java同步例子之CyclicBarrier
它允许一组线程互相等待，直到到达某个公共屏障点，barrier 在释放等待线程后可以重用，所以称它为循环 的 barrier。
package concurrent;import java.util.concurrent.BrokenBarrierException;import java.util.concurrent.CyclicBarrier;/** * 允许一组线程互相等待，直到到达某个公共屏障点 * @author user * */public class CyclicBarrierTest {private int[] numArray = new int[5];private final CyclicBarrier barrier = new CyclicBarrier(5, new Runnable() {@Overridepublic void run() {int sum = 0;for(int i = 0; i < numArray.length; i++){sum += numArray[i];}System.err.println(sum);}});public void start(){for(int i = 0; i < numArray.length; i++){final int j = i;new Thread(new Runnable() {@Overridepublic void run() {numArray[j] = j + 1;try {barrier.await();} catch (InterruptedException e) {e.printStackTrace();} catch (BrokenBarrierException e) {e.printStackTrace();}}}).start();}}/** * @param args */public static void main(String[] args) {CyclicBarrierTest test = new CyclicBarrierTest();test.start();}}