Re: [PATCH v3 5/8] trace2: improve thread-name documentation in the thread-context

From: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Date: Oct 20, 2022, 18:57 UTC
Message-ID: <221020.86y1tafhjo.gmgdl@evledraar.gmail.com>
In-Reply-To: <8cb206b76323e14d8e07f6cfb5aa482a47eb54c5.1666290489.git.gitgitgadget@gmail.com>

On Thu, Oct 20 2022, Jeff Hostetler via GitGitGadget wrote:

> From: Jeff Hostetler <jeffhost@microsoft.com>
>
> Improve the documentation of the tr2tls_thread_ctx.thread_name field
> and its relation to the tr2tls_thread_ctx.thread_id field.

Good to see this split off, thanks!

Show 25 quoted lines

> Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
> ---
>  trace2/tr2_tls.h | 15 +++++++++------
>  1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/trace2/tr2_tls.h b/trace2/tr2_tls.h
> index d4e725f430b..7d1f03a2ea6 100644
> --- a/trace2/tr2_tls.h
> +++ b/trace2/tr2_tls.h
> @@ -25,12 +25,15 @@ struct tr2tls_thread_ctx {
>  /*
>   * Create thread-local storage for the current thread.
>   *
> - * We assume the first thread is "main".  Other threads are given
> - * non-zero thread-ids to help distinguish messages from concurrent
> - * threads.
> - *
> - * Truncate the thread name if necessary to help with column alignment
> - * in printf-style messages.
> + * The first thread in the process will have:
> + *     { .thread_id=0, .thread_name="main" }
> + * Subsequent threads are given a non-zero thread_id and a thread_name
> + * constructed from the id and a thread base name (which is usually just
> + * the name of the thread-proc function).  For example:
> + *     { .thread_id=10, .thread_name="th10fsm-listen" }

I think the example is missing a ":" after the "th10", i.e. it should be "th10:fsm-listen" per the code in 6/8:

	strbuf_addf(&buf, "th%02d:", ctx->thread_id);
        [...]