关于thinkPHP3.2的无限遍历有关问题，困扰了几天了

/**
 * 无限递归
 * @param $data
 * @param $pId
 * @return array
 * @author 郑景强
 */
function getTree($data, $pId = 0){
    $tree = array();
    foreach($data as $k => $v){
        if($v['pid'] == $pId){
            //父亲找到儿子
            $v['children'] = getTree($data, $v['id']);
            $tree[] = $v;
            //unset($data[$k]);
        }
    }
    return $tree;
}