Message-ID: <3df4b075-fb15-4e35-8981-10ed29aef208@iki.fi>
Date: Fri, 1 Dec 2023 01:36:13 +0200
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Subject: Re: Refactoring backend fork+exec code
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To: Andres Freund <andres@anarazel.de>
Cc: Tristan Partin <tristan@neon.tech>,
 pgsql-hackers <pgsql-hackers@postgresql.org>,
 Thomas Munro <thomas.munro@gmail.com>
References: <7a59b073-5b5b-151e-7ed3-8b01ff7ce9ef@iki.fi>
 <20230710225043.svl7fqxecwshwc7a@awork3.anarazel.de>
 <119551e6-60f6-49b2-ae04-a382a89f900c@iki.fi>
 <e0dcfabb-f59a-45e8-bd92-f8d706c92128@iki.fi>
 <20231130202648.7k6agmuizdilufnv@awork3.anarazel.de>
From: Heikki Linnakangas <hlinnaka@iki.fi>
In-Reply-To: <20231130202648.7k6agmuizdilufnv@awork3.anarazel.de>
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On 30/11/2023 22:26, Andres Freund wrote:
> On 2023-11-30 01:36:25 +0200, Heikki Linnakangas wrote:
>>  From a96b6e92fdeaa947bf32774c425419b8f987b8e2 Mon Sep 17 00:00:00 2001
>> From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
>> Date: Thu, 30 Nov 2023 00:01:25 +0200
>> Subject: [PATCH v3 1/7] Refactor CreateSharedMemoryAndSemaphores
>>
>> For clarity, have separate functions for *creating* the shared memory
>> and semaphores at postmaster or single-user backend startup, and
>> for *attaching* to existing shared memory structures in EXEC_BACKEND
>> case. CreateSharedMemoryAndSemaphores() is now called only at
>> postmaster startup, and a new AttachSharedMemoryStructs() function is
>> called at backend startup in EXEC_BACKEND mode.
> 
> I assume CreateSharedMemoryAndSemaphores() is still called during crash
> restart?

Yes.

>  I wonder if it shouldn't split three ways:
> 1) create
> 2) initialize
> 3) attach

Why? What would be the difference between create and initialize phases?

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