스레드 동기화 예제2 - volatile, Atomic

A - (use Atomic)

import java.util.concurrent.atomic.AtomicInteger;

/**
 * Created by chkyu on 2016-03-22.
 */
public class A {


    private static AtomicInteger a ;
    A(){
        a=new AtomicInteger(15);
    }
    public void work(){
        //a--;
        a.decrementAndGet();
    }
    public AtomicInteger getA(){
        return a;
    }

}

D - volatile

import java.util.concurrent.TimeUnit;

public class D  {

    private static volatile boolean stopRequested=false;
    //private static boolean stopRequested=false;

    private static void requestStop(){
        stopRequested = true;
    }

    private static boolean stopRequested(){
        return stopRequested;
    }

    public static void main(String[] args) throws InterruptedException {
        Thread backThread = new Thread(new Runnable(){
            public void run(){
                int i=0;
                System.out.println(2);
                while(!stopRequested)
                    i++;
                System.out.println(4+"/"+i);
            }
        });

        backThread.start();
        System.out.println(1);
        TimeUnit.SECONDS.sleep(1);
        System.out.println(3);
        stopRequested = true;

    }
}

E - Sycnrozied

import java.util.concurrent.TimeUnit;

public class E {

    private static boolean stopRequested;

    private static synchronized void requestStop(){
        stopRequested = true;
    }

    private static synchronized boolean stopRequested(){
        return stopRequested;
    }

    public static void main(String[] args) throws InterruptedException {

        Thread backThread = new Thread(new Runnable(){
            public void run(){
                int i=0;

                System.out.println(2);
                while(!stopRequested())
                    i++;
                System.out.println(4+"/"+i);
            }
        });

        backThread.start();
        System.out.println(1);
        TimeUnit.SECONDS.sleep(1);
        System.out.println(3);
        requestStop();
    }
}

http://changpd.blogspot.kr/2016/03/2-volatile-atomic.html

class A는
스레드 동기화 예제1 - syncronized 의 A에서 수정