test/tck/LongAdderTest.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/
 */

import junit.framework.*;
import java.util.concurrent.*;
import java.util.concurrent.atomic.LongAdder;

public class LongAdderTest extends JSR166TestCase {
    public static void main(String[] args) {
        junit.textui.TestRunner.run(suite());
    }
    public static Test suite() {
        return new TestSuite(LongAdderTest.class);
    }

    /**
     * default constructed initializes to zero
     */
    public void testConstructor() {
        LongAdder ai = new LongAdder();
        assertEquals(0, ai.sum());
    }

    /**
     * add adds given value to current, and sum returns current value
     */
    public void testAddAndSum() {
        LongAdder ai = new LongAdder();
        ai.add(2);
        assertEquals(2, ai.sum());
        ai.add(-4);
        assertEquals(-2, ai.sum());
    }

    /**
     * decrement decrements and sum returns current value
     */
    public void testDecrementAndsum() {
        LongAdder ai = new LongAdder();
        ai.decrement();
        assertEquals(-1, ai.sum());
        ai.decrement();
        assertEquals(-2, ai.sum());
    }

    /**
     * incrementAndGet increments and returns current value
     */
    public void testIncrementAndsum() {
        LongAdder ai = new LongAdder();
        ai.increment();
        assertEquals(1, ai.sum());
        ai.increment();
        assertEquals(2, ai.sum());
    }

    /**
     * reset zeroes sum
     */
    public void testReset() {
        LongAdder ai = new LongAdder();
        ai.add(2);
        assertEquals(2, ai.sum());
        ai.reset();
        assertEquals(0, ai.sum());
    }

    /**
     * sumThenReset returns sum then zeros
     */
    public void testSumThenReset() {
        LongAdder ai = new LongAdder();
        ai.add(2);
        assertEquals(2, ai.sum());
        assertEquals(2, ai.sumThenReset());
        assertEquals(0, ai.sum());
    }

    /**
     * a deserialized serialized adder holds same value
     */
    public void testSerialization() throws Exception {
        LongAdder x = new LongAdder();
        LongAdder y = serialClone(x);
        assertTrue(x != y);
        x.add(-22);
        LongAdder z = serialClone(x);
        assertEquals(-22, x.sum());
        assertEquals(0, y.sum());
        assertEquals(-22, z.sum());
    }

    /**
     * toString returns current value.
     */
    public void testToString() {
        LongAdder ai = new LongAdder();
        assertEquals("0", ai.toString());
        ai.increment();
        assertEquals(Long.toString(1), ai.toString());
    }

    /**
     * intValue returns current value.
     */
    public void testIntValue() {
        LongAdder ai = new LongAdder();
        assertEquals(0, ai.intValue());
        ai.increment();
        assertEquals(1, ai.intValue());
    }

    /**
     * longValue returns current value.
     */
    public void testLongValue() {
        LongAdder ai = new LongAdder();
        assertEquals(0, ai.longValue());
        ai.increment();
        assertEquals(1, ai.longValue());
    }

    /**
     * floatValue returns current value.
     */
    public void testFloatValue() {
        LongAdder ai = new LongAdder();
        assertEquals(0.0f, ai.floatValue());
        ai.increment();
        assertEquals(1.0f, ai.floatValue());
    }

    /**
     * doubleValue returns current value.
     */
    public void testDoubleValue() {
        LongAdder ai = new LongAdder();
        assertEquals(0.0, ai.doubleValue());
        ai.increment();
        assertEquals(1.0, ai.doubleValue());
    }

    /**
     * adds by multiple threads produce correct sum
     */
    public void testAddAndSumMT() {
        final int incs = 1000000;
        final int nthreads = 4;
        final ExecutorService pool = Executors.newCachedThreadPool();
        LongAdder a = new LongAdder();
        Phaser phaser = new Phaser(nthreads + 1);
        for (int i = 0; i < nthreads; ++i)
            pool.execute(new AdderTask(a, phaser, incs));
        phaser.arriveAndAwaitAdvance();
        phaser.arriveAndAwaitAdvance();
        long total = (long)nthreads * incs;
        long sum = a.sum();
        assertEquals(sum, total);
        pool.shutdown();
    }

   static final class AdderTask implements Runnable {
        final LongAdder adder;
        final Phaser phaser;
        final int incs;
        volatile long result;
        AdderTask(LongAdder adder, Phaser phaser, int incs) { 
            this.adder = adder; 
            this.phaser = phaser;
            this.incs = incs;
        }

        public void run() {
            phaser.arriveAndAwaitAdvance();
            LongAdder a = adder;
            for (int i = 0; i < incs; ++i)
                a.add(1L);
            result = a.sum();
            phaser.arrive();
        }
    }

}
Revision:	1.1
Committed:	Wed Mar 20 20:29:02 2013 UTC (11 years, 1 month ago) by dl
Branch:	MAIN
Log Message:	Basic coverage for LongAdder and friends
#	User	Rev	Content
1	dl	1.1	/*
2			* 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			* http://creativecommons.org/publicdomain/zero/1.0/
5			*/
6
7			import junit.framework.*;
8			import java.util.concurrent.*;
9			import java.util.concurrent.atomic.LongAdder;
10
11			public class LongAdderTest extends JSR166TestCase {
12			public static void main(String[] args) {
13			junit.textui.TestRunner.run(suite());
14			}
15			public static Test suite() {
16			return new TestSuite(LongAdderTest.class);
17			}
18
19			/**
20			* default constructed initializes to zero
21			*/
22			public void testConstructor() {
23			LongAdder ai = new LongAdder();
24			assertEquals(0, ai.sum());
25			}
26
27			/**
28			* add adds given value to current, and sum returns current value
29			*/
30			public void testAddAndSum() {
31			LongAdder ai = new LongAdder();
32			ai.add(2);
33			assertEquals(2, ai.sum());
34			ai.add(-4);
35			assertEquals(-2, ai.sum());
36			}
37
38			/**
39			* decrement decrements and sum returns current value
40			*/
41			public void testDecrementAndsum() {
42			LongAdder ai = new LongAdder();
43			ai.decrement();
44			assertEquals(-1, ai.sum());
45			ai.decrement();
46			assertEquals(-2, ai.sum());
47			}
48
49			/**
50			* incrementAndGet increments and returns current value
51			*/
52			public void testIncrementAndsum() {
53			LongAdder ai = new LongAdder();
54			ai.increment();
55			assertEquals(1, ai.sum());
56			ai.increment();
57			assertEquals(2, ai.sum());
58			}
59
60			/**
61			* reset zeroes sum
62			*/
63			public void testReset() {
64			LongAdder ai = new LongAdder();
65			ai.add(2);
66			assertEquals(2, ai.sum());
67			ai.reset();
68			assertEquals(0, ai.sum());
69			}
70
71			/**
72			* sumThenReset returns sum then zeros
73			*/
74			public void testSumThenReset() {
75			LongAdder ai = new LongAdder();
76			ai.add(2);
77			assertEquals(2, ai.sum());
78			assertEquals(2, ai.sumThenReset());
79			assertEquals(0, ai.sum());
80			}
81
82			/**
83			* a deserialized serialized adder holds same value
84			*/
85			public void testSerialization() throws Exception {
86			LongAdder x = new LongAdder();
87			LongAdder y = serialClone(x);
88			assertTrue(x != y);
89			x.add(-22);
90			LongAdder z = serialClone(x);
91			assertEquals(-22, x.sum());
92			assertEquals(0, y.sum());
93			assertEquals(-22, z.sum());
94			}
95
96			/**
97			* toString returns current value.
98			*/
99			public void testToString() {
100			LongAdder ai = new LongAdder();
101			assertEquals("0", ai.toString());
102			ai.increment();
103			assertEquals(Long.toString(1), ai.toString());
104			}
105
106			/**
107			* intValue returns current value.
108			*/
109			public void testIntValue() {
110			LongAdder ai = new LongAdder();
111			assertEquals(0, ai.intValue());
112			ai.increment();
113			assertEquals(1, ai.intValue());
114			}
115
116			/**
117			* longValue returns current value.
118			*/
119			public void testLongValue() {
120			LongAdder ai = new LongAdder();
121			assertEquals(0, ai.longValue());
122			ai.increment();
123			assertEquals(1, ai.longValue());
124			}
125
126			/**
127			* floatValue returns current value.
128			*/
129			public void testFloatValue() {
130			LongAdder ai = new LongAdder();
131			assertEquals(0.0f, ai.floatValue());
132			ai.increment();
133			assertEquals(1.0f, ai.floatValue());
134			}
135
136			/**
137			* doubleValue returns current value.
138			*/
139			public void testDoubleValue() {
140			LongAdder ai = new LongAdder();
141			assertEquals(0.0, ai.doubleValue());
142			ai.increment();
143			assertEquals(1.0, ai.doubleValue());
144			}
145
146			/**
147			* adds by multiple threads produce correct sum
148			*/
149			public void testAddAndSumMT() {
150			final int incs = 1000000;
151			final int nthreads = 4;
152			final ExecutorService pool = Executors.newCachedThreadPool();
153			LongAdder a = new LongAdder();
154			Phaser phaser = new Phaser(nthreads + 1);
155			for (int i = 0; i < nthreads; ++i)
156			pool.execute(new AdderTask(a, phaser, incs));
157			phaser.arriveAndAwaitAdvance();
158			phaser.arriveAndAwaitAdvance();
159			long total = (long)nthreads * incs;
160			long sum = a.sum();
161			assertEquals(sum, total);
162			pool.shutdown();
163			}
164
165			static final class AdderTask implements Runnable {
166			final LongAdder adder;
167			final Phaser phaser;
168			final int incs;
169			volatile long result;
170			AdderTask(LongAdder adder, Phaser phaser, int incs) {
171			this.adder = adder;
172			this.phaser = phaser;
173			this.incs = incs;
174			}
175
176			public void run() {
177			phaser.arriveAndAwaitAdvance();
178			LongAdder a = adder;
179			for (int i = 0; i < incs; ++i)
180			a.add(1L);
181			result = a.sum();
182			phaser.arrive();
183			}
184			}
185
186			}