test/tck/AtomicStampedReferenceTest.java

/*
 * 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<Item> ai = new AtomicStampedReference<>(one, 0);
        assertSame(one, ai.getReference());
        assertEquals(0, ai.getStamp());
        AtomicStampedReference<Item> 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<Item> 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<Item> 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<Item> 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, minusThree, 0, 1));
        assertSame(minusThree, ai.get(mark));
        assertEquals(1, mark[0]);

        assertFalse(ai.compareAndSet(two, minusThree, 1, 1));
        assertSame(minusThree, 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<Item> 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<Item> 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<Item> 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, minusThree, 0, 1));
        assertSame(minusThree, ai.get(mark));
        assertEquals(1, mark[0]);
    }

}
Revision:	1.25
Committed:	Wed Jan 27 01:57:24 2021 UTC (3 years, 3 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.24:	+8 -8 lines
Log Message:	use diamond <> pervasively
#	User	Rev	Content
1	dl	1.1	/*
2	dl	1.5	* Written by Doug Lea with assistance from members of JCP JSR-166
3			* Expert Group and released to the public domain, as explained at
4	jsr166	1.17	* http://creativecommons.org/publicdomain/zero/1.0/
5	jsr166	1.8	* Other contributors include Andrew Wright, Jeffrey Hayes,
6			* Pat Fisher, Mike Judd.
7	dl	1.5	*/
8	dl	1.1
9	jsr166	1.18	import java.util.concurrent.atomic.AtomicStampedReference;
10	dl	1.1
11	jsr166	1.21	import junit.framework.Test;
12			import junit.framework.TestSuite;
13
14	jsr166	1.10	public class AtomicStampedReferenceTest extends JSR166TestCase {
15	jsr166	1.15	public static void main(String[] args) {
16	jsr166	1.23	main(suite(), args);
17	dl	1.1	}
18			public static Test suite() {
19			return new TestSuite(AtomicStampedReferenceTest.class);
20			}
21	jsr166	1.8
22	dl	1.3	/**
23	dl	1.7	* constructor initializes to given reference and stamp
24	dl	1.3	*/
25	jsr166	1.10	public void testConstructor() {
26	jsr166	1.25	AtomicStampedReference<Item> ai = new AtomicStampedReference<>(one, 0);
27	jsr166	1.19	assertSame(one, ai.getReference());
28	jsr166	1.13	assertEquals(0, ai.getStamp());
29	jsr166	1.25	AtomicStampedReference<Item> a2 = new AtomicStampedReference<>(null, 1);
30	jsr166	1.13	assertNull(a2.getReference());
31			assertEquals(1, a2.getStamp());
32	dl	1.1	}
33
34	dl	1.3	/**
35	jsr166	1.16	* get returns the last values of reference and stamp set
36	dl	1.3	*/
37	jsr166	1.10	public void testGetSet() {
38	dl	1.1	int[] mark = new int[1];
39	jsr166	1.25	AtomicStampedReference<Item> ai = new AtomicStampedReference<>(one, 0);
40	jsr166	1.19	assertSame(one, ai.getReference());
41	jsr166	1.13	assertEquals(0, ai.getStamp());
42	jsr166	1.14	assertSame(one, ai.get(mark));
43	dl	1.1	assertEquals(0, mark[0]);
44	jsr166	1.13	ai.set(two, 0);
45	jsr166	1.19	assertSame(two, ai.getReference());
46	jsr166	1.13	assertEquals(0, ai.getStamp());
47	jsr166	1.14	assertSame(two, ai.get(mark));
48	dl	1.1	assertEquals(0, mark[0]);
49	jsr166	1.13	ai.set(one, 1);
50	jsr166	1.19	assertSame(one, ai.getReference());
51	jsr166	1.13	assertEquals(1, ai.getStamp());
52	jsr166	1.14	assertSame(one, ai.get(mark));
53	jsr166	1.19	assertEquals(1, mark[0]);
54	dl	1.1	}
55
56	dl	1.3	/**
57	jsr166	1.16	* attemptStamp succeeds in single thread
58	dl	1.3	*/
59	jsr166	1.10	public void testAttemptStamp() {
60	dl	1.1	int[] mark = new int[1];
61	jsr166	1.25	AtomicStampedReference<Item> ai = new AtomicStampedReference<>(one, 0);
62	dl	1.1	assertEquals(0, ai.getStamp());
63			assertTrue(ai.attemptStamp(one, 1));
64	jsr166	1.13	assertEquals(1, ai.getStamp());
65	jsr166	1.14	assertSame(one, ai.get(mark));
66	dl	1.1	assertEquals(1, mark[0]);
67			}
68
69	dl	1.3	/**
70	dl	1.4	* compareAndSet succeeds in changing values if equal to expected reference
71			* and stamp else fails
72	dl	1.3	*/
73	jsr166	1.10	public void testCompareAndSet() {
74	dl	1.1	int[] mark = new int[1];
75	jsr166	1.25	AtomicStampedReference<Item> ai = new AtomicStampedReference<>(one, 0);
76	jsr166	1.14	assertSame(one, ai.get(mark));
77	dl	1.1	assertEquals(0, ai.getStamp());
78	jsr166	1.13	assertEquals(0, mark[0]);
79	dl	1.1
80			assertTrue(ai.compareAndSet(one, two, 0, 0));
81	jsr166	1.14	assertSame(two, ai.get(mark));
82	jsr166	1.13	assertEquals(0, mark[0]);
83	dl	1.1
84	dl	1.24	assertTrue(ai.compareAndSet(two, minusThree, 0, 1));
85			assertSame(minusThree, ai.get(mark));
86	jsr166	1.13	assertEquals(1, mark[0]);
87	dl	1.1
88	dl	1.24	assertFalse(ai.compareAndSet(two, minusThree, 1, 1));
89			assertSame(minusThree, ai.get(mark));
90	jsr166	1.13	assertEquals(1, mark[0]);
91	dl	1.1	}
92
93	dl	1.3	/**
94	dl	1.4	* compareAndSet in one thread enables another waiting for reference value
95			* to succeed
96			*/
97	jsr166	1.11	public void testCompareAndSetInMultipleThreads() throws Exception {
98	jsr166	1.25	final AtomicStampedReference<Item> ai = new AtomicStampedReference<>(one, 0);
99	jsr166	1.12	Thread t = new Thread(new CheckedRunnable() {
100			public void realRun() {
101			while (!ai.compareAndSet(two, three, 0, 0))
102			Thread.yield();
103			}});
104	jsr166	1.11
105			t.start();
106			assertTrue(ai.compareAndSet(one, two, 0, 0));
107			t.join(LONG_DELAY_MS);
108			assertFalse(t.isAlive());
109	jsr166	1.20	assertSame(three, ai.getReference());
110			assertEquals(0, ai.getStamp());
111	dl	1.4	}
112
113			/**
114			* compareAndSet in one thread enables another waiting for stamp value
115			* to succeed
116			*/
117	jsr166	1.11	public void testCompareAndSetInMultipleThreads2() throws Exception {
118	jsr166	1.25	final AtomicStampedReference<Item> ai = new AtomicStampedReference<>(one, 0);
119	jsr166	1.12	Thread t = new Thread(new CheckedRunnable() {
120			public void realRun() {
121			while (!ai.compareAndSet(one, one, 1, 2))
122			Thread.yield();
123			}});
124	jsr166	1.11
125			t.start();
126			assertTrue(ai.compareAndSet(one, one, 0, 1));
127			t.join(LONG_DELAY_MS);
128			assertFalse(t.isAlive());
129	jsr166	1.20	assertSame(one, ai.getReference());
130			assertEquals(2, ai.getStamp());
131	dl	1.4	}
132
133			/**
134			* repeated weakCompareAndSet succeeds in changing values when equal
135	jsr166	1.8	* to expected
136	dl	1.3	*/
137	jsr166	1.10	public void testWeakCompareAndSet() {
138	dl	1.1	int[] mark = new int[1];
139	jsr166	1.25	AtomicStampedReference<Item> ai = new AtomicStampedReference<>(one, 0);
140	jsr166	1.14	assertSame(one, ai.get(mark));
141	jsr166	1.15	assertEquals(0, ai.getStamp());
142	jsr166	1.13	assertEquals(0, mark[0]);
143	dl	1.1
144	jsr166	1.22	do {} while (!ai.weakCompareAndSet(one, two, 0, 0));
145	jsr166	1.14	assertSame(two, ai.get(mark));
146	jsr166	1.13	assertEquals(0, mark[0]);
147	dl	1.1
148	dl	1.24	do {} while (!ai.weakCompareAndSet(two, minusThree, 0, 1));
149			assertSame(minusThree, ai.get(mark));
150	jsr166	1.13	assertEquals(1, mark[0]);
151	dl	1.1	}
152
153			}