Mercurial > hg > openjdk > lambda > nashorn
view src/jdk/nashorn/internal/runtime/CompiledFunctions.java @ 667:71cfb21c68dc
8027301: Optimizations for Function.prototype.apply
Reviewed-by: jlaskey
author | hannesw |
---|---|
date | Fri, 25 Oct 2013 15:21:12 +0200 |
parents | 5a3f7867e19c |
children |
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/* * 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 java.lang.invoke.MethodHandle; import java.lang.invoke.MethodType; import java.util.Iterator; import java.util.TreeSet; /** * This is a list of code versions of a function. * The list is sorted in ascending order of generic descriptors */ @SuppressWarnings("serial") final class CompiledFunctions extends TreeSet<CompiledFunction> { private CompiledFunction generic; CompiledFunction best(final MethodType type) { final Iterator<CompiledFunction> iter = iterator(); while (iter.hasNext()) { final CompiledFunction next = iter.next(); if (next.typeCompatible(type)) { return next; } } return generic(); } boolean needsCallee() { return ScriptFunctionData.needsCallee(mostGeneric().getInvoker()); } CompiledFunction mostGeneric() { return last(); } CompiledFunction generic() { CompiledFunction gen = this.generic; if (gen == null) { gen = this.generic = makeGeneric(mostGeneric()); } return gen; } private static CompiledFunction makeGeneric(final CompiledFunction func) { final MethodHandle invoker = composeGenericMethod(func.getInvoker()); final MethodHandle constructor = func.hasConstructor() ? composeGenericMethod(func.getConstructor()) : null; return new CompiledFunction(invoker.type(), invoker, constructor); } /** * Takes a method handle, and returns a potentially different method handle that can be used in * {@code ScriptFunction#invoke(Object, Object...)} or {code ScriptFunction#construct(Object, Object...)}. * The returned method handle will be sure to return {@code Object}, and will have all its parameters turned into * {@code Object} as well, except for the following ones: * <ul> * <li>a last parameter of type {@code Object[]} which is used for vararg functions,</li> * <li>the first argument, which is forced to be {@link ScriptFunction}, in case the function receives itself * (callee) as an argument.</li> * </ul> * * @param mh the original method handle * * @return the new handle, conforming to the rules above. */ private static MethodHandle composeGenericMethod(final MethodHandle mh) { final MethodType type = mh.type(); final boolean isVarArg = ScriptFunctionData.isVarArg(mh); final int paramCount = isVarArg ? type.parameterCount() - 1 : type.parameterCount(); MethodType newType = MethodType.genericMethodType(paramCount, isVarArg); if (ScriptFunctionData.needsCallee(mh)) { newType = newType.changeParameterType(0, ScriptFunction.class); } return type.equals(newType) ? mh : mh.asType(newType); } /** * Is the given type even more specific than this entire list? That means * we have an opportunity for more specific versions of the method * through lazy code generation * * @param type type to check against * @return true if the given type is more specific than all invocations available */ boolean isLessSpecificThan(final MethodType type) { return best(type).moreGenericThan(type); } }