public class BlockArrayList extends ArrayList
{
/**
* long serialVersionUID:TODO（用一句话描述这个变量表示什么）
*
* @since 1.0.0
*/
private static final long serialVersionUID = 1L;
private ReentrantLock lock = new ReentrantLock();
private Condition notEmpty = lock.newCondition();
public int i = 0;
public Exception ee;
public E take() throws InterruptedException
{
try
{
lock.lock();
E e = null;
int size = this.size();
if(size == 0)
{
notEmpty.await();
}
i++;
System.out.println(i);
try
{
e = this.remove(0);
}
catch(Exception e1)
{
ee = e1;
}
return e;
}
finally
{
lock.unlock();
}
}
public boolean offer(E e)
{
try
{
lock.lock();
this.add(e);
notEmpty.signal();
return true;
}
finally
{
lock.unlock();
}
}
public void op()
{
E s = null;
try
{
s = this.take();
}
catch (InterruptedException e)
{
System.out.println(Thread.currentThread().getName() +" 被动结束");
e.printStackTrace();
}
}
public class MyThreadFactory implements ThreadFactory
{
private AtomicInteger NUMBER = new AtomicInteger(0);
@Override
public Thread newThread(Runnable r)
{
Thread t = new Thread(r);
t.setName("shaoweiThread-"+NUMBER.decrementAndGet());
return t;
}
}
public static void main(String[] args)
{
final BlockArrayList<String> list = new BlockArrayList<String>();
ThreadFactory threadThread = list.new MyThreadFactory();
Thread t = threadThread.newThread(new Runnable()
{
@Override
public void run()
{
int i = 0;
while(i <410000)
{
list.op();
}
}
});
t.start();
threadThread.newThread(new Runnable()
{
@Override
public void run()
{
int i = 0;
while(i <410000)
{
list.op();
}
}
}).start();
threadThread.newThread(new Runnable()
{
@Override
public void run()
{
for(int i=0;i<400000;i++)
{
boolean flag = list.offer("item" + i);
if(!flag)
{
System.out.println("添加元素失败");
}
}
System.out.println(list.ee);
}
}).start();
System.out.println("主线程结束");
}
}
多个线程去取阻塞队列为啥会有并发问题呢？i正常应该为400000的，谁能给解释下
