maria-developers team mailing list archive

[Sergei Golubchik <serg@xxxxxxxxxxx>]

Hi, Michael!

On Mar 27, Michael Widenius wrote:
> revision-id: c157c285db9 (mariadb-10.5.2-514-gc157c285db9)
> parent(s): 16e38888c06
> author: Michael Widenius <michael.widenius@xxxxxxxxx>
> committer: Michael Widenius <michael.widenius@xxxxxxxxx>
> timestamp: 2021-03-24 14:31:53 +0200
> message:
> 
> Optimize Sql_alloc
> 
> - Remove 'dummy_for_valgrind' overrun marker as this doesn't help much.
>   The element also distorts the sizes of objects a bit, which makes it
>   harder to calculate gain in object sizes when doing size optimizations.
> - Avoid one extra call indirection when using thd_get_current_thd(), which
>   is used by Sql_alloc.
> 
> diff --git a/sql/mysqld.cc b/sql/mysqld.cc
> index 4f522d96a9f..1ab52401705 100644
> --- a/sql/mysqld.cc
> +++ b/sql/mysqld.cc
> @@ -662,7 +662,15 @@ static std::atomic<char*> shutdown_user;
>  
>  static thread_local THD *THR_THD;
>  
> +/**
> +  Get current THD object from thread local data
> +
> +  @retval     The THD object for the thread, NULL if not connection thread
> +*/
> +
>  MYSQL_THD _current_thd() { return THR_THD; }
> +THD *thd_get_current_thd() { return THR_THD; }

I'd rather remove thd_get_current_thd() completely, why do we need two
identical functions?

Sql_alloc can use _current_thd() just fine, I've tried (also rocksdb
uses thd_get_current_thd in one place, but it can use current_thd like
the rest of the server code).

Regards,
Sergei
VP of MariaDB Server Engineering
and security@xxxxxxxxxxx