Java并发编程示例代码-----ReentrantLock

public class ReenterLock implements Runnable{
    public static ReentrantLock lock=new ReentrantLock();
    public static int i=0;
    @Override
    public void run() {
        for(int j=0;j<10000000;j++){
            lock.lock();
            try{
                i++;
            }finally{
                lock.unlock();
            }
        }
    }
    public static void main(String[] args) throws InterruptedException {
        ReenterLock tl=new ReenterLock();
        Thread t1=new Thread(tl);
        Thread t2=new Thread(tl);
        t1.start();t2.start();
        t1.join();t2.join();
        System.out.println(i);
    }
}

重用lock:

 public class ReenterLock2 implements Runnable{
     public static ReentrantLock lock=new ReentrantLock();
     public static int i=0;
     @Override
     public void run() {
         for(int j=0;j<10000000;j++){
             lock.lock();
             lock.lock();
             try{
                 i++;
             }finally{
                 lock.unlock();
                 lock.unlock();
             }
         }
     }
     public static void main(String[] args) throws InterruptedException {
         ReenterLock2 tl=new ReenterLock2();
         Thread t1=new Thread(tl);
         Thread t2=new Thread(tl);
         t1.start();t2.start();
         t1.join();t2.join();
         System.out.println(i);
     }
 }