08_CountDownLatch

CountDownLatch是一个同步工具类，用来协调多个线程之间的同步。CountDownLatch的原理是，一个线程等待其他线程完成某个操作后，再继续执行。

CountDownLatch的使用

package io.alex.concurrent;
import java.util.concurrent.CountDownLatch;
public class CountDownLatchExample {
    public static void main(String[] args) throws InterruptedException {
        // 创建一个CountDownLatch对象，计数器的值为20
        CountDownLatch countDownLatch = new CountDownLatch(20);
        // 启动线程
        for (int i = 0; i < 20; i++) {
            Thread thread = new Thread(() -> {
                System.out.println("Thread "+Thread.currentThread().getName()+" is running...count->"+countDownLatch.getCount());
                countDownLatch.countDown();
            }, "Thread-" + i);
            thread.start();
        }
        // 当计数器的值为0时，所有等待的线程将被唤醒
        countDownLatch.await();
        System.out.println("All threads are finished.");
    }
}