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.dynalink;

    85 

    86 import java.lang.invoke.MethodHandle;

    87 import java.lang.invoke.MethodHandles;

    88 import java.lang.invoke.MethodHandles.Lookup;

    89 import java.lang.invoke.MethodType;

    90 import java.util.Objects;

    91 import java.util.function.Supplier;

    92 import jdk.dynalink.linker.ConversionComparator.Comparison;

    93 import jdk.dynalink.linker.GuardedInvocation;

    94 import jdk.dynalink.linker.GuardingDynamicLinker;

    95 import jdk.dynalink.linker.LinkRequest;

    96 import jdk.dynalink.linker.LinkerServices;

    97 import jdk.dynalink.linker.MethodHandleTransformer;

    98 

    99 /**

   100  * Default implementation of the {@link LinkerServices} interface.

   101  */

   102 final class LinkerServicesImpl implements LinkerServices {

   103     private static final ThreadLocal<SecureLookupSupplier> threadLookupSupplier = new ThreadLocal<>();

   104 

   105     private final TypeConverterFactory typeConverterFactory;

   106     private final GuardingDynamicLinker topLevelLinker;

   107     private final MethodHandleTransformer internalObjectsFilter;

   108 

   109     /**

   110      * Creates a new linker services object.

   111      *

   112      * @param typeConverterFactory the type converter factory exposed by the services.

   113      * @param topLevelLinker the top level linker used by the services.

   114      * @param internalObjectsFilter a method handle transformer that is supposed to act as the implementation of this

   115      * services' {@link #filterInternalObjects(java.lang.invoke.MethodHandle)} method.

   116      */

   117     LinkerServicesImpl(final TypeConverterFactory typeConverterFactory,

   118             final GuardingDynamicLinker topLevelLinker, final MethodHandleTransformer internalObjectsFilter) {

   119         this.typeConverterFactory = typeConverterFactory;

   120         this.topLevelLinker = topLevelLinker;

   121         this.internalObjectsFilter = internalObjectsFilter;

   122     }

   123 

   124     @Override

   125     public boolean canConvert(final Class<?> from, final Class<?> to) {

   126         return typeConverterFactory.canConvert(from, to);

   127     }

   128 

   129     @Override

   130     public MethodHandle asType(final MethodHandle handle, final MethodType fromType) {

   131         return typeConverterFactory.asType(handle, fromType);

   132     }

   133 

   134     @Override

   135     public MethodHandle getTypeConverter(final Class<?> sourceType, final Class<?> targetType) {

   136         return typeConverterFactory.getTypeConverter(sourceType, targetType);

   137     }

   138 

   139     @Override

   140     public Comparison compareConversion(final Class<?> sourceType, final Class<?> targetType1, final Class<?> targetType2) {

   141         return typeConverterFactory.compareConversion(sourceType, targetType1, targetType2);

   142     }

   143 

   144     /**

   145      * Used to marshal a checked exception out of Supplier.get() in getGuardedInvocation.

   146      */

   147     private static class LinkerException extends RuntimeException {

   148         private static final long serialVersionUID = 1L;

   149 

   150         public LinkerException(final Exception cause) {

   151             super(null, cause, true, false);

   152         }

   153     }

   154 

   155     @Override

   156     public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest) throws Exception {

   157         try {

   158             return getWithLookupInternal(() -> {

   159                 try {

   160                     return topLevelLinker.getGuardedInvocation(linkRequest, this);

   161                 } catch (final RuntimeException e) {

   162                     throw e;

   163                 } catch (final Exception e) {

   164                     throw new LinkerException(e);

   165                 }

   166             }, linkRequest.getCallSiteDescriptor());

   167         } catch (final LinkerException e) {

   168             throw (Exception)e.getCause();

   169         }

   170     }

   171 

   172     @Override

   173     public MethodHandle filterInternalObjects(final MethodHandle target) {

   174         return internalObjectsFilter != null ? internalObjectsFilter.transform(target) : target;

   175     }

   176 

   177     @Override

   178     public <T> T getWithLookup(final Supplier<T> operation, final SecureLookupSupplier lookupSupplier) {

   179         return getWithLookupInternal(

   180                 Objects.requireNonNull(operation, "action"),

   181                 Objects.requireNonNull(lookupSupplier, "lookupSupplier"));

   182     }

   183 

   184     private static <T> T getWithLookupInternal(final Supplier<T> operation, final SecureLookupSupplier lookupSupplier) {

   185         final SecureLookupSupplier prevLookupSupplier = threadLookupSupplier.get();

   186         final boolean differ = prevLookupSupplier != lookupSupplier;

   187         if (differ) {

   188             threadLookupSupplier.set(lookupSupplier);

   189         }

   190         try {

   191             return operation.get();

   192         } finally {

   193             if (differ) {

   194                 threadLookupSupplier.set(prevLookupSupplier);

   195             }

   196         }

   197     }

   198 

   199     static Lookup getCurrentLookup() {

   200         final SecureLookupSupplier lookupSupplier = threadLookupSupplier.get();

   201         if (lookupSupplier != null) {

   202             return lookupSupplier.getLookup();

   203         }

   204         return MethodHandles.publicLookup();

   205     }

   206 }