几个小时后共享变量不断丢失

发布于 2025-01-08 05:25:58 字数 699 浏览 1 评论 0原文

我正在使用 shm_ 函数向我的 API 提供共享数组。该数组存储客户端数据，有助于限制传入请求（速率限制等）我使用 suhosin 补丁运行 PHP 5.2.6-1

这是代码，对于正在寻找在 PHP 中创建/读取/写入/存储共享内存数据的代码的人来说，它实际上可能很有用。

$shm_key=ftok(__FILE__, 'S' ); 
$data=shm_attach($shm_key,500000);
$ar=shm_get_var($data,"variable");
if ($ar === FALSE))
{
// this should rarely ever happen !
// recreate empty arry
}
//...
// reading and changing the $ar array contents
//...
shm_put_var($data,"variable",$ar);
shm_detach($data);

序列化变量数据很少超过 10-11kb，因此 500kb 应该是足够的可用空间。每小时总共有 10,000-50,000 次 php 脚本调用。

($ar === FALSE) 每天被击中 4-5 次，导致所有节流数据完全丢失。多年来我已经接受了这种行为，但仍然希望看到它得到解决。

我的猜测是，这要么是 shm_ 中的错误，要么是写入/读取时的竞争条件，并且多个客户端同时调用脚本。

原文

I'm using the shm_ functions to provide a shared array to an API of mine.
The array stores client data which helps to throttle incomming requests (rate limiting etc)
I run PHP 5.2.6-1 with suhosin patch

Here is the code, it might actually be useful to someone who's looking for code to create/read/write/store shared memory data in PHP.

$shm_key=ftok(__FILE__, 'S' ); 
$data=shm_attach($shm_key,500000);
$ar=shm_get_var($data,"variable");
if ($ar === FALSE))
{
// this should rarely ever happen !
// recreate empty arry
}
//...
// reading and changing the $ar array contents
//...
shm_put_var($data,"variable",$ar);
shm_detach($data);

The serialized variable data is rarely ever larger than 10-11kb, so 500kb should be plenty of free space.
In total there 10,000-50,000 of php script calls per hour.

The ($ar === FALSE) is hit 4-5 times a day resulting in a complete loss of all throttling data.
I've accepted this behaviour for years but would still like to see it solved.

My guess is that it's either a bug in shm_ or a race condition when writing/reading and multiple clients call the script at the same moment.

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