database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-27 18:02:13 +03:00
Code Activity

Merge fix for lp:910817: Race condition in kill_threads_for_user().

Browse Source
This commit is contained in:
unknown
2012-02-10 21:58:39 +01:00
parent 804c69ab83 3d61c1399d
commit 0e6dd6713c
1 changed files with 13 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
sql/sql_parse.cc
View File

@ -6674,13 +6674,23 @@ static uint kill_threads_for_user(THD *thd, LEX_USER *user,
if (!threads_to_kill.is_empty()) if (!threads_to_kill.is_empty())
{ {
List_iterator_fast<THD> it(threads_to_kill); List_iterator_fast<THD> it(threads_to_kill);
THD *ptr; THD *next_ptr;
while ((ptr= it++)) THD *ptr= it++;
do
{ {
ptr->awake(kill_signal); ptr->awake(kill_signal);
/*
Careful here: The list nodes are allocated on the memroots of the
THDs to be awakened.
But those THDs may be terminated and deleted as soon as we release
LOCK_thd_data, which will make the list nodes invalid.
Since the operation "it++" dereferences the "next" pointer of the
previous list node, we need to do this while holding LOCK_thd_data.
*/
next_ptr= it++;
mysql_mutex_unlock(&ptr->LOCK_thd_data); mysql_mutex_unlock(&ptr->LOCK_thd_data);
(*rows)++; (*rows)++;
} } while ((ptr= next_ptr));
} }
DBUG_RETURN(0); DBUG_RETURN(0);
} }