redis锁

/**
 * redis锁
 * $mkey string 键值
 * $second string 秒，锁定多少秒,-1时销毁
 * return bool
 */
function redisLook($mkey = '',$second = 5){
    $cache = \think\facade\Cache::init();
    $_redis = $cache->handler();
    if ($second == -1){
        return $_redis->del($mkey);
    }
    $lock_time = $_redis->setnx($mkey,time()+$second);
    if ($lock_time == false){
        $lock_time = $_redis->get($mkey);
        if(time()>$lock_time){
            $_redis->del($mkey);
            $lock_time = $_redis->setnx($mkey,time()+$second);
            if ($lock_time == false) return false;
        }else{
            return false;
        }
    }
    return true;
}