Bug#34409 LOCK_plugin contention via ha_release_temporary_latches/plugin_foreach

  @return

    always 0

*/

static my_bool release_temporary_latches(THD *thd, plugin_ref plugin,

                                 void *unused)

{

  handlerton *hton= plugin_data(plugin, handlerton *);

  if (hton->state == SHOW_OPTION_YES && hton->release_temporary_latches)

    hton->release_temporary_latches(hton, thd);

  return FALSE;

}

int ha_release_temporary_latches(THD *thd)

{

  plugin_foreach(thd, release_temporary_latches, MYSQL_STORAGE_ENGINE_PLUGIN, 

                 NULL);

  Ha_trx_info *info;

  /*

    Note that below we assume that only transactional storage engines

    may need release_temporary_latches(). If this will ever become false,

    we could iterate on thd->open_tables instead (and remove duplicates

    as if (!seen[hton->slot]) { seen[hton->slot]=1; ... }).

  */

  for (info= thd->transaction.stmt.ha_list; info; info= info->next())

  {

    handlerton *hton= info->ht();

    if (hton && hton->release_temporary_latches)

        hton->release_temporary_latches(hton, thd);

  }

  return 0;

}