AtomicLong与LongAdder执行效率对比

浅浅的花香味﹌ 2023-10-06 08:15 3阅读 0赞

> AtomicLong与LongAdder执行效率对比：

package com.mashibing.juc.c_018_00_AtomicXXX;
    
    import java.util.concurrent.TimeUnit;
    import java.util.concurrent.atomic.AtomicLong;
    import java.util.concurrent.atomic.LongAdder;
    
    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();
            }
        }
    
    }

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[202005071259236.png]: https://img-blog.csdnimg.cn/202005071259236.png