Mercurial > hg > truffle
diff graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/CyclicAssumption.java @ 13322:f28ea693056f
New assumption utilities.
author | Chris Seaton <chris.seaton@oracle.com> |
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date | Fri, 13 Dec 2013 15:53:30 +0000 |
parents | |
children | dc7189b2bb5f |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/CyclicAssumption.java Fri Dec 13 15:53:30 2013 +0000 @@ -0,0 +1,58 @@ +/* + * 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 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 Assumption assumption; + + public CyclicAssumption(String name) { + this.name = name; + invalidate(); + } + + public void invalidate() { + if (assumption != null) { + assumption.invalidate(); + } + + assumption = Truffle.getRuntime().createAssumption(name); + } + + public Assumption getAssumption() { + return assumption; + } + +}