maria-developers team mailing list archive

[Sergei Golubchik <serg@xxxxxxxxxxx>]

Hi, Seppo, Jan!

Looks pretty much ok too.
A few comments, see below

On Oct 29, sjaakola wrote:
> revision-id: 778d88ea2d9 (mariadb-10.4.21-76-g778d88ea2d9)
> parent(s): e2e4e06f081
> author: sjaakola
> committer: Jan Lindström
> timestamp: 2021-10-28 11:06:22 +0300
> message:
> 
> MDEV-23328 Server hang due to Galera lock conflict resolution
> 
> diff --git a/sql/log_event.cc b/sql/log_event.cc
> index c1c753d69fd..a1562016aa4 100644
> --- a/sql/log_event.cc
> +++ b/sql/log_event.cc
> @@ -8987,6 +8987,18 @@ bool Xid_log_event::print(FILE* file, PRINT_EVENT_INFO* print_event_info)
>  
>  
>  #if defined(HAVE_REPLICATION) && !defined(MYSQL_CLIENT)
> +static bool wsrep_must_replay(THD *thd)
> +{
> +#ifdef WITH_WSREP
> +  mysql_mutex_lock(&thd->LOCK_thd_data);
> +  bool res= WSREP(thd) && thd->wsrep_trx().state() == wsrep::transaction::s_must_replay;

check WSREP(thd) outside of the mutex

> +  mysql_mutex_unlock(&thd->LOCK_thd_data);
> +  return res;
> +#else
> +  return false;
> +#endif
> +}
> +
>  int Xid_log_event::do_apply_event(rpl_group_info *rgi)
>  {
>    bool res;
> diff --git a/sql/service_wsrep.cc b/sql/service_wsrep.cc
> index 6566bb372d8..18067a4d0ec 100644
> --- a/sql/service_wsrep.cc
> +++ b/sql/service_wsrep.cc
> @@ -29,12 +29,14 @@ extern "C" my_bool wsrep_on(const THD *thd)
>  
>  extern "C" void wsrep_thd_LOCK(const THD *thd)
>  {
> +  mysql_mutex_lock(&thd->LOCK_thd_kill);
>    mysql_mutex_lock(&thd->LOCK_thd_data);

I presume, you can remove wsrep_thd_kill_LOCK() and
wsrep_thd_kill_UNLOCK() that I've added

>  }
>  
>  extern "C" void wsrep_thd_UNLOCK(const THD *thd)
>  {
>    mysql_mutex_unlock(&thd->LOCK_thd_data);
> +  mysql_mutex_unlock(&thd->LOCK_thd_kill);
>  }
>  
>  extern "C" void wsrep_thd_kill_LOCK(const THD *thd)
> @@ -295,8 +301,6 @@ extern "C" my_bool wsrep_thd_is_aborting(const MYSQL_THD thd)
>      default:
>        return false;
>    }
> -
> -  return false;

this looks like it begs for the compiler warning.
please, keep the return where it was.

>  }

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