Semaphore信号量

说明

Semaphore信号量作为一种流控手段
1.连接池的并发数
2.有界阻塞容器的容量等
3.acquire与release并没有强制的一对一关系，release一次就相当于新增一个许可

最大并发数

Semaphore信号量

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

public class SemaporeTest {
    private static int threadTotal = 200;
    private static int clientTotal = 5000;
    private static int count = 0;
    public static void main(String[] args) {
        ExecutorService executorService = Executors.newCachedThreadPool();
        final Semaphore semaphore = new Semaphore(threadTotal);
        for (int i = 0; i < clientTotal; i++) {
            executorService.execute(()->{
                try {
                    semaphore.acquire();
                    add();
                    semaphore.release();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            });
        }
        System.out.println(count);
    }

    private static void add() {
        count++;
    }
}