Mon, 27 Mar 2017 14:14:49 -0700
Added tag jdk8u141-b02 for changeset a67daf8d1982
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 */
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
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.
40 You may not use this file except in compliance with either the Apache
41 License or the BSD License.
43 If you choose to use this file in compliance with the Apache License, the
44 following notice applies to you:
46 You may obtain a copy of the Apache License at
48 http://www.apache.org/licenses/LICENSE-2.0
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.
56 If you choose to use this file in compliance with the BSD License, the
57 following notice applies to you:
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.
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 */
84 package jdk.internal.dynalink;
86 import java.lang.invoke.MutableCallSite;
87 import java.security.AccessController;
88 import java.security.PrivilegedAction;
89 import java.util.ArrayList;
90 import java.util.Arrays;
91 import java.util.Collections;
92 import java.util.HashSet;
93 import java.util.LinkedList;
94 import java.util.List;
95 import java.util.Set;
96 import jdk.internal.dynalink.beans.BeansLinker;
97 import jdk.internal.dynalink.linker.GuardingDynamicLinker;
98 import jdk.internal.dynalink.linker.GuardingTypeConverterFactory;
99 import jdk.internal.dynalink.linker.LinkRequest;
100 import jdk.internal.dynalink.linker.LinkerServices;
101 import jdk.internal.dynalink.linker.MethodHandleTransformer;
102 import jdk.internal.dynalink.linker.MethodTypeConversionStrategy;
103 import jdk.internal.dynalink.support.AutoDiscovery;
104 import jdk.internal.dynalink.support.BottomGuardingDynamicLinker;
105 import jdk.internal.dynalink.support.ClassLoaderGetterContextProvider;
106 import jdk.internal.dynalink.support.CompositeGuardingDynamicLinker;
107 import jdk.internal.dynalink.support.CompositeTypeBasedGuardingDynamicLinker;
108 import jdk.internal.dynalink.support.DefaultPrelinkFilter;
109 import jdk.internal.dynalink.support.LinkerServicesImpl;
110 import jdk.internal.dynalink.support.TypeConverterFactory;
111 import jdk.internal.dynalink.support.TypeUtilities;
113 /**
114 * A factory class for creating {@link DynamicLinker}s. The most usual dynamic linker is a linker that is a composition
115 * of all {@link GuardingDynamicLinker}s known and pre-created by the caller as well as any
116 * {@link AutoDiscovery automatically discovered} guarding linkers and the standard fallback {@link BeansLinker} and a
117 * {@link DefaultPrelinkFilter}. See {@link DynamicLinker} documentation for tips on how to use this class.
118 *
119 * @author Attila Szegedi
120 */
121 public class DynamicLinkerFactory {
122 /**
123 * Default value for {@link #setUnstableRelinkThreshold(int) unstable relink threshold}.
124 */
125 public static final int DEFAULT_UNSTABLE_RELINK_THRESHOLD = 8;
127 private boolean classLoaderExplicitlySet = false;
128 private ClassLoader classLoader;
130 private List<? extends GuardingDynamicLinker> prioritizedLinkers;
131 private List<? extends GuardingDynamicLinker> fallbackLinkers;
132 private int runtimeContextArgCount = 0;
133 private boolean syncOnRelink = false;
134 private int unstableRelinkThreshold = DEFAULT_UNSTABLE_RELINK_THRESHOLD;
135 private GuardedInvocationFilter prelinkFilter;
136 private MethodTypeConversionStrategy autoConversionStrategy;
137 private MethodHandleTransformer internalObjectsFilter;
139 /**
140 * Sets the class loader for automatic discovery of available linkers. If not set explicitly, then the thread
141 * context class loader at the time of {@link #createLinker()} invocation will be used.
142 *
143 * @param classLoader the class loader used for the autodiscovery of available linkers.
144 */
145 public void setClassLoader(final ClassLoader classLoader) {
146 this.classLoader = classLoader;
147 classLoaderExplicitlySet = true;
148 }
150 /**
151 * Sets the prioritized linkers. Language runtimes using this framework will usually precreate at least the linker
152 * for their own language. These linkers will be consulted first in the resulting dynamic linker, before any
153 * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the prioritized
154 * linkers, it will be ignored and the explicit prioritized instance will be used.
155 *
156 * @param prioritizedLinkers the list of prioritized linkers. Null can be passed to indicate no prioritized linkers
157 * (this is also the default value).
158 */
159 public void setPrioritizedLinkers(final List<? extends GuardingDynamicLinker> prioritizedLinkers) {
160 this.prioritizedLinkers =
161 prioritizedLinkers == null ? null : new ArrayList<>(prioritizedLinkers);
162 }
164 /**
165 * Sets the prioritized linkers. Language runtimes using this framework will usually precreate at least the linker
166 * for their own language. These linkers will be consulted first in the resulting dynamic linker, before any
167 * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the prioritized
168 * linkers, it will be ignored and the explicit prioritized instance will be used.
169 *
170 * @param prioritizedLinkers a list of prioritized linkers.
171 */
172 public void setPrioritizedLinkers(final GuardingDynamicLinker... prioritizedLinkers) {
173 setPrioritizedLinkers(Arrays.asList(prioritizedLinkers));
174 }
176 /**
177 * Sets a single prioritized linker. Identical to calling {@link #setPrioritizedLinkers(List)} with a single-element
178 * list.
179 *
180 * @param prioritizedLinker the single prioritized linker. Must not be null.
181 * @throws IllegalArgumentException if null is passed.
182 */
183 public void setPrioritizedLinker(final GuardingDynamicLinker prioritizedLinker) {
184 if(prioritizedLinker == null) {
185 throw new IllegalArgumentException("prioritizedLinker == null");
186 }
187 this.prioritizedLinkers = Collections.singletonList(prioritizedLinker);
188 }
190 /**
191 * Sets the fallback linkers. These linkers will be consulted last in the resulting composite linker, after any
192 * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the fallback
193 * linkers, it will be ignored and the explicit fallback instance will be used.
194 *
195 * @param fallbackLinkers the list of fallback linkers. Can be empty to indicate the caller wishes to set no
196 * fallback linkers.
197 */
198 public void setFallbackLinkers(final List<? extends GuardingDynamicLinker> fallbackLinkers) {
199 this.fallbackLinkers = fallbackLinkers == null ? null : new ArrayList<>(fallbackLinkers);
200 }
202 /**
203 * Sets the fallback linkers. These linkers will be consulted last in the resulting composite linker, after any
204 * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the fallback
205 * linkers, it will be ignored and the explicit fallback instance will be used.
206 *
207 * @param fallbackLinkers the list of fallback linkers. Can be empty to indicate the caller wishes to set no
208 * fallback linkers. If it is left as null, the standard fallback {@link BeansLinker} will be used.
209 */
210 public void setFallbackLinkers(final GuardingDynamicLinker... fallbackLinkers) {
211 setFallbackLinkers(Arrays.asList(fallbackLinkers));
212 }
214 /**
215 * Sets the number of arguments in the call sites that represent the stack context of the language runtime creating
216 * the linker. If the language runtime uses no context information passed on stack, then it should be zero
217 * (the default value). If it is set to nonzero value, then every dynamic call site emitted by this runtime must
218 * have the argument list of the form: {@code (this, contextArg1[, contextArg2[, ...]], normalArgs)}. It is
219 * advisable to only pass one context-specific argument, though, of an easily recognizable, runtime specific type
220 * encapsulating the runtime thread local state.
221 *
222 * @param runtimeContextArgCount the number of language runtime context arguments in call sites.
223 */
224 public void setRuntimeContextArgCount(final int runtimeContextArgCount) {
225 if(runtimeContextArgCount < 0) {
226 throw new IllegalArgumentException("runtimeContextArgCount < 0");
227 }
228 this.runtimeContextArgCount = runtimeContextArgCount;
229 }
231 /**
232 * Sets whether the linker created by this factory will invoke {@link MutableCallSite#syncAll(MutableCallSite[])}
233 * after a call site is relinked. Defaults to false. You probably want to set it to true if your runtime supports
234 * multithreaded execution of dynamically linked code.
235 * @param syncOnRelink true for invoking sync on relink, false otherwise.
236 */
237 public void setSyncOnRelink(final boolean syncOnRelink) {
238 this.syncOnRelink = syncOnRelink;
239 }
241 /**
242 * Sets the unstable relink threshold; the number of times a call site is relinked after which it will be
243 * considered unstable, and subsequent link requests for it will indicate this.
244 * @param unstableRelinkThreshold the new threshold. Must not be less than zero. The value of zero means that
245 * call sites will never be considered unstable.
246 * @see LinkRequest#isCallSiteUnstable()
247 */
248 public void setUnstableRelinkThreshold(final int unstableRelinkThreshold) {
249 if(unstableRelinkThreshold < 0) {
250 throw new IllegalArgumentException("unstableRelinkThreshold < 0");
251 }
252 this.unstableRelinkThreshold = unstableRelinkThreshold;
253 }
255 /**
256 * Set the pre-link filter. This is a {@link GuardedInvocationFilter} that will get the final chance to modify the
257 * guarded invocation after it has been created by a component linker and before the dynamic linker links it into
258 * the call site. It is normally used to adapt the return value type of the invocation to the type of the call site.
259 * When not set explicitly, {@link DefaultPrelinkFilter} will be used.
260 * @param prelinkFilter the pre-link filter for the dynamic linker.
261 */
262 public void setPrelinkFilter(final GuardedInvocationFilter prelinkFilter) {
263 this.prelinkFilter = prelinkFilter;
264 }
266 /**
267 * Sets an object representing the conversion strategy for automatic type conversions. After
268 * {@link TypeConverterFactory#asType(java.lang.invoke.MethodHandle, java.lang.invoke.MethodType)} has
269 * applied all custom conversions to a method handle, it still needs to effect
270 * {@link TypeUtilities#isMethodInvocationConvertible(Class, Class) method invocation conversions} that
271 * can usually be automatically applied as per
272 * {@link java.lang.invoke.MethodHandle#asType(java.lang.invoke.MethodType)}.
273 * However, sometimes language runtimes will want to customize even those conversions for their own call
274 * sites. A typical example is allowing unboxing of null return values, which is by default prohibited by
275 * ordinary {@code MethodHandles.asType}. In this case, a language runtime can install its own custom
276 * automatic conversion strategy, that can deal with null values. Note that when the strategy's
277 * {@link MethodTypeConversionStrategy#asType(java.lang.invoke.MethodHandle, java.lang.invoke.MethodType)}
278 * is invoked, the custom language conversions will already have been applied to the method handle, so by
279 * design the difference between the handle's current method type and the desired final type will always
280 * only be ones that can be subjected to method invocation conversions. The strategy also doesn't need to
281 * invoke a final {@code MethodHandle.asType()} as the converter factory will do that as the final step.
282 * @param autoConversionStrategy the strategy for applying method invocation conversions for the linker
283 * created by this factory.
284 */
285 public void setAutoConversionStrategy(final MethodTypeConversionStrategy autoConversionStrategy) {
286 this.autoConversionStrategy = autoConversionStrategy;
287 }
289 /**
290 * Sets a method handle transformer that is supposed to act as the implementation of this linker factory's linkers'
291 * services {@link LinkerServices#filterInternalObjects(java.lang.invoke.MethodHandle)} method.
292 * @param internalObjectsFilter a method handle transformer filtering out internal objects, or null.
293 */
294 public void setInternalObjectsFilter(final MethodHandleTransformer internalObjectsFilter) {
295 this.internalObjectsFilter = internalObjectsFilter;
296 }
298 /**
299 * Creates a new dynamic linker consisting of all the prioritized, autodiscovered, and fallback linkers as well as
300 * the pre-link filter.
301 *
302 * @return the new dynamic Linker
303 */
304 public DynamicLinker createLinker() {
305 // Treat nulls appropriately
306 if(prioritizedLinkers == null) {
307 prioritizedLinkers = Collections.emptyList();
308 }
309 if(fallbackLinkers == null) {
310 fallbackLinkers = Collections.singletonList(new BeansLinker());
311 }
313 // Gather classes of all precreated (prioritized and fallback) linkers.
314 // We'll filter out any discovered linkers of the same class.
315 final Set<Class<? extends GuardingDynamicLinker>> knownLinkerClasses =
316 new HashSet<>();
317 addClasses(knownLinkerClasses, prioritizedLinkers);
318 addClasses(knownLinkerClasses, fallbackLinkers);
320 final ClassLoader effectiveClassLoader = classLoaderExplicitlySet ? classLoader : getThreadContextClassLoader();
321 final List<GuardingDynamicLinker> discovered = AutoDiscovery.loadLinkers(effectiveClassLoader);
322 // Now, concatenate ...
323 final List<GuardingDynamicLinker> linkers =
324 new ArrayList<>(prioritizedLinkers.size() + discovered.size()
325 + fallbackLinkers.size());
326 // ... prioritized linkers, ...
327 linkers.addAll(prioritizedLinkers);
328 // ... filtered discovered linkers, ...
329 for(final GuardingDynamicLinker linker: discovered) {
330 if(!knownLinkerClasses.contains(linker.getClass())) {
331 linkers.add(linker);
332 }
333 }
334 // ... and finally fallback linkers.
335 linkers.addAll(fallbackLinkers);
336 final List<GuardingDynamicLinker> optimized = CompositeTypeBasedGuardingDynamicLinker.optimize(linkers);
337 final GuardingDynamicLinker composite;
338 switch(linkers.size()) {
339 case 0: {
340 composite = BottomGuardingDynamicLinker.INSTANCE;
341 break;
342 }
343 case 1: {
344 composite = optimized.get(0);
345 break;
346 }
347 default: {
348 composite = new CompositeGuardingDynamicLinker(optimized);
349 break;
350 }
351 }
353 final List<GuardingTypeConverterFactory> typeConverters = new LinkedList<>();
354 for(final GuardingDynamicLinker linker: linkers) {
355 if(linker instanceof GuardingTypeConverterFactory) {
356 typeConverters.add((GuardingTypeConverterFactory)linker);
357 }
358 }
360 if(prelinkFilter == null) {
361 prelinkFilter = new DefaultPrelinkFilter();
362 }
364 return new DynamicLinker(new LinkerServicesImpl(new TypeConverterFactory(typeConverters,
365 autoConversionStrategy), composite, internalObjectsFilter), prelinkFilter, runtimeContextArgCount,
366 syncOnRelink, unstableRelinkThreshold);
367 }
369 private static ClassLoader getThreadContextClassLoader() {
370 return AccessController.doPrivileged(new PrivilegedAction<ClassLoader>() {
371 @Override
372 public ClassLoader run() {
373 return Thread.currentThread().getContextClassLoader();
374 }
375 }, ClassLoaderGetterContextProvider.GET_CLASS_LOADER_CONTEXT);
376 }
378 private static void addClasses(final Set<Class<? extends GuardingDynamicLinker>> knownLinkerClasses,
379 final List<? extends GuardingDynamicLinker> linkers) {
380 for(final GuardingDynamicLinker linker: linkers) {
381 knownLinkerClasses.add(linker.getClass());
382 }
383 }
384 }