We replace the old lock_sys.mutex (which was renamed to lock_sys.latch)
with a combination of a global lock_sys.latch and table or page hash lock
mutexes.
The global lock_sys.latch can be acquired in exclusive mode, or
it can be acquired in shared mode and another mutex will be acquired
to protect the locks for a particular page or a table.
This is inspired by
mysql/mysql-server@1d259b87a6
but the optimization of lock_release() will be done in the next commit.
Also, we will interleave mutexes with the hash table elements, similar
to how buf_pool.page_hash was optimized
in commit 5155a300fa (MDEV-22871).
dict_table_t::autoinc_trx: Use Atomic_relaxed.
dict_table_t::autoinc_mutex: Use srw_mutex in order to reduce the
memory footprint. On 64-bit Linux or OpenBSD, both this and the new
dict_table_t::lock_mutex should be 32 bits and be stored in the same
64-bit word. On Microsoft Windows, the underlying SRWLOCK is 32 or 64
bits, and on other systems, sizeof(pthread_mutex_t) can be much larger.
ib_lock_t::trx_locks, trx_lock_t::trx_locks: Document the new rules.
Writers must assert lock_sys.is_writer() || trx->mutex_is_owner().
LockGuard: A RAII wrapper for acquiring a page hash table lock.
LockGGuard: Like LockGuard, but when Galera Write-Set Replication
is enabled, we must acquire all shards, for updating arbitrary trx_locks.
LockMultiGuard: A RAII wrapper for acquiring two page hash table locks.
lock_rec_create_wsrep(), lock_table_create_wsrep(): Special
Galera conflict resolution in non-inlined functions in order
to keep the common code paths shorter.
lock_sys_t::prdt_page_free_from_discard(): Refactored from
lock_prdt_page_free_from_discard() and
lock_rec_free_all_from_discard_page().
trx_t::commit_tables(): Replaces trx_update_mod_tables_timestamp().
lock_release(): Let trx_t::commit_tables() invalidate the query cache
for those tables that were actually modified by the transaction.
Merge lock_check_dict_lock() to lock_release().
We must never release lock_sys.latch while holding any
lock_sys_t::hash_latch. Failure to do that could lead to
memory corruption if the buffer pool is resized between
the time lock_sys.latch is released and the hash_latch is released.
We implement an idea that was suggested by Michael 'Monty' Widenius
in October 2017: When InnoDB is inserting into an empty table or partition,
we can write a single undo log record TRX_UNDO_EMPTY, which will cause
ROLLBACK to clear the table.
For this to work, the insert into an empty table or partition must be
covered by an exclusive table lock that will be held until the transaction
has been committed or rolled back, or the INSERT operation has been
rolled back (and the table is empty again), in lock_table_x_unlock().
Clustered index records that are covered by the TRX_UNDO_EMPTY record
will carry DB_TRX_ID=0 and DB_ROLL_PTR=1<<55, and thus they cannot
be distinguished from what MDEV-12288 leaves behind after purging the
history of row-logged operations.
Concurrent non-locking reads must be adjusted: If the read view was
created before the INSERT into an empty table, then we must continue
to imagine that the table is empty, and not try to read any records.
If the read view was created after the INSERT was committed, then
all records must be visible normally. To implement this, we introduce
the field dict_table_t::bulk_trx_id.
This special handling only applies to the very first INSERT statement
of a transaction for the empty table or partition. If a subsequent
statement in the transaction is modifying the initially empty table again,
we must enable row-level undo logging, so that we will be able to
roll back to the start of the statement in case of an error (such as
duplicate key).
INSERT IGNORE will continue to use row-level logging and locking, because
implementing it would require the ability to roll back the latest row.
Since the undo log that we write only allows us to roll back the entire
statement, we cannot support INSERT IGNORE. We will introduce a
handler::extra() parameter HA_EXTRA_IGNORE_INSERT to indicate to storage
engines that INSERT IGNORE is being executed.
In many test cases, we add an extra record to the table, so that during
the 'interesting' part of the test, row-level locking and logging will
be used.
Replicas will continue to use row-level logging and locking until
MDEV-24622 has been addressed. Likewise, this optimization will be
disabled in Galera cluster until MDEV-24623 enables it.
dict_table_t::bulk_trx_id: The latest active or committed transaction
that initiated an insert into an empty table or partition.
Protected by exclusive table lock and a clustered index leaf page latch.
ins_node_t::bulk_insert: Whether bulk insert was initiated.
trx_t::mod_tables: Use C++11 style accessors (emplace instead of insert).
Unlike earlier, this collection will cover also temporary tables.
trx_mod_table_time_t: Add start_bulk_insert(), end_bulk_insert(),
is_bulk_insert(), was_bulk_insert().
trx_undo_report_row_operation(): Before accessing any undo log pages,
invoke trx->mod_tables.emplace() in order to determine whether undo
logging was disabled, or whether this is the first INSERT and we are
supposed to write a TRX_UNDO_EMPTY record.
row_ins_clust_index_entry_low(): If we are inserting into an empty
clustered index leaf page, set the ins_node_t::bulk_insert flag for
the subsequent trx_undo_report_row_operation() call.
lock_rec_insert_check_and_lock(), lock_prdt_insert_check_and_lock():
Remove the redundant parameter 'flags' that can be checked in the caller.
btr_cur_ins_lock_and_undo(): Simplify the logic. Correctly write
DB_TRX_ID,DB_ROLL_PTR after invoking trx_undo_report_row_operation().
trx_mark_sql_stat_end(), ha_innobase::extra(HA_EXTRA_IGNORE_INSERT),
ha_innobase::external_lock(): Invoke trx_t::end_bulk_insert() so that
the next statement will not be covered by table-level undo logging.
ReadView::changes_visible(trx_id_t) const: New accessor for the case
where the trx_id_t is not read from a potentially corrupted index page
but directly from the memory. In this case, we can skip a sanity check.
row_sel(), row_sel_try_search_shortcut(), row_search_mvcc():
row_sel_try_search_shortcut_for_mysql(),
row_merge_read_clustered_index(): Check dict_table_t::bulk_trx_id.
row_sel_clust_sees(): Replaces lock_clust_rec_cons_read_sees().
lock_sec_rec_cons_read_sees(): Replaced with lower-level code.
btr_root_page_init(): Refactored from btr_create().
dict_index_t::clear(), dict_table_t::clear(): Empty an index or table,
for the ROLLBACK of an INSERT operation.
ROW_T_EMPTY, ROW_OP_EMPTY: Note a concurrent ROLLBACK of an INSERT
into an empty table.
This is joint work with Thirunarayanan Balathandayuthapani,
who created a working prototype.
Thanks to Matthias Leich for extensive testing.
Since commit 8ccb3caafb it should be
more efficient to use page_id_t rather than two separate variables
for tablespace identifier and page number.
lock_rec_fold(): Replaced with page_id_t::fold().
lock_rec_hash(): Replaced with lock_sys.hash(page_id).
lock_rec_expl_exist_on_page(), lock_rec_get_first_on_page_addr(),
lock_rec_get_first_on_page(): Replaced with lock_sys.get_first().
Also, related to MDEV-15522, MDEV-17304, MDEV-17835,
remove the Galera xtrabackup tests, because xtrabackup never worked
with MariaDB Server 10.3 due to InnoDB redo log format changes.
Remove unused InnoDB function parameters and functions.
i_s_sys_virtual_fill_table(): Do not allocate heap memory.
mtr_is_block_fix(): Replace with mtr_memo_contains().
mtr_is_page_fix(): Replace with mtr_memo_contains_page().
InnoDB defines some functions that are not called at all.
Other functions are called, but only from the same compilation unit.
Remove some function declarations and definitions, and add 'static'
keywords. Some symbols must be kept for separately compiled tools,
such as innochecksum.
Contains also:
MDEV-10549 mysqld: sql/handler.cc:2692: int handler::ha_index_first(uchar*): Assertion `table_share->tmp_table != NO_TMP_TABLE || m_lock_type != 2' failed. (branch bb-10.2-jan)
Unlike MySQL, InnoDB still uses THR_LOCK in MariaDB
MDEV-10548 Some of the debug sync waits do not work with InnoDB 5.7 (branch bb-10.2-jan)
enable tests that were fixed in MDEV-10549
MDEV-10548 Some of the debug sync waits do not work with InnoDB 5.7 (branch bb-10.2-jan)
fix main.innodb_mysql_sync - re-enable online alter for partitioned innodb tables
Contains also
MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7
The failure happened because 5.7 has changed the signature of
the bool handler::primary_key_is_clustered() const
virtual function ("const" was added). InnoDB was using the old
signature which caused the function not to be used.
MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7
Fixed mutexing problem on lock_trx_handle_wait. Note that
rpl_parallel and rpl_optimistic_parallel tests still
fail.
MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan)
Reason: incorrect merge
MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan)
Reason: incorrect merge
