src/jdk.dynalink/share/classes/jdk/dynalink/LinkerServicesImpl.java
changeset 47216 71c04702a3d5
parent 36686 a351eacd4c42
child 50695 36ca515343e0
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.dynalink/share/classes/jdk/dynalink/LinkerServicesImpl.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,206 @@
+/*
+ * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * 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).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * 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.dynalink;
+
+import java.lang.invoke.MethodHandle;
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.MethodHandles.Lookup;
+import java.lang.invoke.MethodType;
+import java.util.Objects;
+import java.util.function.Supplier;
+import jdk.dynalink.linker.ConversionComparator.Comparison;
+import jdk.dynalink.linker.GuardedInvocation;
+import jdk.dynalink.linker.GuardingDynamicLinker;
+import jdk.dynalink.linker.LinkRequest;
+import jdk.dynalink.linker.LinkerServices;
+import jdk.dynalink.linker.MethodHandleTransformer;
+
+/**
+ * Default implementation of the {@link LinkerServices} interface.
+ */
+final class LinkerServicesImpl implements LinkerServices {
+    private static final ThreadLocal<SecureLookupSupplier> threadLookupSupplier = new ThreadLocal<>();
+
+    private final TypeConverterFactory typeConverterFactory;
+    private final GuardingDynamicLinker topLevelLinker;
+    private final MethodHandleTransformer internalObjectsFilter;
+
+    /**
+     * Creates a new linker services object.
+     *
+     * @param typeConverterFactory the type converter factory exposed by the services.
+     * @param topLevelLinker the top level linker used by the services.
+     * @param internalObjectsFilter a method handle transformer that is supposed to act as the implementation of this
+     * services' {@link #filterInternalObjects(java.lang.invoke.MethodHandle)} method.
+     */
+    LinkerServicesImpl(final TypeConverterFactory typeConverterFactory,
+            final GuardingDynamicLinker topLevelLinker, final MethodHandleTransformer internalObjectsFilter) {
+        this.typeConverterFactory = typeConverterFactory;
+        this.topLevelLinker = topLevelLinker;
+        this.internalObjectsFilter = internalObjectsFilter;
+    }
+
+    @Override
+    public boolean canConvert(final Class<?> from, final Class<?> to) {
+        return typeConverterFactory.canConvert(from, to);
+    }
+
+    @Override
+    public MethodHandle asType(final MethodHandle handle, final MethodType fromType) {
+        return typeConverterFactory.asType(handle, fromType);
+    }
+
+    @Override
+    public MethodHandle getTypeConverter(final Class<?> sourceType, final Class<?> targetType) {
+        return typeConverterFactory.getTypeConverter(sourceType, targetType);
+    }
+
+    @Override
+    public Comparison compareConversion(final Class<?> sourceType, final Class<?> targetType1, final Class<?> targetType2) {
+        return typeConverterFactory.compareConversion(sourceType, targetType1, targetType2);
+    }
+
+    /**
+     * Used to marshal a checked exception out of Supplier.get() in getGuardedInvocation.
+     */
+    private static class LinkerException extends RuntimeException {
+        private static final long serialVersionUID = 1L;
+
+        public LinkerException(final Exception cause) {
+            super(null, cause, true, false);
+        }
+    }
+
+    @Override
+    public GuardedInvocation getGuardedInvocation(final LinkRequest linkRequest) throws Exception {
+        try {
+            return getWithLookupInternal(() -> {
+                try {
+                    return topLevelLinker.getGuardedInvocation(linkRequest, this);
+                } catch (final RuntimeException e) {
+                    throw e;
+                } catch (final Exception e) {
+                    throw new LinkerException(e);
+                }
+            }, linkRequest.getCallSiteDescriptor());
+        } catch (final LinkerException e) {
+            throw (Exception)e.getCause();
+        }
+    }
+
+    @Override
+    public MethodHandle filterInternalObjects(final MethodHandle target) {
+        return internalObjectsFilter != null ? internalObjectsFilter.transform(target) : target;
+    }
+
+    @Override
+    public <T> T getWithLookup(final Supplier<T> operation, final SecureLookupSupplier lookupSupplier) {
+        return getWithLookupInternal(
+                Objects.requireNonNull(operation, "action"),
+                Objects.requireNonNull(lookupSupplier, "lookupSupplier"));
+    }
+
+    private static <T> T getWithLookupInternal(final Supplier<T> operation, final SecureLookupSupplier lookupSupplier) {
+        final SecureLookupSupplier prevLookupSupplier = threadLookupSupplier.get();
+        final boolean differ = prevLookupSupplier != lookupSupplier;
+        if (differ) {
+            threadLookupSupplier.set(lookupSupplier);
+        }
+        try {
+            return operation.get();
+        } finally {
+            if (differ) {
+                threadLookupSupplier.set(prevLookupSupplier);
+            }
+        }
+    }
+
+    static Lookup getCurrentLookup() {
+        final SecureLookupSupplier lookupSupplier = threadLookupSupplier.get();
+        if (lookupSupplier != null) {
+            return lookupSupplier.getLookup();
+        }
+        return MethodHandles.publicLookup();
+    }
+}