Jdk8 AdderTest

DemoClass.java

/**
 * Created by madhub_2 on 3/15/2015.
 */
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 */

package javaapplication1;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.LongAdder;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author madhub_2
 */
class DemoClass {

    public static void main(String[] args) {
        // Utilize a DoubleAdder or LongAdder to contain the value that is being summed across multiple threads in order
        // to ensure safe handling
        ExecutorService es = Executors.newFixedThreadPool(5);

        LongAdder sumOfAllValues = new LongAdder();
        AtomicLong sum = new AtomicLong();

        CountDownLatch startSignal = new CountDownLatch(5);

        es.submit( () -> {
            try {
                startSignal.await();
            } catch (InterruptedException ex) {
                Logger.getLogger(DemoClass.class.getName()).log(Level.SEVERE, null, ex);
            }

            for( int i =0; i < 10;i++) {
                sumOfAllValues.add(i);
                sum.addAndGet(i);
            }

        });

        es.submit( () -> {

            try {
                System.out.println("Thread-"+Thread.currentThread().getId()+" waiting");
                startSignal.await();
                System.out.println("Thread-"+Thread.currentThread().getId()+" started");
            } catch (InterruptedException ex) {
                Logger.getLogger(DemoClass.class.getName()).log(Level.SEVERE, null, ex);
            }
            for( int i =0; i < 10;i++) {
                sumOfAllValues.add(i);
                sum.addAndGet(i);
            }

        });

        es.submit( () -> {

            try {
                System.out.println("Thread-"+Thread.currentThread().getId()+" waiting");
                startSignal.await();
                System.out.println("Thread-"+Thread.currentThread().getId()+" started");
            } catch (InterruptedException ex) {
                Logger.getLogger(DemoClass.class.getName()).log(Level.SEVERE, null, ex);
            }

            for( int i =0; i < 10;i++) {
                sumOfAllValues.add(i);
                sum.addAndGet(i);
            }

        });

        es.submit( () -> {
            try {
                System.out.println("Thread-"+Thread.currentThread().getId()+" waiting");
                startSignal.await();
                System.out.println("Thread-"+Thread.currentThread().getId()+" started");
            } catch (InterruptedException ex) {
                Logger.getLogger(DemoClass.class.getName()).log(Level.SEVERE, null, ex);
            }
            for( int i =0; i < 10;i++) {
                sumOfAllValues.add(i);
                sum.addAndGet(i);
            }

        });

        es.submit( () -> {
            try {
                System.out.println("Thread-"+Thread.currentThread().getId()+" waiting");
                startSignal.await();
                System.out.println("Thread-"+Thread.currentThread().getId()+" started");
            } catch (InterruptedException ex) {
                Logger.getLogger(DemoClass.class.getName()).log(Level.SEVERE, null, ex);
            }
            for( int i =0; i < 10;i++) {
                sumOfAllValues.add(i);
                sum.addAndGet(i);
            }

        });
        while ( startSignal.getCount() != 0 ) {
            startSignal.countDown();
        }
        es.shutdown();
        try {
            es.awaitTermination(1, TimeUnit.DAYS);
        } catch (InterruptedException ex) {
            Logger.getLogger(DemoClass.class.getName()).log(Level.SEVERE, null, ex);
        }
        System.out.println("Done "+sumOfAllValues.longValue());
        System.out.println("Done "+sum.longValue());


    }
}