Re: [PATCH 2/3] t/lib-httpd: make http-429 first-request check atomic

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 8, 2026, 20:02 UTC
Message-ID: <xmqqcxwxtfkp.fsf@gitster.g>
In-Reply-To: <efd34c17157b3183cdc851c8b17e7967b6c85506.1783479584.git.gitgitgadget@gmail.com>

"Michael Montalbo via GitGitGadget" <gitgitgadget@gmail.com> writes:

Show 7 quoted lines

> -# Check if this is the first call (no state file exists)
> -if test -f "$state_file"
> +# Apache can run this CGI for concurrent requests, so the script decides
> +# whether this is the first call with a single atomic "mkdir": it succeeds for
> +# exactly one of any racing requests and fails for the rest. "permanent"
> +# always rate-limits and records no state.
> +if test "$retry_after" != permanent && ! mkdir "$state" 2>/dev/null

I think the last sentence in the above comment was meant to explain why the new code checks the value of "$retry_after", but it is not clear if it is needed for correctness (in other words, the original was wrong to do "test -f && touch" but also was wrong to do so even when "$retry_after" is set to "permanent), or if it is a mere "optimization opportunity" you are taking advantage of. In either case, it would be nice to see it explained in the proposed commit log message.

Thanks.