtime/ScriptObject.java@a2065f67857c (annotated)

src/jdk/nashorn/internal/runtime/ScriptObject.java