1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/jdk/internal/dynalink/support/CompositeTypeBasedGuardingDynamicLinker.java Thu Feb 14 13:22:26 2013 +0100
1.3 @@ -0,0 +1,226 @@
1.4 +/*
1.5 + * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Oracle designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Oracle in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.25 + * or visit www.oracle.com if you need additional information or have any
1.26 + * questions.
1.27 + */
1.28 +
1.29 +/*
1.30 + * This file is available under and governed by the GNU General Public
1.31 + * License version 2 only, as published by the Free Software Foundation.
1.32 + * However, the following notice accompanied the original version of this
1.33 + * file, and Oracle licenses the original version of this file under the BSD
1.34 + * license:
1.35 + */
1.36 +/*
1.37 + Copyright 2009-2013 Attila Szegedi
1.38 +
1.39 + Licensed under both the Apache License, Version 2.0 (the "Apache License")
1.40 + and the BSD License (the "BSD License"), with licensee being free to
1.41 + choose either of the two at their discretion.
1.42 +
1.43 + You may not use this file except in compliance with either the Apache
1.44 + License or the BSD License.
1.45 +
1.46 + If you choose to use this file in compliance with the Apache License, the
1.47 + following notice applies to you:
1.48 +
1.49 + You may obtain a copy of the Apache License at
1.50 +
1.51 + http://www.apache.org/licenses/LICENSE-2.0
1.52 +
1.53 + Unless required by applicable law or agreed to in writing, software
1.54 + distributed under the License is distributed on an "AS IS" BASIS,
1.55 + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
1.56 + implied. See the License for the specific language governing
1.57 + permissions and limitations under the License.
1.58 +
1.59 + If you choose to use this file in compliance with the BSD License, the
1.60 + following notice applies to you:
1.61 +
1.62 + Redistribution and use in source and binary forms, with or without
1.63 + modification, are permitted provided that the following conditions are
1.64 + met:
1.65 + * Redistributions of source code must retain the above copyright
1.66 + notice, this list of conditions and the following disclaimer.
1.67 + * Redistributions in binary form must reproduce the above copyright
1.68 + notice, this list of conditions and the following disclaimer in the
1.69 + documentation and/or other materials provided with the distribution.
1.70 + * Neither the name of the copyright holder nor the names of
1.71 + contributors may be used to endorse or promote products derived from
1.72 + this software without specific prior written permission.
1.73 +
1.74 + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
1.75 + IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
1.76 + TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
1.77 + PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
1.78 + BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
1.79 + CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
1.80 + SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
1.81 + BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
1.82 + WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
1.83 + OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
1.84 + ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.85 +*/
1.86 +
1.87 +package jdk.internal.dynalink.support;
1.88 +
1.89 +import java.io.Serializable;
1.90 +import java.util.Collections;
1.91 +import java.util.LinkedList;
1.92 +import java.util.List;
1.93 +import jdk.internal.dynalink.linker.GuardedInvocation;
1.94 +import jdk.internal.dynalink.linker.GuardingDynamicLinker;
1.95 +import jdk.internal.dynalink.linker.LinkRequest;
1.96 +import jdk.internal.dynalink.linker.LinkerServices;
1.97 +import jdk.internal.dynalink.linker.TypeBasedGuardingDynamicLinker;
1.98 +
1.99 +
1.100 +/**
1.101 + * A composite type-based guarding dynamic linker. When a receiver of a not yet seen class is encountered, all linkers
1.102 + * are queried sequentially on their {@link TypeBasedGuardingDynamicLinker#canLinkType(Class)} method. The linkers
1.103 + * returning true are then bound to the class, and next time a receiver of same type is encountered, the linking is
1.104 + * delegated to those linkers only, speeding up dispatch.
1.105 + *
1.106 + * @author Attila Szegedi
1.107 + */
1.108 +public class CompositeTypeBasedGuardingDynamicLinker implements TypeBasedGuardingDynamicLinker, Serializable {
1.109 + private static final long serialVersionUID = 1L;
1.110 +
1.111 + // Using a separate static class instance so there's no strong reference from the class value back to the composite
1.112 + // linker.
1.113 + private static class ClassToLinker extends ClassValue<List<TypeBasedGuardingDynamicLinker>> {
1.114 + private static final List<TypeBasedGuardingDynamicLinker> NO_LINKER = Collections.emptyList();
1.115 + private final TypeBasedGuardingDynamicLinker[] linkers;
1.116 + private final List<TypeBasedGuardingDynamicLinker>[] singletonLinkers;
1.117 +
1.118 + @SuppressWarnings("unchecked")
1.119 + ClassToLinker(TypeBasedGuardingDynamicLinker[] linkers) {
1.120 + this.linkers = linkers;
1.121 + singletonLinkers = new List[linkers.length];
1.122 + for(int i = 0; i < linkers.length; ++i) {
1.123 + singletonLinkers[i] = Collections.singletonList(linkers[i]);
1.124 + }
1.125 + }
1.126 +
1.127 + @Override
1.128 + protected List<TypeBasedGuardingDynamicLinker> computeValue(Class<?> clazz) {
1.129 + List<TypeBasedGuardingDynamicLinker> list = NO_LINKER;
1.130 + for(int i = 0; i < linkers.length; ++i) {
1.131 + final TypeBasedGuardingDynamicLinker linker = linkers[i];
1.132 + if(linker.canLinkType(clazz)) {
1.133 + switch(list.size()) {
1.134 + case 0: {
1.135 + list = singletonLinkers[i];
1.136 + break;
1.137 + }
1.138 + case 1: {
1.139 + list = new LinkedList<>(list);
1.140 + }
1.141 + //$FALL-THROUGH$
1.142 + default: {
1.143 + list.add(linker);
1.144 + }
1.145 + }
1.146 + }
1.147 + }
1.148 + return list;
1.149 + }
1.150 + }
1.151 +
1.152 + private final ClassValue<List<TypeBasedGuardingDynamicLinker>> classToLinker;
1.153 +
1.154 + /**
1.155 + * Creates a new composite type-based linker.
1.156 + *
1.157 + * @param linkers the component linkers
1.158 + */
1.159 + public CompositeTypeBasedGuardingDynamicLinker(Iterable<? extends TypeBasedGuardingDynamicLinker> linkers) {
1.160 + final List<TypeBasedGuardingDynamicLinker> l = new LinkedList<>();
1.161 + for(TypeBasedGuardingDynamicLinker linker: linkers) {
1.162 + l.add(linker);
1.163 + }
1.164 + this.classToLinker = new ClassToLinker(l.toArray(new TypeBasedGuardingDynamicLinker[l.size()]));
1.165 + }
1.166 +
1.167 + @Override
1.168 + public boolean canLinkType(Class<?> type) {
1.169 + return !classToLinker.get(type).isEmpty();
1.170 + }
1.171 +
1.172 + @Override
1.173 + public GuardedInvocation getGuardedInvocation(LinkRequest linkRequest, final LinkerServices linkerServices)
1.174 + throws Exception {
1.175 + final Object obj = linkRequest.getReceiver();
1.176 + if(obj == null) {
1.177 + return null;
1.178 + }
1.179 + for(TypeBasedGuardingDynamicLinker linker: classToLinker.get(obj.getClass())) {
1.180 + final GuardedInvocation invocation = linker.getGuardedInvocation(linkRequest, linkerServices);
1.181 + if(invocation != null) {
1.182 + return invocation;
1.183 + }
1.184 + }
1.185 + return null;
1.186 + }
1.187 +
1.188 + /**
1.189 + * Optimizes a list of type-based linkers. If a group of adjacent linkers in the list all implement
1.190 + * {@link TypeBasedGuardingDynamicLinker}, they will be replaced with a single instance of
1.191 + * {@link CompositeTypeBasedGuardingDynamicLinker} that contains them.
1.192 + *
1.193 + * @param linkers the list of linkers to optimize
1.194 + * @return the optimized list
1.195 + */
1.196 + public static List<GuardingDynamicLinker> optimize(Iterable<? extends GuardingDynamicLinker> linkers) {
1.197 + final List<GuardingDynamicLinker> llinkers = new LinkedList<>();
1.198 + final List<TypeBasedGuardingDynamicLinker> tblinkers = new LinkedList<>();
1.199 + for(GuardingDynamicLinker linker: linkers) {
1.200 + if(linker instanceof TypeBasedGuardingDynamicLinker) {
1.201 + tblinkers.add((TypeBasedGuardingDynamicLinker)linker);
1.202 + } else {
1.203 + addTypeBased(llinkers, tblinkers);
1.204 + llinkers.add(linker);
1.205 + }
1.206 + }
1.207 + addTypeBased(llinkers, tblinkers);
1.208 + return llinkers;
1.209 + }
1.210 +
1.211 + private static void addTypeBased(List<GuardingDynamicLinker> llinkers,
1.212 + List<TypeBasedGuardingDynamicLinker> tblinkers) {
1.213 + switch(tblinkers.size()) {
1.214 + case 0: {
1.215 + break;
1.216 + }
1.217 + case 1: {
1.218 + llinkers.addAll(tblinkers);
1.219 + tblinkers.clear();
1.220 + break;
1.221 + }
1.222 + default: {
1.223 + llinkers.add(new CompositeTypeBasedGuardingDynamicLinker(tblinkers));
1.224 + tblinkers.clear();
1.225 + break;
1.226 + }
1.227 + }
1.228 + }
1.229 +}
1.230 \ No newline at end of file
