Date: Wed, 22 Jul 2026 09:31:49 -0400
From: Nathan Bossart <nathandbossart@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: Peter Eisentraut <peter@eisentraut.org>, pgsql-hackers@postgresql.org
Subject: Re: convert various variables to atomics
Message-ID: <amDGRZxnlmTVjkCe@nathan>
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On Wed, Jul 22, 2026 at 09:19:39AM -0400, Andres Freund wrote:
> On 2026-07-22 09:06:44 -0400, Nathan Bossart wrote:
>> >  	/* Buffer id of the buffer that Startup process waits for pin on, or -1 */
>> > -	int			startupBufferPinWaitBufId;
>> > +	pg_atomic_uint32 startupBufferPinWaitBufId;
>> 
>> I may just be undercaffeinated, but what is wrong with this case?  AFAICT
>> the casting should work as expected, and I see other examples that do
>> something similar, like avLauncherProc.
> 
> The comment says -1, which doesn't really make sense for an unsigned variable.

Ah.  It looks like we could use 0 as the sentinel and simplify the call
sites.  They subtract one before calling SetStartupBufferPinWaitBufId() and
add one after calling GetStartupBufferPinWaitBufId().

-- 
nathan