| /* |
| * 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. |
| */ |
| |
| /* |
| * This file is available under and governed by the GNU General Public |
| * License version 2 only, as published by the Free Software Foundation. |
| * However, the following notice accompanied the original version of this |
| * file: |
| * |
| * Written by Doug Lea with assistance from members of JCP JSR-166 |
| * Expert Group and released to the public domain, as explained at |
| * http://creativecommons.org/publicdomain/zero/1.0/ |
| * Other contributors include Andrew Wright, Jeffrey Hayes, |
| * Pat Fisher, Mike Judd. |
| */ |
| |
| import java.util.concurrent.atomic.AtomicStampedReference; |
| |
| import junit.framework.Test; |
| import junit.framework.TestSuite; |
| |
| public class AtomicStampedReferenceTest extends JSR166TestCase { |
| public static void main(String[] args) { |
| main(suite(), args); |
| } |
| public static Test suite() { |
| return new TestSuite(AtomicStampedReferenceTest.class); |
| } |
| |
| /** |
| * constructor initializes to given reference and stamp |
| */ |
| public void testConstructor() { |
| AtomicStampedReference ai = new AtomicStampedReference(one, 0); |
| assertSame(one, ai.getReference()); |
| assertEquals(0, ai.getStamp()); |
| AtomicStampedReference a2 = new AtomicStampedReference(null, 1); |
| assertNull(a2.getReference()); |
| assertEquals(1, a2.getStamp()); |
| } |
| |
| /** |
| * get returns the last values of reference and stamp set |
| */ |
| public void testGetSet() { |
| int[] mark = new int[1]; |
| AtomicStampedReference ai = new AtomicStampedReference(one, 0); |
| assertSame(one, ai.getReference()); |
| assertEquals(0, ai.getStamp()); |
| assertSame(one, ai.get(mark)); |
| assertEquals(0, mark[0]); |
| ai.set(two, 0); |
| assertSame(two, ai.getReference()); |
| assertEquals(0, ai.getStamp()); |
| assertSame(two, ai.get(mark)); |
| assertEquals(0, mark[0]); |
| ai.set(one, 1); |
| assertSame(one, ai.getReference()); |
| assertEquals(1, ai.getStamp()); |
| assertSame(one, ai.get(mark)); |
| assertEquals(1, mark[0]); |
| } |
| |
| /** |
| * attemptStamp succeeds in single thread |
| */ |
| public void testAttemptStamp() { |
| int[] mark = new int[1]; |
| AtomicStampedReference ai = new AtomicStampedReference(one, 0); |
| assertEquals(0, ai.getStamp()); |
| assertTrue(ai.attemptStamp(one, 1)); |
| assertEquals(1, ai.getStamp()); |
| assertSame(one, ai.get(mark)); |
| assertEquals(1, mark[0]); |
| } |
| |
| /** |
| * compareAndSet succeeds in changing values if equal to expected reference |
| * and stamp else fails |
| */ |
| public void testCompareAndSet() { |
| int[] mark = new int[1]; |
| AtomicStampedReference ai = new AtomicStampedReference(one, 0); |
| assertSame(one, ai.get(mark)); |
| assertEquals(0, ai.getStamp()); |
| assertEquals(0, mark[0]); |
| |
| assertTrue(ai.compareAndSet(one, two, 0, 0)); |
| assertSame(two, ai.get(mark)); |
| assertEquals(0, mark[0]); |
| |
| assertTrue(ai.compareAndSet(two, m3, 0, 1)); |
| assertSame(m3, ai.get(mark)); |
| assertEquals(1, mark[0]); |
| |
| assertFalse(ai.compareAndSet(two, m3, 1, 1)); |
| assertSame(m3, ai.get(mark)); |
| assertEquals(1, mark[0]); |
| } |
| |
| /** |
| * compareAndSet in one thread enables another waiting for reference value |
| * to succeed |
| */ |
| public void testCompareAndSetInMultipleThreads() throws Exception { |
| final AtomicStampedReference ai = new AtomicStampedReference(one, 0); |
| Thread t = new Thread(new CheckedRunnable() { |
| public void realRun() { |
| while (!ai.compareAndSet(two, three, 0, 0)) |
| Thread.yield(); |
| }}); |
| |
| t.start(); |
| assertTrue(ai.compareAndSet(one, two, 0, 0)); |
| t.join(LONG_DELAY_MS); |
| assertFalse(t.isAlive()); |
| assertSame(three, ai.getReference()); |
| assertEquals(0, ai.getStamp()); |
| } |
| |
| /** |
| * compareAndSet in one thread enables another waiting for stamp value |
| * to succeed |
| */ |
| public void testCompareAndSetInMultipleThreads2() throws Exception { |
| final AtomicStampedReference ai = new AtomicStampedReference(one, 0); |
| Thread t = new Thread(new CheckedRunnable() { |
| public void realRun() { |
| while (!ai.compareAndSet(one, one, 1, 2)) |
| Thread.yield(); |
| }}); |
| |
| t.start(); |
| assertTrue(ai.compareAndSet(one, one, 0, 1)); |
| t.join(LONG_DELAY_MS); |
| assertFalse(t.isAlive()); |
| assertSame(one, ai.getReference()); |
| assertEquals(2, ai.getStamp()); |
| } |
| |
| /** |
| * repeated weakCompareAndSet succeeds in changing values when equal |
| * to expected |
| */ |
| public void testWeakCompareAndSet() { |
| int[] mark = new int[1]; |
| AtomicStampedReference ai = new AtomicStampedReference(one, 0); |
| assertSame(one, ai.get(mark)); |
| assertEquals(0, ai.getStamp()); |
| assertEquals(0, mark[0]); |
| |
| do {} while (!ai.weakCompareAndSet(one, two, 0, 0)); |
| assertSame(two, ai.get(mark)); |
| assertEquals(0, mark[0]); |
| |
| do {} while (!ai.weakCompareAndSet(two, m3, 0, 1)); |
| assertSame(m3, ai.get(mark)); |
| assertEquals(1, mark[0]); |
| } |
| |
| } |