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()
The test was not deterministic and would occasionally fail, due to the
use of `sleep`.
This patch is a complete rewrite of the test using proper sync points.
These test can sporadically show mutex deadlock warnings between LOCK_wsrep_thd
and LOCK_thd_data mutexes. This means that these mutexes can be locked in opposite
order by different threads, and thus result in deadlock situation.
To fix such issue, the locking policy of these mutexes should be revised and
enforced to be uniform. However, a quick code review shows that the number of
lock/unlock operations for these mutexes combined is between 100-200, and all these
mutex invocations should be checked/fixed.
On the other hand, it turns out that LOCK_wsrep_thd is used for protecting access to
wsrep variables of THD (wsrep_conflict_state, wsrep_query_state), whereas LOCK_thd_data
protects query, db and mysys_var variables in THD. Extending LOCK_thd_data to protect
also wsrep variables looks like a viable solution, as there should not be a use case
where separate threads need simultaneous access to wsrep variables and THD data variables.
In this commit LOCK_wsrep_thd mutex is refactored to be replaced by LOCK_thd_data.
By bluntly replacing LOCK_wsrep_thd by LOCK_thd_data, will result in double locking
of LOCK_thd_data, and some adjustements have been performed to fix such situations.
Modern compilers (such as GCC 8) emit warnings that the
'register' keyword is deprecated and not valid C++17.
Let us remove most use of the 'register' keyword.
Code in 'extra/' is not touched.
Problem was that we did not delete explain information
when Galera must replay a query.
Could not find easily repeatable test case that would not
cause other problems.
Problem was that we did not delete explain information
when Galera must replay a query.
Could not find easily repeatable test case that would not
cause other problems.
Problem was that we did not delete explain information
when Galera must replay a query.
Could not find easily repeatable test case that would not
cause other problems.
numerous fixes for CREATE ... SELECT with system versioning:
In CREATE ... SELECT the table is created based on the result set,
field properties do not count. That is
* field invisibility is *not* copied over
* AS ROW START/END is *not* copied over
* the history is *not* copied over
* system row_start/row_end fields can *not* be created from the SELECT part
The following changes are committed:
* `RESET MASTER` at the end of the test. This was necessary to allow the test
to run on repeated runs.
* `--source include/galera_wait_ready.inc` after setting `gmcast.isolate=0` to
get back to a primary component.
* Fix for assertion in `Protocol::end_statement()`. The assertion is due to
the fact that function `do_command()` calls `thd->protocol->end_statement()`,
without setting an error, when it is detected that galera is not ready yet.
Following line somehow disappeared in a past merge:
```
my_message(ER_UNKNOWN_COM_ERROR,
"WSREP has not yet prepared node for application use", MYF(0));
```
Remove clause on `thd->variables.wsrep_on` in the following code:
if (WSREP(thd))
{
...
if (thd->variables.wsrep_on &&
...
In the above snippet, `WSREP(thd)` already ensures thd->variables.wsrep_on
It doesn't make sense to allow selects from I_S but disallow selects
that don't use any tables at all, because any (disallowed) select that
doesn't use tables can be made allowed by adding
"FROM I_S.COLLATIONS LIMIT 1" to the end.
And it break mysql-test rather badly, even check-testcase.test
fails on its first `SELECT '$tmp' = 'No such row'`
This reverts 9a896148576, c5dd2abf4ca, and 33028f7c4bc:
Refs: MW-245 - changed logic so that in non primary node it is possible to do SET + SHOW + SELECT from information and pfs schema, when dirty reads are not enabled - however, non table selects are not allowed (e.g. SELECT 1)
Refs MW-245 - logic was wrong in detecting if queries are allowed in non primary node. it allowed select with no table list to execute even if dirty reads was not specified
Refs: MW-245 - Adjust tests to account for the new behavior.
Test MW-286 occasionally failed with error the following message:
```
safe_mutex: Found wrong usage of mutex 'LOCK_wsrep_thd' and 'LOCK_thd_kill'
Mutex currently locked (in reverse order):
LOCK_thd_kill mariadb-server/sql/sql_class.h line 3535
LOCK_wsrep_thd mariadb-server/sql/wsrep_thd.cc line 88
```
The fix consists in calling thd->reset_killed() in wsrep_mysql_parse() after
LOCK_wsrep_thd is unlocked. Which avoids the taking locks LOCK_wsrep_thd and
LOCK_thd_kill in reverse order.
- CREATE PACKAGE [BODY] statements are now
entirely written to mysql.proc with type='PACKAGE' and type='PACKAGE BODY'.
- CREATE PACKAGE BODY now supports IF NOT EXISTS
- DROP PACKAGE BODY now supports IF EXISTS
- CREATE OR REPLACE PACKAGE [BODY] is now supported
- CREATE PACKAGE [BODY] now support the DEFINER clause:
CREATE DEFINER user@host PACKAGE pkg ... END;
CREATE DEFINER user@host PACKAGE BODY pkg ... END;
- CREATE PACKAGE [BODY] now supports SQL SECURITY and COMMENT clauses, e.g.:
CREATE PACKAGE p1 SQL SECURITY INVOKER COMMENT "comment" AS ... END;
- Package routines are now created from the package CREATE PACKAGE BODY
statement and don't produce individual records in mysql.proc.
- CREATE PACKAGE BODY now supports package-wide variables.
Package variables can be read and set inside package routines.
Package variables are stored in a separate sp_rcontext,
which is cached in THD on the first packate routine call.
- CREATE PACKAGE BODY now supports the initialization section.
- All public routines (i.e. declared in CREATE PACKAGE)
must have implementations in CREATE PACKAGE BODY
- Only public package routines are available outside of the package
- {CREATE|DROP} PACKAGE [BODY] now respects CREATE ROUTINE and ALTER ROUTINE
privileges
- "GRANT EXECUTE ON PACKAGE BODY pkg" is now supported
- SHOW CREATE PACKAGE [BODY] is now supported
- SHOW PACKAGE [BODY] STATUS is now supported
- CREATE and DROP for PACKAGE [BODY] now works for non-current databases
- mysqldump now supports packages
- "SHOW {PROCEDURE|FUNCTION) CODE pkg.routine" now works for package routines
- "SHOW PACKAGE BODY CODE pkg" now works (the package initialization section)
- A new package body level MDL was added
- Recursive calls for package procedures are now possible
- Routine forward declarations in CREATE PACKATE BODY are now supported.
- Package body variables now work as SP OUT parameters
- Package body variables now work as SELECT INTO targets
- Package body variables now support ROW, %ROWTYPE, %TYPE
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.
Counter for select numbering made stored with the statement (before was global)
So now it does have always accurate value which does not depend on
interruption of statement prepare by errors like lack of table in
a view definition.
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 "")
