05.线程在睡眠时拥有的监视器资源不会被释放(这里使用重入锁ReentrantLock)

时间:2023-02-03 20:05:08
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock; public class SleepDemo {
//创建一个独占锁
private static final Lock lock = new ReentrantLock();
public static void main(String[] args) throws InterruptedException{
//线程在睡眠时拥有的监视器资源不会被释放
Thread threadA = new Thread(new Runnable() {
@Override
public void run() {
//获取独占锁
lock.lock();
try {
System.out.println("threadA is in sleep");
Thread.sleep(10000);
System.out.println("threadA is in waked");
} catch (InterruptedException e) {
e.printStackTrace();
}finally {
//释放锁
lock.unlock();
}
}
});
Thread threadB = new Thread(new Runnable() {
@Override
public void run() {
//获取独占锁
lock.lock();
try {
System.out.println("threadB is in sleep");
Thread.sleep(10000);
System.out.println("threadB is in waked");
} catch (InterruptedException e) {
e.printStackTrace();
}finally {
//释放锁
lock.unlock();
}
}
});
// threadA.start();
// threadB.start();
//threadA is in sleep
//threadA is in waked
//threadB is in sleep
//threadB is in waked
//线程 A 先获取了锁,那么线程 A 会先输出一行,然后调用 sleep 方法让自己睡眠 10s,
//在线程 A 睡眠的这 10s 内那个独占锁 lock 还是线程 A 自己持有,线程 B 会一直阻塞直到线程 A 醒来后执行 unlock 释放锁 final Thread thread = new Thread(new Runnable() {
@Override
public void run() {
try {
System.out.println("thread is in sleep");
// Thread.sleep(10000);
Thread.sleep(-1);
System.out.println("thread is in waked");
} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
thread.start();
Thread.sleep(2000);
//主线程中断子线程
//thread is in sleep
//java.lang.InterruptedException: sleep interrupted
thread.interrupt();
//子线程在睡眠期间, 主线程中断了它,所以子线程在调用 sleep 方法处抛出了 InterruptedException 异常 //sleep为负数
//thread is in sleep
//Exception in thread "Thread-2" java.lang.IllegalArgumentException: timeout value is negative
}
}