lock_sys_t::deadlock_check(): Assume that only lock_sys.wait_mutex
is being held by the caller.

lock_sys_t::rd_lock_try(): New function.

lock_sys_t::cancel(trx_t*): Kill an active transaction that may be
holding a lock.

lock_sys_t::cancel(trx_t*, lock_t*): Cancel a waiting lock request.

lock_trx_handle_wait(): Avoid acquiring mutexes in some cases,
and in never acquire lock_sys.latch in exclusive mode.
This function is only invoked in a semi-consistent read
(locking a clustered index record only if it matches the search condition).
Normally, lock_wait() will take care of lock waits.

lock_wait(): Invoke the new function lock_sys_t::cancel() at the end,
to avoid acquiring exclusive lock_sys.latch.

lock_rec_other_trx_holds_expl(): Use LockGuard instead of LockMutexGuard.

lock_release_autoinc_locks(): Explicitly acquire table->lock_mutex,
in case only a shared lock_sys.latch is being held. Deadlock::report()
will still hold exclusive lock_sys.latch while invoking
lock_cancel_waiting_and_release().

lock_cancel_waiting_and_release(): Acquire trx->mutex in this function,
instead of expecting the caller to do so.

lock_unlock_table_autoinc(): Only acquire shared lock_sys.latch.

lock_table_has_locks(): Do not acquire lock_sys.latch at all.

Deadlock::check_and_resolve(): Only acquire shared lock_sys.latchm
for invoking lock_sys_t::cancel(trx, wait_lock).

innobase_query_caching_table_check_low(),
row_drop_tables_for_mysql_in_background(): Do not acquire lock_sys.latch.

Added a new wsrep_mode feature DISALLOW_LOCAL_GTID for this.
Nodes can have GTIDs for local transactions in the following scenarios:

A DDL statement is executed with wsrep_OSU_method=RSU set.
A DML statement writes to a non-InnoDB table.
A DML statement writes to an InnoDB table with wsrep_on=OFF set.

If user has set wsrep_mode=DISALLOW_LOCAL_GTID these operations
produce a error ERROR HY000: Galera replication not supported

A performance regression was introduced by
commit e71e6133 (MDEV-24671)
and mostly addressed by
commit 455514c8.

The regression is likely caused by increased contention
lock_sys.latch (former lock_sys.mutex), possibly indirectly
caused by contention on lock_sys.wait_mutex. This change aims to
reduce both, but further improvements will be needed.

lock_wait(): Minimize the lock_sys.wait_mutex hold time.

lock_sys_t::deadlock_check(): Add a parameter for indicating
whether lock_sys.latch is exclusively locked.

trx_t::was_chosen_as_deadlock_victim: Always use atomics.

lock_wait_wsrep(): Assume that no mutex is being held.

Deadlock::report(): Always kill the victim transaction.

lock_sys_t::timeout: New counter to back MONITOR_TIMEOUT.

MDEV-7409 On RBR, extend the PROCESSLIST info to include at least the name of the recently used table

When RBR is used, add the db name to db Field and table name to Status
Field  of the "SHOW FULL PROCESSLIST" command for SQL thread.

Introduced two new wsrep_mode options
* REPLICATE_MYISAM
* REPLICATE_ARIA

Depracated wsrep_replicate_myisam parameter and we use
wsrep_mode = REPLICATE_MYISAM instead.

This required small refactoring of wsrep_check_mode_after_open_table
so that both MyISAM and Aria are handled on required DML cases.
Similarly, added Aria to wsrep_should_replicate_ddl to handle DDL
for Aria tables using TOI. Added test cases and improved MyISAM testing.
Changed use of wsrep_replicate_myisam to wsrep_mode = REPLICATE_MYISAM

Correcting an incorrect merge from 10.2

Backport of 4bc31a90

Include client libraries for auth caching_sha2_password and
sha256_password in the libmariadb3 client library package.

Like the 10.2 version 1635686b,
except C++ on internal functions for my_assume_aligned.

volatile != atomic.

volatile has no memory barrier schemantics, its for mmaped IO
so lets allow some optimizer gains and stop pretending it helps
with memory atomicity.

The MDEV lists a SEGV an assumption is made that an address was
partially read. As C packs structs strictly in order and on arm64 the
cache line size is 128 bits. A pointer (link - 64 bits), followed
by a hashnr (uint32 - 32 bits), leaves the following key (uchar *
64 bits), neither naturally aligned to any pointer and worse, split
across a cache line which is the processors view of an atomic
reservation of memory.

lf_dynarray_lvalue is assumed to return a 64 bit aligned address.

As a solution move the 32bit hashnr to the end so we don't get the
*key pointer split across two cache lines.

Tested by: Krunal Bauskar
Reviewer: Marko Mäkelä

volatile != atomic.

volatile has no memory barrier schemantics, its for mmaped IO
so lets allow some optimizer gains and stop pretending it helps
with memory atomicity.

The MDEV lists a SEGV an assumption is made that an address was
partially read. As C packs structs strictly in order and on arm64 the
cache line size is 128 bits. A pointer (link - 64 bits), followed
by a hashnr (uint32 - 32 bits), leaves the following key (uchar *
64 bits), neither naturally aligned to any pointer and worse, split
across a cache line which is the processors view of an atomic
reservation of memory.

lf_dynarray_lvalue is assumed to return a 64 bit aligned address.

As a solution move the 32bit hashnr to the end so we don't get the
*key pointer split across two cache lines.

Tested by: Krunal Bauskar
Reviewer: Marko Mäkelä

This bug caused crashes of the server when processing queries with table
value constructors (TVC) that contained subqueries and were used itself as
subselects. For such TVCs the following transformation is applied at the
prepare stage:
  VALUES (v1), ... (vn) => SELECT * FROM (VALUES (v1), ... (vn)) tvc_x.
This transformation allows to reduce the problem of evaluation of TVCs used
as subselects to the problem of evaluation of regular subselects.
The transformation is implemented in the wrap_tvc(). The code the function
to mimic the behaviour of the parser when processing the result of the
transformation. However this imitation was not free of some flaws. First
the function called the method exclude() that completely destroyed the
select tree structures below the transformed TVC. Second the function
used the procedure mysql_new_select to create st_select_lex nodes for
both wrapping select of the transformation and TVC. This also led to
constructing of invalid select tree structures.
The patch actually re-engineers the code of wrap_tvc().

Approved by Oleksandr Byelkin <sanja@mariadb.com>

Problem was that we used heap allocated key using too small
array. Fixed by using dynamic memory allocation using actual
needed size.

rw_lock::upgrade_trylock(): If the compare-and-swap fails,
only assert that we are still holding the U lock and that
no conflicting lock exists. If the upgrade to X would fail due
to some thread holding an S latch, we will terminate the loop.

trx_t::commit_in_memory(): Invoke mod_tables.clear().

trx_free_at_shutdown(): Invoke mod_tables.clear() for transactions
that are discarded on shutdown.

Everywhere else, assert mod_tables.empty() on freed transaction objects.

Let us calculate the hash table cell address while we are calculating
the latch address, to avoid repeated computations of the address.
The latch address can be derived from the cell address with a simple
bitmask operation.

Null poiter reference in case where bf_thd has no trx .e.g. when
we have MDL-conflict.

Null poiter reference in case where bf_thd has no trx .e.g. when
we have MDL-conflict.

The problem was in and_all_keys(), the code of MDEV-9759 which calculates
the new tree weight:

First, it didn't take into account the case when

(next->next_key_part=tmp) == NULL

and dereferenced a NULL pointer when getting tmp->weight.

Second, "if (param->alloced_sel_args > SEL_ARG::MAX_SEL_ARGS) break"
could leave the loop with incorrect value of weight.

Fixed by introducing SEL_ARG::update_weight_locally() and calling it
at the end of the function. This allows to avoid caring about all the
above cases.

filename_hash is a function from libiberty.a from the system
but also an expored name in the perf schema static library.

We'll use a different name.

Introduced by 85828b8f

This is running 2 git processes in parallel, which, if unlucky can cause
either of them to fail with "File already exists" error.

Given PASSWORD EXPIRE and PASSWORD EXPIRE [NEVER|INTERVAL x DAY] are
two different mechanisms, SHOW CREATE USER should display all the
information required to restore the state of an account which
includes both a manual expired state and an automatic policy.

The solution proposed here keeps a CREATE USER ... PASSWORD EXPIRE
statement and adds an aditional
ALTER USER .. PASSWORD EXPIRE [NEVER|INTERVAL x DAY] when necessary

This way a tool can restore almost the complete state of an account
as it was before a dump. The only information left still is the
value of the password_last_changed column from mysql.global_priv

- The commit 5fd3c747(MDEV-24709)
resets the recv_no_ibuf_operations in
recv_recovery_from_checkpoint_start(), but InnoDB fails to reset
the variable recv_no_log_write() during that time and that leads
to the assert failure.