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comparison graal/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/CyclicAssumption.java @ 19706:dc7189b2bb5f

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CyclicAssumption: Use an AtomicReference to ensure invalidation.
author Benoit Daloze <benoit.daloze@jku.at>
date Mon, 09 Mar 2015 14:22:15 +0100
parents f28ea693056f
children
comparison
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19705:2f5d4df2af90 19706:dc7189b2bb5f
22 * or visit www.oracle.com if you need additional information or have any 22 * or visit www.oracle.com if you need additional information or have any
23 * questions. 23 * questions.
24 */ 24 */
25 package com.oracle.truffle.api.utilities; 25 package com.oracle.truffle.api.utilities;
26 26
27 import java.util.concurrent.atomic.*;
28
27 import com.oracle.truffle.api.*; 29 import com.oracle.truffle.api.*;
28 30
29 /** 31 /**
30 * Holds an {@link Assumption}, and knows how to recreate it with the same properties on 32 * 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 33 * invalidation. Used so that mutability is isolated in this class, and all other classes that need
34 * same way that you would with any other assumption. 36 * same way that you would with any other assumption.
35 */ 37 */
36 public class CyclicAssumption { 38 public class CyclicAssumption {
37 39
38 private final String name; 40 private final String name;
39 private Assumption assumption; 41 private final AtomicReference<Assumption> assumption;
40 42
41 public CyclicAssumption(String name) { 43 public CyclicAssumption(String name) {
42 this.name = name; 44 this.name = name;
43 invalidate(); 45 this.assumption = new AtomicReference<>(Truffle.getRuntime().createAssumption(name));
44 } 46 }
45 47
46 public void invalidate() { 48 public void invalidate() {
47 if (assumption != null) { 49 Assumption newAssumption = Truffle.getRuntime().createAssumption(name);
48 assumption.invalidate(); 50 Assumption oldAssumption = assumption.getAndSet(newAssumption);
49 } 51 oldAssumption.invalidate();
50
51 assumption = Truffle.getRuntime().createAssumption(name);
52 } 52 }
53 53
54 public Assumption getAssumption() { 54 public Assumption getAssumption() {
55 return assumption; 55 return assumption.get();
56 } 56 }
57 57
58 } 58 }