Re: Trying out <stdatomic.h>

Thomas Munro <thomas.munro@gmail.com>

From: Thomas Munro <thomas.munro@gmail.com>

To: Heikki Linnakangas <hlinnaka@iki.fi>

Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2025-11-13T11:35:48Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Add some missing #include <limits.h>.
- 017249b82888 19 (unreleased) landed
Enable MSVC conforming preprocessor
- 8fd9bb1d9654 19 (unreleased) cited

Attachments

v2-0001-ci-Use-Visual-Studio-2022-for-stdatomic.h.patch (application/octet-stream) patch v2-0001
v2-0002-Enable-Visual-Studio-s-stdatomic.h-support.patch (application/octet-stream) patch v2-0002
v2-0003-Redefine-port-atomics.h-on-top-of-stdatomic.h.patch (application/octet-stream) patch v2-0003
v2-0004-Use-atomics-API-to-implement-spinlocks.patch (application/octet-stream) patch v2-0004
v2-0005-Remove-configure-meson-checks-for-atomics.patch (application/octet-stream) patch v2-0005

On Tue, Nov 11, 2025 at 2:57 AM Heikki Linnakangas <hlinnaka@iki.fi> wrote:
> > [PATCH v1 1/4] Add some missing #include <limits.h>.
>
> This seems like a good thing regardless of the other patches.

Pushed.

> The patch removes 'src/template/solaris'. Is that on purpose?

Fixed.

It passes with VS 2022 on CI.  I had to skip some assertions about
macros promising lock-free implementation, that it doesn't define in C
mode yet.  They are definitely lock-free though[1], and the macros are
defined for C++, and the same under the covers...  Perhaps
feature/conformance macros won't be defined until a few remaining
pieces (things we don't care about) are accessible from C?  (I see
that Visual Studio 2026 has also just shipped a couple of days ago,
not investigated.)

[1] https://devblogs.microsoft.com/cppblog/c11-atomics-in-visual-studio-2022-version-17-5-preview-2/