nashorn/src/jdk.scripting.nashorn/share/classes/jdk/internal/dynalink/CallSiteDescriptor.java
changeset 34456 84eaea8d0574
parent 34096 5ac6287ec71a
parent 34455 cc9f05d3caf0
child 34457 81a65a2faef3
--- a/nashorn/src/jdk.scripting.nashorn/share/classes/jdk/internal/dynalink/CallSiteDescriptor.java	Wed Jul 05 21:04:26 2017 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,287 +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.invoke.MethodHandles;
-import java.lang.invoke.MethodHandles.Lookup;
-import java.lang.invoke.MethodType;
-import java.util.Objects;
-
-/**
- * Call site descriptors contain all the information necessary for linking a
- * call site. This information is normally passed as parameters to bootstrap
- * methods and consists of the {@code MethodHandles.Lookup} object on the caller
- * class in which the call site occurs, the dynamic operation at the call
- * site, and the method type of the call site. {@code CallSiteDescriptor}
- * objects are used in Dynalink to capture and store these parameters for
- * subsequent use by the {@link DynamicLinker}.
- * <p>
- * The constructors of built-in {@link RelinkableCallSite} implementations all
- * take a call site descriptor.
- * <p>
- * Call site descriptors must be immutable. You can use this class as-is or you
- * can subclass it, especially if you need to add further information to the
- * descriptors (typically, values passed in additional parameters to the
- * bootstrap method. Since the descriptors must be immutable, you can set up a
- * cache for equivalent descriptors to have the call sites share them.
- */
-public class CallSiteDescriptor {
-    private final MethodHandles.Lookup lookup;
-    private final Operation operation;
-    private final MethodType methodType;
-
-    /**
-     * The name of a runtime permission to invoke the {@link #getLookup()}
-     * method.
-     */
-    public static final String GET_LOOKUP_PERMISSION_NAME = "dynalink.getLookup";
-
-    private static final RuntimePermission GET_LOOKUP_PERMISSION = new RuntimePermission(GET_LOOKUP_PERMISSION_NAME);
-
-    /**
-     * Creates a new call site descriptor.
-     * @param lookup the lookup object describing the class the call site belongs to.
-     * @param operation the dynamic operation at the call site.
-     * @param methodType the method type of the call site.
-     */
-    public CallSiteDescriptor(final Lookup lookup, final Operation operation, final MethodType methodType) {
-        this.lookup = Objects.requireNonNull(lookup, "lookup");
-        this.operation = Objects.requireNonNull(operation, "name");
-        this.methodType = Objects.requireNonNull(methodType, "methodType");
-    }
-
-    /**
-     * Returns the operation at the call site.
-     * @return the operation at the call site.
-     */
-    public final Operation getOperation() {
-        return operation;
-    }
-
-    /**
-     * The type of the method at the call site.
-     *
-     * @return type of the method at the call site.
-     */
-    public final MethodType getMethodType() {
-        return methodType;
-    }
-
-    /**
-     * Returns the lookup that should be used to find method handles to set as
-     * targets of the call site described by this descriptor. When creating
-     * descriptors from a {@link java.lang.invoke} bootstrap method, it should
-     * be the lookup passed to the bootstrap.
-     * @return the lookup that should be used to find method handles to set as
-     * targets of the call site described by this descriptor.
-     * @throws SecurityException if the lookup isn't the
-     * {@link MethodHandles#publicLookup()} and a security manager is present,
-     * and a check for {@code RuntimePermission("dynalink.getLookup")} fails.
-     */
-    public final Lookup getLookup() {
-        final SecurityManager sm = System.getSecurityManager();
-        if (sm != null && lookup != MethodHandles.publicLookup()) {
-            sm.checkPermission(GET_LOOKUP_PERMISSION);
-        }
-        return lookup;
-    }
-
-    /**
-     * Returns the value of {@link #getLookup()} without a security check. Can
-     * be used by subclasses to access the lookup quickly.
-     * @return same as returned value of {@link #getLookup()}.
-     */
-    protected final Lookup getLookupPrivileged() {
-        return lookup;
-    }
-
-    /**
-     * Creates a new call site descriptor from this descriptor, which is
-     * identical to this, except it changes the method type. Invokes
-     * {@link #changeMethodTypeInternal(MethodType)} and checks that it returns
-     * a descriptor of the same class as this descriptor.
-     *
-     * @param newMethodType the new method type
-     * @return a new call site descriptor, with the method type changed.
-     * @throws RuntimeException if {@link #changeMethodTypeInternal(MethodType)}
-     * returned a descriptor of different class than this object.
-     * @throws NullPointerException if {@link #changeMethodTypeInternal(MethodType)}
-     * returned null.
-     */
-    public final CallSiteDescriptor changeMethodType(final MethodType newMethodType) {
-        final CallSiteDescriptor changed = Objects.requireNonNull(
-                changeMethodTypeInternal(newMethodType),
-                "changeMethodTypeInternal() must not return null.");
-
-        if (getClass() != changed.getClass()) {
-            throw new RuntimeException(
-                    "changeMethodTypeInternal() must return an object of the same class it is invoked on.");
-        }
-
-        return changed;
-    }
-
-    /**
-     * Creates a new call site descriptor from this descriptor, which is
-     * identical to this, except it changes the method type. Subclasses must
-     * override this method to return an object of their exact class.
-     *
-     * @param newMethodType the new method type
-     * @return a new call site descriptor, with the method type changed.
-     */
-    protected CallSiteDescriptor changeMethodTypeInternal(final MethodType newMethodType) {
-        return new CallSiteDescriptor(lookup, operation, newMethodType);
-    }
-
-    /**
-     * Returns true if this call site descriptor is equal to the passed object.
-     * It is considered equal if the other object is of the exact same class,
-     * their operations and method types are equal, and their lookups have the
-     * same {@link java.lang.invoke.MethodHandles.Lookup#lookupClass()} and
-     * {@link java.lang.invoke.MethodHandles.Lookup#lookupModes()}.
-     */
-    @Override
-    public boolean equals(final Object obj) {
-        if (obj == this) {
-            return true;
-        } else if (obj == null) {
-            return false;
-        } else if (obj.getClass() != getClass()) {
-            return false;
-        }
-        final CallSiteDescriptor other = (CallSiteDescriptor)obj;
-        return operation.equals(other.operation) &&
-               methodType.equals(other.methodType) &&
-               lookupsEqual(lookup, other.lookup);
-    }
-
-    /**
-     * Compares two lookup objects for value-based equality. They are considered
-     * equal if they have the same
-     * {@link java.lang.invoke.MethodHandles.Lookup#lookupClass()} and
-     * {@link java.lang.invoke.MethodHandles.Lookup#lookupModes()}.
-     * @param l1 first lookup
-     * @param l2 second lookup
-     * @return true if the two lookups are equal, false otherwise.
-     */
-    private static boolean lookupsEqual(final Lookup l1, final Lookup l2) {
-        return l1.lookupClass() == l2.lookupClass() && l1.lookupModes() == l2.lookupModes();
-    }
-
-    /**
-     * Returns a value-based hash code of this call site descriptor computed
-     * from its operation, method type, and lookup object's lookup class and
-     * lookup modes.
-     * @return value-based hash code for this call site descriptor.
-     */
-    @Override
-    public int hashCode() {
-        return operation.hashCode() + 31 * methodType.hashCode() + 31 * 31 * lookupHashCode(lookup);
-    }
-
-    /**
-     * Returns a value-based hash code for the passed lookup object. It is
-     * based on the lookup object's
-     * {@link java.lang.invoke.MethodHandles.Lookup#lookupClass()} and
-     * {@link java.lang.invoke.MethodHandles.Lookup#lookupModes()} values.
-     * @param lookup the lookup object.
-     * @return a hash code for the object..
-     */
-    private static int lookupHashCode(final Lookup lookup) {
-        return lookup.lookupClass().hashCode() + 31 * lookup.lookupModes();
-    }
-
-    /**
-     * Returns the string representation of this call site descriptor, of the
-     * format {@code name(parameterTypes)returnType@lookup}.
-     */
-    @Override
-    public String toString() {
-        final String mt = methodType.toString();
-        final String l = lookup.toString();
-        final String o = operation.toString();
-        final StringBuilder b = new StringBuilder(o.length() + mt.length() + 1 + l.length());
-        return b.append(o).append(mt).append('@').append(l).toString();
-    }
-}