MySQL Bugs: #115524: key_object_cache_mutex and key_object_loading

Bug #115524	key_object_cache_mutex and key_object_loading_cond are not registered
Submitted:	5 Jul 2024 10:13	Modified:	17 Jul 2024 5:44
Reporter:	Huaxiong Song (OCA)	Email Updates:
Status:	Verified	Impact on me:	None
Category:	MySQL Server: Data Dictionary	Severity:	S3 (Non-critical)
Version:	8.0.38, 9.0.0	OS:	Any
Assigned to:		CPU Architecture:	Any
Tags:	Contribution

Description:
From the code, we can find key_object_cache_mutex and key_object_loading_cond are not registered.

When stuck in a wait relationship, performance.events_waits* may show incorrect
'EVENT_NAME'.

In fact, there is a TODO item for initializing them.

This is a small suggestion.

How to repeat:
Simply, the problem can be seen from the code

Suggested fix:
Add them to the corresponding array to be initialized.

Patch to fix this bug (*) I confirm the code being submitted is offered under the terms of the OCA, and that I am authorized to contribute it.

Contribution: bug#115524.patch (application/octet-stream, text), 3.37 KiB.

Hello Huaxiong Song,

Thank you for the report and contribution.

regards,
Umesh

Sorry, there is a problem with my previous fix...
The pfs of the DD(cond and mutex) cannot be added directly as I said before, which will cause memory problems.
I may know why TODO was recorded in the DD-related PFS at that time, because Shared_dictionary_cache is a static singleton object, and its destruction time is later than cleanup_instruments, which will cause memory problems.

My solution is to modify the implementation of the singleton and explicitly control the life cycle of Shared_dictionary_cache.

Bug fix of 115524 (*) I confirm the code being submitted is offered under the terms of the OCA, and that I am authorized to contribute it.

Contribution: bug#115524_new.patch (application/octet-stream, text), 4.91 KiB.