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 java.util.concurrent.atomic.LongAdder;
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:	1.3
Committed:	Sat Mar 26 12:35:00 2016 UTC (8 years, 2 months ago) by dl
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.2:	+3 -2 lines
Log Message:	update tests
#	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	dl	1.3	//import java.util.concurrent.atomic.LongAdder;
12	dl	1.1	import jsr166e.LongAdder;
13
14			public class LongAdderDemo {
15	jsr166	1.2	static final int INCS_PER_THREAD = 10000000;
16	dl	1.1	static final int NCPU = Runtime.getRuntime().availableProcessors();
17			static final ExecutorService pool = Executors.newCachedThreadPool();
18
19			public static void main(String[] args) {
20			System.out.println("Warmup...");
21			int half = NCPU > 1 ? NCPU / 2 : 1;
22	dl	1.3	// casTest(half, 1000);
23	dl	1.1	adderTest(half, 1000);
24
25			for (int reps = 0; reps < 2; ++reps) {
26			System.out.println("Running...");
27			for (int i = 1; i <= NCPU * 2; i <<= 1) {
28	dl	1.3	// casTest(i, INCS_PER_THREAD);
29	dl	1.1	adderTest(i, INCS_PER_THREAD);
30			}
31			}
32			pool.shutdown();
33			}
34
35			static void casTest(int nthreads, int incs) {
36			System.out.print("AtomicLong ");
37			Phaser phaser = new Phaser(nthreads + 1);
38			AtomicLong a = new AtomicLong();
39			for (int i = 0; i < nthreads; ++i)
40			pool.execute(new CasTask(a, phaser, incs));
41			report(nthreads, incs, timeTasks(phaser), a.get());
42			}
43
44			static void adderTest(int nthreads, int incs) {
45			System.out.print("LongAdder ");
46			Phaser phaser = new Phaser(nthreads + 1);
47			LongAdder a = new LongAdder();
48			for (int i = 0; i < nthreads; ++i)
49			pool.execute(new AdderTask(a, phaser, incs));
50			report(nthreads, incs, timeTasks(phaser), a.sum());
51			}
52
53			static void report(int nthreads, int incs, long time, long sum) {
54			long total = (long)nthreads * incs;
55			if (sum != total)
56			throw new Error(sum + " != " + total);
57			double secs = (double)time / (1000L * 1000 * 1000);
58			long rate = total * (1000L) / time;
59			System.out.printf("threads:%3d Time: %7.3fsec Incs per microsec: %4d\n",
60			nthreads, secs, rate);
61			}
62
63			static long timeTasks(Phaser phaser) {
64			phaser.arriveAndAwaitAdvance();
65			long start = System.nanoTime();
66			phaser.arriveAndAwaitAdvance();
67			phaser.arriveAndAwaitAdvance();
68			return System.nanoTime() - start;
69			}
70
71			static final class AdderTask implements Runnable {
72			final LongAdder adder;
73			final Phaser phaser;
74			final int incs;
75			volatile long result;
76	jsr166	1.2	AdderTask(LongAdder adder, Phaser phaser, int incs) {
77			this.adder = adder;
78	dl	1.1	this.phaser = phaser;
79			this.incs = incs;
80			}
81
82			public void run() {
83			phaser.arriveAndAwaitAdvance();
84			phaser.arriveAndAwaitAdvance();
85			LongAdder a = adder;
86			for (int i = 0; i < incs; ++i)
87			a.increment();
88			result = a.sum();
89			phaser.arrive();
90			}
91			}
92
93			static final class CasTask implements Runnable {
94			final AtomicLong adder;
95			final Phaser phaser;
96			final int incs;
97			volatile long result;
98	jsr166	1.2	CasTask(AtomicLong adder, Phaser phaser, int incs) {
99			this.adder = adder;
100	dl	1.1	this.phaser = phaser;
101			this.incs = incs;
102			}
103
104			public void run() {
105			phaser.arriveAndAwaitAdvance();
106			phaser.arriveAndAwaitAdvance();
107			AtomicLong a = adder;
108			for (int i = 0; i < incs; ++i)
109			a.getAndIncrement();
110			result = a.get();
111			phaser.arrive();
112			}
113			}
114
115	jsr166	1.2	}