Commit graph

6869 commits

Author SHA1 Message Date
Marko Mäkelä
453dc4b300 Fixup the parent commit for MSAN and Valgrind
commit 484931325e was a necessary
fix for the buffer pool resizing tests in 10.5 in
AddressSanitizer. However, that change would break the tests
innodb.innodb_buffer_pool_resize and
innodb.innodb_buffer_pool_resize_with_chunks
when run in MemorySanitizer, or presumably in Valgrind as well.
(Those tests run "forever" in Valgrind.)

buf_pool_resize(): Cancel the effect of MEM_NOACCESS() in Valgrind
and ASAN. In MSAN, MEM_NOACCESS() is a no-op, and hence we must do
nothing special here.

MEM_MAKE_ADDRESSABLE() would declare the memory contents undefined.
In this particular case, we must actually declare the contents
defined for Valgrind.
2020-07-04 22:02:30 +03:00
Monty
484931325e Fix for MSAN from Marko related to buf_pool_resize 2020-07-03 18:37:33 +03:00
Marko Mäkelä
b6ec1e8bbf MDEV-20377 post-fix: Introduce MEM_MAKE_ADDRESSABLE
In AddressSanitizer, we only want memory poisoning to happen
in connection with custom memory allocation or freeing.

The primary use of MEM_UNDEFINED is for declaring memory uninitialized
in Valgrind or MemorySanitizer. We do not want MEM_UNDEFINED to
have the unwanted side effect that AddressSanitizer would no longer
be able to complain about accessing unallocated memory.

MEM_UNDEFINED(): Define as no-op for AddressSanitizer.

MEM_MAKE_ADDRESSABLE(): Define as MEM_UNDEFINED() or
ASAN_UNPOISON_MEMORY_REGION().

MEM_CHECK_ADDRESSABLE(): Wrap also __asan_region_is_poisoned().
2020-07-02 17:59:28 +03:00
Monty
65f831d17c Fixed bugs found by valgrind
- 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
2020-07-02 17:57:34 +03:00
Marko Mäkelä
1df1a63924 Merge 10.2 into 10.3 2020-07-02 06:17:51 +03:00
Marko Mäkelä
838a1046b2 MDEV-20377: Fix cmake -DPLUGIN_PERFSCHEMA=NO 2020-07-02 06:03:59 +03:00
Marko Mäkelä
69df4f834b MDEV-20377: Fix -Wunused-but-set-variable 2020-07-01 20:34:06 +03:00
Marko Mäkelä
c36834c832 MDEV-20377: Make WITH_MSAN more usable
MemorySanitizer (clang -fsanitize=memory) requires that all code
be compiled with instrumentation enabled. The only exception is the
C runtime library. Failure to use instrumented libraries will cause
bogus messages about memory being uninitialized.

In WITH_MSAN builds, we must avoid calling getservbyname(),
because even though it is a standard library function, it is
not instrumented, not even in clang 10.

Note: Before MariaDB Server 10.5, ./mtr will typically fail
due to the old PCRE library, which was updated in MDEV-14024.

The following cmake options were tested on 10.5
in commit 94d0bb4dbe:

cmake \
-DCMAKE_C_FLAGS='-march=native -O2' \
-DCMAKE_CXX_FLAGS='-stdlib=libc++ -march=native -O2' \
-DWITH_EMBEDDED_SERVER=OFF -DWITH_UNIT_TESTS=OFF -DCMAKE_BUILD_TYPE=Debug \
-DWITH_INNODB_{BZIP2,LZ4,LZMA,LZO,SNAPPY}=OFF \
-DPLUGIN_{ARCHIVE,TOKUDB,MROONGA,OQGRAPH,ROCKSDB,CONNECT,SPIDER}=NO \
-DWITH_SAFEMALLOC=OFF \
-DWITH_{ZLIB,SSL,PCRE}=bundled \
-DHAVE_LIBAIO_H=0 \
-DWITH_MSAN=ON

MEM_MAKE_DEFINED(): An alias for VALGRIND_MAKE_MEM_DEFINED()
and __msan_unpoison().

MEM_GET_VBITS(), MEM_SET_VBITS(): Aliases for
VALGRIND_GET_VBITS(), VALGRIND_SET_VBITS(), __msan_copy_shadow().

InnoDB: Replace the UNIV_MEM_ macros with corresponding MEM_ macros.

ut_crc32_8_hw(), ut_crc32_64_low_hw(): Use the compiler built-in
functions instead of inline assembler when building WITH_MSAN.
This will require at least -msse4.2 when building for IA-32 or AMD64.
The inline assembler would not be instrumented, and would thus cause
bogus failures.
2020-07-01 17:23:00 +03:00
Marko Mäkelä
ea2bc974dc Merge 10.1 into 10.2 2020-07-01 12:03:55 +03:00
Eugene Kosov
1ea266f3ef MDEV-23003 INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION requires SUPER instead PROCESS privilege
Fix a typo in a source code. Now real required privileges corresponds
to a ones mentions in documentation.

Documentation states that this table requires PROCESS privilege:
https://mariadb.com/kb/en/information-schema-innodb_tablespaces_encryption-table/
2020-06-30 21:31:49 +03:00
Eugene Kosov
17109001d6 speed up fil_validate() in debug builds
This function is very common in a debug build. I can even see it in
profiler.

This patch reduces execution time of fil_validate() from
8948ns
8367ns
8650ns
8906ns
8448ns

to
260ns
232ns
403ns
275ns
169ns
in my environment.

The trick is a faster fil_space_t iteration. Hash table
is typically initialized with a size of 50,000. And looping through
it is slow. Slower, than iterating an exact amount of fil_space_t
which is typically less than ten.

Only debug builds are affected.
2020-06-30 12:17:53 +03:00
Eugene Kosov
e4cff9a855 MDEV-19298 Assertion `space->id != 0xFFFFFFFEU || space == fil_system.temp_space' failed in Check::validate upon crash upgrade from 10.2.22
This issue is pretty much the same as MDEV-20213.
The fix is similar to:
3c238ac51c
52c4abbff2

Check::validate(): fix a debug assertion

SysTablespace::open_or_create(): protect assigning to a shared
variable with a mutex
2020-06-27 12:52:08 +03:00
Eugene Kosov
52c4abbff2 MDEV-20213 binlog_encryption.binlog_incident failed in buildbot, server crashed in Check::validate
follow up

fil_system.sys_space is a shared variable between the thread
which assigns a value to it, and the thread which does Check::validate()

SysTablespace::open_or_create(): protect a shared variable with
a mutex to avoid any data race surprises.
2020-06-27 12:21:37 +03:00
Eugene Kosov
3c238ac51c MDEV-20213 binlog_encryption.binlog_incident failed in buildbot, server crashed in Check::validate
Check::validate(): Relax a debug assertion. TRX_SYS_SPACE fil_space_t
can be created and became visible to this assertion before
fil_system.sys_space becomes initialized
2020-06-27 11:54:59 +03:00
Thirunarayanan Balathandayuthapani
e30c4cfc7a MDEV-22811 DDL fails to drop and re-create FTS index
Problem:
========
- InnoDB clears the fts resource when last FTS index is being dropped
if the table has user defined FTS_DOC_ID. While creating the new fts
index, InnoDB expects to have FTS resources.

Fix:
===
fts_drop_index(): Removed the fts resource clear.

fts_clear_all(): Clear the fts resource when there are no new fts
index to be added.

commit_cache_norebuild(), row_merge_drop_indexes():
Tries to call fts resource after removing associated fts index
from table object
2020-06-18 15:49:39 +05:30
Thirunarayanan Balathandayuthapani
9f37323f06 MDEV-22901 Accessing btr_search_sys->hash_tables when buffer pool resize happens
btr_search_build_page_hash_index(): Reduce the scope of the variable 'i'
2020-06-16 12:30:04 +05:30
Thirunarayanan Balathandayuthapani
29a5829c37 MDEV-22901 Accessing btr_search_sys->hash_tables when buffer pool resize happens
- btr_get_search_table() is accessing btr_search_sys->hash_tables,
which is not safe if the buffer pool resize happens concurrently.
2020-06-16 12:27:09 +05:30
Marko Mäkelä
d83a443250 Merge 10.2 into 10.3 2020-06-13 15:11:43 +03:00
Marko Mäkelä
b68f1d847f MDEV-21217 innodb_force_recovery=2 may wrongly abort rollback
trx_roll_must_shutdown(): Correct the condition that detects
the start of shutdown.
2020-06-13 14:45:52 +03:00
Daniel Black
902742789e
innodb: dict_mem_table_add_col - compile warning fix argument 1 null where non-null expected (#1584)
cd /build-mariadb-server-10.5-mysql_release/storage/innobase && /usr/bin/powerpc64le-linux-gnu-g++  -DBTR_CUR_ADAPT -DBTR_CUR_HASH_ADAPT -DCOMPILER_HINTS -DDBUG_TRACE -DEMBEDDED_LIBRARY -DHAVE_BZIP2=1 -DHAVE_C99_INITIALIZERS -DHAVE_CONFIG_H -DHAVE_FALLOC_PUNCH_HOLE_AND_KEEP_SIZE=1 -DHAVE_IB_LINUX_FUTEX=1 -DHAVE_LZ4=1 -DHAVE_LZ4_COMPRESS_DEFAULT=1 -DHAVE_LZMA=1 -DHAVE_NANOSLEEP=1 -DHAVE_OPENSSL -DHAVE_SCHED_GETCPU=1 -DLINUX_NATIVE_AIO=1 -DMUTEX_EVENT -DWITH_INNODB_DISALLOW_WRITES -D_FILE_OFFSET_BITS=64 -Iwsrep-lib/include -Iwsrep-lib/wsrep-API/v26 -I/home/dan/build-mariadb-server-10.5-mysql_release/include -Istorage/innobase/include -Istorage/innobase/handler -Ilibbinlogevents/include -Itpool -Iinclude -Isql  -pie -fPIC -Wl,-z,relro,-z,now -fstack-protector --param=ssp-buffer-size=4 -Wconversion -Wno-sign-conversion -O3 -g -static-libgcc -fno-omit-frame-pointer -fno-strict-aliasing -Wno-uninitialized -D_FORTIFY_SOURCE=2 -DDBUG_OFF -Wall -Wextra -Wformat-security -Wno-format-truncation -Wno-init-self -Wno-nonnull-compare -Wno-unused-parameter -Woverloaded-virtual -Wnon-virtual-dtor -Wvla -Wwrite-strings   -DUNIV_LINUX -D_GNU_SOURCE=1 -fPIC -fvisibility=hidden -std=gnu++11 -o CMakeFiles/innobase_embedded.dir/dict/dict0load.cc.o -c storage/innobase/dict/dict0load.cc
storage/innobase/dict/dict0load.cc: In function ‘const char* dict_process_sys_columns_rec(mem_heap_t*, const rec_t*, dict_col_t*, table_id_t*, const char**, ulint*)’:
storage/innobase/dict/dict0load.cc:1653:26: warning: argument 1 null where non-null expected [-Wnonnull]
    dict_mem_table_add_col(table, heap, name, mtype,
    ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
             prtype, col_len);
             ~~~~~~~~~~~~~~~~
In file included from storage/innobase/include/dict0dict.h:32:0,
                 from storage/innobase/include/btr0pcur.h:30,
                 from storage/innobase/dict/dict0load.cc:31:
storage/innobase/include/dict0mem.h:323:1: note: in a call to function ‘void dict_mem_table_add_col(dict_table_t*, mem_heap_t*, const char*, ulint, ulint, ulint)’ declared here
 dict_mem_table_add_col(
 ^~~~~~~~~~~~~~~~~~~~~~
2020-06-09 14:54:42 +03:00
Marko Mäkelä
befb0bed68 Merge 10.2 into 10.3 2020-06-08 11:09:49 +03:00
Marko Mäkelä
f458b40f66 MDEV-22827 InnoDB: Failing assertion: purge_sys->n_stop == 0
When MDEV-22769 introduced srv_shutdown_state=SRV_SHUTDOWN_INITIATED in
commit efc70da5fd
we forgot to adjust a few checks for SRV_SHUTDOWN_NONE.

In the initial shutdown step, we are waiting for the background
DROP TABLE queue to be processed or discarded. At that time,
some background tasks (such as buffer pool resizing or dumping
or encryption key rotation) may be terminated, but others must
remain running normally.

srv_purge_coordinator_suspend(), srv_purge_coordinator_thread(),
srv_start_wait_for_purge_to_start(): Treat SRV_SHUTDOWN_NONE
and SRV_SHUTDOWN_INITIATED equally.
2020-06-08 10:35:06 +03:00
Marko Mäkelä
b3e395a13e Merge 10.2 into 10.3 2020-06-06 18:50:25 +03:00
Marko Mäkelä
e14ffd85d0 MDEV-22721 fixup for 32-bit GCC
lock_check_trx_id_sanity(): Because the argument of UNIV_LIKELY
or __builtin_expect() can be less than sizeof(trx_id_t) on 32-bit
systems, it cannot reliably perform an implicit comparison to 0.
2020-06-06 18:18:40 +03:00
Marko Mäkelä
1bd5b75c73 MDEV-22818 Server crash on corrupted ROW_FORMAT=COMPRESSED page
page_zip_fields_decode(): Do not dereference index=NULL.
Instead, return NULL early. The only caller does not care
about the values of output parameters in that case.

This bug was introduced in MySQL 5.7.6 by
mysql/mysql-server@9eae0edb7a
and in MariaDB 10.2.2 by
commit 2e814d4702.

Thanks to my son for pointing this out after investigating
the output of a static analysis tool.
2020-06-06 09:33:48 +03:00
Marko Mäkelä
286e52e948 After-merge fix: GCC -Wmaybe-uninitialized 2020-06-05 17:45:27 +03:00
Marko Mäkelä
680463a8d9 Merge 10.2 into 10.3 2020-06-05 16:51:26 +03:00
Marko Mäkelä
efc70da5fd MDEV-22769 Shutdown hang or crash due to XA breaking locks
The background drop table queue in InnoDB is a work-around for
cases where the SQL layer is requesting DDL on tables on which
transactional locks exist.

One such case are XA transactions. Our test case exploits the
fact that the recovery of XA PREPARE transactions will
only resurrect InnoDB table locks, but not MDL that should
block any concurrent DDL.

srv_shutdown_t: Introduce the srv_shutdown_state=SRV_SHUTDOWN_INITIATED
for the initial part of shutdown, to wait for the background drop
table queue to be emptied.

srv_shutdown_bg_undo_sources(): Assign
srv_shutdown_state=SRV_SHUTDOWN_INITIATED
before waiting for the background drop table queue to be emptied.

row_drop_tables_for_mysql_in_background(): On slow shutdown, if
no active transactions exist (excluding ones that are in
XA PREPARE state), skip any tables on which locks exist.

row_drop_table_for_mysql(): Do not unnecessarily attempt to
drop InnoDB persistent statistics for tables that have
already been added to the background drop table queue.

row_mysql_close(): Relax an assertion, and free all memory
even if innodb_force_recovery=2 would prevent the background
drop table queue from being emptied.
2020-06-05 15:22:46 +03:00
Marko Mäkelä
138c11cce5 MDEV-22790 Race between btr_page_mtr_lock() dropping AHI on the same block
This race condition was introduced by
commit ad6171b91c (MDEV-22456).

In the observed case, two threads were executing
btr_search_drop_page_hash_index() on the same block,
to free a stale entry that was attached to a dropped index.
Both threads were holding an S latch on the block.

We must prevent the double-free of block->index by holding
block->lock in exclusive mode.

btr_search_guess_on_hash(): Do not invoke
btr_search_drop_page_hash_index(block) to get rid of
stale entries, because we are not necessarily holding
an exclusive block->lock here.

buf_defer_drop_ahi(): New function, to safely drop stale
entries in buf_page_mtr_lock(). We will skip the call to
btr_search_drop_page_hash_index(block) when only requesting
bufferfixing (no page latch), because in that case, we should
not be accessing the adaptive hash index, and we might get
a deadlock if we acquired the page latch.
2020-06-05 15:22:46 +03:00
Marko Mäkelä
3677dd5cb4 MDEV-22646: Fix a memory leak
btr_search_sys_free(): Free btr_search_sys->hash_tables.

The leak was introduced in commit ad2bf1129c.
2020-06-05 15:22:46 +03:00
Marko Mäkelä
c5883debd6 dict_check_sys_tables(): Do not rely on buf_page_optimistic_get()
We are supposed to commit and restart the mini-transaction
between records. There is no point to store and restore the
persistent cursor position otherwise.

If buf_page_optimistic_get() is patched to always fail, the
debug build would fail to start up due to trying to re-acquire
an already S-latched block.

This bug (which should not have visible impact to users, because
the code is only executed during startup, while no other threads
are accessing B-trees or causing pages to be evicted from the
buffer pool) was caught as part of a debugging effort for
something else.

The debugging approach was: Make buf_page_optimistic_get()
always return FALSE, and add ut_a(block->lock.lock_word == X_LOCK_DECR)
to both buf_LRU_get_free_only() and buf_LRU_block_free_non_file_page().
This would catch misuse of the buffer pool. If it were not for
buf_page_optimistic_get(), no buf_block_t::lock of any BUF_BLOCK_NOT_USED
block would ever be acquired.
2020-06-04 16:31:29 +03:00
Marko Mäkelä
eba2d10ac5 MDEV-22721 Remove bloat caused by InnoDB logger class
Introduce a new ATTRIBUTE_NOINLINE to
ib::logger member functions, and add UNIV_UNLIKELY hints to callers.

Also, remove some crash reporting output. If needed, the
information will be available using debugging tools.

Furthermore, remove some fts_enable_diag_print output that included
indexed words in raw form. The code seemed to assume that words are
NUL-terminated byte strings. It is not clear whether a NUL terminator
is always guaranteed to be present. Also, UCS2 or UTF-16 strings would
typically contain many NUL bytes.
2020-06-04 10:24:10 +03:00
Thirunarayanan Balathandayuthapani
ad2bf1129c MDEV-22646 Assertion `table2->cached' failed in dict_table_t::add_to_cache
Problem:
========
  During buffer pool resizing, InnoDB recreates the dictionary hash
tables. Dictionary hash table reuses the heap of AHI hash tables.
It leads to memory corruption.

Fix:
====
- While disabling AHI, free the heap and AHI hash tables. Recreate the
AHI hash tables and assign new heap when AHI is enabled.

- btr_blob_free() access invalid page if page was reallocated during
buffer poolresizing. So btr_blob_free() should get the page from
buf_pool instead of using existing block.

- btr_search_enabled and block->index should be checked after
acquiring the btr_search_sys latch

- Moved the buffer_pool_scan debug sync to earlier before accessing the
btr_search_sys latches to avoid the hang of truncate_purge_debug
test case

- srv_printf_innodb_monitor() should acquire btr_search_sys latches
before AHI hash tables.
2020-06-03 16:02:02 +05:30
Marko Mäkelä
ca3aa67964 MDEV-22577 innodb_fast_shutdown=0 fails to report purge progress
srv_purge_should_exit(): Report progress on slow shutdown
not only to systemd, but also to the error log.
2020-06-03 12:14:11 +03:00
Marko Mäkelä
8300f639a1 Merge 10.2 into 10.3 2020-06-02 10:25:11 +03:00
Marko Mäkelä
804761a844 MDEV-22770 trx_undo_report_rename() fails to release page latches
commit f74023b955 (MDEV-15090)
inadvertently removed a mtr_t::commit() call from
trx_undo_report_rename(), causing an InnoDB hang if
we failed to log a RENAME operation.

It is unclear whether this condition is possible in practice.
The test case involved SET GLOBAL innodb_trx_rseg_n_slots_debug=1
and a failed CREATE TABLE...SELECT, whose error handling would
internally invoke RENAME in InnoDB.
2020-06-02 08:23:43 +03:00
Thirunarayanan Balathandayuthapani
02f68552a4 MDEV-22650 Dirty compressed page checksum validation fails
Problem:
=======
  While evicting the uncompressed page from buffer pool, InnoDB writes
the checksum for the compressed page in buf_LRU_free_page().
So while flushing the compressed page, checksum validation fails
when innodb_checksum_algorithm variable changed to strict_none.

Solution:
========
- Calculate the checksum only during flushing of page. Removed the
checksum write in buf_LRU_free_page().
2020-06-01 14:34:16 +05:30
Marko Mäkelä
83d0e72b34 Cleanup: Remove thr_is_recv(), trx_is_recv()
Compare to trx_roll_crash_recv_trx directly where needed.
2020-06-01 10:23:11 +03:00
Marko Mäkelä
c50b7bee33 MDEV-21615 InnoDB: innodb_page_size=x requires... should be logged as error
innobase_init(): On every path to refused startup, log the reason
to refuse startup as an error, instead of a note.
2020-06-01 10:18:47 +03:00
Marko Mäkelä
dad7a8ee7d Merge 10.2 into 10.3 2020-05-27 17:10:39 +03:00
Eugene Kosov
18d8f06f31 intrusive::list fixes
namespace intrusive: removed

split class into two: ilist<T> and sized_ilist<T> which has a size field.

ilist<T> no more NULLify pointers to bring a slignly better performance.
As a consequence, fil_space_t::is_in_unflushed_spaces and
fil_space_t::is_in_rotation_list boolean members are needed now.
2020-05-27 02:34:25 +03:00
Thirunarayanan Balathandayuthapani
7476e8c7cd MDEV-22637 Rollback of insert fails when column reorder happens
- During column reorder table rebuild, rollback of insert fails.
Reason is that InnoDB tries to fetch the column position from
new clustered index and it exceeds default column value tuple fields.
So InnoDB should use the table column position while searching for
defaults column value.
2020-05-26 12:44:33 +05:30
Marko Mäkelä
ecc7f305dd Merge 10.2 into 10.3 2020-05-25 19:41:58 +03:00
Marko Mäkelä
5530a93f47 MDEV-17092 use-after-poison around lock_trx_handle_wait_low
There was a race condition where the connection of the
victim of a KILL statement is disconnected while the
KILL statement is executing.

As a side effect of this fix, we will make XA PREPARE
transactions immune to KILL statements.

Starting with MariaDB 10.2, we have a pool of trx_t objects.
trx_free() would only free memory to the pool. We poison the
contents of freed objects in the pool in order to catch misuse.

trx_free(): Unpoison also trx->mysql_thd and trx->state.
This is to counter the poisoning of *trx in trx_pools->mem_free().
Unpoison only on AddressSanitizer or Valgrind, but not on MemorySanitizer.

Pool: Unpoison allocated objects only on AddressSanitizer or
Valgrind, but not on MemorySanitizer.

innobase_kill_query(): Properly protect trx, acquiring also
trx_sys_t::mutex and checking trx_t::mysql_thd and trx_t::state.
2020-05-25 18:57:14 +03:00
Monty
be647ff14d Fixed deadlock with LOCK TABLES and ALTER TABLE
MDEV-21398 Deadlock (server hang) or assertion failure in
Diagnostics_area::set_error_status upon ALTER under lock

This failure could only happen if one locked the same table
multiple times and then did an ALTER TABLE on the table.

Major change is to change all instances of
table->m_needs_reopen= true;
to
table->mark_table_for_reopen();

The main fix for the problem was to ensure that we mark all
instances of the table in the locked_table_list and when we
reopen the tables, we first close all tables before reopening
and locking them.

Other things:
- Don't call thd->locked_tables_list.reopen_tables if there
  are no tables marked for reopen. (performance)
2020-05-23 14:58:33 +03:00
Marko Mäkelä
ed41947b78 Merge 10.2 into 10.3 2020-05-20 17:07:09 +03:00
Marko Mäkelä
22a6fa572b MDEV-19114 post-push fix: SIGSEGV on INSERT
ins_node_create_entry_list(): Create dummy empty tuples for
corrupted or incomplete indexes, to avoid dereferencing a NULL
dict_field_t::col pointer in row_build_index_entry_low().

This issue was found by a crash in the test gcol.innodb_virtual_basic
when merging the fix to 10.5.
2020-05-20 16:35:48 +03:00
Marko Mäkelä
f4f0ef3e37 Merge 10.2 into 10.3 2020-05-20 11:41:51 +03:00
Marko Mäkelä
e380f44742 Merge 10.1 into 10.2 2020-05-20 11:13:40 +03:00
Thirunarayanan Balathandayuthapani
1893a1370d MDEV-22633 Assertion failed in prepare_inplace_alter_table_dict
prepare_inplace_alter_table_dict(): In the error handling, relax
a debug assertion for the case that we did not execute
dict_stats_wait_bg_to_stop_using_table() yet.
2020-05-20 11:13:02 +03:00