package com.basic;

import java.util.concurrent.TimeUnit;

import java.util.concurrent.locks.Lock;

import java.util.concurrent.locks.ReentrantLock;

/**

* @program JavaBooks

* @description: trylock

* @author: mf

* @create: 2019/12/30 20:16

*/

public class T13 {

Lock lock = new ReentrantLock();

void m1() {

try {

lock.lock();

for (int i = 0; i < 10; i++) {

TimeUnit.SECONDS.sleep(1);

System.out.println(i);

}

} catch (Exception e) {

e.printStackTrace();

} finally {

lock.unlock();

}

}

/**

* 使用tryLock进行尝试锁定，不管锁定与否，方法都将继续执行

* 也可以根据tryLock的返回值来判定是否锁定

* 也可以指定tryLock的时间，由于tryLock(time)抛出异常，所以要注意unlock的处理，必须放到finally中

*/

void m2() {

boolean locked = false;

try {

locked = lock.tryLock(5, TimeUnit.SECONDS);

System.out.println("m2 ..." + locked);

} catch (Exception e) {

e.printStackTrace();

} finally {

if (locked) lock.unlock();

}

}

public static void main(String[] args) {

T13 t13 = new T13();

new Thread(t13::m1).start();

try {

TimeUnit.SECONDS.sleep(1);

} catch (InterruptedException e) {

e.printStackTrace();

}

new Thread(t13::m2).start();

}

}