/******************************************************************************
* Copyright (c) 2009 - 2015 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*****************************************************************************/
/**
*
*/
package data.causality;
/**
* Causality test case 3 from
* http://www.cs.umd.edu/~pugh/java/memoryModel/CausalityTestCases.html
*
*<pre>
* Initially, x = y = 0
*
* Thread 1:
* r1 = x
* r2 = x
* if r1 == r2
* y = 1
*
* Thread 2:
* r3 = y
* x = r3
*
* Thread 3:
* x = 2
*
* Behavior in question: r1 == r2 == r3 == 1
*
* Decision: Allowed, since redundant read elimination could result in simplification
* of r1 == r2 to true, allowing y = 1 to be moved early.
*
* Notes: Same as test case 2, except there are SC executions in which r1 != r2
* </pre>
*
* @author etorlak
*/
public final class Test03 {
static int x = 0, y = 0;
public static final void thread1() {
final int r1 = x;
final int r2 = x;
if (r1==r2)
y = 1;
assert r1==1;
assert r2==1;
}
public static final void thread2() {
final int r3 = y;
x = r3;
assert r3==1;
}
public static final void thread3() {
x = 2;
}
}