test/tck/AtomicReferenceTest.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.AtomicReference;

import junit.framework.Test;
import junit.framework.TestSuite;

public class AtomicReferenceTest extends JSR166TestCase {
    public static void main(String[] args) {
        main(suite(), args);
    }
    public static Test suite() {
        return new TestSuite(AtomicReferenceTest.class);
    }

    /**
     * constructor initializes to given value
     */
    public void testConstructor() {
        AtomicReference<Item> ai = new AtomicReference<>(one);
        assertSame(one, ai.get());
    }

    /**
     * default constructed initializes to null
     */
    public void testConstructor2() {
        AtomicReference<Item> ai = new AtomicReference<>();
        assertNull(ai.get());
    }

    /**
     * get returns the last value set
     */
    public void testGetSet() {
        AtomicReference<Item> ai = new AtomicReference<>(one);
        assertSame(one, ai.get());
        ai.set(two);
        assertSame(two, ai.get());
        ai.set(minusThree);
        assertSame(minusThree, ai.get());
    }

    /**
     * get returns the last value lazySet in same thread
     */
    public void testGetLazySet() {
        AtomicReference<Item> ai = new AtomicReference<>(one);
        assertSame(one, ai.get());
        ai.lazySet(two);
        assertSame(two, ai.get());
        ai.lazySet(minusThree);
        assertSame(minusThree, ai.get());
    }

    /**
     * compareAndSet succeeds in changing value if equal to expected else fails
     */
    public void testCompareAndSet() {
        AtomicReference<Item> ai = new AtomicReference<>(one);
        assertTrue(ai.compareAndSet(one, two));
        assertTrue(ai.compareAndSet(two, minusFour));
        assertSame(minusFour, ai.get());
        assertFalse(ai.compareAndSet(minusFive, seven));
        assertSame(minusFour, ai.get());
        assertTrue(ai.compareAndSet(minusFour, seven));
        assertSame(seven, ai.get());
    }

    /**
     * compareAndSet in one thread enables another waiting for value
     * to succeed
     */
    public void testCompareAndSetInMultipleThreads() throws Exception {
        final AtomicReference<Item> ai = new AtomicReference<>(one);
        Thread t = new Thread(new CheckedRunnable() {
            public void realRun() {
                while (!ai.compareAndSet(two, three))
                    Thread.yield();
            }});

        t.start();
        assertTrue(ai.compareAndSet(one, two));
        t.join(LONG_DELAY_MS);
        assertFalse(t.isAlive());
        assertSame(three, ai.get());
    }

    /**
     * repeated weakCompareAndSet succeeds in changing value when equal
     * to expected
     */
    @SuppressWarnings("deprecation")
    public void testWeakCompareAndSet() {
        AtomicReference<Item> ai = new AtomicReference<>(one);
        do {} while (!ai.weakCompareAndSet(one, two));
        do {} while (!ai.weakCompareAndSet(two, minusFour));
        assertSame(minusFour, ai.get());
        do {} while (!ai.weakCompareAndSet(minusFour, seven));
        assertSame(seven, ai.get());
    }

    /**
     * getAndSet returns previous value and sets to given value
     */
    public void testGetAndSet() {
        AtomicReference<Item> ai = new AtomicReference<>(one);
        assertSame(one, ai.getAndSet(zero));
        assertSame(zero, ai.getAndSet(minusTen));
        assertSame(minusTen, ai.getAndSet(one));
    }

    /**
     * a deserialized/reserialized atomic holds same value
     */
    public void testSerialization() throws Exception {
        AtomicReference<Item> x = new AtomicReference<>();
        AtomicReference<Item> y = serialClone(x);
        assertNotSame(x, y);
        x.set(one);
        AtomicReference<Item> z = serialClone(x);
        assertNotSame(y, z);
        assertEquals(one, x.get());
        assertNull(y.get());
        assertEquals(one, z.get());
    }

    /**
     * toString returns current value.
     */
    public void testToString() {
        AtomicReference<Item> ai = new AtomicReference<>(one);
        assertEquals(one.toString(), ai.toString());
        ai.set(two);
        assertEquals(two.toString(), ai.toString());
    }

}
Revision:	1.31
Committed:	Wed Jan 27 01:57:24 2021 UTC (3 years, 3 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.30:	+10 -10 lines
Log Message:	use diamond <> pervasively
#	User	Rev	Content
1	dl	1.1	/*
2	dl	1.6	* 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	1.9	* Other contributors include Andrew Wright, Jeffrey Hayes,
6			* Pat Fisher, Mike Judd.
7	dl	1.1	*/
8
9	jsr166	1.18	import java.util.concurrent.atomic.AtomicReference;
10	dl	1.1
11	jsr166	1.22	import junit.framework.Test;
12			import junit.framework.TestSuite;
13
14	dl	1.3	public class AtomicReferenceTest extends JSR166TestCase {
15	jsr166	1.16	public static void main(String[] args) {
16	jsr166	1.24	main(suite(), args);
17	dl	1.1	}
18			public static Test suite() {
19			return new TestSuite(AtomicReferenceTest.class);
20			}
21
22	dl	1.4	/**
23	dl	1.5	* constructor initializes to given value
24	dl	1.4	*/
25	jsr166	1.11	public void testConstructor() {
26	jsr166	1.31	AtomicReference<Item> ai = new AtomicReference<>(one);
27	jsr166	1.19	assertSame(one, ai.get());
28	dl	1.1	}
29
30	dl	1.4	/**
31	dl	1.5	* default constructed initializes to null
32	dl	1.4	*/
33	jsr166	1.11	public void testConstructor2() {
34	jsr166	1.31	AtomicReference<Item> ai = new AtomicReference<>();
35	jsr166	1.14	assertNull(ai.get());
36	dl	1.1	}
37
38	dl	1.4	/**
39	dl	1.5	* get returns the last value set
40	dl	1.4	*/
41	jsr166	1.11	public void testGetSet() {
42	jsr166	1.31	AtomicReference<Item> ai = new AtomicReference<>(one);
43	jsr166	1.19	assertSame(one, ai.get());
44	jsr166	1.14	ai.set(two);
45	jsr166	1.19	assertSame(two, ai.get());
46	dl	1.30	ai.set(minusThree);
47			assertSame(minusThree, ai.get());
48	dl	1.1	}
49	dl	1.8
50			/**
51			* get returns the last value lazySet in same thread
52			*/
53	jsr166	1.11	public void testGetLazySet() {
54	jsr166	1.31	AtomicReference<Item> ai = new AtomicReference<>(one);
55	jsr166	1.19	assertSame(one, ai.get());
56	jsr166	1.14	ai.lazySet(two);
57	jsr166	1.19	assertSame(two, ai.get());
58	dl	1.30	ai.lazySet(minusThree);
59			assertSame(minusThree, ai.get());
60	dl	1.8	}
61
62	dl	1.4	/**
63	dl	1.5	* compareAndSet succeeds in changing value if equal to expected else fails
64	dl	1.4	*/
65	jsr166	1.11	public void testCompareAndSet() {
66	jsr166	1.31	AtomicReference<Item> ai = new AtomicReference<>(one);
67	jsr166	1.19	assertTrue(ai.compareAndSet(one, two));
68	dl	1.30	assertTrue(ai.compareAndSet(two, minusFour));
69			assertSame(minusFour, ai.get());
70			assertFalse(ai.compareAndSet(minusFive, seven));
71			assertSame(minusFour, ai.get());
72			assertTrue(ai.compareAndSet(minusFour, seven));
73	jsr166	1.19	assertSame(seven, ai.get());
74	dl	1.1	}
75
76	dl	1.4	/**
77	dl	1.5	* compareAndSet in one thread enables another waiting for value
78			* to succeed
79			*/
80	jsr166	1.12	public void testCompareAndSetInMultipleThreads() throws Exception {
81	jsr166	1.31	final AtomicReference<Item> ai = new AtomicReference<>(one);
82	jsr166	1.13	Thread t = new Thread(new CheckedRunnable() {
83			public void realRun() {
84			while (!ai.compareAndSet(two, three))
85			Thread.yield();
86			}});
87	jsr166	1.12
88			t.start();
89			assertTrue(ai.compareAndSet(one, two));
90			t.join(LONG_DELAY_MS);
91			assertFalse(t.isAlive());
92	jsr166	1.20	assertSame(three, ai.get());
93	dl	1.5	}
94
95			/**
96			* repeated weakCompareAndSet succeeds in changing value when equal
97	jsr166	1.9	* to expected
98	dl	1.4	*/
99	dl	1.30	@SuppressWarnings("deprecation")
100	jsr166	1.11	public void testWeakCompareAndSet() {
101	jsr166	1.31	AtomicReference<Item> ai = new AtomicReference<>(one);
102	jsr166	1.23	do {} while (!ai.weakCompareAndSet(one, two));
103	dl	1.30	do {} while (!ai.weakCompareAndSet(two, minusFour));
104			assertSame(minusFour, ai.get());
105			do {} while (!ai.weakCompareAndSet(minusFour, seven));
106	jsr166	1.19	assertSame(seven, ai.get());
107	dl	1.1	}
108
109	dl	1.4	/**
110	dl	1.5	* getAndSet returns previous value and sets to given value
111	dl	1.4	*/
112	jsr166	1.11	public void testGetAndSet() {
113	jsr166	1.31	AtomicReference<Item> ai = new AtomicReference<>(one);
114	jsr166	1.19	assertSame(one, ai.getAndSet(zero));
115	dl	1.30	assertSame(zero, ai.getAndSet(minusTen));
116			assertSame(minusTen, ai.getAndSet(one));
117	dl	1.2	}
118
119	dl	1.4	/**
120	jsr166	1.29	* a deserialized/reserialized atomic holds same value
121	dl	1.4	*/
122	jsr166	1.12	public void testSerialization() throws Exception {
123	jsr166	1.31	AtomicReference<Item> x = new AtomicReference<>();
124	dl	1.30	AtomicReference<Item> y = serialClone(x);
125	jsr166	1.21	assertNotSame(x, y);
126	jsr166	1.18	x.set(one);
127	dl	1.30	AtomicReference<Item> z = serialClone(x);
128	jsr166	1.21	assertNotSame(y, z);
129	jsr166	1.18	assertEquals(one, x.get());
130	jsr166	1.28	assertNull(y.get());
131	jsr166	1.18	assertEquals(one, z.get());
132	dl	1.1	}
133
134	dl	1.7	/**
135			* toString returns current value.
136	jsr166	1.9	*/
137	dl	1.7	public void testToString() {
138	jsr166	1.31	AtomicReference<Item> ai = new AtomicReference<>(one);
139	jsr166	1.20	assertEquals(one.toString(), ai.toString());
140	dl	1.7	ai.set(two);
141	jsr166	1.20	assertEquals(two.toString(), ai.toString());
142	dl	1.7	}
143
144	dl	1.1	}