Partial commit of the greater MDEV-34348 scope.
MDEV-34348: MariaDB is violating clang-16 -Wcast-function-type-strict
Change the type of my_hash_get_key to:
1) Return const
2) Change the context parameter to be const void*
Also fix casting in hash adjacent areas.
Reviewed By:
============
Marko Mäkelä <marko.makela@mariadb.com>
session_track_system_variables and max_relay_log_size.
lock LOCK_global_system_variables around the get_one_variable() call
in the Session_sysvars_tracker::store_variable().
- Some of the bug fixes are backports from 10.5!
- The fix in innobase/fil/fil0fil.cc is just a backport to get less
error messages in mysqld.1.err when running with valgrind.
- Renamed HAVE_valgrind_or_MSAN to HAVE_valgrind
All changes (except one) is of type
thd->transaction. -> thd->transaction->
thd->transaction points by default to 'thd->default_transaction'
This allows us to 'easily' have multiple active transactions for a
THD object, like when reading data from the mysql.proc table
- call current_schema::mark_as_changed() directly
- call state_change::mark_as_changed() directly
- replaced SESSION_TRACKER_CHANGED with dummy tracker
- replaced Session_tracker::mark_as_changed() with
State_tracker::mark_as_changed()
- hide and devirtualize original State_tracker::mark_as_changed(),
rename it to set_changed()
- all implementations of mark_as_changed() now check is_enabled() for
consistency
- no argument casts anymore
- Initialize variables that could be used uninitialized
- Added extra end space to DbugStringItemTypeValue to get rid of warnings
from c_ptr()
- Session_sysvars_tracker::update() accessed unitialized memory if called
with NULL value.
- get_schema_stat_record() accessed unitialized memory if HA_KEY_LONG_HASH
was used
- parse_vcol_defs() accessed random memory for tables without keys.
Originally introduced by e972125f1 to avoid harmless wait for
LOCK_global_system_variables in a newly created thread, which creation was
initiated by system variable update.
At the same time it opens dangerous hole, when system variable update
thread already released LOCK_global_system_variables and ack_receiver
thread haven't yet completed new THD construction. In this case THD
constructor goes completely unprotected.
Since ack_receiver.stop() waits for the thread to go down, we have to
temporarily release LOCK_global_system_variables so that it doesn't
deadlock with ack_receiver.run(). Unfortunately it breaks atomicity
of rpl_semi_sync_master_enabled updates and makes them not serialized.
LOCK_rpl_semi_sync_master_enabled was introduced to workaround the above.
TODO: move ack_receiver start/stop into repl_semisync_master
enable_master/disable_master under LOCK_binlog protection?
Part of MDEV-14984 - regression in connect performance
Only take LOCK_plugin for plugin system variables.
Reverted optimisation that was originally done for session tracker: it
makes much less sense now. Specifically only if connections would want to
track plugin session variables changes and these changes would actually
happen frequently. If this ever becomes an issue, there're much better
ways to optimise this workload.
Part of MDEV-14984 - regression in connect performance
Rather than parsing session_track_system_variables when thread starts, do
it when first trackable event occurs.
Benchmarked on a 2socket/20core/40threads Broadwell system using sysbench
connect brencmark @40 threads (with select 1 disabled):
101379.77 -> 143016.68 CPS, whereas 10.2 is currently at 137766.31 CPS.
Part of MDEV-14984 - regression in connect performance
When enabling system variables tracker, make a copy of
global_system_variables.session_track_system_variables
under LOCK_global_system_variables. This protects from concurrent variable
updates and potential freed memory access, as well as from variable
reconstruction (which was previously protected by LOCK_plugin).
We can also use this copy as a session variable pointer, so that we don't
have to allocate memory and reconstruct it every time it is referenced.
For this very reason we don't need buffer_length stuff anymore.
As well as don't we need to take LOCK_plugin early in ::enable().
Unified ::parse_var_list() to acquire LOCK_plugin unconditionally.
For no apparent reason it wasn't previously acquired for global
variable update.
Part of MDEV-14984 - regression in connect performance
One less new/delete per connection.
Removed m_mem_flag since most allocs are thread specific. The only
exception are allocs performed during initialization.
Removed State_tracker and Session_tracker constructors as they don't make
sense anymore.
No reason to access session_sysvars_tracker via get_tracker(), so access
it directly instead.
Part of MDEV-14984 - regression in connect performance
tool_list is a temporary list needed only for SET SESSION
session_track_system_variables, so allocate it on stack instead.
Sane reinit() calls.
Saves 2 new/delete per connection.
Part of MDEV-14984 - regression in connect performance
- m_enabled is initialised by the base class constructor
- removed unused schema_track_inited
- moved Transaction_state_tracker constructor to declaration
- common enable()
- removed unused Session_sysvars_tracker::check_str()
- classes are "private" by default
- don't even try to compile for embedded
Part of MDEV-14984 - regression in connect performance
- return proper type
- removed useless node argument
- removed useless mem_flag
- classes are "private" by default
- simplified iterators
Part of MDEV-14984 - regression in connect performance
