| /* |
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| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
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| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
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| |
| /* |
| * This file is available under and governed by the GNU General Public |
| * License version 2 only, as published by the Free Software Foundation. |
| * However, the following notice accompanied the original version of this |
| * file, and Oracle licenses the original version of this file under the BSD |
| * license: |
| */ |
| /* |
| Copyright 2009-2013 Attila Szegedi |
| |
| Licensed under both the Apache License, Version 2.0 (the "Apache License") |
| and the BSD License (the "BSD License"), with licensee being free to |
| choose either of the two at their discretion. |
| |
| You may not use this file except in compliance with either the Apache |
| License or the BSD License. |
| |
| If you choose to use this file in compliance with the Apache License, the |
| following notice applies to you: |
| |
| You may obtain a copy of the Apache License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or |
| implied. See the License for the specific language governing |
| permissions and limitations under the License. |
| |
| If you choose to use this file in compliance with the BSD License, the |
| following notice applies to you: |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions are |
| met: |
| * Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| * Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| * Neither the name of the copyright holder nor the names of |
| contributors may be used to endorse or promote products derived from |
| this software without specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS |
| IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
| TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A |
| PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER |
| BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR |
| BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| package jdk.internal.dynalink; |
| |
| import java.lang.invoke.MutableCallSite; |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.Set; |
| import jdk.internal.dynalink.beans.BeansLinker; |
| import jdk.internal.dynalink.linker.GuardingDynamicLinker; |
| import jdk.internal.dynalink.linker.GuardingTypeConverterFactory; |
| import jdk.internal.dynalink.linker.LinkRequest; |
| import jdk.internal.dynalink.linker.LinkerServices; |
| import jdk.internal.dynalink.linker.MethodHandleTransformer; |
| import jdk.internal.dynalink.linker.MethodTypeConversionStrategy; |
| import jdk.internal.dynalink.support.AutoDiscovery; |
| import jdk.internal.dynalink.support.BottomGuardingDynamicLinker; |
| import jdk.internal.dynalink.support.ClassLoaderGetterContextProvider; |
| import jdk.internal.dynalink.support.CompositeGuardingDynamicLinker; |
| import jdk.internal.dynalink.support.CompositeTypeBasedGuardingDynamicLinker; |
| import jdk.internal.dynalink.support.DefaultPrelinkFilter; |
| import jdk.internal.dynalink.support.LinkerServicesImpl; |
| import jdk.internal.dynalink.support.TypeConverterFactory; |
| import jdk.internal.dynalink.support.TypeUtilities; |
| |
| /** |
| * A factory class for creating {@link DynamicLinker}s. The most usual dynamic linker is a linker that is a composition |
| * of all {@link GuardingDynamicLinker}s known and pre-created by the caller as well as any |
| * {@link AutoDiscovery automatically discovered} guarding linkers and the standard fallback {@link BeansLinker} and a |
| * {@link DefaultPrelinkFilter}. See {@link DynamicLinker} documentation for tips on how to use this class. |
| * |
| * @author Attila Szegedi |
| */ |
| public class DynamicLinkerFactory { |
| /** |
| * Default value for {@link #setUnstableRelinkThreshold(int) unstable relink threshold}. |
| */ |
| public static final int DEFAULT_UNSTABLE_RELINK_THRESHOLD = 8; |
| |
| private boolean classLoaderExplicitlySet = false; |
| private ClassLoader classLoader; |
| |
| private List<? extends GuardingDynamicLinker> prioritizedLinkers; |
| private List<? extends GuardingDynamicLinker> fallbackLinkers; |
| private int runtimeContextArgCount = 0; |
| private boolean syncOnRelink = false; |
| private int unstableRelinkThreshold = DEFAULT_UNSTABLE_RELINK_THRESHOLD; |
| private GuardedInvocationFilter prelinkFilter; |
| private MethodTypeConversionStrategy autoConversionStrategy; |
| private MethodHandleTransformer internalObjectsFilter; |
| |
| /** |
| * Sets the class loader for automatic discovery of available linkers. If not set explicitly, then the thread |
| * context class loader at the time of {@link #createLinker()} invocation will be used. |
| * |
| * @param classLoader the class loader used for the autodiscovery of available linkers. |
| */ |
| public void setClassLoader(final ClassLoader classLoader) { |
| this.classLoader = classLoader; |
| classLoaderExplicitlySet = true; |
| } |
| |
| /** |
| * Sets the prioritized linkers. Language runtimes using this framework will usually precreate at least the linker |
| * for their own language. These linkers will be consulted first in the resulting dynamic linker, before any |
| * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the prioritized |
| * linkers, it will be ignored and the explicit prioritized instance will be used. |
| * |
| * @param prioritizedLinkers the list of prioritized linkers. Null can be passed to indicate no prioritized linkers |
| * (this is also the default value). |
| */ |
| public void setPrioritizedLinkers(final List<? extends GuardingDynamicLinker> prioritizedLinkers) { |
| this.prioritizedLinkers = |
| prioritizedLinkers == null ? null : new ArrayList<>(prioritizedLinkers); |
| } |
| |
| /** |
| * Sets the prioritized linkers. Language runtimes using this framework will usually precreate at least the linker |
| * for their own language. These linkers will be consulted first in the resulting dynamic linker, before any |
| * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the prioritized |
| * linkers, it will be ignored and the explicit prioritized instance will be used. |
| * |
| * @param prioritizedLinkers a list of prioritized linkers. |
| */ |
| public void setPrioritizedLinkers(final GuardingDynamicLinker... prioritizedLinkers) { |
| setPrioritizedLinkers(Arrays.asList(prioritizedLinkers)); |
| } |
| |
| /** |
| * Sets a single prioritized linker. Identical to calling {@link #setPrioritizedLinkers(List)} with a single-element |
| * list. |
| * |
| * @param prioritizedLinker the single prioritized linker. Must not be null. |
| * @throws IllegalArgumentException if null is passed. |
| */ |
| public void setPrioritizedLinker(final GuardingDynamicLinker prioritizedLinker) { |
| if(prioritizedLinker == null) { |
| throw new IllegalArgumentException("prioritizedLinker == null"); |
| } |
| this.prioritizedLinkers = Collections.singletonList(prioritizedLinker); |
| } |
| |
| /** |
| * Sets the fallback linkers. These linkers will be consulted last in the resulting composite linker, after any |
| * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the fallback |
| * linkers, it will be ignored and the explicit fallback instance will be used. |
| * |
| * @param fallbackLinkers the list of fallback linkers. Can be empty to indicate the caller wishes to set no |
| * fallback linkers. |
| */ |
| public void setFallbackLinkers(final List<? extends GuardingDynamicLinker> fallbackLinkers) { |
| this.fallbackLinkers = fallbackLinkers == null ? null : new ArrayList<>(fallbackLinkers); |
| } |
| |
| /** |
| * Sets the fallback linkers. These linkers will be consulted last in the resulting composite linker, after any |
| * autodiscovered linkers. If the framework also autodiscovers a linker of the same class as one of the fallback |
| * linkers, it will be ignored and the explicit fallback instance will be used. |
| * |
| * @param fallbackLinkers the list of fallback linkers. Can be empty to indicate the caller wishes to set no |
| * fallback linkers. If it is left as null, the standard fallback {@link BeansLinker} will be used. |
| */ |
| public void setFallbackLinkers(final GuardingDynamicLinker... fallbackLinkers) { |
| setFallbackLinkers(Arrays.asList(fallbackLinkers)); |
| } |
| |
| /** |
| * Sets the number of arguments in the call sites that represent the stack context of the language runtime creating |
| * the linker. If the language runtime uses no context information passed on stack, then it should be zero |
| * (the default value). If it is set to nonzero value, then every dynamic call site emitted by this runtime must |
| * have the argument list of the form: {@code (this, contextArg1[, contextArg2[, ...]], normalArgs)}. It is |
| * advisable to only pass one context-specific argument, though, of an easily recognizable, runtime specific type |
| * encapsulating the runtime thread local state. |
| * |
| * @param runtimeContextArgCount the number of language runtime context arguments in call sites. |
| */ |
| public void setRuntimeContextArgCount(final int runtimeContextArgCount) { |
| if(runtimeContextArgCount < 0) { |
| throw new IllegalArgumentException("runtimeContextArgCount < 0"); |
| } |
| this.runtimeContextArgCount = runtimeContextArgCount; |
| } |
| |
| /** |
| * Sets whether the linker created by this factory will invoke {@link MutableCallSite#syncAll(MutableCallSite[])} |
| * after a call site is relinked. Defaults to false. You probably want to set it to true if your runtime supports |
| * multithreaded execution of dynamically linked code. |
| * @param syncOnRelink true for invoking sync on relink, false otherwise. |
| */ |
| public void setSyncOnRelink(final boolean syncOnRelink) { |
| this.syncOnRelink = syncOnRelink; |
| } |
| |
| /** |
| * Sets the unstable relink threshold; the number of times a call site is relinked after which it will be |
| * considered unstable, and subsequent link requests for it will indicate this. |
| * @param unstableRelinkThreshold the new threshold. Must not be less than zero. The value of zero means that |
| * call sites will never be considered unstable. |
| * @see LinkRequest#isCallSiteUnstable() |
| */ |
| public void setUnstableRelinkThreshold(final int unstableRelinkThreshold) { |
| if(unstableRelinkThreshold < 0) { |
| throw new IllegalArgumentException("unstableRelinkThreshold < 0"); |
| } |
| this.unstableRelinkThreshold = unstableRelinkThreshold; |
| } |
| |
| /** |
| * Set the pre-link filter. This is a {@link GuardedInvocationFilter} that will get the final chance to modify the |
| * guarded invocation after it has been created by a component linker and before the dynamic linker links it into |
| * the call site. It is normally used to adapt the return value type of the invocation to the type of the call site. |
| * When not set explicitly, {@link DefaultPrelinkFilter} will be used. |
| * @param prelinkFilter the pre-link filter for the dynamic linker. |
| */ |
| public void setPrelinkFilter(final GuardedInvocationFilter prelinkFilter) { |
| this.prelinkFilter = prelinkFilter; |
| } |
| |
| /** |
| * Sets an object representing the conversion strategy for automatic type conversions. After |
| * {@link TypeConverterFactory#asType(java.lang.invoke.MethodHandle, java.lang.invoke.MethodType)} has |
| * applied all custom conversions to a method handle, it still needs to effect |
| * {@link TypeUtilities#isMethodInvocationConvertible(Class, Class) method invocation conversions} that |
| * can usually be automatically applied as per |
| * {@link java.lang.invoke.MethodHandle#asType(java.lang.invoke.MethodType)}. |
| * However, sometimes language runtimes will want to customize even those conversions for their own call |
| * sites. A typical example is allowing unboxing of null return values, which is by default prohibited by |
| * ordinary {@code MethodHandles.asType}. In this case, a language runtime can install its own custom |
| * automatic conversion strategy, that can deal with null values. Note that when the strategy's |
| * {@link MethodTypeConversionStrategy#asType(java.lang.invoke.MethodHandle, java.lang.invoke.MethodType)} |
| * is invoked, the custom language conversions will already have been applied to the method handle, so by |
| * design the difference between the handle's current method type and the desired final type will always |
| * only be ones that can be subjected to method invocation conversions. The strategy also doesn't need to |
| * invoke a final {@code MethodHandle.asType()} as the converter factory will do that as the final step. |
| * @param autoConversionStrategy the strategy for applying method invocation conversions for the linker |
| * created by this factory. |
| */ |
| public void setAutoConversionStrategy(final MethodTypeConversionStrategy autoConversionStrategy) { |
| this.autoConversionStrategy = autoConversionStrategy; |
| } |
| |
| /** |
| * Sets a method handle transformer that is supposed to act as the implementation of this linker factory's linkers' |
| * services {@link LinkerServices#filterInternalObjects(java.lang.invoke.MethodHandle)} method. |
| * @param internalObjectsFilter a method handle transformer filtering out internal objects, or null. |
| */ |
| public void setInternalObjectsFilter(final MethodHandleTransformer internalObjectsFilter) { |
| this.internalObjectsFilter = internalObjectsFilter; |
| } |
| |
| /** |
| * Creates a new dynamic linker consisting of all the prioritized, autodiscovered, and fallback linkers as well as |
| * the pre-link filter. |
| * |
| * @return the new dynamic Linker |
| */ |
| public DynamicLinker createLinker() { |
| // Treat nulls appropriately |
| if(prioritizedLinkers == null) { |
| prioritizedLinkers = Collections.emptyList(); |
| } |
| if(fallbackLinkers == null) { |
| fallbackLinkers = Collections.singletonList(new BeansLinker()); |
| } |
| |
| // Gather classes of all precreated (prioritized and fallback) linkers. |
| // We'll filter out any discovered linkers of the same class. |
| final Set<Class<? extends GuardingDynamicLinker>> knownLinkerClasses = |
| new HashSet<>(); |
| addClasses(knownLinkerClasses, prioritizedLinkers); |
| addClasses(knownLinkerClasses, fallbackLinkers); |
| |
| final ClassLoader effectiveClassLoader = classLoaderExplicitlySet ? classLoader : getThreadContextClassLoader(); |
| final List<GuardingDynamicLinker> discovered = AutoDiscovery.loadLinkers(effectiveClassLoader); |
| // Now, concatenate ... |
| final List<GuardingDynamicLinker> linkers = |
| new ArrayList<>(prioritizedLinkers.size() + discovered.size() |
| + fallbackLinkers.size()); |
| // ... prioritized linkers, ... |
| linkers.addAll(prioritizedLinkers); |
| // ... filtered discovered linkers, ... |
| for(final GuardingDynamicLinker linker: discovered) { |
| if(!knownLinkerClasses.contains(linker.getClass())) { |
| linkers.add(linker); |
| } |
| } |
| // ... and finally fallback linkers. |
| linkers.addAll(fallbackLinkers); |
| final List<GuardingDynamicLinker> optimized = CompositeTypeBasedGuardingDynamicLinker.optimize(linkers); |
| final GuardingDynamicLinker composite; |
| switch(linkers.size()) { |
| case 0: { |
| composite = BottomGuardingDynamicLinker.INSTANCE; |
| break; |
| } |
| case 1: { |
| composite = optimized.get(0); |
| break; |
| } |
| default: { |
| composite = new CompositeGuardingDynamicLinker(optimized); |
| break; |
| } |
| } |
| |
| final List<GuardingTypeConverterFactory> typeConverters = new LinkedList<>(); |
| for(final GuardingDynamicLinker linker: linkers) { |
| if(linker instanceof GuardingTypeConverterFactory) { |
| typeConverters.add((GuardingTypeConverterFactory)linker); |
| } |
| } |
| |
| if(prelinkFilter == null) { |
| prelinkFilter = new DefaultPrelinkFilter(); |
| } |
| |
| return new DynamicLinker(new LinkerServicesImpl(new TypeConverterFactory(typeConverters, |
| autoConversionStrategy), composite, internalObjectsFilter), prelinkFilter, runtimeContextArgCount, |
| syncOnRelink, unstableRelinkThreshold); |
| } |
| |
| private static ClassLoader getThreadContextClassLoader() { |
| return AccessController.doPrivileged(new PrivilegedAction<ClassLoader>() { |
| @Override |
| public ClassLoader run() { |
| return Thread.currentThread().getContextClassLoader(); |
| } |
| }, ClassLoaderGetterContextProvider.GET_CLASS_LOADER_CONTEXT); |
| } |
| |
| private static void addClasses(final Set<Class<? extends GuardingDynamicLinker>> knownLinkerClasses, |
| final List<? extends GuardingDynamicLinker> linkers) { |
| for(final GuardingDynamicLinker linker: linkers) { |
| knownLinkerClasses.add(linker.getClass()); |
| } |
| } |
| } |