Java多线程编程中使用Condition类操作锁的方法详解

// 造成当前线程在接到信号或被中断之前一直处于等待状态。
void await()
// 造成当前线程在接到信号、被中断或到达指定等待时间之前一直处于等待状态。
boolean await(long time, TimeUnit unit)
// 造成当前线程在接到信号、被中断或到达指定等待时间之前一直处于等待状态。
long awaitNanos(long nanosTimeout)
// 造成当前线程在接到信号之前一直处于等待状态。
void awaitUninterruptibly()
// 造成当前线程在接到信号、被中断或到达指定最后期限之前一直处于等待状态。
boolean awaitUntil(Date deadline)
// 唤醒一个等待线程。
void signal()
// 唤醒所有等待线程。
void signalAll()

public class ThreadTest2 { 
  public static void main(String[] args) { 
    final Business business = new Business(); 
    new Thread(new Runnable() { 
      @Override 
      public void run() { 
        threadExecute(business, "sub"); 
      } 
    }).start(); 
    threadExecute(business, "main"); 
  }   
  public static void threadExecute(Business business, String threadType) { 
    for(int i = 0; i < 100; i++) { 
      try { 
        if("main".equals(threadType)) { 
          business.main(i); 
        } else { 
          business.sub(i); 
        } 
      } catch (InterruptedException e) { 
        e.printStackTrace(); 
      } 
    } 
  } 
} 
class Business { 
  private boolean bool = true; 
  private Lock lock = new ReentrantLock(); 
  private Condition condition = lock.newCondition();  
  public /*synchronized*/ void main(int loop) throws InterruptedException { 
    lock.lock(); 
    try { 
      while(bool) {         
        condition.await();//this.wait(); 
      } 
      for(int i = 0; i < 100; i++) { 
        System.out.println("main thread seq of " + i + ", loop of " + loop); 
      } 
      bool = true; 
      condition.signal();//this.notify(); 
    } finally { 
      lock.unlock(); 
    } 
  }   
  public /*synchronized*/ void sub(int loop) throws InterruptedException { 
    lock.lock(); 
    try { 
      while(!bool) { 
        condition.await();//this.wait(); 
      } 
      for(int i = 0; i < 10; i++) { 
        System.out.println("sub thread seq of " + i + ", loop of " + loop); 
      } 
      bool = false; 
      condition.signal();//this.notify(); 
    } finally { 
      lock.unlock(); 
    } 
  } 
} 

class BoundedBuffer { 
  final Lock lock = new ReentrantLock();//锁对象 
  final Condition notFull = lock.newCondition();//写线程条件  
  final Condition notEmpty = lock.newCondition();//读线程条件  
 
  final Object[] items = new Object[100];//缓存队列 
  int putptr/*写索引*/, takeptr/*读索引*/, count/*队列中存在的数据个数*/; 
 
  public void put(Object x) throws InterruptedException { 
   lock.lock(); 
   try { 
    while (count == items.length)//如果队列满了  
     notFull.await();//阻塞写线程 
    items[putptr] = x;//赋值  
    if (++putptr == items.length) putptr = 0;//如果写索引写到队列的最后一个位置了，那么置为0 
    ++count;//个数++ 
    notEmpty.signal();//唤醒读线程 
   } finally { 
    lock.unlock(); 
   } 
  } 
 
  public Object take() throws InterruptedException { 
   lock.lock(); 
   try { 
    while (count == 0)//如果队列为空 
     notEmpty.await();//阻塞读线程 
    Object x = items[takeptr];//取值  
    if (++takeptr == items.length) takeptr = 0;//如果读索引读到队列的最后一个位置了，那么置为0 
    --count;//个数-- 
    notFull.signal();//唤醒写线程 
    return x; 
   } finally { 
    lock.unlock(); 
   } 
  }  
 }