Java holdLock()方法
如果当前线程在指定对象上持有监视器锁，则线程类的
holdLock()方法返回true。
语法
public static boolean holdsLock(Object obj)
参数
obj : 它定义要在其上测试锁所有权的对象
返回
当且仅当当前线程在指定对象上持有监视器锁时，它才返回true。否则，它返回false。
异常
NullPointerException: 如果obj为null，则抛出此异常。
示例
public class JavaHoldLockExp implements Runnable
{
public void run()
{
// print currently executing thread
System.out.println("Currently executing thread is: " + Thread.currentThread().getName());
// returns true if the current thread holds the lock on the specified object
System.out.println("Does thread holds lock? " + Thread.holdsLock(this));
synchronized (this)
{
System.out.println("Does thread holds lock? " + Thread.holdsLock(this));
}
}
public static void main(String[] args)
{
JavaHoldLockExp g1 = new JavaHoldLockExp();
// create a thread
Thread t1 = new Thread(g1);
// this will call run() function
t1.start();
}
}
输出:
Currently executing thread is: Thread-0
Does thread holds lock? false
Does thread holds lock? true
