8134609: Allow constructors with same prototoype map to share the allocator map

Reviewed-by: attila, sundar

nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/objects/NativeJSAdapter.java

@@ -627,7 +627,7 @@ public final class NativeJSAdapter extends ScriptObject {
                     return new GuardedInvocation(MH.dropArguments(MH.constant(Object.class,
                             func.createBound(this, new Object[] { name })), 0, Object.class),
                             testJSAdaptor(adaptee, null, null, null),
-                            adaptee.getProtoSwitchPoint(__call__, find.getOwner()));
+                            adaptee.getProtoSwitchPoints(__call__, find.getOwner()), null);
                 }
             }
             throw typeError("no.such.function", desc.getNameToken(2), ScriptRuntime.safeToString(this));
@@ -698,7 +698,7 @@ public final class NativeJSAdapter extends ScriptObject {
                     return new GuardedInvocation(
                             methodHandle,
                             testJSAdaptor(adaptee, findData.getGetter(Object.class, INVALID_PROGRAM_POINT, null), findData.getOwner(), func),
-                            adaptee.getProtoSwitchPoint(hook, findData.getOwner()));
+                            adaptee.getProtoSwitchPoints(hook, findData.getOwner()), null);
                 }
              }
         }
@@ -710,7 +710,7 @@ public final class NativeJSAdapter extends ScriptObject {
             final MethodHandle methodHandle = hook.equals(__put__) ?
             MH.asType(Lookup.EMPTY_SETTER, type) :
             Lookup.emptyGetter(type.returnType());
-            return new GuardedInvocation(methodHandle, testJSAdaptor(adaptee, null, null, null), adaptee.getProtoSwitchPoint(hook, null));
+            return new GuardedInvocation(methodHandle, testJSAdaptor(adaptee, null, null, null), adaptee.getProtoSwitchPoints(hook, null), null);
         }
     }
 

nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/AllocationStrategy.java

@@ -29,6 +29,7 @@ import static jdk.nashorn.internal.lookup.Lookup.MH;
 import java.io.Serializable;
 import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
+import java.lang.ref.WeakReference;
 import jdk.nashorn.internal.codegen.Compiler;
 import jdk.nashorn.internal.codegen.CompilerConstants;
 import jdk.nashorn.internal.codegen.ObjectClassGenerator;
@@ -53,6 +54,9 @@ final public class AllocationStrategy implements Serializable {
     /** lazily generated allocator */
     private transient MethodHandle allocator;
 
+    /** Last used allocator map */
+    private transient AllocatorMap lastMap;
+
     /**
      * Construct an allocation strategy with the given map and class name.
      * @param fieldCount number of fields in the allocated object
@@ -71,11 +75,49 @@ final public class AllocationStrategy implements Serializable {
         return allocatorClassName;
     }
 
-    PropertyMap getAllocatorMap() {
-        // Create a new map for each function instance
-        return PropertyMap.newMap(null, getAllocatorClassName(), 0, fieldCount, 0);
+    /**
+     * Get the property map for the allocated object.
+     * @param prototype the prototype object
+     * @return the property map
+     */
+    synchronized PropertyMap getAllocatorMap(final ScriptObject prototype) {
+        assert prototype != null;
+        final PropertyMap protoMap = prototype.getMap();
+
+        if (lastMap != null) {
+            if (!lastMap.hasSharedProtoMap()) {
+                if (lastMap.hasSamePrototype(prototype)) {
+                    return lastMap.allocatorMap;
+                }
+                if (lastMap.hasSameProtoMap(protoMap) && lastMap.hasUnchangedProtoMap()) {
+                    // Convert to shared prototype map. Allocated objects will use the same property map
+                    // that can be used as long as none of the prototypes modify the shared proto map.
+                    final PropertyMap allocatorMap = PropertyMap.newMap(null, getAllocatorClassName(), 0, fieldCount, 0);
+                    final SharedPropertyMap sharedProtoMap = new SharedPropertyMap(protoMap);
+                    allocatorMap.setSharedProtoMap(sharedProtoMap);
+                    prototype.setMap(sharedProtoMap);
+                    lastMap = new AllocatorMap(prototype, protoMap, allocatorMap);
+                    return allocatorMap;
+                }
+            }
+
+            if (lastMap.hasValidSharedProtoMap() && lastMap.hasSameProtoMap(protoMap)) {
+                prototype.setMap(lastMap.getSharedProtoMap());
+                return lastMap.allocatorMap;
+            }
+        }
+
+        final PropertyMap allocatorMap = PropertyMap.newMap(null, getAllocatorClassName(), 0, fieldCount, 0);
+        lastMap = new AllocatorMap(prototype, protoMap, allocatorMap);
+
+        return allocatorMap;
     }
 
+    /**
+     * Allocate an object with the given property map
+     * @param map the property map
+     * @return the allocated object
+     */
     ScriptObject allocate(final PropertyMap map) {
         try {
             if (allocator == null) {
@@ -94,4 +136,43 @@ final public class AllocationStrategy implements Serializable {
     public String toString() {
         return "AllocationStrategy[fieldCount=" + fieldCount + "]";
     }
+
+    static class AllocatorMap {
+        final private WeakReference<ScriptObject> prototype;
+        final private WeakReference<PropertyMap> prototypeMap;
+
+        private PropertyMap allocatorMap;
+
+        AllocatorMap(final ScriptObject prototype, final PropertyMap protoMap, final PropertyMap allocMap) {
+            this.prototype = new WeakReference<>(prototype);
+            this.prototypeMap = new WeakReference<>(protoMap);
+            this.allocatorMap = allocMap;
+        }
+
+        boolean hasSamePrototype(final ScriptObject proto) {
+            return prototype.get() == proto;
+        }
+
+        boolean hasSameProtoMap(final PropertyMap protoMap) {
+            return prototypeMap.get() == protoMap || allocatorMap.getSharedProtoMap() == protoMap;
+        }
+
+        boolean hasUnchangedProtoMap() {
+            final ScriptObject proto = prototype.get();
+            return proto != null && proto.getMap() == prototypeMap.get();
+        }
+
+        boolean hasSharedProtoMap() {
+            return getSharedProtoMap() != null;
+        }
+
+        boolean hasValidSharedProtoMap() {
+            return hasSharedProtoMap() && getSharedProtoMap().isValidSharedProtoMap();
+        }
+
+        PropertyMap getSharedProtoMap() {
+            return allocatorMap.getSharedProtoMap();
+        }
+
+    }
 }

nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/Debug.java

@@ -26,6 +26,8 @@
 package jdk.nashorn.internal.runtime;
 
 import static jdk.nashorn.internal.parser.TokenType.EOF;
+
+import jdk.nashorn.api.scripting.NashornException;
 import jdk.nashorn.internal.parser.Lexer;
 import jdk.nashorn.internal.parser.Token;
 import jdk.nashorn.internal.parser.TokenStream;
@@ -62,6 +64,15 @@ public final class Debug {
         return firstJSFrame(new Throwable());
     }
 
+    /**
+     * Return a formatted script stack trace string with frames information separated by '\n'.
+     * This is a shortcut for {@code NashornException.getScriptStackString(new Throwable())}.
+     * @return formatted stack trace string
+     */
+    public static String scriptStack() {
+        return NashornException.getScriptStackString(new Throwable());
+    }
+
     /**
      * Return the system identity hashcode for an object as a human readable
      * string

nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/PropertyListeners.java

@@ -75,16 +75,20 @@ public class PropertyListeners {
     }
 
     /**
-     * Return listeners added to this ScriptObject.
+     * Return number of listeners added to a ScriptObject.
      * @param obj the object
      * @return the listener count
      */
     public static int getListenerCount(final ScriptObject obj) {
-        final PropertyListeners propertyListeners = obj.getMap().getListeners();
-        if (propertyListeners != null) {
-            return propertyListeners.listeners == null ? 0 : propertyListeners.listeners.size();
-        }
-        return 0;
+        return obj.getMap().getListenerCount();
+    }
+
+    /**
+     * Return the number of listeners added to this PropertyListeners instance.
+     * @return the listener count;
+     */
+    public int getListenerCount() {
+        return listeners == null ? 0 : listeners.size();
     }
 
     // Property listener management methods
@@ -156,7 +160,7 @@ public class PropertyListeners {
             final WeakPropertyMapSet set = listeners.get(prop.getKey());
             if (set != null) {
                 for (final PropertyMap propertyMap : set.elements()) {
-                    propertyMap.propertyAdded(prop);
+                    propertyMap.propertyAdded(prop, false);
                 }
                 listeners.remove(prop.getKey());
                 if (Context.DEBUG) {
@@ -176,7 +180,7 @@ public class PropertyListeners {
             final WeakPropertyMapSet set = listeners.get(prop.getKey());
             if (set != null) {
                 for (final PropertyMap propertyMap : set.elements()) {
-                    propertyMap.propertyDeleted(prop);
+                    propertyMap.propertyDeleted(prop, false);
                 }
                 listeners.remove(prop.getKey());
                 if (Context.DEBUG) {
@@ -198,7 +202,7 @@ public class PropertyListeners {
             final WeakPropertyMapSet set = listeners.get(oldProp.getKey());
             if (set != null) {
                 for (final PropertyMap propertyMap : set.elements()) {
-                    propertyMap.propertyModified(oldProp, newProp);
+                    propertyMap.propertyModified(oldProp, newProp, false);
                 }
                 listeners.remove(oldProp.getKey());
                 if (Context.DEBUG) {
@@ -215,7 +219,7 @@ public class PropertyListeners {
         if (listeners != null) {
             for (final WeakPropertyMapSet set : listeners.values()) {
                 for (final PropertyMap propertyMap : set.elements()) {
-                    propertyMap.protoChanged();
+                    propertyMap.protoChanged(false);
                 }
             }
             listeners.clear();

nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/RecompilableScriptFunctionData.java

@@ -368,8 +368,8 @@ public final class RecompilableScriptFunctionData extends ScriptFunctionData imp
     }
 
     @Override
-    PropertyMap getAllocatorMap() {
-        return allocationStrategy.getAllocatorMap();
+    PropertyMap getAllocatorMap(final ScriptObject prototype) {
+        return allocationStrategy.getAllocatorMap(prototype);
     }
 
     @Override

nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/ScriptFunction.java

@@ -521,35 +521,39 @@ public class ScriptFunction extends ScriptObject {
 
         assert !isBoundFunction(); // allocate never invoked on bound functions
 
-        final ScriptObject object = data.allocate(getAllocatorMap());
+        final ScriptObject prototype = getAllocatorPrototype();
+        final ScriptObject object = data.allocate(getAllocatorMap(prototype));
 
         if (object != null) {
-            final Object prototype = getPrototype();
-            if (prototype instanceof ScriptObject) {
-                object.setInitialProto((ScriptObject) prototype);
-            }
-
-            if (object.getProto() == null) {
-                object.setInitialProto(getObjectPrototype());
-            }
+            object.setInitialProto(prototype);
         }
 
         return object;
     }
 
-    private PropertyMap getAllocatorMap() {
-        if (allocatorMap == null) {
-            allocatorMap = data.getAllocatorMap();
+    /**
+     * Get the property map used by "allocate"
+     * @param prototype actual prototype object
+     * @return property map
+     */
+    private synchronized PropertyMap getAllocatorMap(final ScriptObject prototype) {
+        if (allocatorMap == null || allocatorMap.isInvalidSharedMapFor(prototype)) {
+            // The prototype map has changed since this function was last used as constructor.
+            // Get a new allocator map.
+            allocatorMap = data.getAllocatorMap(prototype);
         }
         return allocatorMap;
     }
 
     /**
-     * Return Object.prototype - used by "allocate"
-     *
-     * @return Object.prototype
+     * Return the actual prototype used by "allocate"
+     * @return allocator prototype
      */
-    protected final ScriptObject getObjectPrototype() {
+    private ScriptObject getAllocatorPrototype() {
+        final Object prototype = getPrototype();
+        if (prototype instanceof ScriptObject) {
+            return (ScriptObject) prototype;
+        }
         return Global.objectPrototype();
     }
 
@@ -591,10 +595,10 @@ public class ScriptFunction extends ScriptObject {
      *
      * @param newPrototype new prototype object
      */
-    public final void setPrototype(final Object newPrototype) {
+    public synchronized final void setPrototype(final Object newPrototype) {
         if (newPrototype instanceof ScriptObject && newPrototype != this.prototype && allocatorMap != null) {
-            // Replace our current allocator map with one that is associated with the new prototype.
-            allocatorMap = allocatorMap.changeProto((ScriptObject) newPrototype);
+            // Unset allocator map to be replaced with one matching the new prototype.
+            allocatorMap = null;
         }
         this.prototype = newPrototype;
     }

nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/ScriptFunctionData.java

@@ -389,9 +389,10 @@ public abstract class ScriptFunctionData implements Serializable {
     /**
      * Get the property map to use for objects allocated by this function.
      *
+     * @param prototype the prototype of the allocated object
      * @return the property map for allocated objects.
      */
-    PropertyMap getAllocatorMap() {
+    PropertyMap getAllocatorMap(final ScriptObject prototype) {
         return null;
     }
 

nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/ScriptObject.java

@@ -809,9 +809,11 @@ public abstract class ScriptObject implements PropertyAccess, Cloneable {
 
         if (deep) {
             final ScriptObject myProto = getProto();
-            if (myProto != null) {
-                return myProto.findProperty(key, deep, start);
-            }
+            final FindProperty find = myProto == null ? null : myProto.findProperty(key, true, start);
+            // checkSharedProtoMap must be invoked after myProto.checkSharedProtoMap to propagate
+            // shared proto invalidation up the prototype chain. It also must be invoked when prototype is null.
+            checkSharedProtoMap();
+            return find;
         }
 
         return null;
@@ -832,7 +834,7 @@ public abstract class ScriptObject implements PropertyAccess, Cloneable {
         if (deep) {
             final ScriptObject myProto = getProto();
             if (myProto != null) {
-                return myProto.hasProperty(key, deep);
+                return myProto.hasProperty(key, true);
             }
         }
 
@@ -1258,11 +1260,8 @@ public abstract class ScriptObject implements PropertyAccess, Cloneable {
         if (oldProto != newProto) {
             proto = newProto;
 
-            // Let current listeners know that the prototype has changed and set our map
-            final PropertyListeners listeners = getMap().getListeners();
-            if (listeners != null) {
-                listeners.protoChanged();
-            }
+            // Let current listeners know that the prototype has changed
+            getMap().protoChanged(true);
             // Replace our current allocator map with one that is associated with the new prototype.
             setMap(getMap().changeProto(newProto));
         }
@@ -1314,7 +1313,7 @@ public abstract class ScriptObject implements PropertyAccess, Cloneable {
                 }
                 p = p.getProto();
             }
-            setProto((ScriptObject)newProto);
+            setProto((ScriptObject) newProto);
         } else {
             throw typeError("cant.set.proto.to.non.object", ScriptRuntime.safeToString(this), ScriptRuntime.safeToString(newProto));
         }
@@ -2012,11 +2011,11 @@ public abstract class ScriptObject implements PropertyAccess, Cloneable {
         final ScriptObject owner = find.getOwner();
         final Class<ClassCastException> exception = explicitInstanceOfCheck ? null : ClassCastException.class;
 
-        final SwitchPoint protoSwitchPoint;
+        final SwitchPoint[] protoSwitchPoints;
 
         if (mh == null) {
             mh = Lookup.emptyGetter(returnType);
-            protoSwitchPoint = getProtoSwitchPoint(name, owner);
+            protoSwitchPoints = getProtoSwitchPoints(name, owner);
         } else if (!find.isSelf()) {
             assert mh.type().returnType().equals(returnType) :
                     "return type mismatch for getter " + mh.type().returnType() + " != " + returnType;
@@ -2024,12 +2023,12 @@ public abstract class ScriptObject implements PropertyAccess, Cloneable {
                 // Add a filter that replaces the self object with the prototype owning the property.
                 mh = addProtoFilter(mh, find.getProtoChainLength());
             }
-            protoSwitchPoint = getProtoSwitchPoint(name, owner);
+            protoSwitchPoints = getProtoSwitchPoints(name, owner);
         } else {
-            protoSwitchPoint = null;
+            protoSwitchPoints = null;
         }
 
-        final GuardedInvocation inv = new GuardedInvocation(mh, guard, protoSwitchPoint, exception);
+        final GuardedInvocation inv = new GuardedInvocation(mh, guard, protoSwitchPoints, exception);
         return inv.addSwitchPoint(findBuiltinSwitchPoint(name));
     }
 
@@ -2128,17 +2127,32 @@ public abstract class ScriptObject implements PropertyAccess, Cloneable {
      * @param owner the property owner, null if property is not defined
      * @return a SwitchPoint or null
      */
-    public final SwitchPoint getProtoSwitchPoint(final String name, final ScriptObject owner) {
+    public final SwitchPoint[] getProtoSwitchPoints(final String name, final ScriptObject owner) {
         if (owner == this || getProto() == null) {
             return null;
         }
 
+        final List<SwitchPoint> switchPoints = new ArrayList<>();
         for (ScriptObject obj = this; obj != owner && obj.getProto() != null; obj = obj.getProto()) {
             final ScriptObject parent = obj.getProto();
             parent.getMap().addListener(name, obj.getMap());
+            final SwitchPoint sp = parent.getMap().getSharedProtoSwitchPoint();
+            if (sp != null && !sp.hasBeenInvalidated()) {
+                switchPoints.add(sp);
+            }
         }
 
-        return getMap().getSwitchPoint(name);
+        switchPoints.add(getMap().getSwitchPoint(name));
+        return switchPoints.toArray(new SwitchPoint[switchPoints.size()]);
+    }
+
+    private void checkSharedProtoMap() {
+        // Check if our map has an expected shared prototype property map. If it has, make sure that
+        // the prototype map has not been invalidated, and that it does match the actual map of the prototype.
+        if (getMap().isInvalidSharedMapFor(getProto())) {
+            // Change our own map to one that does not assume a shared prototype map.
+            setMap(getMap().makeUnsharedCopy());
+        }
     }
 
     /**
@@ -2220,7 +2234,7 @@ public abstract class ScriptObject implements PropertyAccess, Cloneable {
         return new GuardedInvocation(
                 Lookup.EMPTY_SETTER,
                 NashornGuards.getMapGuard(getMap(), explicitInstanceOfCheck),
-                getProtoSwitchPoint(name, null),
+                getProtoSwitchPoints(name, null),
                 explicitInstanceOfCheck ? null : ClassCastException.class);
     }
 
@@ -2366,7 +2380,7 @@ public abstract class ScriptObject implements PropertyAccess, Cloneable {
                                 find.getGetter(Object.class, INVALID_PROGRAM_POINT, request),
                                 find.getProtoChainLength(),
                                 func),
-                        getProtoSwitchPoint(NO_SUCH_PROPERTY_NAME, find.getOwner()),
+                        getProtoSwitchPoints(NO_SUCH_PROPERTY_NAME, find.getOwner()),
                         //TODO this doesn't need a ClassCastException as guard always checks script object
                         null);
             }
@@ -2438,7 +2452,7 @@ public abstract class ScriptObject implements PropertyAccess, Cloneable {
         }
 
         return new GuardedInvocation(Lookup.emptyGetter(desc.getMethodType().returnType()),
-                NashornGuards.getMapGuard(getMap(), explicitInstanceOfCheck), getProtoSwitchPoint(name, null),
+                NashornGuards.getMapGuard(getMap(), explicitInstanceOfCheck), getProtoSwitchPoints(name, null),
                 explicitInstanceOfCheck ? null : ClassCastException.class);
     }
 

nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/SetMethodCreator.java

@@ -186,10 +186,7 @@ final class SetMethodCreator {
 
     private SetMethod createNewPropertySetter(final SwitchPoint builtinSwitchPoint) {
         final SetMethod sm = map.getFreeFieldSlot() > -1 ? createNewFieldSetter(builtinSwitchPoint) : createNewSpillPropertySetter(builtinSwitchPoint);
-        final PropertyListeners listeners = map.getListeners();
-        if (listeners != null) {
-            listeners.propertyAdded(sm.property);
-        }
+        map.propertyAdded(sm.property, true);
         return sm;
     }
 
@@ -204,7 +201,7 @@ final class SetMethodCreator {
         //fast type specific setter
         final MethodHandle fastSetter = property.getSetter(type, newMap); //0 sobj, 1 value, slot folded for spill property already
 
-        //slow setter, that calls ScriptObject.set with appropraite type and key name
+        //slow setter, that calls ScriptObject.set with appropriate type and key name
         MethodHandle slowSetter = ScriptObject.SET_SLOW[getAccessorTypeIndex(type)];
         slowSetter = MH.insertArguments(slowSetter, 3, NashornCallSiteDescriptor.getFlags(desc));
         slowSetter = MH.insertArguments(slowSetter, 1, name);

nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/SharedPropertyMap.java

+/*
+ * Copyright (c) 2015, 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 java.lang.invoke.SwitchPoint;
+
+/**
+ * This class represents a property map that can be shared among multiple prototype objects, allowing all inheriting
+ * top-level objects to also share one property map. This is class is only used for prototype objects, the
+ * top-level objects use ordinary {@link PropertyMap}s with the {@link PropertyMap#sharedProtoMap} field
+ * set to the expected shared prototype map.
+ *
+ * <p>When an instance of this class is evolved because a property is added, removed, or modified in an object
+ * using it, the {@link #invalidateSwitchPoint()} method is invoked to signal to all callsites and inheriting
+ * objects that the assumption of a single shared prototype map is no longer valid. The property map resulting
+ * from the modification will no longer be an instance of this class.</p>
+ */
+public final class SharedPropertyMap extends PropertyMap {
+
+    private SwitchPoint switchPoint;
+
+    private static final long serialVersionUID = 2166297719721778876L;
+
+    /**
+     * Create a new shared property map from the given {@code map}.
+     * @param map property map to copy
+     */
+    public SharedPropertyMap(final PropertyMap map) {
+        super(map);
+        this.switchPoint = new SwitchPoint();
+    }
+
+    @Override
+    public void propertyAdded(final Property property, final boolean isSelf) {
+        if (isSelf) {
+            invalidateSwitchPoint();
+        }
+        super.propertyAdded(property, isSelf);
+    }
+
+    @Override
+    public void propertyDeleted(final Property property, final boolean isSelf) {
+        if (isSelf) {
+            invalidateSwitchPoint();
+        }
+        super.propertyDeleted(property, isSelf);
+    }
+
+    @Override
+    public void propertyModified(final Property oldProperty, final Property newProperty, final boolean isSelf) {
+        if (isSelf) {
+            invalidateSwitchPoint();
+        }
+        super.propertyModified(oldProperty, newProperty, isSelf);
+    }
+
+    @Override
+    synchronized boolean isValidSharedProtoMap() {
+        return switchPoint != null;
+    }
+
+    @Override
+    synchronized SwitchPoint getSharedProtoSwitchPoint() {
+        return switchPoint;
+    }
+
+    /**
+     * Invalidate the shared prototype switch point if this is a shared prototype map.
+     */
+    synchronized void invalidateSwitchPoint() {
+        if (switchPoint != null) {
+            assert !switchPoint.hasBeenInvalidated();
+            SwitchPoint.invalidateAll(new SwitchPoint[]{ switchPoint });
+            switchPoint = null;
+        }
+    }
+}

nashorn/src/jdk.scripting.nashorn/share/classes/jdk/nashorn/internal/runtime/WithObject.java

@@ -46,7 +46,7 @@ import jdk.nashorn.internal.runtime.linker.NashornGuards;
  *
  */
 public final class WithObject extends Scope {
-    private static final MethodHandle WITHEXPRESSIONGUARD    = findOwnMH("withExpressionGuard",  boolean.class, Object.class, PropertyMap.class, SwitchPoint.class);
+    private static final MethodHandle WITHEXPRESSIONGUARD    = findOwnMH("withExpressionGuard",  boolean.class, Object.class, PropertyMap.class, SwitchPoint[].class);
     private static final MethodHandle WITHEXPRESSIONFILTER   = findOwnMH("withFilterExpression", Object.class, Object.class);
     private static final MethodHandle WITHSCOPEFILTER        = findOwnMH("withFilterScope",      Object.class, Object.class);
     private static final MethodHandle BIND_TO_EXPRESSION_OBJ = findOwnMH("bindToExpression",     Object.class, Object.class, Object.class);
@@ -360,13 +360,24 @@ public final class WithObject extends Scope {
 
     private MethodHandle expressionGuard(final String name, final ScriptObject owner) {
         final PropertyMap map = expression.getMap();
-        final SwitchPoint sp = expression.getProtoSwitchPoint(name, owner);
+        final SwitchPoint[] sp = expression.getProtoSwitchPoints(name, owner);
         return MH.insertArguments(WITHEXPRESSIONGUARD, 1, map, sp);
     }
 
     @SuppressWarnings("unused")
-    private static boolean withExpressionGuard(final Object receiver, final PropertyMap map, final SwitchPoint sp) {
-        return ((WithObject)receiver).expression.getMap() == map && (sp == null || !sp.hasBeenInvalidated());
+    private static boolean withExpressionGuard(final Object receiver, final PropertyMap map, final SwitchPoint[] sp) {
+        return ((WithObject)receiver).expression.getMap() == map && !hasBeenInvalidated(sp);
+    }
+
+    private static boolean hasBeenInvalidated(final SwitchPoint[] switchPoints) {
+        if (switchPoints != null) {
+            for (final SwitchPoint switchPoint : switchPoints) {
+                if (switchPoint.hasBeenInvalidated()) {
+                    return true;
+                }
+            }
+        }
+        return false;
     }
 
     /**

nashorn/test/script/basic/JDK-8134569.js

@@ -62,67 +62,146 @@ function createDeep() {
     return new C();
 }
 
+function createDeeper() {
+    function C() {
+        this.i1 = 1;
+        this.i2 = 2;
+        this.i3 = 3;
+        return this;
+    }
+    function D() {
+        this.p1 = 1;
+        this.p2 = 2;
+        this.p3 = 3;
+        return this;
+    }
+    function E() {
+        this.e1 = 1;
+        this.e2 = 2;
+        this.e3 = 3;
+        return this;
+    }
+    D.prototype = new E();
+    C.prototype = new D();
+    return new C();
+}
+
 function createEval() {
     return eval("Object.create({})");
 }
 
 function p(o) { print(o.x) }
 
-var a, b;
+function e(o) { print(o.e1) }
+
+var a, b, c;
 
 create();
 a = create();
 b = create();
+c = create();
 a.__proto__.x = 123;
 
 p(a);
 p(b);
+p(c);
 
 a = create();
 b = create();
+c = create();
 b.__proto__.x = 123;
 
 p(a);
 p(b);
+p(c);
 
 a = createEmpty();
 b = createEmpty();
+c = createEmpty();
 a.__proto__.x = 123;
 
 p(a);
 p(b);
+p(c);
 
 a = createEmpty();
 b = createEmpty();
+c = createEmpty();
 b.__proto__.x = 123;
 
 p(a);
 p(b);
+p(c);
 
 a = createDeep();
 b = createDeep();
+c = createDeep();
 a.__proto__.__proto__.x = 123;
 
 p(a);
 p(b);
+p(c);
 
 a = createDeep();
 b = createDeep();
+c = createDeep();
 b.__proto__.__proto__.x = 123;
 
 p(a);
 p(b);
+p(c);
+
+a = createDeeper();
+b = createDeeper();
+c = createDeeper();
+a.__proto__.__proto__.__proto__.x = 123;
+
+p(a);
+p(b);
+p(c);
+
+a = createDeeper();
+b = createDeeper();
+c = createDeeper();
+b.__proto__.__proto__.__proto__.x = 123;
+
+p(a);
+p(b);
+p(c);
+
+a = createDeeper();
+b = createDeeper();
+c = createDeeper();
+a.__proto__.__proto__ = null;
+
+e(a);
+e(b);
+e(c);
+
+a = createDeeper();
+b = createDeeper();
+c = createDeeper();
+b.__proto__.__proto__ = null;
+
+e(a);
+e(b);
+e(c);
+
 
 a = createEval();
 b = createEval();
+c = createEval();
 a.__proto__.x = 123;
 
 p(a);
 p(b);
+p(c);
 
 a = createEval();
 b = createEval();
+c = createEval();
 b.__proto__.x = 123;
 
 p(a);
 p(b);
+p(c);

nashorn/test/script/basic/JDK-8134569.js.EXPECTED

 123
 undefined
 undefined
+undefined
+123
+undefined
+123
+undefined
+undefined
+undefined
 123
+undefined
 123
 undefined
 undefined
+undefined
 123
+undefined
 123
 undefined
 undefined
+undefined
 123
+undefined
+undefined
+1
+1
+1
+undefined
+1
 123
 undefined
 undefined
+undefined
 123
+undefined

nashorn/test/script/basic/JDK-8134609.js

+/*
+ * Copyright (c) 2015, 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.
+ * 
+ * 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.
+ */
+
+/**
+ * JDK-8134609: Allow constructors with same prototoype map to share the allocator map
+ *
+ * @test
+ * @run
+ * @fork
+ * @option -Dnashorn.debug
+ */
+
+function createProto(members) {
+    function P() {
+        for (var id in members) {
+            if (members.hasOwnProperty(id)) {
+                this[id] = members[id];
+            }
+        }
+        return this;
+    }
+    return new P();
+}
+
+function createSubclass(prototype, members) {
+    function C() {
+        for (var id in members) {
+            if (members.hasOwnProperty(id)) {
+                this[id] = members[id];
+            }
+        }
+        return this;
+    }
+
+    C.prototype = prototype;
+
+    return new C();
+}
+
+function assertP1(object, value) {
+    Assert.assertTrue(object.p1 === value);
+}
+
+// First prototype will have non-shared proto-map. Second and third will be shared.
+var proto0 = createProto({p1: 0, p2: 1});
+var proto1 = createProto({p1: 1, p2: 2});
+var proto2 = createProto({p1: 2, p2: 3});
+
+Assert.assertTrue(Debug.map(proto1) === Debug.map(proto2));
+
+assertP1(proto1, 1);
+assertP1(proto2, 2);
+
+// First instantiation will have a non-shared prototype map, from the second one
+// maps will be shared until a different proto map comes along.
+var child0 = createSubclass(proto1, {c1: 1, c2: 2});
+var child1 = createSubclass(proto2, {c1: 2, c2: 3});
+var child2 = createSubclass(proto1, {c1: 3, c2: 4});
+var child3 = createSubclass(proto2, {c1: 1, c2: 2});
+var child4 = createSubclass(proto0, {c1: 3, c2: 2});
+
+Assert.assertTrue(Debug.map(child1) === Debug.map(child2));
+Assert.assertTrue(Debug.map(child1) === Debug.map(child3));
+Assert.assertTrue(Debug.map(child3) !== Debug.map(child4));
+
+assertP1(child1, 2);
+assertP1(child2, 1);
+assertP1(child3, 2);
+assertP1(child4, 0);
+
+Assert.assertTrue(delete proto2.p1);
+
+assertP1(child3, undefined);
+assertP1(child2, 1);
+Assert.assertTrue(Debug.map(child1) !== Debug.map(child3));