Atomic Sync LongAdder的比较

package cn.qqjx.thread;


import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.LongAdder;


/*
 * @Auther  wangpeng
 * @Date 2021/1/9
 */

public class T02_AtomicVsSyncVsLongAdder {
    
    

    static long count2 = 0L;
    static AtomicLong count1 = new AtomicLong(0L);
    static LongAdder count3 = new LongAdder();

    public static void main(String[] args) throws Exception {
    
    
        Thread[] threads = new Thread[1000];

        for(int i=0; i<threads.length; i++) {
    
    
            threads[i] =
                    new Thread(()-> {
    
    
                        for(int k=0; k<100000; k++) count1.incrementAndGet();
                    });
        }

        long start = System.currentTimeMillis();

        for(Thread t : threads ) t.start();

        for (Thread t : threads) t.join();

        long end = System.currentTimeMillis();

        //TimeUnit.SECONDS.sleep(10);

        System.out.println("Atomic: " + count1.get() + " time " + (end-start));
        //-----------------------------------------------------------
        Object lock = new Object();

        for(int i=0; i<threads.length; i++) {
    
    
            threads[i] =
                    new Thread(new Runnable() {
    
    
                        @Override
                        public void run() {
    
    

                            for (int k = 0; k < 100000; k++)
                                synchronized (lock) {
    
    
                                    count2++;
                                }
                        }
                    });
        }

        start = System.currentTimeMillis();

        for(Thread t : threads ) t.start();

        for (Thread t : threads) t.join();

        end = System.currentTimeMillis();


        System.out.println("Sync: " + count2 + " time " + (end-start));


        //----------------------------------
        for(int i=0; i<threads.length; i++) {
    
    
            threads[i] =
                    new Thread(()-> {
    
    
                        for(int k=0; k<100000; k++) count3.increment();
                    });
        }

        start = System.currentTimeMillis();

        for(Thread t : threads ) t.start();

        for (Thread t : threads) t.join();

        end = System.currentTimeMillis();

        //TimeUnit.SECONDS.sleep(10);

        System.out.println("LongAdder: " + count1.longValue() + " time " + (end-start));

    }

    static void microSleep(int m) {
    
    
        try {
    
    
            TimeUnit.MICROSECONDS.sleep(m);
        } catch (InterruptedException e) {
    
    
            e.printStackTrace();
        }
    }


}

Atomic: 100000000 time 1730
Sync: 100000000 time 3376
LongAdder: 100000000 time 240