多线程通讯轮询卖票了解一下

Posted 2020-11-19

package com.xp.test;

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

public class ABC_Lock {

public static void main(String[] args) {
    Print print = new Print();

    // new Thread(new Runnable() {
    // @Override
    // public void run() {
    // for (int i = 1; i <= 34; i++) {
    // print.loopA(i);
    // }
    // }
    // }, "A").start();
    // new Thread(new Runnable() {
    // @Override
    // public void run() {
    // for (int i = 1; i <= 33; i++) {
    // print.loopB(i);
    // }
    // }
    // }, "B").start();
    // new Thread(new Runnable() {
    // @Override
    // public void run() {
    // for (int i = 1; i <= 33; i++) {
    // print.loopC(i);
    // }
    // }
    // }, "C").start();
    // }
    int i = 33;
    while (i > 0) {
        i--;
        new Thread(new Runnable() {
            @Override
            public void run() {
                print.loopA();
            }
        }, "A").start();
        new Thread(new Runnable() {
            @Override
            public void run() {
                print.loopB();
            }
        }, "B").start();
        new Thread(new Runnable() {
            @Override
            public void run() {
                print.loopC();
            }
        }, "C").start();
    }

}

}

class Print {
private Lock lock = new ReentrantLock();
private Condition conditionA = lock.newCondition();
private Condition conditionB = lock.newCondition();
private Condition conditionC = lock.newCondition();

int tick = 100;
String mark = "a";

public void loopA() {
    lock.lock();
    try {
        if (!"a".equals(mark)) {
            try {
                conditionA.await();
            } catch (InterruptedException e) {
            }
        }
        System.out.println(Thread.currentThread().getName() + "完成售票，剩余： " + --tick);
        mark = "b";
        conditionB.signal();
    } finally {
        lock.unlock();
    }
}

public void loopB() {
    lock.lock();
    try {
        if (!"b".equals(mark)) {
            try {
                conditionB.await();
            } catch (InterruptedException e) {
            }
        }
        System.out.println(Thread.currentThread().getName() + "完成售票，剩余： " + --tick);
        mark = "c";
        conditionC.signal();
    } finally {
        lock.unlock();
    }
}

public void loopC() {
    lock.lock();
    try {
        if (!"c".equals(mark)) {
            try {
                conditionC.await();
            } catch (InterruptedException e) {
            }
        }
        System.out.println(Thread.currentThread().getName() + "完成售票，剩余： " + --tick);
        mark = "a";
        conditionA.signal();
    } finally {
        lock.unlock();
    }
}

}