Re: Refactoring backend fork+exec code

On 11/10/2023 14:12, Heikki Linnakangas wrote:
> On 11/07/2023 01:50, Andres Freund wrote:
>>> Subject: [PATCH 3/9] Refactor CreateSharedMemoryAndSemaphores.
>>>
>>> Moves InitProcess calls a little later in EXEC_BACKEND case.
>>
>> What's the reason for this part?
>
> The point is that with this commit, InitProcess() is called at same
> place in EXEC_BACKEND mode and !EXEC_BACKEND. It feels more consistent
> that way.
>
>> ISTM that we'd really want to get away from plastering duplicated
>> InitProcess() etc everywhere.
>
> Sure, we could do more to reduce the duplication. I think this is a step
> in the right direction, though.

Here's another rebased patch set. Compared to previous version, I did a
little more refactoring around CreateSharedMemoryAndSemaphores and
InitProcess:

- patch 1 splits CreateSharedMemoryAndSemaphores into two functions:
CreateSharedMemoryAndSemaphores is now only called at postmaster
startup, and a new function called AttachSharedMemoryStructs() is called
in backends in EXEC_BACKEND mode. I extracted the common parts of those
functions to a new static function. (Some of this refactoring used to be
part of the 3rd patch in the series, but it seems useful on its own, so
I split it out.)

- patch 3 moves the call to AttachSharedMemoryStructs() to
InitProcess(), reducing the boilerplate code a little.

The patches are incrementally useful, so if you don't have time to
review all of them, a review on a subset would be useful too.

--
Heikki Linnakangas
Neon (https://neon.tech)