Java线程(24):新特征-条件变量(二)

2014-11-24 08:24:20 · 作者: · 浏览: 1
t(String oid, int cash) {
this.oid = oid;
this.cash = cash;
}
/**
* 存款
*
* @param x 操作金额
* @param name 操作人
*/
public void saving( int x, String name) {
lock.lock(); //获取锁
if (x > 0) {
cash += x; //存款
System.out.println(name + "存款" + x + ",当前余额为" + cash);
}
_draw.signalAll(); //唤醒所有等待线程。
lock.unlock(); //释放锁
}
/**
* 取款
*
* @param x 操作金额
* @param name 操作人
*/
public void drawing( int x, String name) {
lock.lock(); //获取锁
try {
if (cash - x < 0) {
_draw.await(); //阻塞取款操作
} else {
cash -= x; //取款
System.out.println(name + "取款" + x + ",当前余额为" + cash);
}
_save.signalAll(); //唤醒所有存款操作
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
lock.unlock(); //释放锁
}
}
}
李四存款3600,当前余额为13600
张三存款2000,当前余额为15600
老张存款600,当前余额为16200
老牛取款1300,当前余额为14900
胖子取款800,当前余额为14100
王五取款2700,当前余额为11400
Process finished with exit code 0
假如我们不用锁和条件变量,如何实现此功能呢?下面是实现代码:
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
/**
* Java线程:不用条件变量
*
* @author leizhimin 2009-11-5 10:57:29
*/
public class Test {
public static void main(String[] args) {
//创建并发访问的账户
MyCount myCount = new MyCount( "95599200901215522", 10000);
//创建一个线程池
ExecutorService pool = Executors.newFixedThreadPool(2);
Thread t1 = new SaveThread( "张三", myCount, 2000);
Thread t2 = new SaveThread( "李四", myCount, 3600);
Thread t3 = new DrawThread( "王五", myCount, 2700);
Thread t4 = new SaveThread( "老张", myCount, 600);
Thread t5 = new DrawThread( "老牛", myCount, 1300);
Thread t6 = new DrawThread( "胖子", myCount, 800);
//执行各个线程
pool.execute(t1);
pool.execute(t2);
pool.execute(t3);
pool.execute(t4);
pool.execute(t5);
pool.execute(t6);
//关闭线程池
pool.shutdown();
}
}
/**
* 存款线程类
*/
class SaveThread extends Thread {
private String name; //操作人
private MyCount myCount; //账户
private int x; //存款金额
SaveThread(String name, MyCount myCount, int x) {
this.name = name;
this.myCount = myCount;
this.x = x;
}
public void run() {
myCount.saving(x, name);
}
}
/**
* 取款线程类
*/
class DrawThread extends Thread {
private String name; //操作人
private MyCount myCount; //账户
private int x; //存款金额
DrawThread(String name, MyCount myCo