nashorn/src/jdk.scripting.nashorn/share/classes/jdk/internal/dynalink/ClassMap.java
changeset 34453 0d6925c03155
parent 34019 b4a0a6c5333f
parent 34452 c34f322b89b9
child 34454 735fec4e8ee8
--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/internal/dynalink/ClassMap.java	Sun Nov 29 11:00:11 2015 -0800
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,183 +0,0 @@
-/*
- * 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.internal.dynalink;
-
-import java.lang.ref.Reference;
-import java.lang.ref.SoftReference;
-import java.security.AccessControlContext;
-import java.security.AccessController;
-import java.security.PrivilegedAction;
-import java.util.Map;
-import java.util.WeakHashMap;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.ConcurrentMap;
-import jdk.internal.dynalink.internal.AccessControlContextFactory;
-import jdk.internal.dynalink.internal.InternalTypeUtilities;
-
-/**
- * A dual map that can either strongly or weakly reference a given class depending on whether the class is visible from
- * a class loader or not.
- *
- * @param <T> the type of the values in the map
- */
-abstract class ClassMap<T> {
-    private static final AccessControlContext GET_CLASS_LOADER_CONTEXT =
-            AccessControlContextFactory.createAccessControlContext("getClassLoader");
-
-    private final ConcurrentMap<Class<?>, T> map = new ConcurrentHashMap<>();
-    private final Map<Class<?>, Reference<T>> weakMap = new WeakHashMap<>();
-    private final ClassLoader classLoader;
-
-    /**
-     * Creates a new class map. It will use strong references for all keys and values where the key is a class visible
-     * from the class loader, and will use weak keys and soft values for all other classes.
-     *
-     * @param classLoader the classloader that determines strong referenceability.
-     */
-    ClassMap(final ClassLoader classLoader) {
-        this.classLoader = classLoader;
-    }
-
-    /**
-     * Compute the value associated with the given class. It is possible that the method will be invoked several times
-     * (or even concurrently) for the same class parameter.
-     *
-     * @param clazz the class to compute the value for
-     * @return the return value. Must not be null.
-     */
-    abstract T computeValue(Class<?> clazz);
-
-    /**
-     * Returns the value associated with the class
-     *
-     * @param clazz the class
-     * @return the value associated with the class
-     */
-    T get(final Class<?> clazz) {
-        // Check in fastest first - objects we're allowed to strongly reference
-        final T v = map.get(clazz);
-        if(v != null) {
-            return v;
-        }
-        // Check objects we're not allowed to strongly reference
-        Reference<T> ref;
-        synchronized(weakMap) {
-            ref = weakMap.get(clazz);
-        }
-        if(ref != null) {
-            final T refv = ref.get();
-            if(refv != null) {
-                return refv;
-            }
-        }
-        // Not found in either place; create a new value
-        final T newV = computeValue(clazz);
-        assert newV != null;
-
-        final Boolean canReferenceDirectly = AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
-            @Override
-            public Boolean run() {
-                return InternalTypeUtilities.canReferenceDirectly(classLoader, clazz.getClassLoader());
-            }
-        }, GET_CLASS_LOADER_CONTEXT);
-
-        // If allowed to strongly reference, put it in the fast map
-        if(canReferenceDirectly) {
-            final T oldV = map.putIfAbsent(clazz, newV);
-            return oldV != null ? oldV : newV;
-        }
-        // Otherwise, put it into the weak map
-        synchronized(weakMap) {
-            ref = weakMap.get(clazz);
-            if(ref != null) {
-                final T oldV = ref.get();
-                if(oldV != null) {
-                    return oldV;
-                }
-            }
-            weakMap.put(clazz, new SoftReference<>(newV));
-            return newV;
-        }
-    }
-}