Mercurial > jdk8-mips64-public > nashorn / file comparison

comparison: src/jdk/internal/dynalink/support/CompositeTypeBasedGuardingDynamicLinker.java

src/jdk/internal/dynalink/support/CompositeTypeBasedGuardingDynamicLinker.java

changeset 90
5a820fb11814
child 101
f8221ce53c2e
equal deleted inserted replaced
89:43e32b36153c 90:5a820fb11814
1 /*
2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 /*
27 * This file is available under and governed by the GNU General Public
28 * License version 2 only, as published by the Free Software Foundation.
29 * However, the following notice accompanied the original version of this
30 * file, and Oracle licenses the original version of this file under the BSD
31 * license:
32 */
33 /*
34 Copyright 2009-2013 Attila Szegedi
35
36 Licensed under both the Apache License, Version 2.0 (the "Apache License")
37 and the BSD License (the "BSD License"), with licensee being free to
38 choose either of the two at their discretion.
39
40 You may not use this file except in compliance with either the Apache
41 License or the BSD License.
42
43 If you choose to use this file in compliance with the Apache License, the
44 following notice applies to you:
45
46 You may obtain a copy of the Apache License at
47
48 http://www.apache.org/licenses/LICENSE-2.0
49
50 Unless required by applicable law or agreed to in writing, software
51 distributed under the License is distributed on an "AS IS" BASIS,
52 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
53 implied. See the License for the specific language governing
54 permissions and limitations under the License.
55
56 If you choose to use this file in compliance with the BSD License, the
57 following notice applies to you:
58
59 Redistribution and use in source and binary forms, with or without
60 modification, are permitted provided that the following conditions are
61 met:
62 * Redistributions of source code must retain the above copyright
63 notice, this list of conditions and the following disclaimer.
64 * Redistributions in binary form must reproduce the above copyright
65 notice, this list of conditions and the following disclaimer in the
66 documentation and/or other materials provided with the distribution.
67 * Neither the name of the copyright holder nor the names of
68 contributors may be used to endorse or promote products derived from
69 this software without specific prior written permission.
70
71 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
72 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
73 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
74 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
75 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
76 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
77 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
78 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
79 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
80 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
81 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
82 */
83
84 package jdk.internal.dynalink.support;
85
86 import java.io.Serializable;
87 import java.util.Collections;
88 import java.util.LinkedList;
89 import java.util.List;
90 import jdk.internal.dynalink.linker.GuardedInvocation;
91 import jdk.internal.dynalink.linker.GuardingDynamicLinker;
92 import jdk.internal.dynalink.linker.LinkRequest;
93 import jdk.internal.dynalink.linker.LinkerServices;
94 import jdk.internal.dynalink.linker.TypeBasedGuardingDynamicLinker;
95
96
97 /**
98 * A composite type-based guarding dynamic linker. When a receiver of a not yet seen class is encountered, all linkers
99 * are queried sequentially on their {@link TypeBasedGuardingDynamicLinker#canLinkType(Class)} method. The linkers
100 * returning true are then bound to the class, and next time a receiver of same type is encountered, the linking is
101 * delegated to those linkers only, speeding up dispatch.
102 *
103 * @author Attila Szegedi
104 */
105 public class CompositeTypeBasedGuardingDynamicLinker implements TypeBasedGuardingDynamicLinker, Serializable {
106 private static final long serialVersionUID = 1L;
107
108 // Using a separate static class instance so there's no strong reference from the class value back to the composite
109 // linker.
110 private static class ClassToLinker extends ClassValue<List<TypeBasedGuardingDynamicLinker>> {
111 private static final List<TypeBasedGuardingDynamicLinker> NO_LINKER = Collections.emptyList();
112 private final TypeBasedGuardingDynamicLinker[] linkers;
113 private final List<TypeBasedGuardingDynamicLinker>[] singletonLinkers;
114
115 @SuppressWarnings("unchecked")
116 ClassToLinker(TypeBasedGuardingDynamicLinker[] linkers) {
117 this.linkers = linkers;
118 singletonLinkers = new List[linkers.length];
119 for(int i = 0; i < linkers.length; ++i) {
120 singletonLinkers[i] = Collections.singletonList(linkers[i]);
121 }
122 }
123
124 @Override
125 protected List<TypeBasedGuardingDynamicLinker> computeValue(Class<?> clazz) {
126 List<TypeBasedGuardingDynamicLinker> list = NO_LINKER;
127 for(int i = 0; i < linkers.length; ++i) {
128 final TypeBasedGuardingDynamicLinker linker = linkers[i];
129 if(linker.canLinkType(clazz)) {
130 switch(list.size()) {
131 case 0: {
132 list = singletonLinkers[i];
133 break;
134 }
135 case 1: {
136 list = new LinkedList<>(list);
137 }
138 //$FALL-THROUGH$
139 default: {
140 list.add(linker);
141 }
142 }
143 }
144 }
145 return list;
146 }
147 }
148
149 private final ClassValue<List<TypeBasedGuardingDynamicLinker>> classToLinker;
150
151 /**
152 * Creates a new composite type-based linker.
153 *
154 * @param linkers the component linkers
155 */
156 public CompositeTypeBasedGuardingDynamicLinker(Iterable<? extends TypeBasedGuardingDynamicLinker> linkers) {
157 final List<TypeBasedGuardingDynamicLinker> l = new LinkedList<>();
158 for(TypeBasedGuardingDynamicLinker linker: linkers) {
159 l.add(linker);
160 }
161 this.classToLinker = new ClassToLinker(l.toArray(new TypeBasedGuardingDynamicLinker[l.size()]));
162 }
163
164 @Override
165 public boolean canLinkType(Class<?> type) {
166 return !classToLinker.get(type).isEmpty();
167 }
168
169 @Override
170 public GuardedInvocation getGuardedInvocation(LinkRequest linkRequest, final LinkerServices linkerServices)
171 throws Exception {
172 final Object obj = linkRequest.getReceiver();
173 if(obj == null) {
174 return null;
175 }
176 for(TypeBasedGuardingDynamicLinker linker: classToLinker.get(obj.getClass())) {
177 final GuardedInvocation invocation = linker.getGuardedInvocation(linkRequest, linkerServices);
178 if(invocation != null) {
179 return invocation;
180 }
181 }
182 return null;
183 }
184
185 /**
186 * Optimizes a list of type-based linkers. If a group of adjacent linkers in the list all implement
187 * {@link TypeBasedGuardingDynamicLinker}, they will be replaced with a single instance of
188 * {@link CompositeTypeBasedGuardingDynamicLinker} that contains them.
189 *
190 * @param linkers the list of linkers to optimize
191 * @return the optimized list
192 */
193 public static List<GuardingDynamicLinker> optimize(Iterable<? extends GuardingDynamicLinker> linkers) {
194 final List<GuardingDynamicLinker> llinkers = new LinkedList<>();
195 final List<TypeBasedGuardingDynamicLinker> tblinkers = new LinkedList<>();
196 for(GuardingDynamicLinker linker: linkers) {
197 if(linker instanceof TypeBasedGuardingDynamicLinker) {
198 tblinkers.add((TypeBasedGuardingDynamicLinker)linker);
199 } else {
200 addTypeBased(llinkers, tblinkers);
201 llinkers.add(linker);
202 }
203 }
204 addTypeBased(llinkers, tblinkers);
205 return llinkers;
206 }
207
208 private static void addTypeBased(List<GuardingDynamicLinker> llinkers,
209 List<TypeBasedGuardingDynamicLinker> tblinkers) {
210 switch(tblinkers.size()) {
211 case 0: {
212 break;
213 }
214 case 1: {
215 llinkers.addAll(tblinkers);
216 tblinkers.clear();
217 break;
218 }
219 default: {
220 llinkers.add(new CompositeTypeBasedGuardingDynamicLinker(tblinkers));
221 tblinkers.clear();
222 break;
223 }
224 }
225 }
226 }

Mercurial Repository: jdk8-mips64-public/nashorn

mercurial