test/jsr166e/LongAdderDemo.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 java.util.concurrent.Phaser;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicLong;
import jsr166e.LongAdder;

public class LongAdderDemo {
    static final int INCS_PER_THREAD = 10000000; 
    static final int NCPU = Runtime.getRuntime().availableProcessors();
    static final ExecutorService pool = Executors.newCachedThreadPool();

    public static void main(String[] args) {
        System.out.println("Warmup...");
        int half = NCPU > 1 ? NCPU / 2 : 1;
        casTest(half, 1000);
        adderTest(half, 1000);

        for (int reps = 0; reps < 2; ++reps) {
            System.out.println("Running...");
            for (int i = 1; i <= NCPU * 2; i <<= 1) {
                casTest(i, INCS_PER_THREAD);
                adderTest(i, INCS_PER_THREAD);
            }
        }
        pool.shutdown();
    }

    static void casTest(int nthreads, int incs) {
        System.out.print("AtomicLong ");
        Phaser phaser = new Phaser(nthreads + 1);
        AtomicLong a = new AtomicLong();
        for (int i = 0; i < nthreads; ++i)
            pool.execute(new CasTask(a, phaser, incs));
        report(nthreads, incs, timeTasks(phaser), a.get());
    }

    static void adderTest(int nthreads, int incs) {
        System.out.print("LongAdder  ");
        Phaser phaser = new Phaser(nthreads + 1);
        LongAdder a = new LongAdder();
        for (int i = 0; i < nthreads; ++i)
            pool.execute(new AdderTask(a, phaser, incs));
        report(nthreads, incs, timeTasks(phaser), a.sum());
    }

    static void report(int nthreads, int incs, long time, long sum) {
        long total = (long)nthreads * incs;
        if (sum != total)
            throw new Error(sum + " != " + total);
        double secs = (double)time / (1000L * 1000 * 1000);
        long rate = total * (1000L) / time;
        System.out.printf("threads:%3d  Time: %7.3fsec  Incs per microsec: %4d\n",
                          nthreads, secs, rate);
    }

    static long timeTasks(Phaser phaser) {
        phaser.arriveAndAwaitAdvance();
        long start = System.nanoTime();
        phaser.arriveAndAwaitAdvance();
        phaser.arriveAndAwaitAdvance();
        return System.nanoTime() - start;
    }

    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();
            phaser.arriveAndAwaitAdvance();
            LongAdder a = adder;
            for (int i = 0; i < incs; ++i)
                a.increment();
            result = a.sum();
            phaser.arrive();
        }
    }

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

        public void run() {
            phaser.arriveAndAwaitAdvance();
            phaser.arriveAndAwaitAdvance();
            AtomicLong a = adder;
            for (int i = 0; i < incs; ++i)
                a.getAndIncrement();
            result = a.get();
            phaser.arrive();
        }
    }

}
Revision:	1.1
Committed:	Sun Jul 31 14:20:11 2011 UTC (12 years, 10 months ago) by dl
Branch:	MAIN
Log Message:	Rename classes
#	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 java.util.concurrent.Phaser;
8			import java.util.concurrent.ExecutorService;
9			import java.util.concurrent.Executors;
10			import java.util.concurrent.atomic.AtomicLong;
11			import jsr166e.LongAdder;
12
13			public class LongAdderDemo {
14			static final int INCS_PER_THREAD = 10000000;
15			static final int NCPU = Runtime.getRuntime().availableProcessors();
16			static final ExecutorService pool = Executors.newCachedThreadPool();
17
18			public static void main(String[] args) {
19			System.out.println("Warmup...");
20			int half = NCPU > 1 ? NCPU / 2 : 1;
21			casTest(half, 1000);
22			adderTest(half, 1000);
23
24			for (int reps = 0; reps < 2; ++reps) {
25			System.out.println("Running...");
26			for (int i = 1; i <= NCPU * 2; i <<= 1) {
27			casTest(i, INCS_PER_THREAD);
28			adderTest(i, INCS_PER_THREAD);
29			}
30			}
31			pool.shutdown();
32			}
33
34			static void casTest(int nthreads, int incs) {
35			System.out.print("AtomicLong ");
36			Phaser phaser = new Phaser(nthreads + 1);
37			AtomicLong a = new AtomicLong();
38			for (int i = 0; i < nthreads; ++i)
39			pool.execute(new CasTask(a, phaser, incs));
40			report(nthreads, incs, timeTasks(phaser), a.get());
41			}
42
43			static void adderTest(int nthreads, int incs) {
44			System.out.print("LongAdder ");
45			Phaser phaser = new Phaser(nthreads + 1);
46			LongAdder a = new LongAdder();
47			for (int i = 0; i < nthreads; ++i)
48			pool.execute(new AdderTask(a, phaser, incs));
49			report(nthreads, incs, timeTasks(phaser), a.sum());
50			}
51
52			static void report(int nthreads, int incs, long time, long sum) {
53			long total = (long)nthreads * incs;
54			if (sum != total)
55			throw new Error(sum + " != " + total);
56			double secs = (double)time / (1000L * 1000 * 1000);
57			long rate = total * (1000L) / time;
58			System.out.printf("threads:%3d Time: %7.3fsec Incs per microsec: %4d\n",
59			nthreads, secs, rate);
60			}
61
62			static long timeTasks(Phaser phaser) {
63			phaser.arriveAndAwaitAdvance();
64			long start = System.nanoTime();
65			phaser.arriveAndAwaitAdvance();
66			phaser.arriveAndAwaitAdvance();
67			return System.nanoTime() - start;
68			}
69
70			static final class AdderTask implements Runnable {
71			final LongAdder adder;
72			final Phaser phaser;
73			final int incs;
74			volatile long result;
75			AdderTask(LongAdder adder, Phaser phaser, int incs) {
76			this.adder = adder;
77			this.phaser = phaser;
78			this.incs = incs;
79			}
80
81			public void run() {
82			phaser.arriveAndAwaitAdvance();
83			phaser.arriveAndAwaitAdvance();
84			LongAdder a = adder;
85			for (int i = 0; i < incs; ++i)
86			a.increment();
87			result = a.sum();
88			phaser.arrive();
89			}
90			}
91
92			static final class CasTask implements Runnable {
93			final AtomicLong adder;
94			final Phaser phaser;
95			final int incs;
96			volatile long result;
97			CasTask(AtomicLong adder, Phaser phaser, int incs) {
98			this.adder = adder;
99			this.phaser = phaser;
100			this.incs = incs;
101			}
102
103			public void run() {
104			phaser.arriveAndAwaitAdvance();
105			phaser.arriveAndAwaitAdvance();
106			AtomicLong a = adder;
107			for (int i = 0; i < incs; ++i)
108			a.getAndIncrement();
109			result = a.get();
110			phaser.arrive();
111			}
112			}
113
114			}