From 67e2028161d1f653a852f1a4679ff5e523296218 Mon Sep 17 00:00:00 2001 From: Sergei Golubchik Date: Sat, 14 Jan 2017 14:56:01 +0100 Subject: MDEV-9690 concurrent queries with virtual columns crash in temporal code Item_func_le included Arg_comparator. Arg_comparator remembered the current_thd during fix_fields and used that value during execution to allocate Item_cache in get_datetime_value(). But for vcols fix_fields and val_int can happen in different threads. Same bug for Item_func_in using in_datetime or cmp_item_datetime, both also remembered current_thd at fix_fields() to use it later for get_datetime_value(). As a fix, these objects no longer remember the current_thd, and get_datetime_value() uses current_thd at run time. This should not increase the number of current_thd calls much, as Item_cache is created only once anyway. --- sql/item_cmpfunc.h | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) (limited to 'sql/item_cmpfunc.h') diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h index 0194f9cd0e0..a8befa47b95 100644 --- a/sql/item_cmpfunc.h +++ b/sql/item_cmpfunc.h @@ -44,7 +44,6 @@ class Arg_comparator: public Sql_alloc Arg_comparator *comparators; // used only for compare_row() double precision; /* Fields used in DATE/DATETIME comparison. */ - THD *thd; Item *a_cache, *b_cache; // Cached values of a and b items // when one of arguments is NULL. public: @@ -52,10 +51,10 @@ public: /* Allow owner function to use string buffers. */ String value1, value2; - Arg_comparator(): set_null(TRUE), comparators(0), thd(0), + Arg_comparator(): set_null(TRUE), comparators(0), a_cache(0), b_cache(0) {}; Arg_comparator(Item **a1, Item **a2): a(a1), b(a2), set_null(TRUE), - comparators(0), thd(0), a_cache(0), b_cache(0) {}; + comparators(0), a_cache(0), b_cache(0) {}; int set_compare_func(Item_result_field *owner, Item_result type); inline int set_compare_func(Item_result_field *owner_arg) @@ -944,15 +943,13 @@ public: class in_datetime :public in_longlong { public: - THD *thd; /* An item used to issue warnings. */ Item *warn_item; /* Cache for the left item. */ Item *lval_cache; in_datetime(Item *warn_item_arg, uint elements) - :in_longlong(elements), thd(current_thd), warn_item(warn_item_arg), - lval_cache(0) {}; + :in_longlong(elements), warn_item(warn_item_arg), lval_cache(0) {}; void set(uint pos,Item *item); uchar *get_value(Item *item); Item* create_item() @@ -1112,14 +1109,13 @@ class cmp_item_datetime :public cmp_item { longlong value; public: - THD *thd; /* Item used for issuing warnings. */ Item *warn_item; /* Cache for the left item. */ Item *lval_cache; cmp_item_datetime(Item *warn_item_arg) - :thd(current_thd), warn_item(warn_item_arg), lval_cache(0) {} + : warn_item(warn_item_arg), lval_cache(0) {} void store_value(Item *item); int cmp(Item *arg); int compare(cmp_item *ci); -- cgit v1.2.1