多線程（七、同步計(jì)數(shù)器-CountDownLatch）

CountDownLatch是一個(gè)線程的同步計(jì)數(shù)器，主要有2個(gè)使用場(chǎng)景。

1、作為一個(gè)開(kāi)關(guān)，N個(gè)子線程準(zhǔn)備就緒，等待主線程的放行，然后子線程一起開(kāi)始執(zhí)行。

Task

package com.jane;

import java.util.concurrent.CountDownLatch;

public class Task implements Runnable {
    private CountDownLatch countDownLatch;
    private String name;

    public Task(CountDownLatch countDownLatch, String name) {
        this.countDownLatch = countDownLatch;
        this.name = name;
    }

    @Override
    public void run() {
        try {
            System.out.println(name + "開(kāi)始等待開(kāi)關(guān)......");
            countDownLatch.await();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println(name + "執(zhí)行任務(wù)完成");
    }
}

主線程

public class Main {

    public static void main(String[] args) throws InterruptedException {
        //主線程創(chuàng)建，和子線程共享
        CountDownLatch countDownLatch = new CountDownLatch(1);

        System.out.println("主線程啟動(dòng)......");

        //創(chuàng)建3個(gè)子線程
        Thread t1 = new Thread(new Task(countDownLatch, "線程-1"));
        Thread t2 = new Thread(new Task(countDownLatch, "線程-2"));
        Thread t3 = new Thread(new Task(countDownLatch, "線程-3"));

        t1.start();
        t2.start();
        t3.start();

        Thread.sleep(2000);
        System.out.println("主線程執(zhí)行任務(wù)完畢，放行......");
        countDownLatch.countDown();
        System.out.println("主線程執(zhí)行完畢");

    }
}

執(zhí)行結(jié)果

創(chuàng)新互聯(lián)建站成都網(wǎng)站建設(shè)按需求定制制作，是成都網(wǎng)站建設(shè)公司,為人造霧提供網(wǎng)站建設(shè)服務(wù),有成熟的網(wǎng)站定制合作流程，提供網(wǎng)站定制設(shè)計(jì)服務(wù)：原型圖制作、網(wǎng)站創(chuàng)意設(shè)計(jì)、前端HTML5制作、后臺(tái)程序開(kāi)發(fā)等。成都網(wǎng)站建設(shè)熱線：13518219792

2、主線程等待N個(gè)子線程的處理結(jié)果，子線程都完成后，主線程繼續(xù)執(zhí)行。

Task

package com.jane;

import java.util.concurrent.CountDownLatch;

public class Task1 implements Runnable {
    private CountDownLatch countDownLatch;
    private String name;

    public Task1(CountDownLatch countDownLatch, String name) {
        this.countDownLatch = countDownLatch;
        this.name = name;
    }

    @Override
    public void run() {
        try {
            System.out.println(name + "開(kāi)始開(kāi)始執(zhí)行任務(wù)......");
            Thread.sleep(2000);
            System.out.println(name + "執(zhí)行任務(wù)完成");
            countDownLatch.countDown();
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}

主線程

package com.jane;

import java.util.concurrent.CountDownLatch;

public class Main1 {

    public static void main(String[] args) throws InterruptedException {
        //主線程創(chuàng)建，和子線程共享
        CountDownLatch countDownLatch = new CountDownLatch(3);

        System.out.println("主線程啟動(dòng)......");

        //創(chuàng)建3個(gè)子線程
        Thread t1 = new Thread(new Task1(countDownLatch, "線程-1"));
        Thread t2 = new Thread(new Task1(countDownLatch, "線程-2"));
        Thread t3 = new Thread(new Task1(countDownLatch, "線程-3"));

        t1.start();
        t2.start();
        t3.start();

        System.out.println("主線程等待子線程執(zhí)行結(jié)果......");
        countDownLatch.await();
        System.out.println("主線程執(zhí)行完畢");

    }
}

執(zhí)行結(jié)果

注意：CountDownLatch的計(jì)數(shù)只能使用一次，不會(huì)自動(dòng)重新開(kāi)始。

本文題目：多線程（七、同步計(jì)數(shù)器-CountDownLatch）
分享路徑：http://muchs.cn/article6/pgodog.html

成都網(wǎng)站建設(shè)公司_創(chuàng)新互聯(lián)，為您提供手機(jī)網(wǎng)站建設(shè)、外貿(mào)網(wǎng)站建設(shè)、網(wǎng)站改版、定制開(kāi)發(fā)、網(wǎng)站內(nèi)鏈、網(wǎng)頁(yè)設(shè)計(jì)公司

廣告

聲明：本網(wǎng)站發(fā)布的內(nèi)容（圖片、視頻和文字）以用戶(hù)投稿、用戶(hù)轉(zhuǎn)載內(nèi)容為主，如果涉及侵權(quán)請(qǐng)盡快告知，我們將會(huì)在第一時(shí)間刪除。文章觀點(diǎn)不代表本網(wǎng)站立場(chǎng)，如需處理請(qǐng)聯(lián)系客服。電話：028-86922220；郵箱：631063699@qq.com。內(nèi)容未經(jīng)允許不得轉(zhuǎn)載，或轉(zhuǎn)載時(shí)需注明來(lái)源： 創(chuàng)新互聯(lián)