生产者消费者模式代码简单实现

看见有些作者在书上用synchronized同步锁去实现，利用wait()和notify()发信号。

其实锁方法是没办法并发的，这样做会把并行变成串行计算了。

信号量最好是创建一个新的类包含生产者和消费者的信号，再使用关键字volatile保证有序性。

代码如下:

public class Main {
    public static void main(String[]args){
        LinkedListqueen = new LinkedList();
        Sign sign = new Sign();
        sign.iniSign();
        new Thread(new Business(new Productor(),queen,500,100,sign)).start();
        new Thread(new Business(new Customer(),queen,5,1000,sign)).start();
    }
} 

/**
 * 信号
 */
public class Sign {
    public  volatile int sign_p = 0;
    public  volatile int sing_c = 0;

    public void iniSign(){
        this.sign_p = 1;
        this.sing_c = 0;
    }
} 

public class Business implements Runnable {
    Person person;
    LinkedList queen;
    int len;
    int time;
    Sign sign;
    public Business(Person person,LinkedList queen, int len,int time,Sign sign) {
        this.person = person;
        this.queen = queen;
        this.len = len;
        this.time = time;
        this.sign = sign;
    }
    @Override
    public void run() {
        person.doThis(queen,len,time,sign);
    }
}

public  interface Person {

    void doThis(LinkedListqueen,int len,int time,Sign sign);
} 

/**
 * 消费者，如果队列无数据，无法消费
 */
public class Customer implements Person {
    public synchronized void doThis(LinkedList queen, int len, int time, Sign sign) {
        System.out.println("消费者就绪");
        while (true) {
            while (sign.sing_c == 0) {

            }
            try {
                Thread.sleep(time);
            } catch (InterruptedException e) {
            }
            if (queen.size() > 0) {
                System.out.println("消费者消费数据: " + queen.removeFirst());
                sign.sign_p = 1;//释放生产信号
            } else {
                sign.sing_c = 0; //冻结消费信号
            }
        }
    }
}

public synchronized void doThis(LinkedList queen, int len, int time,Sign sign) {
        System.out.printf("生产者就绪");
        int i = 0;
        while (true) {
            while(sign.sign_p == 0){
//                System.out.println("生产者阻塞！！！");
            }
            try {
                Thread.sleep(time);
            } catch (InterruptedException e) {
            }
            if (queen.size() < len) {
                queen.addLast(i);
                System.out.println("生产者，生产数据： " + i++);
                sign.sing_c = 1;//释放消费信号
            } else {
                sign.sign_p = 0; //冻结生产信号
            }
        }
    }
}