atomic write: 25377ms, synchronized write: 56757ms, atomic read: 639ms, synchronized read: 56181ms, volatile read: 43ms, normal read: 640ms,

AtomicTest.java

package pig.pigtest;

import java.util.concurrent.atomic.AtomicLong;

import org.junit.Test;

public class AtomicTest {

    private AtomicLong v1 = new AtomicLong(0);
    private long v2 = 0;
    private volatile long v3 = Integer.MAX_VALUE;
    private long v4 = Integer.MAX_VALUE;

    public long incr1() {
        return v1.getAndIncrement();
    }

    public synchronized long incr2() {
        return v2++;
    }

    public long get1() {
        return v1.get();
    }

    public synchronized long get2() {
        return v2;
    }

    public long get3() {
        return v3;
    }

    public long get4() {
        return v4;
    }

    @Test
    public void testAtomicLong() {
        int count = Integer.MAX_VALUE;

        long s = System.currentTimeMillis();
        for (int i = 0; i < count; i++) {
            incr1();
        }
        System.out.printf("atomic write: %sms%n", System.currentTimeMillis() - s);

        s = System.currentTimeMillis();
        for (int i = 0; i < count; i++) {
            incr2();
        }
        System.out.printf("synchronized write: %sms%n", System.currentTimeMillis() - s);

        s = System.currentTimeMillis();
        for (int i = 0; i < count; i++) {
            get1();
        }
        System.out.printf("atomic read: %sms%n", System.currentTimeMillis() - s);

        s = System.currentTimeMillis();
        for (int i = 0; i < count; i++) {
            get2();
        }
        System.out.printf("synchronized read: %sms%n", System.currentTimeMillis() - s);

        s = System.currentTimeMillis();
        for (int i = 0; i < count; i++) {
            get3();
        }
        System.out.printf("volatile read: %sms%n", System.currentTimeMillis() - s);

        s = System.currentTimeMillis();
        for (int i = 0; i < count; i++) {
            get4();
        }
        System.out.printf("normal read: %sms%n", System.currentTimeMillis() - s);
    }

}