Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:130375
Message-ID: <1c9534ff-d8c6-4939-a6f2-85a4c547ac0b@bastelstu.be>
Date: Mon, 16 Mar 2026 21:26:26 +0100
Precedence: list
MIME-Version: 1.0
Subject: Re: [PHP-DEV] [RFC] SNMP MIB reset function
To: "swilton@fluentit.au" <swilton@fluentit.au>, internals@lists.php.net
References: <5a2-69b78f00-11-50bc7700@253019388>
Content-Language: en-US
In-Reply-To: <5a2-69b78f00-11-50bc7700@253019388>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
From: tim@bastelstu.be (=?UTF-8?Q?Tim_D=C3=BCsterhus?=)

Hi

On 3/16/26 06:03, swilton@fluentit.au wrote:
> I believe that the process is to send a message to the list, and gauge whether there is positive feedback before creating the RFC for voting.  Please let me know if I should create the RFC first?
> The PR is here: https://github.com/php/php-src/pull/21452/changes

I suspect that SNMP is such a specialized and rarely used extension that 
folks will be unable to meaningfully discuss an RFC for this feature - 
at least not without you doing quite a bit of explaining. This might be 
case where it's best to just find an informal agreement with you 
providing a well-tested and well-explained patch rather than doing a 
full RFC.

----------

That said, I did some research, finding this man page: 
https://linux.die.net/man/3/shutdown_mib.

I'm seeing that the manpage states for init_mib():
> It should be called before any other routine that manipulates or accesses the MIB tree. 

I'm seing that init_mib() is not currently called at all in ext/snmp. Is 
the initialization implicitly happening as part of init_snmp()?

For shutdown_mib() I'm seeing:

> It is strongly recommended that one does not invoke shutdown_mib while there are SNMP sessions being actively managed.

Will calling your proposed `snmp_init_mib()` function cause issues when 
an existing SNMP object is being used after the call to `snmp_init_mib()`?

----------

In your email you mention:

> Another consideration is that the MIB tree persists across FPM requests because the MIB tree is kept as a global structure within SNMP library memory.

Would calling `shutdown_mib()` in RSHUTDOWN (i.e. the end-of-request 
handler) solve the problem of the MIB persisting across requests or is 
it sometimes desirable that the MIB is persisted?

Best regards
Tim Düsterhus