3.1.3 允许多个线程同时访问：信号量

package 第三章.信号量;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;

/**
 * Created by zzq on 2018/1/23.
 */
public class SimpoTest implements Runnable {
    final Semaphore semaphore=new Semaphore(5);
    public void run() {
        try {
            semaphore.acquire();
            System.out.println(Thread.currentThread().getName() + "-------获取执行权");
            Thread.sleep(2000);
            semaphore.release();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        ExecutorService executorService = Executors.newFixedThreadPool(20);
      final   SimpoTest simpoTest=new SimpoTest();
        for (int i = 0; i < 10; i++) {
            executorService.submit(simpoTest);
        }
        executorService.shutdown();

    }
}