JUC---06线程间通信

Posted 2020-11-29 jenne-blog

二、线程间定制化调用通信

　　要使多线程之间按顺序调用，实现A->B->C按顺序输出，使用Lock锁实现,通过Lock锁创建三个Condition实例（三把钥匙），通过不同的条件，调用不同钥匙的awite（）跟singnal（）方法，阻塞或唤醒其他线程

　　代码实现：

package com.jenne.mydemo;


import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

class ShareData {

    private int num = 1;//1:AA,2:BB,3:CC

    private Lock lock = new ReentrantLock();
    Condition cd1 = lock.newCondition();
    Condition cd2 = lock.newCondition();
    Condition cd3 = lock.newCondition();

    public void print5(int total) {
        lock.lock();
        try {
            //判断
            while (num != 1) {
                cd1.await();
            }
            //干活
            System.out.println(Thread.currentThread().getName() + "	 " + total + "	");

            //通知
            num = 2;
            cd2.signal();

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }


    }

    public void print10(int total) {
        lock.lock();
        try {
            //判断
            while (num != 2) {
                cd2.await();
            }
            //干活
            System.out.println(Thread.currentThread().getName() + "	 " + total + "	");

            //通知
            num = 3;
            cd3.signal();

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }

    }

    public void print15(int total) {
        lock.lock();
        try {
            //判断
            while (num != 3) {
                cd3.await();
            }
            //干活
            System.out.println(Thread.currentThread().getName() + "	 " + total + "	");

            //通知
            num = 1;
            cd1.signal();

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }
}

public class TestThreadOrderAccess {

    public static void main(String[] args) {
        ShareData shareData = new ShareData();

        new Thread(() -> {
            for (int i = 1; i <= 10; i++) {
                shareData.print5(i);
            }
        }, "AA").start();

        new Thread(() -> {
            for (int i = 1; i <= 10; i++) {
                shareData.print10(i);
            }
        }, "BB").start();

        new Thread(() -> {
            for (int i = 1; i <= 10; i++) {
                shareData.print15(i);
            }
        }, "CC").start();
    }
}