test/loops/LongAdderLoops.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.*;
import java.util.concurrent.atomic.LongAdder;
import java.util.concurrent.Executors;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Phaser;

public class LongAdderLoops {
    static final int ITERS = 10000000;
    static final int NCPU = Runtime.getRuntime().availableProcessors();
    static final int MAX_THREADS = NCPU * 2;
    static final long NPS = (1000L * 1000 * 1000);

    static final ExecutorService pool = Executors.newCachedThreadPool();

    public static void main(String[] args) {
        for (int i = 1; i < MAX_THREADS; ++i)
            adderTest(i, ITERS);
        pool.shutdown();
    }

    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();
        }
    }

}
Revision:	1.1
Committed:	Mon Jan 26 14:23:10 2015 UTC (9 years, 3 months ago) by dl
Branch:	MAIN
Log Message:	Convert jsr166e version
#	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.*;
8			import java.util.concurrent.atomic.LongAdder;
9			import java.util.concurrent.Executors;
10			import java.util.concurrent.ExecutorService;
11			import java.util.concurrent.Phaser;
12
13			public class LongAdderLoops {
14			static final int ITERS = 10000000;
15			static final int NCPU = Runtime.getRuntime().availableProcessors();
16			static final int MAX_THREADS = NCPU * 2;
17			static final long NPS = (1000L * 1000 * 1000);
18
19			static final ExecutorService pool = Executors.newCachedThreadPool();
20
21			public static void main(String[] args) {
22			for (int i = 1; i < MAX_THREADS; ++i)
23			adderTest(i, ITERS);
24			pool.shutdown();
25			}
26
27			static void adderTest(int nthreads, int incs) {
28			System.out.print("LongAdder ");
29			Phaser phaser = new Phaser(nthreads + 1);
30			LongAdder a = new LongAdder();
31			for (int i = 0; i < nthreads; ++i)
32			pool.execute(new AdderTask(a, phaser, incs));
33			report(nthreads, incs, timeTasks(phaser), a.sum());
34			}
35
36			static void report(int nthreads, int incs, long time, long sum) {
37			long total = (long)nthreads * incs;
38			if (sum != total)
39			throw new Error(sum + " != " + total);
40			double secs = (double)time / (1000L * 1000 * 1000);
41			long rate = total * (1000L) / time;
42			System.out.printf("threads:%3d Time: %7.3fsec Incs per microsec: %4d\n",
43			nthreads, secs, rate);
44			}
45
46			static long timeTasks(Phaser phaser) {
47			phaser.arriveAndAwaitAdvance();
48			long start = System.nanoTime();
49			phaser.arriveAndAwaitAdvance();
50			phaser.arriveAndAwaitAdvance();
51			return System.nanoTime() - start;
52			}
53
54			static final class AdderTask implements Runnable {
55			final LongAdder adder;
56			final Phaser phaser;
57			final int incs;
58			volatile long result;
59			AdderTask(LongAdder adder, Phaser phaser, int incs) {
60			this.adder = adder;
61			this.phaser = phaser;
62			this.incs = incs;
63			}
64
65			public void run() {
66			phaser.arriveAndAwaitAdvance();
67			phaser.arriveAndAwaitAdvance();
68			LongAdder a = adder;
69			for (int i = 0; i < incs; ++i)
70			a.increment();
71			result = a.sum();
72			phaser.arrive();
73			}
74			}
75
76			}