Java的多线程有关问题

2012-03-27

Java的多线程问题直接上源码：Java codepackage com.workclass Resource{int Goods0boolean choosefals

Java的多线程问题
直接上源码：

Java code

package com.work;class Resource{     int Goods=0;     boolean choose=false;}class Consumer implements Runnable{  //消费者    Resource r;    public Consumer(Resource r){        this.r=r;    }    public void run() {       synchronized (r) {        while (true) {            if (r.choose==true) {                r.Goods--;                r.choose=false;                System.out.println("消费了"+r.Goods);            }         }      }            }  }class Producer implements Runnable{  //生产者    Resource r;    public Producer(Resource r){        this.r=r;    }    public void run() {         synchronized (r) {            while (true) {                if (r.choose==false) {                    r.Goods++;  //1                    r.choose=true;                    System.out.println("生产了"+r.Goods);                }            }              }                }       }public class Sample {        public static void main(String[] args) {       Resource r=new Resource();       Consumer con=new Consumer(r);       Producer pro=new Producer(r);       Thread b=new Thread(pro);       b.start();       Thread a=new Thread(con);       a.start();     }}

现象：
只答应了生产了1，然后线程停在哪？

求解释，谢谢各位！！！

[解决办法]

Java code

         synchronized (r) {            while (true) {                if (r.choose==false) {                    r.Goods++;  //1                    r.choose=true;                    System.out.println("生产了"+r.Goods);                }            }              }
[解决办法]
Java codeclass Resource {    int Goods = 0;    boolean choose = false;}class Consumer implements Runnable { // 消费者    Resource r;    public Consumer(Resource r) {        this.r = r;    }    public void run() {        while (true) {            synchronized (r) {                if (r.choose == true) {                    r.choose = false;                    System.out.println("消费了" + r.Goods--);                }            }        }    }}class Producer implements Runnable { // 生产者    Resource r;    public Producer(Resource r) {        this.r = r;    }    public void run() {        while (true) {            synchronized (r) {                if (r.choose == false) {                    r.Goods++; // 1                    r.choose = true;                    System.out.println("生产了" + r.Goods);                }            }        }    }}public class Sample {    public static void main(String[] args) {        Resource r = new Resource();        Consumer con = new Consumer(r);        Producer pro = new Producer(r);        Thread b = new Thread(pro);        b.start();        Thread a = new Thread(con);        a.start();    }}
[解决办法]
我觉得不会. 执行完后还要回来执行的. 只有同步块的程序执行完,才释放锁.
[解决办法]
class Resource{
   int Goods=0;
   boolean choose=false;
}
class Consumer implements Runnable{  //消费者
  Resource r;
  public Consumer(Resource r){
      this.r=r;
  }
  public void run() {
      while (true) {
          synchronized (r) {
          if (r.choose==true) {
              r.Goods--;
              r.choose=false;
              System.out.println("消费了"+r.Goods);
          }
       }
    }       
  }
  }
class Producer implements Runnable{  //生产者
  Resource r;
  public Producer(Resource r){
      this.r=r; 
 
  }
  public void run() {
          while (true) {
            synchronized (r) {
              if (r.choose==false) {
                  r.Goods++;  //1
                  r.choose=true;
                  System.out.println("生产了"+r.Goods);
              }
          }   
        }       
      }
     }
把这两行对调以下位置就好了，你应该是想在操作Resource的时候互斥，可你把死循环也放在同步块里面，线程根本就跳不出去抢用资源，所以就出现你这种情况了

热点排行

Bad Request.

J2SE开发

Java的多线程有关问题