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view graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/CyclicAssumption.java @ 21468:99942eac9c6d
Introducing TruffleVM - a central place to invoke code in any registered TruffleLanguage.
author | Jaroslav Tulach <jaroslav.tulach@oracle.com> |
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date | Fri, 22 May 2015 13:41:10 +0200 |
parents | dc7189b2bb5f |
children |
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/* * Copyright (c) 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. */ package com.oracle.truffle.api.utilities; import java.util.concurrent.atomic.*; import com.oracle.truffle.api.*; /** * Holds an {@link Assumption}, and knows how to recreate it with the same properties on * invalidation. Used so that mutability is isolated in this class, and all other classes that need * an assumption that may be recreated can have a final reference to an object of this class. Note * that you should be careful that repeated invalidations do not cause a deoptimization loop in that * same way that you would with any other assumption. */ public class CyclicAssumption { private final String name; private final AtomicReference<Assumption> assumption; public CyclicAssumption(String name) { this.name = name; this.assumption = new AtomicReference<>(Truffle.getRuntime().createAssumption(name)); } public void invalidate() { Assumption newAssumption = Truffle.getRuntime().createAssumption(name); Assumption oldAssumption = assumption.getAndSet(newAssumption); oldAssumption.invalidate(); } public Assumption getAssumption() { return assumption.get(); } }