1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/jdk/internal/dynalink/DynamicLinkerFactory.java Wed Apr 27 01:36:41 2016 +0800
1.3 @@ -0,0 +1,328 @@
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;
1.88 +
1.89 +import java.lang.invoke.MutableCallSite;
1.90 +import java.security.AccessController;
1.91 +import java.security.PrivilegedAction;
1.92 +import java.util.ArrayList;
1.93 +import java.util.Arrays;
1.94 +import java.util.Collections;
1.95 +import java.util.HashSet;
1.96 +import java.util.LinkedList;
1.97 +import java.util.List;
1.98 +import java.util.Set;
1.99 +import jdk.internal.dynalink.beans.BeansLinker;
1.100 +import jdk.internal.dynalink.linker.GuardingDynamicLinker;
1.101 +import jdk.internal.dynalink.linker.GuardingTypeConverterFactory;
1.102 +import jdk.internal.dynalink.linker.LinkRequest;
1.103 +import jdk.internal.dynalink.support.AutoDiscovery;
1.104 +import jdk.internal.dynalink.support.BottomGuardingDynamicLinker;
1.105 +import jdk.internal.dynalink.support.ClassLoaderGetterContextProvider;
1.106 +import jdk.internal.dynalink.support.CompositeGuardingDynamicLinker;
1.107 +import jdk.internal.dynalink.support.CompositeTypeBasedGuardingDynamicLinker;
1.108 +import jdk.internal.dynalink.support.LinkerServicesImpl;
1.109 +import jdk.internal.dynalink.support.TypeConverterFactory;
1.110 +
1.111 +/**
1.112 + * A factory class for creating {@link DynamicLinker}s. The most usual dynamic linker is a linker that is a composition
1.113 + * of all {@link GuardingDynamicLinker}s known and pre-created by the caller as well as any
1.114 + * {@link AutoDiscovery automatically discovered} guarding linkers and the standard fallback {@link BeansLinker}. See
1.115 + * {@link DynamicLinker} documentation for tips on how to use this class.
1.116 + *
1.117 + * @author Attila Szegedi
1.118 + */
1.119 +public class DynamicLinkerFactory {
1.120 +
1.121 + /**
1.122 + * Default value for {@link #setUnstableRelinkThreshold(int) unstable relink threshold}.
1.123 + */
1.124 + public static final int DEFAULT_UNSTABLE_RELINK_THRESHOLD = 8;
1.125 +
1.126 + private boolean classLoaderExplicitlySet = false;
1.127 + private ClassLoader classLoader;
1.128 +
1.129 + private List<? extends GuardingDynamicLinker> prioritizedLinkers;
1.130 + private List<? extends GuardingDynamicLinker> fallbackLinkers;
1.131 + private int runtimeContextArgCount = 0;
1.132 + private boolean syncOnRelink = false;
1.133 + private int unstableRelinkThreshold = DEFAULT_UNSTABLE_RELINK_THRESHOLD;
1.134 +
1.135 + /**
1.136 + * Sets the class loader for automatic discovery of available linkers. If not set explicitly, then the thread
1.137 + * context class loader at the time of {@link #createLinker()} invocation will be used.
1.138 + *
1.139 + * @param classLoader the class loader used for the autodiscovery of available linkers.
1.140 + */
1.141 + public void setClassLoader(ClassLoader classLoader) {
1.142 + this.classLoader = classLoader;
1.143 + classLoaderExplicitlySet = true;
1.144 + }
1.145 +
1.146 + /**
1.147 + * Sets the prioritized linkers. Language runtimes using this framework will usually precreate at least the linker
1.148 + * for their own language. These linkers will be consulted first in the resulting dynamic linker, before any
1.149 + * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the prioritized
1.150 + * linkers, it will be ignored and the explicit prioritized instance will be used.
1.151 + *
1.152 + * @param prioritizedLinkers the list of prioritized linkers. Null can be passed to indicate no prioritized linkers
1.153 + * (this is also the default value).
1.154 + */
1.155 + public void setPrioritizedLinkers(List<? extends GuardingDynamicLinker> prioritizedLinkers) {
1.156 + this.prioritizedLinkers =
1.157 + prioritizedLinkers == null ? null : new ArrayList<>(prioritizedLinkers);
1.158 + }
1.159 +
1.160 + /**
1.161 + * Sets the prioritized linkers. Language runtimes using this framework will usually precreate at least the linker
1.162 + * for their own language. These linkers will be consulted first in the resulting dynamic linker, before any
1.163 + * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the prioritized
1.164 + * linkers, it will be ignored and the explicit prioritized instance will be used.
1.165 + *
1.166 + * @param prioritizedLinkers a list of prioritized linkers.
1.167 + */
1.168 + public void setPrioritizedLinkers(GuardingDynamicLinker... prioritizedLinkers) {
1.169 + setPrioritizedLinkers(Arrays.asList(prioritizedLinkers));
1.170 + }
1.171 +
1.172 + /**
1.173 + * Sets a single prioritized linker. Identical to calling {@link #setPrioritizedLinkers(List)} with a single-element
1.174 + * list.
1.175 + *
1.176 + * @param prioritizedLinker the single prioritized linker. Must not be null.
1.177 + * @throws IllegalArgumentException if null is passed.
1.178 + */
1.179 + public void setPrioritizedLinker(GuardingDynamicLinker prioritizedLinker) {
1.180 + if(prioritizedLinker == null) {
1.181 + throw new IllegalArgumentException("prioritizedLinker == null");
1.182 + }
1.183 + this.prioritizedLinkers = Collections.singletonList(prioritizedLinker);
1.184 + }
1.185 +
1.186 + /**
1.187 + * Sets the fallback linkers. These linkers will be consulted last in the resulting composite linker, after any
1.188 + * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the fallback
1.189 + * linkers, it will be ignored and the explicit fallback instance will be used.
1.190 + *
1.191 + * @param fallbackLinkers the list of fallback linkers. Can be empty to indicate the caller wishes to set no
1.192 + * fallback linkers.
1.193 + */
1.194 + public void setFallbackLinkers(List<? extends GuardingDynamicLinker> fallbackLinkers) {
1.195 + this.fallbackLinkers = fallbackLinkers == null ? null : new ArrayList<>(fallbackLinkers);
1.196 + }
1.197 +
1.198 + /**
1.199 + * Sets the fallback linkers. These linkers will be consulted last in the resulting composite linker, after any
1.200 + * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the fallback
1.201 + * linkers, it will be ignored and the explicit fallback instance will be used.
1.202 + *
1.203 + * @param fallbackLinkers the list of fallback linkers. Can be empty to indicate the caller wishes to set no
1.204 + * fallback linkers. If it is left as null, the standard fallback {@link BeansLinker} will be used.
1.205 + */
1.206 + public void setFallbackLinkers(GuardingDynamicLinker... fallbackLinkers) {
1.207 + setFallbackLinkers(Arrays.asList(fallbackLinkers));
1.208 + }
1.209 +
1.210 + /**
1.211 + * Sets the number of arguments in the call sites that represent the stack context of the language runtime creating
1.212 + * the linker. If the language runtime uses no context information passed on stack, then it should be zero
1.213 + * (the default value). If it is set to nonzero value, then every dynamic call site emitted by this runtime must
1.214 + * have the argument list of the form: {@code (this, contextArg1[, contextArg2[, ...]], normalArgs)}. It is
1.215 + * advisable to only pass one context-specific argument, though, of an easily recognizable, runtime specific type
1.216 + * encapsulating the runtime thread local state.
1.217 + *
1.218 + * @param runtimeContextArgCount the number of language runtime context arguments in call sites.
1.219 + */
1.220 + public void setRuntimeContextArgCount(int runtimeContextArgCount) {
1.221 + if(runtimeContextArgCount < 0) {
1.222 + throw new IllegalArgumentException("runtimeContextArgCount < 0");
1.223 + }
1.224 + this.runtimeContextArgCount = runtimeContextArgCount;
1.225 + }
1.226 +
1.227 + /**
1.228 + * Sets whether the linker created by this factory will invoke {@link MutableCallSite#syncAll(MutableCallSite[])}
1.229 + * after a call site is relinked. Defaults to false. You probably want to set it to true if your runtime supports
1.230 + * multithreaded execution of dynamically linked code.
1.231 + * @param syncOnRelink true for invoking sync on relink, false otherwise.
1.232 + */
1.233 + public void setSyncOnRelink(boolean syncOnRelink) {
1.234 + this.syncOnRelink = syncOnRelink;
1.235 + }
1.236 +
1.237 + /**
1.238 + * Sets the unstable relink threshold; the number of times a call site is relinked after which it will be
1.239 + * considered unstable, and subsequent link requests for it will indicate this.
1.240 + * @param unstableRelinkThreshold the new threshold. Must not be less than zero. The value of zero means that
1.241 + * call sites will never be considered unstable.
1.242 + * @see LinkRequest#isCallSiteUnstable()
1.243 + */
1.244 + public void setUnstableRelinkThreshold(int unstableRelinkThreshold) {
1.245 + if(unstableRelinkThreshold < 0) {
1.246 + throw new IllegalArgumentException("unstableRelinkThreshold < 0");
1.247 + }
1.248 + this.unstableRelinkThreshold = unstableRelinkThreshold;
1.249 + }
1.250 +
1.251 + /**
1.252 + * Creates a new dynamic linker consisting of all the prioritized, autodiscovered, and fallback linkers.
1.253 + *
1.254 + * @return the new dynamic Linker
1.255 + */
1.256 + public DynamicLinker createLinker() {
1.257 + // Treat nulls appropriately
1.258 + if(prioritizedLinkers == null) {
1.259 + prioritizedLinkers = Collections.emptyList();
1.260 + }
1.261 + if(fallbackLinkers == null) {
1.262 + fallbackLinkers = Collections.singletonList(new BeansLinker());
1.263 + }
1.264 +
1.265 + // Gather classes of all precreated (prioritized and fallback) linkers.
1.266 + // We'll filter out any discovered linkers of the same class.
1.267 + final Set<Class<? extends GuardingDynamicLinker>> knownLinkerClasses =
1.268 + new HashSet<>();
1.269 + addClasses(knownLinkerClasses, prioritizedLinkers);
1.270 + addClasses(knownLinkerClasses, fallbackLinkers);
1.271 +
1.272 + final ClassLoader effectiveClassLoader = classLoaderExplicitlySet ? classLoader : getThreadContextClassLoader();
1.273 + final List<GuardingDynamicLinker> discovered = AutoDiscovery.loadLinkers(effectiveClassLoader);
1.274 + // Now, concatenate ...
1.275 + final List<GuardingDynamicLinker> linkers =
1.276 + new ArrayList<>(prioritizedLinkers.size() + discovered.size()
1.277 + + fallbackLinkers.size());
1.278 + // ... prioritized linkers, ...
1.279 + linkers.addAll(prioritizedLinkers);
1.280 + // ... filtered discovered linkers, ...
1.281 + for(GuardingDynamicLinker linker: discovered) {
1.282 + if(!knownLinkerClasses.contains(linker.getClass())) {
1.283 + linkers.add(linker);
1.284 + }
1.285 + }
1.286 + // ... and finally fallback linkers.
1.287 + linkers.addAll(fallbackLinkers);
1.288 + final List<GuardingDynamicLinker> optimized = CompositeTypeBasedGuardingDynamicLinker.optimize(linkers);
1.289 + final GuardingDynamicLinker composite;
1.290 + switch(linkers.size()) {
1.291 + case 0: {
1.292 + composite = BottomGuardingDynamicLinker.INSTANCE;
1.293 + break;
1.294 + }
1.295 + case 1: {
1.296 + composite = optimized.get(0);
1.297 + break;
1.298 + }
1.299 + default: {
1.300 + composite = new CompositeGuardingDynamicLinker(optimized);
1.301 + break;
1.302 + }
1.303 + }
1.304 +
1.305 + final List<GuardingTypeConverterFactory> typeConverters = new LinkedList<>();
1.306 + for(GuardingDynamicLinker linker: linkers) {
1.307 + if(linker instanceof GuardingTypeConverterFactory) {
1.308 + typeConverters.add((GuardingTypeConverterFactory)linker);
1.309 + }
1.310 + }
1.311 +
1.312 + return new DynamicLinker(new LinkerServicesImpl(new TypeConverterFactory(typeConverters), composite),
1.313 + runtimeContextArgCount, syncOnRelink, unstableRelinkThreshold);
1.314 + }
1.315 +
1.316 + private static ClassLoader getThreadContextClassLoader() {
1.317 + return AccessController.doPrivileged(new PrivilegedAction<ClassLoader>() {
1.318 + @Override
1.319 + public ClassLoader run() {
1.320 + return Thread.currentThread().getContextClassLoader();
1.321 + }
1.322 + }, ClassLoaderGetterContextProvider.GET_CLASS_LOADER_CONTEXT);
1.323 + }
1.324 +
1.325 + private static void addClasses(Set<Class<? extends GuardingDynamicLinker>> knownLinkerClasses,
1.326 + List<? extends GuardingDynamicLinker> linkers) {
1.327 + for(GuardingDynamicLinker linker: linkers) {
1.328 + knownLinkerClasses.add(linker.getClass());
1.329 + }
1.330 + }
1.331 +}
