Re: convert SpinLock* macros to static inline functions
Nathan Bossart <nathandbossart@gmail.com>
From: Nathan Bossart <nathandbossart@gmail.com>
To: Fabrízio de Royes Mello <fabriziomello@gmail.com>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>, Andres Freund <andres@anarazel.de>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2026-02-18T18:03:19Z
Lists: pgsql-hackers
On Wed, Feb 18, 2026 at 02:52:46PM -0300, Fabrízio de Royes Mello wrote: > On Wed, Feb 18, 2026 at 2:28 PM Nathan Bossart <nathandbossart@gmail.com> > wrote: >> However, as soon as I did this, I got a bunch of build failures because >> various parts of the code still use volatile qualifiers quite liberally. >> It looks like most of these (e.g., see code from commits 2487d872e0, >> 966fb05b58, 4bc15a8bfb, and 4db3744f1f) predate making spinlocks compiler >> barriers (commit 0709b7ee72) or were cargo-culted from code that predated >> it. So, IIUC, it's probably safe to remove these volatile qualifiers now. >> We could alternatively add volatile qualifiers to the new static inline >> function parameters, but that seems like it might just encourage continued >> unnecessary use. > > Just wondering if there's some code-path that uses it inside > PG_TRY..PG_CATCH that can use longjump. I didn't notice any such code. For reference, we only need "volatile" in PG_TRY..PG_CATCH code if a local variable is modified in the PG_TRY section and used in the PG_CATCH section. -- nathan
Commits
-
Convert SpinLock* macros to static inline functions.
- bfc321b4723e 19 (unreleased) landed
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Remove SpinLockFree() and S_LOCK_FREE().
- ba401828c194 19 (unreleased) landed
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Change the spinlock primitives to function as compiler barriers.
- 0709b7ee72e4 9.5.0 cited