This reverts commit 21b2fada7a
and commit 81d71ee6b2.
The MDEV-18464 change introduces a few data race issues. Contrary to
the documentation, the field trx_t::victim is not always being protected
by lock_sys_t::mutex and trx_t::mutex. Most importantly, it seems
that KILL QUERY could wrongly avoid acquiring both mutexes when
invoking lock_trx_handle_wait_low(), in case another thread had
already set trx->victim=true.
We also revert MDEV-12009, because it should depend on the MDEV-18464
fix being present.
As noted on kill_one_thread SUPER should be able to kill even
system threads i.e. threads/query flagged as high priority or
wsrep applier thread. Normal user, should not able to kill
threads/query flagged as high priority (BF) or wsrep applier
thread.
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.
