mirror/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-01-29 02:05:57 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions

Fixed close_cached_connection_tables() flushing

Browse source 
Let DROP SERVER and ALTER SERVER perform fair affected tables flushing.
That is acquire MDL_EXCLUSIVE and do tdc_remove_table(TDC_RT_REMOVE_ALL).

Aim of this patch is elimination of another inconsistent use of
TDC_RT_REMOVE_UNUSED. It fixes (to some extent) a problem described in the
beginning of sql_server.cc, when close_cached_connection_tables()
interferes with concurrent transaction.

A better fix should probably introduce proper MDL locks for server
objects?

Part of MDEV-17882 - Cleanup refresh version
This commit is contained in:
Sergey Vojtovich 2019-12-21 01:22:09 +04:00
parent 54c03cb4f0
commit bfdd30d3e9
3 changed files with 73 additions and 88 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

87
sql/sql_base.cc
View file

@ -630,93 +630,6 @@ err:
} }
/**
Close all tables which match specified connection string or
if specified string is NULL, then any table with a connection string.
*/
struct close_cached_connection_tables_arg
{
THD *thd;
LEX_CSTRING *connection;
TABLE_LIST *tables;
};
static my_bool close_cached_connection_tables_callback(
TDC_element *element, close_cached_connection_tables_arg *arg)
{
TABLE_LIST *tmp;
mysql_mutex_lock(&element->LOCK_table_share);
/* Ignore if table is not open or does not have a connect_string */
if (!element->share || !element->share->connect_string.length ||
!element->ref_count)
goto end;
/* Compare the connection string */
if (arg->connection &&
(arg->connection->length > element->share->connect_string.length ||
(arg->connection->length < element->share->connect_string.length &&
(element->share->connect_string.str[arg->connection->length] != '/' &&
element->share->connect_string.str[arg->connection->length] != '\\')) ||
strncasecmp(arg->connection->str, element->share->connect_string.str,
arg->connection->length)))
goto end;
/* close_cached_tables() only uses these elements */
if (!(tmp= (TABLE_LIST*) alloc_root(arg->thd->mem_root, sizeof(TABLE_LIST))) ||
!(arg->thd->make_lex_string(&tmp->db, element->share->db.str, element->share->db.length)) ||
!(arg->thd->make_lex_string(&tmp->table_name, element->share->table_name.str,
element->share->table_name.length)))
{
mysql_mutex_unlock(&element->LOCK_table_share);
return TRUE;
}
tmp->next_local= arg->tables;
arg->tables= tmp;
end:
mysql_mutex_unlock(&element->LOCK_table_share);
return FALSE;
}
/**
Close cached connections
@return false ok
@return true If there was an error from closed_cached_connection_tables or
if there was any open connections that we had to force closed
*/
bool close_cached_connection_tables(THD *thd, LEX_CSTRING *connection)
{
bool res= false;
close_cached_connection_tables_arg argument;
DBUG_ENTER("close_cached_connections");
DBUG_ASSERT(thd);
argument.thd= thd;
argument.connection= connection;
argument.tables= NULL;
if (tdc_iterate(thd,
(my_hash_walk_action) close_cached_connection_tables_callback,
&argument))
DBUG_RETURN(true);
for (TABLE_LIST *table= argument.tables; table; table= table->next_local)
res|= tdc_remove_table(thd, TDC_RT_REMOVE_UNUSED,
table->db.str,
table->table_name.str);
/* Return true if we found any open connections */
DBUG_RETURN(res);
}
/* /*
Mark all tables in the list which were used by current substatement Mark all tables in the list which were used by current substatement
as free for reuse. as free for reuse.

1
sql/sql_base.h
View file

@ -306,7 +306,6 @@ bool close_cached_tables(THD *thd, TABLE_LIST *tables,
bool wait_for_refresh, ulong timeout); bool wait_for_refresh, ulong timeout);
void purge_tables(); void purge_tables();
bool flush_tables(THD *thd, flush_tables_type flag); bool flush_tables(THD *thd, flush_tables_type flag);
bool close_cached_connection_tables(THD *thd, LEX_CSTRING *connect_string);
void close_all_tables_for_name(THD *thd, TABLE_SHARE *share, void close_all_tables_for_name(THD *thd, TABLE_SHARE *share,
ha_extra_function extra, ha_extra_function extra,
TABLE *skip_table); TABLE *skip_table);

73
sql/sql_servers.cc
View file

@ -124,6 +124,79 @@ static void init_servers_cache_psi_keys(void)
} }
#endif /* HAVE_PSI_INTERFACE */ #endif /* HAVE_PSI_INTERFACE */
struct close_cached_connection_tables_arg
{
THD *thd;
LEX_CSTRING *connection;
TABLE_LIST *tables;
};
static my_bool close_cached_connection_tables_callback(
TDC_element *element, close_cached_connection_tables_arg *arg)
{
TABLE_LIST *tmp;
mysql_mutex_lock(&element->LOCK_table_share);
/* Ignore if table is not open or does not have a connect_string */
if (!element->share || !element->share->connect_string.length ||
!element->ref_count)
goto end;
/* Compare the connection string */
if (arg->connection &&
(arg->connection->length > element->share->connect_string.length ||
(arg->connection->length < element->share->connect_string.length &&
(element->share->connect_string.str[arg->connection->length] != '/' &&
element->share->connect_string.str[arg->connection->length] != '\\')) ||
strncasecmp(arg->connection->str, element->share->connect_string.str,
arg->connection->length)))
goto end;
/* close_cached_tables() only uses these elements */
if (!(tmp= (TABLE_LIST*) alloc_root(arg->thd->mem_root, sizeof(TABLE_LIST))) ||
!(arg->thd->make_lex_string(&tmp->db, element->share->db.str, element->share->db.length)) ||
!(arg->thd->make_lex_string(&tmp->table_name, element->share->table_name.str,
element->share->table_name.length)))
{
mysql_mutex_unlock(&element->LOCK_table_share);
return TRUE;
}
tmp->next_local= arg->tables;
arg->tables= tmp;
end:
mysql_mutex_unlock(&element->LOCK_table_share);
return FALSE;
}
/**
Close all tables which match specified connection string or
if specified string is NULL, then any table with a connection string.
@return false ok
@return true error, some tables may keep using old server info
*/
static bool close_cached_connection_tables(THD *thd, LEX_CSTRING *connection)
{
close_cached_connection_tables_arg argument= { thd, connection, 0 };
DBUG_ENTER("close_cached_connections");
if (tdc_iterate(thd,
(my_hash_walk_action) close_cached_connection_tables_callback,
&argument))
DBUG_RETURN(true);
DBUG_RETURN(argument.tables ?
close_cached_tables(thd, argument.tables, true,
thd->variables.lock_wait_timeout) : false);
}
/* /*
Initialize structures responsible for servers used in federated Initialize structures responsible for servers used in federated
server scheme information for them from the server server scheme information for them from the server