Hi Jakub,

I though not only about FPM, but a technology for any SAPI.

Pre-loaded classes and functions might be kept in CG() tables, in the same way 
as "internal" ones.

EG() constants and variables may be re-created at start of request, executing 
pre-loaded PHP code.

Few years ago, I developed something similar for PHP-5.


Thanks. Dmitry.

________________________________
From: jakub....@gmail.com <jakub....@gmail.com> on behalf of Jakub Zelenka 
<bu...@php.net>
Sent: Tuesday, April 17, 2018 5:23:30 PM
To: Dmitry Stogov
Cc: PHP internals list
Subject: FPM preloading of PHP files

Hi Dmitry,

This is a bit different topic to FFI discussion so creating a new thread. You 
wrote this in the FFI extension discussion:

At the same time, we will develop a technology to preload and reuse  PHP files 
across requests.
And allow FFI there.

Have you been thinking about it in the FPM context? I'm asking as I have been 
pondering with a related idea about some restructuring how things work 
currently in the FPM. I will try to give a quick overview of the current way 
how things work (for those who read this and are not familiar with it), the 
problem that it is already causing and finally the idea that I have. :)

The thing is that at the moment there is just a master process that except 
other things does the module init and spawns children. Each child is then 
configured by the pool configuration which means that it can have a different 
effective user id. It's simple and it works in most cases. However there is an 
issue if it tries to access shared resources in other pools running under 
different user which can happen due to the fact that the initialization is done 
during MINIT by master (root user in such case).  One example is the opcache 
that tries to kill lockers as described in 
https://bugs.php.net/bug.php?id=74709 . I think that it's also not ideal to do 
MINIT as a root from security point of view (the last security issue is 
actually good example of that - https://bugs.php.net/bug.php?id=75605 ). 
However not sure if there are some extension that depends on it.

As you can imagine, it would get even worse if you allow preloading of PHP 
script in master so such implementation would be a no-go IMHO.

What I have been thinking about is to have a new process (I will call it a pool 
manager) for each pool that would except other things spawn and manage children 
and run under the same user. It would also do the MINIT and it could possibly 
preload PHP files and load the libraries for FFI (considering there would be a 
support in the engine for that - some kind of partial execution or whatever you 
think would be best). Master would then spawn and manage the pool managers as 
well as doing other things like log handling. That would prevent the user mix 
up mentioned above - in the example case, the opcache would have separate 
shared memory for each pool.

WDYT?

Cheers

Jakub

Reply via email to