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comparison graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/CyclicAssumption.java @ 13322:f28ea693056f

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New assumption utilities.
author Chris Seaton <chris.seaton@oracle.com>
date Fri, 13 Dec 2013 15:53:30 +0000
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children dc7189b2bb5f
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13321:e585ac5a385d 13322:f28ea693056f
1 /*
2 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package com.oracle.truffle.api.utilities;
26
27 import com.oracle.truffle.api.*;
28
29 /**
30 * Holds an {@link Assumption}, and knows how to recreate it with the same properties on
31 * invalidation. Used so that mutability is isolated in this class, and all other classes that need
32 * an assumption that may be recreated can have a final reference to an object of this class. Note
33 * that you should be careful that repeated invalidations do not cause a deoptimization loop in that
34 * same way that you would with any other assumption.
35 */
36 public class CyclicAssumption {
37
38 private final String name;
39 private Assumption assumption;
40
41 public CyclicAssumption(String name) {
42 this.name = name;
43 invalidate();
44 }
45
46 public void invalidate() {
47 if (assumption != null) {
48 assumption.invalidate();
49 }
50
51 assumption = Truffle.getRuntime().createAssumption(name);
52 }
53
54 public Assumption getAssumption() {
55 return assumption;
56 }
57
58 }