高併發計數器

package day01.synchronize;java

/**安全

  • @title: Counter
  • @description:
  • @author: 北京小桔匯金網絡科技有限公司
  • @date: 2018/5/2 13:35 */ import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.AtomicInteger;

/**網絡

  • 關於count++在多線程調用狀況下多線程

  • @author jan / public class Counter { // private volatile int count = 0; private AtomicInteger count = new AtomicInteger(1); /*ide

    • 爲了保證數據的準確性,多線程的狀況下須要加上synchronized關鍵字</br>
    • 不然會出現出乎預料的結果 這也是線程安全的重要體現 */ public void increment() { count.incrementAndGet(); }

    private int getCount() { return count.get(); }atom

    /**.net

    • 這裏模擬一個遞增的任務,遞增目標爲100W */ public static void main(String[] args) throws InterruptedException { final Counter counter = new Counter(); // final AtomicCounter counter = new AtomicCounter(); int workCount = 1000000; ExecutorService executor = Executors.newFixedThreadPool(10); long start = System.currentTimeMillis(); for (int i = 0; i < workCount; i++) { Runnable runnable = new Runnable() { @Override public void run() { counter.increment(); } }; executor.execute(runnable); } // 關閉啓動線程,執行未完成的任務 executor.shutdown(); // 等待全部線程完成任務,完成後才繼續執行下一步 executor.awaitTermination(Long.MAX_VALUE, TimeUnit.DAYS); System.out.println("耗時:" + (System.currentTimeMillis() - start) + "ms"); System.out.println("執行結果:count=" + counter.getCount()); } }
相關文章
相關標籤/搜索