Details
Description
Issue initially observed during testing of MDEV-28856, but present in trunk also:
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preview-11.3-preview a4031e4c051d4fc69f466a5678ceb5d3598bf525 (Debug) |
safe_mutex: Found wrong usage of mutex 'LOCK_thd_data' and 'LOCK_plugin'
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Mutex currently locked (in reverse order):
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LOCK_plugin /test/git-bisect/preview-11.3-preview_MDEV-28856_patched_dbg/sql/sql_plugin.cc line 2481
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LOCK_thd_data /test/git-bisect/preview-11.3-preview_MDEV-28856_patched_dbg/sql/sql_class.h line 3967
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LOCK_thd_kill /test/git-bisect/preview-11.3-preview_MDEV-28856_patched_dbg/sql/sql_class.h line 3966
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The issue can be seen either during normal operation, or during SHUTDOWN. Possibly these are different issues leading to the same outcome.
The issues is highly sporadic, yet regularly seen. Testcase reduction has proven to be very difficult. However, a single occurrence reduced to this SHUTDOWN-based testcase:
INSTALL PLUGIN spider SONAME 'ha_spider.so'; |
CREATE TABLE t (c INT) ENGINE=Spider; |
SET max_session_mem_used=8192; |
UNINSTALL SONAME 'ha_spider'; |
SHUTDOWN;
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This testcase may not be representative of all issues and should not be taken as a typical example, as this issue is during SHUTDOWN and reduced readily compared with the other sporadic occurrences, which do not reduce. Still, it may provide an indication in the code as to the actual bug(s).
Attachments
Issue Links
- duplicates
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MDEV-33443 Unsafe use of LOCK_thd_kill in my_malloc_size_cb_func()
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- Closed
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- relates to
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- Closed
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Activity
Issue is still reproducible in 11.4 debug build 6 Feb 24.
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11.4.0 9b1ea6904965dd345478dedd80e181ad54c767da (Debug) |
11.4.0-dbg>SET @@max_session_mem_used=500000; # Set smaller if needed
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Query OK, 0 rows affected (0.000 sec)
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11.4.0-dbg>SET @@session.query_alloc_block_size=655536;
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Query OK, 0 rows affected, 1 warning (0.001 sec)
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11.4.0-dbg>UNINSTALL PLUGIN IF EXISTS example;
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Query OK, 0 rows affected, 1 warning (0.002 sec)
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11.4.0-dbg>SHUTDOWN;
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Query OK, 0 rows affected (0.000 sec)
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11.4.0-dbg>Ctrl-C -- exit!
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Aborted
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/test/MD060224-mariadb-11.4.0-linux-x86_64-dbg$ t
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MUTEX_ERROR|safe_mutex: Found wrong usage of mutex LOCK_thd_data and LOCK_plugin
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Original testcase also reproduces for me in MTR:
INSTALL PLUGIN spider SONAME 'ha_spider.so'; |
CREATE TABLE t (c INT) ENGINE=Spider; |
SET max_session_mem_used=8192; |
--error ER_SP_DOES_NOT_EXIST
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UNINSTALL SONAME 'ha_spider'; |
SHUTDOWN;
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Leads to:
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11.4.0 9b1ea6904965dd345478dedd80e181ad54c767da (Debug) |
2024-02-12 13:50:52 0 [Note] /test/MD060224-mariadb-11.4.0-linux-x86_64-dbg/bin/mariadbd (initiated by: root[root] @ localhost []): Normal shutdown
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safe_mutex: Found wrong usage of mutex 'LOCK_thd_data' and 'LOCK_plugin'
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Mutex currently locked (in reverse order):
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LOCK_plugin /test/11.4_dbg/sql/sql_plugin.cc line 2525
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LOCK_thd_data /test/11.4_dbg/sql/sql_class.h line 4053
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LOCK_thd_kill /test/11.4_dbg/sql/sql_class.h line 4052
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Assigning to knielsen for closure as he mentioned this bug would be fixed by the patch for MDEV-33443 as well.
Please also note
MDEV-33443, on LOCK_thd_kill