打印机-顾客进程同步

来源：互联网发布：sftp用的什么端口编辑：程序博客网时间：2024/05/16 19:13

系统中有一个打印进程Printer和若干顾客进程Customer_i（i>20）。缓冲池有5个缓冲区。如果

Customer_i进程要打印，则Printer进程阻塞。当Customer_i进程需要打印时，唤醒Printer进程；如果

没有缓冲区，Customer_i则必须放弃打印。请设计同步机制实现以上要求。

package customer;public class ProducerConsumer {/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stub        SyncStack ss=new SyncStack();        Printer p=new Printer(ss);        Consumer c=new Consumer(ss);        new Thread(p).start();         new Thread(c).start();}}class file{int id;    file(int id){this.id=id;}public String toString(){return "第:"+id;}}////这个方法是同步的方法，每次只有5个线程可以进来class SyncStack {  int index = 0;  file[] arrWT = new file[5];  public synchronized void push(file wt) {   while(index == arrWT.length) {    try {    System.out.println("没有空闲的打印机了，请等待！");   System.out.println(wt+"为放弃打印的文件");       this.wait();    } catch (InterruptedException e) {     e.printStackTrace();    }   }   this.notifyAll();     arrWT[index] = wt;   index ++;   System.out.println(wt+"个顾客"+"打印了， "+wt+"份文件"); }  public synchronized file pop() {   while(index == 0) {    try {System.out.println("店里没人了！");    this.wait();    } catch (InterruptedException e) {     e.printStackTrace();    }   }   this.notifyAll();   index--;   System.out.println(arrWT[index]+"份文件打印完毕，店里剩余"+index+"顾客");  return arrWT[index];  } }  class Printer implements Runnable {  SyncStack ss = null;  Printer(SyncStack ss) {   this.ss = ss;  } //打印进程  public void run() {   for(int i=0; i<25; i++) {  file wt = new file(i); ss.push(wt); try{ Thread.sleep((int)(Math.random()*200));  }catch(InterruptedException e){ e.printStackTrace();  }   }  }}class Consumer implements Runnable { SyncStack ss = null; Consumer(SyncStack ss) { this.ss = ss;  } //顾客进程  public void run() {     for(int i=0; i<25; i++) {    ss.pop();     //System.out.println("打印了: " + wt);    try {   Thread.sleep((int)(Math.random() * 1000)); } catch (InterruptedException e) {    e.printStackTrace();  }           }   } }

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