Semaphore

Semaphore 通常用于限制可以访问某些资源的线程数目，demo：

 

package com.jerry.concurrency.semaphore;

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


//排队上厕所
public class Test {
public static void main(String[] args) {
ExecutorService 人 =Executors.newCachedThreadPool();
final Semaphore 茅坑 =new Semaphore(2);
for(int i=0;i<10;i++){
人.submit(new Runnable() {
@Override
public void run() {
try{
茅坑.acquire();
System.out.println("人["+Thread.currentThread().getName()+"]进入厕所，还有"+茅坑.availablePermits()+"个空坑");
System.out.println("人["+Thread.currentThread().getName()+"]获得坑位,开始大便...");
Thread.sleep((int)(Math.random()*1000));
} catch(Exception e){
e.printStackTrace();
}finally{
System.out.println("人["+Thread.currentThread().getName()+"]使用完毕离开，当前还有"+(茅坑.availablePermits()+1)+"个空坑");
茅坑.release();
}
}
});
}
人.shutdown();
茅坑.acquireUninterruptibly(2);
System.out.println("使用完毕，阿姨需要清扫了卫生了！");
茅坑.release(2);
}


}