CountDownLatch
が1に設定され、すべてのスレッドで減少すると、3つのスレッドが実行できる理由はWorker.run()
です。世界でシンプリーCountDownLatchが動作しない
public class App {
public static void main(String[] args){
CountDownLatch latch = new CountDownLatch(1);
Thread t1 = new Thread(new Worker(1, latch));
Thread t2 = new Thread(new Worker(2, latch));
Thread t3 = new Thread(new Worker(3, latch));
t1.start();
t2.start();
t3.start();
try {
t1.join();
t2.join();
t3.join();
latch.await();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("end");
}
}
。
import java.util.concurrent.CountDownLatch;
public class Worker implements Runnable {
int x;
CountDownLatch latch;
public Worker(int x, CountDownLatch latch) {
this.x = x;
this.latch = latch;
}
@Override
public void run() {
latch.countDown();
try {
for (int i = 0; i < 3; i++) {
System.out.println(x);
Thread.sleep(1000);
}
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}