Java Thread holdLock()用法及代码示例

如果当前线程持有指定对象的监视器锁，则线程类的 holdLock() 方法返回 true。

用法

public static boolean holdsLock(Object obj)

参数

obj:它定义了测试锁所有权的对象

当且仅当当前线程持有指定对象的监视器锁时，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

相关用法

注：本文由纯净天空筛选整理自 Java Thread holdLock() method。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。