Mercurial > hg > graal-jvmci-8
view graal/com.oracle.truffle.api/src/com/oracle/truffle/api/Assumption.java @ 10465:699ee4e4f9dc
fixed gate warnings
author | twisti |
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date | Thu, 20 Jun 2013 22:26:38 -0700 |
parents | 324dcaedb1ed |
children | 494b818b527c |
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/* * Copyright (c) 2012, 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. * * 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; import com.oracle.truffle.api.nodes.*; /** * An assumption is a global boolean flag that starts with the value true (i.e., the assumption is * valid) and can subsequently be invalidated (using {@link Assumption#invalidate()}). Once * invalidated, an assumption can never get valid again. Assumptions can be created using the * {@link TruffleRuntime#createAssumption()} or the {@link TruffleRuntime#createAssumption(String)} * method. The Truffle compiler has special knowledge of this class in order to produce efficient * machine code for checking an assumption in case the assumption object is a compile time constant. * Therefore, assumptions should be stored in final fields in Truffle nodes. */ public interface Assumption { /** * Checks that this assumption is still valid. The method throws an exception, if this is no * longer the case. This method is preferred over the {@link #isValid()} method when writing * guest language interpreter code. The catch block should perform a node rewrite (see * {@link Node#replace(Node)}) with a node that no longer relies on the assumption. * * @throws InvalidAssumptionException If the assumption is no longer valid. */ void check() throws InvalidAssumptionException; /** * Checks whether the assumption is still valid. * * @return a boolean value indicating the validity of the assumption */ boolean isValid(); /** * Invalidates this assumption. Performs no operation, if the assumption is already invalid. */ void invalidate(); /** * A name for the assumption that is used for debug output. * * @return the name of the assumption */ String getName(); }