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();
    }
}