| /* |
| * 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 |
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| * 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.linker; |
| |
| import java.lang.invoke.MethodHandle; |
| import java.lang.invoke.MethodType; |
| import java.util.List; |
| import jdk.dynalink.DynamicLinkerFactory; |
| |
| /** |
| * The base interface for language-specific dynamic linkers. Such linkers |
| * always have to produce method handles with guards, as the validity of the |
| * method handle for calls at a call site inevitably depends on some condition |
| * (at the very least, it depends on the receiver belonging to the language |
| * runtime of the linker). Language runtime implementors will normally implement |
| * the linking logic for their own language as one or more |
| * {@link GuardingDynamicLinker} classes. They will typically set them as |
| * {@link DynamicLinkerFactory#setPrioritizedLinkers(List) prioritized linkers} |
| * in the {@code DynamicLinkerFactory} they configure for themselves, and maybe also |
| * set some as {@link DynamicLinkerFactory#setFallbackLinkers(List) fallback |
| * linkers} to handle language-specific "property not found" etc. conditions. |
| * <p> |
| * Consider implementing {@link TypeBasedGuardingDynamicLinker} interface |
| * instead of this interface for those linkers that are based on the Java class |
| * of the objects. If you need to implement language-specific type conversions, |
| * have your {@code GuardingDynamicLinker} also implement the |
| * {@link GuardingTypeConverterFactory} interface. |
| * <p> |
| * Languages can export linkers to other language runtimes for |
| * {@link DynamicLinkerFactory#setClassLoader(ClassLoader) automatic discovery} |
| * using a {@link GuardingDynamicLinkerExporter}. |
| */ |
| public interface GuardingDynamicLinker { |
| /** |
| * Creates a guarded invocation appropriate for a particular invocation with |
| * the specified arguments at a call site. |
| * |
| * @param linkRequest the object describing the request for linking a |
| * particular invocation |
| * @param linkerServices linker services |
| * @return a guarded invocation with a method handle suitable for the |
| * arguments, as well as a guard condition that if fails should trigger |
| * relinking. Must return null if it can't resolve the invocation. If the |
| * returned invocation is unconditional (which is actually quite rare), the |
| * guard in the return value can be null. The invocation can also have any |
| * number of switch points for asynchronous invalidation of the linkage, as |
| * well as a {@link Throwable} subclass that describes an expected exception |
| * condition that also triggers relinking (often it is faster to rely on an |
| * infrequent but expected {@link ClassCastException} than on an always |
| * evaluated {@code instanceof} guard). While the linker must produce an |
| * invocation with parameter types matching those in the call site |
| * descriptor of the link request, it should not try to match the return |
| * type expected at the call site except when it can do it with only the |
| * conversions that lose neither precision nor magnitude, see |
| * {@link LinkerServices#asTypeLosslessReturn(MethodHandle, MethodType)} for |
| * further explanation. |
| * @throws Exception if the operation fails for whatever reason |
| */ |
| public GuardedInvocation getGuardedInvocation(LinkRequest linkRequest, LinkerServices linkerServices) |
| throws Exception; |
| } |