java並發流程式控制制(CountDownLatch-CycliBarrier)__java

1)CountDownLatch 門插銷計數器       1.  啟動線程，然後等待線程結束。即常用的主線程等所有子線程結束後再執行的問題。
public static void main(String[] args)throws Exception { // TODO Auto-generated method stub final int count=10; final CountDownLatch completeLatch = new CountDownLatch(count);//定義了門插銷的數目是10 for(int i=0;i<count;i++){ Thread thread = new Thread("worker thread"+i){ public void run(){ //do xxxx completeLatch.countDown();//減少一根門插銷 } }; thread.start(); } completeLatch.await();//如果門插銷還沒減完則等待。 } 2.啟動很多線程，等待通知才能開始
public static void main(String[] args) throws Exception { // TODO Auto-generated method stub final CountDownLatch startLatch = new CountDownLatch(1);//定義了一根門插銷
for (int i = 0; i < 10; i++) { Thread thread = new Thread("worker thread" + i) { public void run() { try { startLatch.await();//如果門插銷還沒減完則等待 } catch (InterruptedException e) {
} // do xxxx } }; thread.start(); } startLatch.countDown();//減少一根門插銷 }

2) CycliBarrier. 等所有線程都達到一個起跑線後才能開始繼續運行。 public class CycliBarrierTest implements Runnable { private CyclicBarrier barrier;
public CycliBarrierTest(CyclicBarrier barrier) { this.barrier = barrier; }
public void run() { //do xxxx; try { this.barrier.await();//線程運行至此會檢查是否其它線程都到齊了，沒到齊就繼續等待。到齊了就執行barrier的run函數體裡的內容 } catch (Exception e) {
} }
/** * @param args */ public static void main(String[] args) { //參數2代表兩個線程都達到起跑線才開始一起繼續往下執行 CyclicBarrier barrier = new CyclicBarrier(2, new Runnable() { public void run() { //do xxxx; } }); Thread t1 = new Thread(new CycliBarrierTest(barrier)); Thread t2 = new Thread(new CycliBarrierTest(barrier)); t1.start(); t2.start(); }
}