事件重现

在整理 sentry 报错的发现了一个奇怪的 bug。

The script tried to execute a method or
access a property of an incomplete object.
Please ensure that the class definition "XXXModel" of the object
you are trying to operate on was loaded _before_
unserialize() gets called or provide a __autoload() function
to load the class definition 

系统是采用 lumen 构建的,报错的逻辑的地方也没要什么特别的逻辑和写法。大概的写法如下。

<?php

function logic()
{
  return \Cache::remeber('some-key', 10, function () {
    return XXXModel::query()->first();
  });
}

这个怎么看都是挺正常的一个逻辑,为啥会出现上边的报错呢?

原因

最根本的原因是,php 的反序列化函数 unserialize 的时候 XXXModel 类没有被加载进来。

那么我们来进行一下情景重现。

首先创建序列化文件

<?php
// file: a.php

class A {
    public $count = -1;
}

file_put_contents("a.out", serialize(new A()));

执行 php -f a.php, 可在当前目录生成 a.out 文件, 里边是序列化内容。

创建反序列化文件

<?php

// file: b.php

$content = file_get_contents("a.out");

$obj = unserialize($content);

var_dump($obj);

echo $obj->count;

执行 php -f b.php, 可得到如下错误信息:

object(__PHP_Incomplete_Class)#1 (2) {
  ["__PHP_Incomplete_Class_Name"]=>
  string(1) "A"
  ["count"]=>
  int(-1)
}
PHP Notice:  main(): The script tried to execute a method or access a property of an incomplete object. Please ensure that the class definition "A" of the object you are trying to operate on was loaded _before_ unserialize() gets called or provide a __autoload() function to load the class definition  in /tmp/b.php on line 9

Notice: main(): The script tried to execute a method or access a property of an incomplete object. Please ensure that the class definition "A" of the object you are trying to operate on was loaded _before_ unserialize() gets called or provide a __autoload() function to load the class definition  in /tmp/b.php on line 9

结语

  • PS:才发现 php还有一个这么神奇的类 __PHP_Incomplete_Class,用于反序列化使用使用,可以实例化,但是不可以调用任何属性和方法。
  • PPS: 没有在lumen框架中重现这个问题,可能是某个版本的bug?