线程同步工具类,CyclicBarrier日常开发较少涉及,这里只举一个例子,以做备注.N个人一块出去玩,相约去两个地方,CyclicBarrier的主要作用是等待所有人都汇合了,才往下一站出发.
1.效果如下:
2.实现代码:
package com.amos.concurrent; import java.util.Random;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors; /**
* @ClassName: CyclicBarrierTest
* @Description: 线程同步工具类,CyclicBarrier的主要作用是等待所有人都汇合了,才往下一站出发,日常应用中较少涉及
* @author: amosli
* @email:hi_amos@outlook.com
* @date Apr 25, 2014 1:35:34 AM
*/
public class CyclicBarrierTest {
public static void main(String[] args) {
final CyclicBarrier cyclicBarrier = new CyclicBarrier(3);
ExecutorService newCachedThreadPool = Executors.newCachedThreadPool();
for(int i=0;i<3;i++){
Runnable runnable = new Runnable() {
public void run() {
try {
Thread.sleep(new Random().nextInt(1000));
} catch (Exception e1) {
e1.printStackTrace();
}
System.out.println("线程"+Thread.currentThread().getName()+"即将到达集合点1"+",当前已有"+(cyclicBarrier.getNumberWaiting()==2?(cyclicBarrier.getNumberWaiting()+1)+"人,人数已经集合完毕,即将向下一站进发":(cyclicBarrier.getNumberWaiting()+1)+"人"));
try {
cyclicBarrier.await();
} catch (Exception e1) {
e1.printStackTrace();
} try {
Thread.sleep(new Random().nextInt(1000));
} catch (Exception e1) {
e1.printStackTrace();
}
System.out.println("线程"+Thread.currentThread().getName()+"即将到达集合点2"+",当前已有"+(cyclicBarrier.getNumberWaiting()==2?(cyclicBarrier.getNumberWaiting()+1)+"人,人数已经集合完毕,即将向下一站进发":(cyclicBarrier.getNumberWaiting()+1)+"人"));
try {
cyclicBarrier.await();
} catch (Exception e1) {
e1.printStackTrace();
} }
};
newCachedThreadPool.execute(runnable);
}
newCachedThreadPool.shutdown();
}
}
3.用法:
1),如何创建?
CyclicBarrier cyclicBarrier = new CyclicBarrier((int parties);
CyclicBarrier cyclicBarrier =new CyclicBarrier(int parties, Runnable barrierAction)
2).如何控制线程到一个集结点?
cyclicBarrier.await();
调用await()方法即可.
同时可以设置最长待时间,只需要调用await(long timeout, TimeUnit unit)方法即可.
3)如何打破障碍?
breakBarrier();
调用breakBarrier() 方法将可以打破当前的障碍.
如果看其内部实现方法不难发现关于Lock锁的应用.