mariadb/sql/sp.h
unknown d5303b8ab8 Fix for bug #12704 "Server crashes during trigger execution".
This bug occurs when some trigger for table used by DML statement is created
or changed while statement was waiting in lock_tables(). In this situation
prelocking set which we have calculated becames invalid which can easily lead
to errors and even in some cases to crashes.

With proposed patch we no longer silently reopen tables in lock_tables(),
instead caller of lock_tables() becomes responsible for reopening tables and
recalculation of prelocking set.


mysql-test/t/trigger.test:
  Added tests for bug #12704 "Server crashes during trigger execution".
  Unfortunately these tests rely on the order in which tables are locked
  by statement so they are non-determenistic and therefore should be disabled.
sql/lock.cc:
  mysql_lock_tables():
    Now instead of always reopening altered or dropped tables by itself
    mysql_lock_tables() can notify upper level and rely on caller doing this.
sql/mysql_priv.h:
  Now mysql_lock_tables() can either reopen deleted or altered tables by itself
  or notify caller about such situation through 'need_reopen' argument and rely
  on it in this.
  Also lock_tables() has new 'need_reopen' out parameter through which it
  notifies caller that some tables were altered or dropped so he needs to reopen
  them (and rebuild prelocking set some triggers may change or simply appear).
sql/sp.cc:
  sp_add_used_routine():
    To be able to restore LEX::sroutines_list to its state right after parsing
    we now adjust  LEX::sroutines_list_own_last/sroutines_list_own_elements when
    we add directly used routine.
  sp_remove_not_own_routines():
    Added procedure for restoring LEX::sroutines/sroutines_list to their state
    right after parsing (by throwing out non-directly used routines).
  sp_cache_routines_and_add_tables_for_view()/sp_update_stmt_used_routines():
    We should use LEX::sroutines_list instead of LEX::sroutines as source of
    routines used by view, since LEX::sroutines is not availiable for view
    on second attempt to open it (see comment in open_tables() about it).
sql/sp.h:
  sp_remove_not_own_routines():
    Added procedure for restoring LEX::sroutines/sroutines_list to their state
    right after parsing (by throwing out non-directly used routines).
sql/sp_head.cc:
  Removed assert which is no longer always true.
sql/sql_base.cc:
  reopen_table():
    When we re-open table and do shallow copy of TABLE object we should adjust
    pointers to it in associated Table_triggers_list object. Removed nil
    operation.
  open_tables():
    Now this function is able to rebuild prelocking set for statement if it is
    needed. It also correctly handles FLUSH TABLES which may occur during its
    execution.
  lock_tables():
    Instead of allowing mysql_lock_tables() to silently reopen altered or dropped
    tables let us notify caller and rely on that it will do reopen itself.
    This solves the problem when trigger suddenly appears or changed during
    mysq_lock_tables().
  close_tables_for_reopen():
    Added routine for properly preparing for reopening of tables and recalculation
    of set of prelocked tables.
sql/sql_handler.cc:
  Here we let mysql_lock_tables() to reopen dropped or altered tables by itself.
sql/sql_insert.cc:
  Here we let mysql_lock_tables() to reopen dropped or altered tables by itself.
sql/sql_lex.cc:
  LEX:
    Added 'sroutines_list_own_last' and 'sroutines_list_own_elements' members
    which are used for keeping state in which 'sroutines_list' was right after
    statement parsing (and for restoring of this list to this state).
sql/sql_lex.h:
  LEX:
    Added 'sroutines_list_own_last' and 'sroutines_list_own_elements' members
    which are used for keeping state in which 'sroutines_list' was right after
    statement parsing (and for restoring of this list to this state).
    Added chop_off_not_own_tables() method to simplify throwing away list
    of implicitly used (prelocked) tables.
sql/sql_prepare.cc:
  Now instead of silently reopening altered or dropped tables in
  lock_tables() we notify caller and rely on that the caller will
  reopen tables.
sql/sql_table.cc:
  Here we let mysql_lock_tables() to reopen dropped or altered tables by itself.
sql/sql_trigger.cc:
  Added Table_triggers_list::set_table() method to adjust Table_triggers_list
  to new pointer to TABLE instance.
sql/sql_trigger.h:
  Added Table_triggers_list::set_table() method to adjust Table_triggers_list
  to new pointer to TABLE instance.
sql/sql_update.cc:
  Now instead of silently reopening altered or dropped tables in
  lock_tables() we notify caller and rely on that the caller will
  reopen tables.
2005-09-15 03:56:09 +04:00

116 lines
3.5 KiB
C++

/* -*- C++ -*- */
/* Copyright (C) 2002 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#ifndef _SP_H_
#define _SP_H_
// Return codes from sp_create_*, sp_drop_*, and sp_show_*:
#define SP_OK 0
#define SP_KEY_NOT_FOUND -1
#define SP_OPEN_TABLE_FAILED -2
#define SP_WRITE_ROW_FAILED -3
#define SP_DELETE_ROW_FAILED -4
#define SP_GET_FIELD_FAILED -5
#define SP_PARSE_ERROR -6
#define SP_INTERNAL_ERROR -7
#define SP_NO_DB_ERROR -8
#define SP_BAD_IDENTIFIER -9
#define SP_BODY_TOO_LONG -10
/* Drop all routines in database 'db' */
int
sp_drop_db_routines(THD *thd, char *db);
sp_head *
sp_find_procedure(THD *thd, sp_name *name, bool cache_only = 0);
int
sp_exists_routine(THD *thd, TABLE_LIST *procs, bool any, bool no_error);
int
sp_create_procedure(THD *thd, sp_head *sp);
int
sp_drop_procedure(THD *thd, sp_name *name);
int
sp_update_procedure(THD *thd, sp_name *name, st_sp_chistics *chistics);
int
sp_show_create_procedure(THD *thd, sp_name *name);
int
sp_show_status_procedure(THD *thd, const char *wild);
sp_head *
sp_find_function(THD *thd, sp_name *name, bool cache_only = 0);
int
sp_create_function(THD *thd, sp_head *sp);
int
sp_drop_function(THD *thd, sp_name *name);
int
sp_update_function(THD *thd, sp_name *name, st_sp_chistics *chistics);
int
sp_show_create_function(THD *thd, sp_name *name);
int
sp_show_status_function(THD *thd, const char *wild);
/*
Procedures for pre-caching of stored routines and building table list
for prelocking.
*/
void sp_get_prelocking_info(THD *thd, bool *need_prelocking,
bool *first_no_prelocking);
void sp_add_used_routine(LEX *lex, Query_arena *arena,
sp_name *rt, char rt_type);
void sp_remove_not_own_routines(LEX *lex);
void sp_update_sp_used_routines(HASH *dst, HASH *src);
bool sp_cache_routines_and_add_tables(THD *thd, LEX *lex,
bool first_no_prelock);
void sp_cache_routines_and_add_tables_for_view(THD *thd, LEX *lex,
LEX *aux_lex);
void sp_cache_routines_and_add_tables_for_triggers(THD *thd, LEX *lex,
Table_triggers_list *triggers);
extern "C" byte* sp_sroutine_key(const byte *ptr, uint *plen, my_bool first);
/*
Routines which allow open/lock and close mysql.proc table even when
we already have some tables open and locked.
*/
TABLE *open_proc_table_for_read(THD *thd, Open_tables_state *backup);
void close_proc_table(THD *thd, Open_tables_state *backup);
//
// Utilities...
//
// Do a "use newdb". The current db is stored at olddb.
// If newdb is the same as the current one, nothing is changed.
// dbchangedp is set to true if the db was actually changed.
int
sp_use_new_db(THD *thd, char *newdb, char *olddb, uint olddbmax,
bool no_access_check, bool *dbchangedp);
#endif /* _SP_H_ */