Bootstrap in a separate thread was introduced in 746f0b3b7 to workaround
OS/2 small stack size. OS/2 support was discontinued in 2006 and modern
operating systems have default stack size a few times larger than
default thread_stack and it is tunable.
Aim is to reduce usage of LOCK_thread_count and COND_thread_count.
Part of MDEV-15135.
The code passing positions in the query to constructors of
Rewritable_query_parameter descendants (e.g. Item_splocal)
was not reliable. It used various Lex_input_stream methods:
- get_tok_start()
- get_tok_start_prev()
- get_tok_end()
- get_ptr()
to find positions of the recently scanned tokens.
The challenge was mostly to choose between get_tok_start()
and get_tok_start_prev(), taking into account to the current
grammar (depending if lookahead takes place before
or after we read the positions in every particular rule).
But this approach did not work at all in combination
with token contractions, when MYSQLlex() translates
two tokens into one token ID, for example:
WITH ROLLUP -> WITH_ROLLUP_SYM
As a result, the tokenizer is already one more token ahead.
So in query fragment:
"GROUP BY d, spvar WITH ROLLUP"
get_tok_start() points to "ROLLUP".
get_tok_start_prev() points to "WITH".
As a result, it was "WITH" who was erroneously replaced
to NAME_CONST() instead of "spvar".
This patch modifies the code to do it a different way.
Changes:
1. For keywords and identifiers, the tokenizer now
returns LEX_CTRING pointing directly to the query
fragment. So query positions are now just available using:
- $1.str - for the beginning of a token
- $1.str+$1.length - for the end of a token
2. Identifiers are not allocated on the THD memory root
in the tokenizer any more. Allocation is now done
on later stages, in methods like LEX::create_item_ident().
3. Two LEX_CSTRING based structures were added:
- Lex_ident_cli_st - used to store the "client side"
identifier representation, pointing to the
query fragment. Note, these identifiers
are encoded in @@character_set_client
and can have broken byte sequences.
- Lex_ident_sys_st - used to store the "server side"
identifier representation, pointing to the
THD allocated memory. This representation
guarantees that the identifier was checked
for being well-formed, and is encoded in utf8.
4. To distinguish between two identifier types
in the grammar, two Bison types were added:
<ident_cli> and <ident_sys>
5. All non-reserved keywords were marked as
being of the type <ident_cli>.
All reserved keywords are still of the type NONE.
6. All curly brackets in rules collecting
non-reserved keywords into non-terminal
symbols were removed, e.g.:
Was:
keyword_sp_data_type:
BIT_SYM {}
| BOOLEAN_SYM {}
Now:
keyword_sp_data_type:
BIT_SYM
| BOOLEAN_SYM
This is important NOT to have brackets here!!!!
This is needed to make sure that the underlying
Lex_ident_cli_ststructure correctly passes up to
the calling rule.
6. The code to scan identifiers and keywords
was moved from lex_one_token() into new
Lex_input_stream methods:
scan_ident_sysvar()
scan_ident_start()
scan_ident_middle()
scan_ident_delimited()
This was done to:
- get rid of enormous amount of references to &yylval->lex_str
- and remove a lot of references like lip->xxx
7. The allocating functionality which puts identifiers on the
THD memory root now resides in methods of Lex_ident_sys_st,
and in THD::to_ident_sys_alloc().
get_quoted_token() was removed.
8. Cleanup: check_simple_select() was moved as a method to LEX.
9. Cleanup: Some more functionality was moved from *.yy
to new methods were added to LEX:
make_item_colon_ident_ident()
make_item_func_call_generic()
create_item_qualified_asterisk()
Handle string length as size_t, consistently (almost always:))
Change function prototypes to accept size_t, where in the past
ulong or uint were used. change local/member variables to size_t
when appropriate.
This fix excludes rocksdb, spider,spider, sphinx and connect for now.
This preserves const str for constant strings
Other things
- A few variables where changed from LEX_STRING to LEX_CSTRING
- Incident_log_event::Incident_log_event and record_incident where
changed to take LEX_CSTRING* as an argument instead of LEX_STRING
This was done in, among other things:
- thd->db and thd->db_length
- TABLE_LIST tablename, db, alias and schema_name
- Audit plugin database name
- lex->db
- All db and table names in Alter_table_ctx
- st_select_lex db
Other things:
- Changed a lot of functions to take const LEX_CSTRING* as argument
for db, table_name and alias. See init_one_table() as an example.
- Changed some function arguments from LEX_CSTRING to const LEX_CSTRING
- Changed some lists from LEX_STRING to LEX_CSTRING
- threads_mysql.result changed because process list_db wasn't always
correctly updated
- New append_identifier() function that takes LEX_CSTRING* as arguments
- Added new element tmp_buff to Alter_table_ctx to separate temp name
handling from temporary space
- Ensure we store the length after my_casedn_str() of table/db names
- Removed not used version of rename_table_in_stat_tables()
- Changed Natural_join_column::table_name and db_name() to never return
NULL (used for print)
- thd->get_db() now returns db as a printable string (thd->db.str or "")
- Simplified use_trans_cache() to return at once if is_transactional is set
- Indentation and spelling errors fixed
- Don't call signal_update() if update_binlog_end_pos() is called as the
function already calls signal_update()
- Removed not used function wait_for_update_bin_log(), which would cause
errors if ever used.
- Simplified handler::clone() by always allocating 'ref' in ha_open(). To do
this I added an optional MEM_ROOT argument to ha_open() to be used when
allocating 'ref'
- Changed arguments to get_system_var() from LEX_CSTRING to LEX_CSTRING*
- Added THD as argument to create_select_for_variable(). Changed also char*
argument to LEX_CSTRING to avoid strlen() call.
- Change calls to append() to use LEX_CSTRING
- Added sql/mariadb.h file that should be included first by files in sql
directory, if sql_plugin.h is not used (sql_plugin.h adds SHOW variables
that must be done before my_global.h is included)
- Removed a lot of include my_global.h from include files
- Removed include's of some files that my_global.h automatically includes
- Removed duplicated include's of my_sys.h
- Replaced include my_config.h with my_global.h
Benefits of this patch:
- Removed a lot of calls to strlen(), especially for field_string
- Strings generated by parser are now const strings, less chance of
accidently changing a string
- Removed a lot of calls with LEX_STRING as parameter (changed to pointer)
- More uniform code
- Item::name_length was not kept up to date. Now fixed
- Several bugs found and fixed (Access to null pointers,
access of freed memory, wrong arguments to printf like functions)
- Removed a lot of casts from (const char*) to (char*)
Changes:
- This caused some ABI changes
- lex_string_set now uses LEX_CSTRING
- Some fucntions are now taking const char* instead of char*
- Create_field::change and after changed to LEX_CSTRING
- handler::connect_string, comment and engine_name() changed to LEX_CSTRING
- Checked printf() related calls to find bugs. Found and fixed several
errors in old code.
- A lot of changes from LEX_STRING to LEX_CSTRING, especially related to
parsing and events.
- Some changes from LEX_STRING and LEX_STRING & to LEX_CSTRING*
- Some changes for char* to const char*
- Added printf argument checking for my_snprintf()
- Introduced null_clex_str, star_clex_string, temp_lex_str to simplify
code
- Added item_empty_name and item_used_name to be able to distingush between
items that was given an empty name and items that was not given a name
This is used in sql_yacc.yy to know when to give an item a name.
- select table_name."*' is not anymore same as table_name.*
- removed not used function Item::rename()
- Added comparision of item->name_length before some calls to
my_strcasecmp() to speed up comparison
- Moved Item_sp_variable::make_field() from item.h to item.cc
- Some minimal code changes to avoid copying to const char *
- Fixed wrong error message in wsrep_mysql_parse()
- Fixed wrong code in find_field_in_natural_join() where real_item() was
set when it shouldn't
- ER_ERROR_ON_RENAME was used with extra arguments.
- Removed some (wrong) ER_OUTOFMEMORY, as alloc_root will already
give the error.
TODO:
- Check possible unsafe casts in plugin/auth_examples/qa_auth_interface.c
- Change code to not modify LEX_CSTRING for database name
(as part of lower_case_table_names)
Also, implement MDEV-11027 a little differently from 5.5 and 10.0:
recv_apply_hashed_log_recs(): Change the return type back to void
(DB_SUCCESS was always returned).
Report progress also via systemd using sd_notifyf().
A prerequisite change for:
- MDEV-8093 sql_yacc.yy: add %type create_field for field_spec and column_def
- MDEV-8094 sql_yacc.yy: get rid of the rules "opt_if_not_exists_table_element"
and "opt_if_exists_table_element"
- MDEV-8095 Split Create_field
Added mandatory thd parameter to Item (and all derivative classes) constructor.
Added thd parameter to all routines that may create items.
Also removed "current_thd" from Item::Item. This reduced number of
pthread_getspecific() calls from 290 to 177 per OLTP RO transaction.
- Changed ER(ER_...) to ER_THD(thd, ER_...) when thd was known or if there was many calls to current_thd in the same function.
- Changed ER(ER_..) to ER_THD_OR_DEFAULT(current_thd, ER...) in some places where current_thd is not necessary defined.
- Removing calls to current_thd when we have access to thd
Part of this is optimization (not calling current_thd when not needed),
but part is bug fixing for error condition when current_thd is not defined
(For example on startup and end of mysqld)
Notable renames done as otherwise a lot of functions would have to be changed:
- In JOIN structure renamed:
examined_rows -> join_examined_rows
record_count -> join_record_count
- In Field, renamed new_field() to make_new_field()
Other things:
- Added DBUG_ASSERT(thd == tmp_thd) in Item_singlerow_subselect() just to be safe.
- Removed old 'tab' prefix in JOIN_TAB::save_explain_data() and use members directly
- Added 'thd' as argument to a few functions to avoid calling current_thd.
length/dec/charset are still in LEX, because they're also used
for CAST and dynamic columns.
also
1. fix "MDEV-7041 COLLATION(CAST('a' AS CHAR BINARY)) returns a wrong result"
2. allow BINARY modifier in stored function RETURN clause
3. allow "COLLATION without CHARSET" in SP/SF (parameters, RETURN, DECLARE)
4. print correct variable name in error messages for stored routine parameters
CHECK.
Analysis:
----------
Issue here is, while creating or altering the InnoDB table,
if the foreign key defined on the table references a parent
table on which the user has no access privileges then the
table is created without reporting any error.
Currently the privilege level REFERENCES_ACL is unused
and is not used for access evaluation while creating the
table with a foreign key constraint or adding the foreign
key constraint to a table. But when no privileges are granted
to user then also access evaluation on parent table is ignored.
Fix:
---------
For DMLs, irrelevant of the fact, support does not want any
changes to avoid permission checks on every operation.
So, as a fix, added a function "check_fk_parent_table_access"
to check whether any of the SELECT_ACL, INSERT_ACL, UDPATE_ACL,
DELETE_ACL or REFERENCE_ACL privileges are granted for user
at table level. If none of them is granted then error is reported.
This function is called during the table creation and alter
operation.
Merged lp:maria/maria-10.0-galera up to revision 3879.
Added a new functions to handler API to forcefully abort_transaction,
producing fake_trx_id, get_checkpoint and set_checkpoint for XA. These
were added for future possiblity to add more storage engines that
could use galera replication.
