Details
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Bug
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Status: Open (View Workflow)
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Minor
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Resolution: Unresolved
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10.6, 10.7, 10.8
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None
Description
This was found during the investigation of MDEV-28315
Here
https://github.com/MariaDB/server/blob/10.8/sql/sql_string.h#L709
inside `alloc` it increments the length for the size to allocate probably considering a NULL terminator.
However inside `Binary_string::realloc_raw` it increments the length passed in:
https://github.com/MariaDB/server/blob/10.8/sql/sql_string.cc#L92
Therefore the 1st increment should not be necessary. That being said, when I tried omitting the `+1` part I saw a test failure.
worker[1] Using MTR_BUILD_THREAD 300, with reserved ports 16000..16019 |
main.pool_of_threads [ fail ]
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Test ended at 2022-05-22 14:00:32 |
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CURRENT_TEST: main.pool_of_threads
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mysqltest: In included file "./include/common-tests.inc": |
included from /home/norakagi/projects/mariadb-dev/server/MDEV-28315/mysql-test/main/pool_of_threads.test at line 12: |
At line 13: query 'drop table if exists t1,t2,t3,t4' failed: <Unknown> (5): Out of memory (Needed 24 bytes) |
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The result from queries just before the failure was:
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SET optimizer_switch='outer_join_with_cache=off'; |
drop table if exists t1,t2,t3,t4; |
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- saving '/home/norakagi/projects/mariadb-dev/server/MDEV-28315/bld/mysql-test/var/log/main.pool_of_threads/' to '/home/norakagi/projects/mariadb-dev/server/MDEV-28315/bld/mysql-test/var/log/main.pool_of_threads/' |
--------------------------------------------------------------------------
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The servers were restarted 0 times |
Spent 0.000 of 2 seconds executing testcases |
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Failure: Failed 1/1 tests, 0.00% were successful. |
So there has to be an issue related this part. For now, I left this part as it is because there seems to be no prominent error observed and adding one extra byte should no harm.
I am cutting this ticket for future research.
The change was introduced in this commit
commit 36cdd5c3cdb06d8538f64c0b312ffe4672a92e75
Author: Monty
Date: Wed Sep 16 11:23:50 2020 +0300
Optimize usage of c_ptr(), c_ptr_quick() and String::alloc()
Attachments
Issue Links
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