From 49bd559eb8f041de97e4ef55f280f3806d1b6c42 Mon Sep 17 00:00:00 2001 From: unknown Date: Tue, 24 Aug 2004 20:17:11 +0400 Subject: Fix for Bug#5034 "prepared "select 1 into @arg15", second execute crashes server": we were deleting lex->result after each execute, but prepared statements assumed that it's left intact. The fix adds cleanup() method to select_result hierarchy, so that result objects can be reused. Plus we now need to delete result objects more wisely. mysql-test/r/ps.result: Test results fixed: test case for bug#5034 mysql-test/t/ps.test: A test case for bug#5034, few followups sql/sql_class.cc: - fix warning in THD::THD - implementation of cleanup() for select_result hierarchy - select_export::send_eof was identical to select_dump::send_eof: moved to the base class select_to_file. - Statement::end_statement() to end lex, free items, and delete possible select_result sql/sql_class.h: - select_result::cleanup() declaration - sql/sql_insert.cc: - implementation of select_insert::cleanup(): currently we always create a new instance of select_insert/ select_create on each execute. sql/sql_lex.cc: - with more complicated logic of freeing lex->result it's easier to have it non-zero only if it points to a valid result. sql/sql_lex.h: Now st_lex::st_lex is not empty. sql/sql_parse.cc: mysql_execute_command(): - delete select_result *result only if it was created in this function. - use end_statement() to cleanup lex and thd in the end of each statement. - no need to save THD::lock if this is explain. This save apparently left from times when derived tables were materialized here, not in open_and_lock_tables. sql/sql_prepare.cc: - call result->cleanup() in reset_stmt_for_execute - now Statement is responsible for freeing its lex->result. sql/sql_select.cc: handle_select(): - don't delete result, it might be needed for next executions - result is never null --- sql/sql_class.cc | 84 ++++++++++++++++++++++++++++++++++++++------------------ 1 file changed, 57 insertions(+), 27 deletions(-) (limited to 'sql/sql_class.cc') diff --git a/sql/sql_class.cc b/sql/sql_class.cc index 23fef44c964..07df83b78e7 100644 --- a/sql/sql_class.cc +++ b/sql/sql_class.cc @@ -155,10 +155,10 @@ bool foreign_key_prefix(Key *a, Key *b) ** Thread specific functions ****************************************************************************/ -THD::THD():user_time(0), current_arena(this), is_fatal_error(0), - last_insert_id_used(0), +THD::THD():user_time(0), current_arena(this), global_read_lock(0), + is_fatal_error(0), last_insert_id_used(0), insert_id_used(0), rand_used(0), time_zone_used(0), - in_lock_tables(0), global_read_lock(0), bootstrap(0) + in_lock_tables(0), bootstrap(0) { host= user= priv_user= db= ip=0; host_or_ip= "connecting host"; @@ -703,6 +703,12 @@ void select_result::send_error(uint errcode,const char *err) ::send_error(thd, errcode, err); } + +void select_result::cleanup() +{ + /* do nothing */ +} + static String default_line_term("\n",default_charset_info); static String default_escaped("\\",default_charset_info); static String default_field_term("\t",default_charset_info); @@ -808,6 +814,32 @@ void select_to_file::send_error(uint errcode,const char *err) } +bool select_to_file::send_eof() +{ + int error= test(end_io_cache(&cache)); + if (my_close(file,MYF(MY_WME))) + error= 1; + if (!error) + ::send_ok(thd,row_count); + file= -1; + return error; +} + + +void select_to_file::cleanup() +{ + /* In case of error send_eof() may be not called: close the file here. */ + if (file >= 0) + { + (void) end_io_cache(&cache); + (void) my_close(file,MYF(0)); + file= -1; + } + path[0]= '\0'; + row_count= 0; +} + + select_to_file::~select_to_file() { if (file >= 0) @@ -1058,18 +1090,6 @@ err: } -bool select_export::send_eof() -{ - int error=test(end_io_cache(&cache)); - if (my_close(file,MYF(MY_WME))) - error=1; - if (!error) - ::send_ok(thd,row_count); - file= -1; - return error; -} - - /*************************************************************************** ** Dump of select to a binary file ***************************************************************************/ @@ -1123,18 +1143,6 @@ err: } -bool select_dump::send_eof() -{ - int error=test(end_io_cache(&cache)); - if (my_close(file,MYF(MY_WME))) - error=1; - if (!error) - ::send_ok(thd,row_count); - file= -1; - return error; -} - - select_subselect::select_subselect(Item_subselect *item_arg) { item= item_arg; @@ -1301,6 +1309,13 @@ int select_dumpvar::prepare(List &list, SELECT_LEX_UNIT *u) } +void select_dumpvar::cleanup() +{ + vars.empty(); + row_count=0; +} + + Item_arena::Item_arena(THD* thd) :free_list(0), state(INITIALIZED) @@ -1405,6 +1420,21 @@ void Statement::restore_backup_statement(Statement *stmt, Statement *backup) } +void Statement::end_statement() +{ + /* Cleanup SQL processing state to resuse this statement in next query. */ + lex_end(lex); + delete lex->result; + lex->result= 0; + free_items(free_list); + free_list= 0; + /* + Don't free mem_root, as mem_root is freed in the end of dispatch_command + (once for any command). + */ +} + + void Item_arena::set_n_backup_item_arena(Item_arena *set, Item_arena *backup) { backup->set_item_arena(this); -- cgit v1.2.1