多线程生产消费问题

运用Lock和Condition解决多线程容易出现的问题（基础方法）

Lock：lock(); unlock(); newCondition();

Condition: await(); single(); singleAll();

import java.util.concurrent.locks.*;

class ProducerConsumerDemo
{
public static void main(String[] args)
{
Resource r = new Resource();
Producer pro = new Producer(r);
Consumer con = new Consumer(r);

Thread t1 = new Thread(pro);
Thread t2 = new Thread(pro);
Thread
4000
t3 = new Thread(con);
Thread t4 = new Thread(con);

t1.start();
t2.start();
t3.start();
t4.start();

}
}

class Resource
{
private String name;
private int count = 1;
private Boolean flag = false;
public Lock lock = new ReentrantLock();

private Condition condition_pro = lock.newCondition();
private Condition condition_con = lock.newCondition();

public void set(String name)throws InterruptedException
{
lock.lock();//上锁
try
{
while(flag)
condition_pro.await();//pro进入等待
this.name = name+"--"+count++;

System.out.println(Thread.currentThread().getName()+"...生产者.."+this.name);
flag = true;
condition_con.signal();//唤醒con一个等待线程

}
finally
{
lock.unlock();//锁必须释放
}
}

public void out()throws InterruptedException
{
lock.lock();
try
{
while(!flag)
condition_con.await();//con进入等待
this.name = name+"--"+count++;

System.out.println(Thread.currentThread().getName()+"...消费者.."+this.name);
flag = false;
condition_pro.signal();//唤醒一个pro线程

}
finally
{
lock.unlock();
}
}
}

class Producer implements Runnable
{
private Resource res;
Producer(Resource res)
{
this.res = res;
}
public void run()
{
while(true)
{
try
{
res.set("+商品+");
}
catch (InterruptedException e)
{
}

}
}
}

class Consumer implements Runnable
{
private Resource res;

Consumer(Resource res)
{
this.res = res;
}
public void run()
{
while(true)
{
try
{
res.out();
}
catch (InterruptedException e)
{
}
}
}
}