src/jdk/internal/dynalink/DynamicLinkerFactory.java

Mon, 03 Nov 2014 09:49:52 +0100

author
attila
date
Mon, 03 Nov 2014 09:49:52 +0100
changeset 1090
99571b7922c0
parent 963
e2497b11a021
child 1205
4112748288bb
child 1239
e1146c9cc758
permissions
-rw-r--r--

8059443: NPE when unboxing return values
Reviewed-by: lagergren, sundar

attila@90 1 /*
attila@90 2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
attila@90 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
attila@90 4 *
attila@90 5 * This code is free software; you can redistribute it and/or modify it
attila@90 6 * under the terms of the GNU General Public License version 2 only, as
attila@90 7 * published by the Free Software Foundation. Oracle designates this
attila@90 8 * particular file as subject to the "Classpath" exception as provided
attila@90 9 * by Oracle in the LICENSE file that accompanied this code.
attila@90 10 *
attila@90 11 * This code is distributed in the hope that it will be useful, but WITHOUT
attila@90 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
attila@90 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
attila@90 14 * version 2 for more details (a copy is included in the LICENSE file that
attila@90 15 * accompanied this code).
attila@90 16 *
attila@90 17 * You should have received a copy of the GNU General Public License version
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attila@90 20 *
attila@90 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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attila@90 23 * questions.
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attila@90 25
attila@90 26 /*
attila@90 27 * This file is available under and governed by the GNU General Public
attila@90 28 * License version 2 only, as published by the Free Software Foundation.
attila@90 29 * However, the following notice accompanied the original version of this
attila@90 30 * file, and Oracle licenses the original version of this file under the BSD
attila@90 31 * license:
attila@90 32 */
attila@90 33 /*
attila@90 34 Copyright 2009-2013 Attila Szegedi
attila@90 35
attila@90 36 Licensed under both the Apache License, Version 2.0 (the "Apache License")
attila@90 37 and the BSD License (the "BSD License"), with licensee being free to
attila@90 38 choose either of the two at their discretion.
attila@90 39
attila@90 40 You may not use this file except in compliance with either the Apache
attila@90 41 License or the BSD License.
attila@90 42
attila@90 43 If you choose to use this file in compliance with the Apache License, the
attila@90 44 following notice applies to you:
attila@90 45
attila@90 46 You may obtain a copy of the Apache License at
attila@90 47
attila@90 48 http://www.apache.org/licenses/LICENSE-2.0
attila@90 49
attila@90 50 Unless required by applicable law or agreed to in writing, software
attila@90 51 distributed under the License is distributed on an "AS IS" BASIS,
attila@90 52 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
attila@90 53 implied. See the License for the specific language governing
attila@90 54 permissions and limitations under the License.
attila@90 55
attila@90 56 If you choose to use this file in compliance with the BSD License, the
attila@90 57 following notice applies to you:
attila@90 58
attila@90 59 Redistribution and use in source and binary forms, with or without
attila@90 60 modification, are permitted provided that the following conditions are
attila@90 61 met:
attila@90 62 * Redistributions of source code must retain the above copyright
attila@90 63 notice, this list of conditions and the following disclaimer.
attila@90 64 * Redistributions in binary form must reproduce the above copyright
attila@90 65 notice, this list of conditions and the following disclaimer in the
attila@90 66 documentation and/or other materials provided with the distribution.
attila@90 67 * Neither the name of the copyright holder nor the names of
attila@90 68 contributors may be used to endorse or promote products derived from
attila@90 69 this software without specific prior written permission.
attila@90 70
attila@90 71 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
attila@90 72 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
attila@90 73 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
attila@90 74 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
attila@90 75 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
attila@90 76 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
attila@90 77 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
attila@90 78 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
attila@90 79 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
attila@90 80 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
attila@90 81 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
attila@90 82 */
attila@90 83
attila@90 84 package jdk.internal.dynalink;
attila@90 85
attila@90 86 import java.lang.invoke.MutableCallSite;
attila@488 87 import java.security.AccessController;
attila@488 88 import java.security.PrivilegedAction;
attila@90 89 import java.util.ArrayList;
attila@90 90 import java.util.Arrays;
attila@90 91 import java.util.Collections;
attila@90 92 import java.util.HashSet;
attila@90 93 import java.util.LinkedList;
attila@90 94 import java.util.List;
attila@90 95 import java.util.Set;
attila@90 96 import jdk.internal.dynalink.beans.BeansLinker;
attila@90 97 import jdk.internal.dynalink.linker.GuardingDynamicLinker;
attila@90 98 import jdk.internal.dynalink.linker.GuardingTypeConverterFactory;
attila@90 99 import jdk.internal.dynalink.linker.LinkRequest;
attila@1090 100 import jdk.internal.dynalink.linker.MethodTypeConversionStrategy;
attila@90 101 import jdk.internal.dynalink.support.AutoDiscovery;
attila@90 102 import jdk.internal.dynalink.support.BottomGuardingDynamicLinker;
attila@494 103 import jdk.internal.dynalink.support.ClassLoaderGetterContextProvider;
attila@90 104 import jdk.internal.dynalink.support.CompositeGuardingDynamicLinker;
attila@90 105 import jdk.internal.dynalink.support.CompositeTypeBasedGuardingDynamicLinker;
attila@963 106 import jdk.internal.dynalink.support.DefaultPrelinkFilter;
attila@90 107 import jdk.internal.dynalink.support.LinkerServicesImpl;
attila@90 108 import jdk.internal.dynalink.support.TypeConverterFactory;
attila@1090 109 import jdk.internal.dynalink.support.TypeUtilities;
attila@90 110
attila@90 111 /**
attila@90 112 * A factory class for creating {@link DynamicLinker}s. The most usual dynamic linker is a linker that is a composition
attila@90 113 * of all {@link GuardingDynamicLinker}s known and pre-created by the caller as well as any
attila@963 114 * {@link AutoDiscovery automatically discovered} guarding linkers and the standard fallback {@link BeansLinker} and a
attila@963 115 * {@link DefaultPrelinkFilter}. See {@link DynamicLinker} documentation for tips on how to use this class.
attila@90 116 *
attila@90 117 * @author Attila Szegedi
attila@90 118 */
attila@90 119 public class DynamicLinkerFactory {
attila@90 120 /**
attila@90 121 * Default value for {@link #setUnstableRelinkThreshold(int) unstable relink threshold}.
attila@90 122 */
attila@90 123 public static final int DEFAULT_UNSTABLE_RELINK_THRESHOLD = 8;
attila@90 124
attila@488 125 private boolean classLoaderExplicitlySet = false;
attila@488 126 private ClassLoader classLoader;
attila@488 127
attila@90 128 private List<? extends GuardingDynamicLinker> prioritizedLinkers;
attila@90 129 private List<? extends GuardingDynamicLinker> fallbackLinkers;
attila@90 130 private int runtimeContextArgCount = 0;
attila@90 131 private boolean syncOnRelink = false;
attila@90 132 private int unstableRelinkThreshold = DEFAULT_UNSTABLE_RELINK_THRESHOLD;
attila@963 133 private GuardedInvocationFilter prelinkFilter;
attila@1090 134 private MethodTypeConversionStrategy autoConversionStrategy;
attila@90 135
attila@90 136 /**
attila@90 137 * Sets the class loader for automatic discovery of available linkers. If not set explicitly, then the thread
attila@488 138 * context class loader at the time of {@link #createLinker()} invocation will be used.
attila@90 139 *
attila@90 140 * @param classLoader the class loader used for the autodiscovery of available linkers.
attila@90 141 */
attila@962 142 public void setClassLoader(final ClassLoader classLoader) {
attila@90 143 this.classLoader = classLoader;
attila@488 144 classLoaderExplicitlySet = true;
attila@90 145 }
attila@90 146
attila@90 147 /**
attila@90 148 * Sets the prioritized linkers. Language runtimes using this framework will usually precreate at least the linker
attila@90 149 * for their own language. These linkers will be consulted first in the resulting dynamic linker, before any
attila@90 150 * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the prioritized
attila@90 151 * linkers, it will be ignored and the explicit prioritized instance will be used.
attila@90 152 *
attila@90 153 * @param prioritizedLinkers the list of prioritized linkers. Null can be passed to indicate no prioritized linkers
attila@90 154 * (this is also the default value).
attila@90 155 */
attila@962 156 public void setPrioritizedLinkers(final List<? extends GuardingDynamicLinker> prioritizedLinkers) {
attila@90 157 this.prioritizedLinkers =
attila@90 158 prioritizedLinkers == null ? null : new ArrayList<>(prioritizedLinkers);
attila@90 159 }
attila@90 160
attila@90 161 /**
attila@90 162 * Sets the prioritized linkers. Language runtimes using this framework will usually precreate at least the linker
attila@90 163 * for their own language. These linkers will be consulted first in the resulting dynamic linker, before any
attila@90 164 * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the prioritized
attila@90 165 * linkers, it will be ignored and the explicit prioritized instance will be used.
attila@90 166 *
attila@90 167 * @param prioritizedLinkers a list of prioritized linkers.
attila@90 168 */
attila@962 169 public void setPrioritizedLinkers(final GuardingDynamicLinker... prioritizedLinkers) {
attila@90 170 setPrioritizedLinkers(Arrays.asList(prioritizedLinkers));
attila@90 171 }
attila@90 172
attila@90 173 /**
attila@90 174 * Sets a single prioritized linker. Identical to calling {@link #setPrioritizedLinkers(List)} with a single-element
attila@90 175 * list.
attila@90 176 *
attila@90 177 * @param prioritizedLinker the single prioritized linker. Must not be null.
attila@90 178 * @throws IllegalArgumentException if null is passed.
attila@90 179 */
attila@962 180 public void setPrioritizedLinker(final GuardingDynamicLinker prioritizedLinker) {
attila@90 181 if(prioritizedLinker == null) {
attila@90 182 throw new IllegalArgumentException("prioritizedLinker == null");
attila@90 183 }
attila@90 184 this.prioritizedLinkers = Collections.singletonList(prioritizedLinker);
attila@90 185 }
attila@90 186
attila@90 187 /**
attila@90 188 * Sets the fallback linkers. These linkers will be consulted last in the resulting composite linker, after any
attila@90 189 * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the fallback
attila@90 190 * linkers, it will be ignored and the explicit fallback instance will be used.
attila@90 191 *
attila@90 192 * @param fallbackLinkers the list of fallback linkers. Can be empty to indicate the caller wishes to set no
attila@90 193 * fallback linkers.
attila@90 194 */
attila@962 195 public void setFallbackLinkers(final List<? extends GuardingDynamicLinker> fallbackLinkers) {
attila@90 196 this.fallbackLinkers = fallbackLinkers == null ? null : new ArrayList<>(fallbackLinkers);
attila@90 197 }
attila@90 198
attila@90 199 /**
attila@90 200 * Sets the fallback linkers. These linkers will be consulted last in the resulting composite linker, after any
attila@90 201 * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the fallback
attila@90 202 * linkers, it will be ignored and the explicit fallback instance will be used.
attila@90 203 *
attila@90 204 * @param fallbackLinkers the list of fallback linkers. Can be empty to indicate the caller wishes to set no
attila@90 205 * fallback linkers. If it is left as null, the standard fallback {@link BeansLinker} will be used.
attila@90 206 */
attila@962 207 public void setFallbackLinkers(final GuardingDynamicLinker... fallbackLinkers) {
attila@90 208 setFallbackLinkers(Arrays.asList(fallbackLinkers));
attila@90 209 }
attila@90 210
attila@90 211 /**
attila@90 212 * Sets the number of arguments in the call sites that represent the stack context of the language runtime creating
attila@90 213 * the linker. If the language runtime uses no context information passed on stack, then it should be zero
attila@90 214 * (the default value). If it is set to nonzero value, then every dynamic call site emitted by this runtime must
attila@90 215 * have the argument list of the form: {@code (this, contextArg1[, contextArg2[, ...]], normalArgs)}. It is
attila@90 216 * advisable to only pass one context-specific argument, though, of an easily recognizable, runtime specific type
attila@90 217 * encapsulating the runtime thread local state.
attila@90 218 *
attila@90 219 * @param runtimeContextArgCount the number of language runtime context arguments in call sites.
attila@90 220 */
attila@962 221 public void setRuntimeContextArgCount(final int runtimeContextArgCount) {
attila@90 222 if(runtimeContextArgCount < 0) {
attila@90 223 throw new IllegalArgumentException("runtimeContextArgCount < 0");
attila@90 224 }
attila@90 225 this.runtimeContextArgCount = runtimeContextArgCount;
attila@90 226 }
attila@90 227
attila@90 228 /**
attila@90 229 * Sets whether the linker created by this factory will invoke {@link MutableCallSite#syncAll(MutableCallSite[])}
attila@90 230 * after a call site is relinked. Defaults to false. You probably want to set it to true if your runtime supports
attila@90 231 * multithreaded execution of dynamically linked code.
attila@90 232 * @param syncOnRelink true for invoking sync on relink, false otherwise.
attila@90 233 */
attila@962 234 public void setSyncOnRelink(final boolean syncOnRelink) {
attila@90 235 this.syncOnRelink = syncOnRelink;
attila@90 236 }
attila@90 237
attila@90 238 /**
attila@90 239 * Sets the unstable relink threshold; the number of times a call site is relinked after which it will be
attila@90 240 * considered unstable, and subsequent link requests for it will indicate this.
attila@90 241 * @param unstableRelinkThreshold the new threshold. Must not be less than zero. The value of zero means that
attila@90 242 * call sites will never be considered unstable.
attila@90 243 * @see LinkRequest#isCallSiteUnstable()
attila@90 244 */
attila@962 245 public void setUnstableRelinkThreshold(final int unstableRelinkThreshold) {
attila@90 246 if(unstableRelinkThreshold < 0) {
attila@90 247 throw new IllegalArgumentException("unstableRelinkThreshold < 0");
attila@90 248 }
attila@90 249 this.unstableRelinkThreshold = unstableRelinkThreshold;
attila@90 250 }
attila@90 251
attila@90 252 /**
attila@963 253 * Set the pre-link filter. This is a {@link GuardedInvocationFilter} that will get the final chance to modify the
attila@963 254 * guarded invocation after it has been created by a component linker and before the dynamic linker links it into
attila@963 255 * the call site. It is normally used to adapt the return value type of the invocation to the type of the call site.
attila@963 256 * When not set explicitly, {@link DefaultPrelinkFilter} will be used.
attila@963 257 * @param prelinkFilter the pre-link filter for the dynamic linker.
attila@963 258 */
attila@963 259 public void setPrelinkFilter(final GuardedInvocationFilter prelinkFilter) {
attila@963 260 this.prelinkFilter = prelinkFilter;
attila@963 261 }
attila@963 262
attila@963 263 /**
attila@1090 264 * Sets an object representing the conversion strategy for automatic type conversions. After
attila@1090 265 * {@link TypeConverterFactory#asType(java.lang.invoke.MethodHandle, java.lang.invoke.MethodType)} has
attila@1090 266 * applied all custom conversions to a method handle, it still needs to effect
attila@1090 267 * {@link TypeUtilities#isMethodInvocationConvertible(Class, Class) method invocation conversions} that
attila@1090 268 * can usually be automatically applied as per
attila@1090 269 * {@link java.lang.invoke.MethodHandle#asType(java.lang.invoke.MethodType)}.
attila@1090 270 * However, sometimes language runtimes will want to customize even those conversions for their own call
attila@1090 271 * sites. A typical example is allowing unboxing of null return values, which is by default prohibited by
attila@1090 272 * ordinary {@code MethodHandles.asType}. In this case, a language runtime can install its own custom
attila@1090 273 * automatic conversion strategy, that can deal with null values. Note that when the strategy's
attila@1090 274 * {@link MethodTypeConversionStrategy#asType(java.lang.invoke.MethodHandle, java.lang.invoke.MethodType)}
attila@1090 275 * is invoked, the custom language conversions will already have been applied to the method handle, so by
attila@1090 276 * design the difference between the handle's current method type and the desired final type will always
attila@1090 277 * only be ones that can be subjected to method invocation conversions. The strategy also doesn't need to
attila@1090 278 * invoke a final {@code MethodHandle.asType()} as the converter factory will do that as the final step.
attila@1090 279 * @param autoConversionStrategy the strategy for applying method invocation conversions for the linker
attila@1090 280 * created by this factory.
attila@1090 281 */
attila@1090 282 public void setAutoConversionStrategy(final MethodTypeConversionStrategy autoConversionStrategy) {
attila@1090 283 this.autoConversionStrategy = autoConversionStrategy;
attila@1090 284 }
attila@1090 285
attila@1090 286 /**
attila@963 287 * Creates a new dynamic linker consisting of all the prioritized, autodiscovered, and fallback linkers as well as
attila@963 288 * the pre-link filter.
attila@90 289 *
attila@90 290 * @return the new dynamic Linker
attila@90 291 */
attila@90 292 public DynamicLinker createLinker() {
attila@90 293 // Treat nulls appropriately
attila@90 294 if(prioritizedLinkers == null) {
attila@90 295 prioritizedLinkers = Collections.emptyList();
attila@90 296 }
attila@90 297 if(fallbackLinkers == null) {
attila@90 298 fallbackLinkers = Collections.singletonList(new BeansLinker());
attila@90 299 }
attila@90 300
attila@90 301 // Gather classes of all precreated (prioritized and fallback) linkers.
attila@90 302 // We'll filter out any discovered linkers of the same class.
attila@101 303 final Set<Class<? extends GuardingDynamicLinker>> knownLinkerClasses =
attila@101 304 new HashSet<>();
attila@90 305 addClasses(knownLinkerClasses, prioritizedLinkers);
attila@90 306 addClasses(knownLinkerClasses, fallbackLinkers);
attila@90 307
attila@488 308 final ClassLoader effectiveClassLoader = classLoaderExplicitlySet ? classLoader : getThreadContextClassLoader();
attila@488 309 final List<GuardingDynamicLinker> discovered = AutoDiscovery.loadLinkers(effectiveClassLoader);
attila@90 310 // Now, concatenate ...
attila@101 311 final List<GuardingDynamicLinker> linkers =
attila@101 312 new ArrayList<>(prioritizedLinkers.size() + discovered.size()
attila@101 313 + fallbackLinkers.size());
attila@90 314 // ... prioritized linkers, ...
attila@90 315 linkers.addAll(prioritizedLinkers);
attila@90 316 // ... filtered discovered linkers, ...
attila@962 317 for(final GuardingDynamicLinker linker: discovered) {
attila@90 318 if(!knownLinkerClasses.contains(linker.getClass())) {
attila@90 319 linkers.add(linker);
attila@90 320 }
attila@90 321 }
attila@90 322 // ... and finally fallback linkers.
attila@90 323 linkers.addAll(fallbackLinkers);
attila@90 324 final List<GuardingDynamicLinker> optimized = CompositeTypeBasedGuardingDynamicLinker.optimize(linkers);
attila@90 325 final GuardingDynamicLinker composite;
attila@90 326 switch(linkers.size()) {
attila@90 327 case 0: {
attila@90 328 composite = BottomGuardingDynamicLinker.INSTANCE;
attila@90 329 break;
attila@90 330 }
attila@90 331 case 1: {
attila@90 332 composite = optimized.get(0);
attila@90 333 break;
attila@90 334 }
attila@90 335 default: {
attila@90 336 composite = new CompositeGuardingDynamicLinker(optimized);
attila@90 337 break;
attila@90 338 }
attila@90 339 }
attila@90 340
attila@90 341 final List<GuardingTypeConverterFactory> typeConverters = new LinkedList<>();
attila@962 342 for(final GuardingDynamicLinker linker: linkers) {
attila@90 343 if(linker instanceof GuardingTypeConverterFactory) {
attila@90 344 typeConverters.add((GuardingTypeConverterFactory)linker);
attila@90 345 }
attila@90 346 }
attila@90 347
attila@963 348 if(prelinkFilter == null) {
attila@963 349 prelinkFilter = new DefaultPrelinkFilter();
attila@963 350 }
attila@963 351
attila@1090 352 return new DynamicLinker(new LinkerServicesImpl(new TypeConverterFactory(typeConverters,
attila@1090 353 autoConversionStrategy), composite), prelinkFilter, runtimeContextArgCount, syncOnRelink,
attila@1090 354 unstableRelinkThreshold);
attila@90 355 }
attila@90 356
attila@488 357 private static ClassLoader getThreadContextClassLoader() {
attila@488 358 return AccessController.doPrivileged(new PrivilegedAction<ClassLoader>() {
attila@488 359 @Override
attila@488 360 public ClassLoader run() {
attila@488 361 return Thread.currentThread().getContextClassLoader();
attila@488 362 }
attila@494 363 }, ClassLoaderGetterContextProvider.GET_CLASS_LOADER_CONTEXT);
attila@488 364 }
attila@488 365
attila@962 366 private static void addClasses(final Set<Class<? extends GuardingDynamicLinker>> knownLinkerClasses,
attila@962 367 final List<? extends GuardingDynamicLinker> linkers) {
attila@962 368 for(final GuardingDynamicLinker linker: linkers) {
attila@90 369 knownLinkerClasses.add(linker.getClass());
attila@90 370 }
attila@90 371 }
attila@101 372 }

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