MySQL Bugs: #96401: No-op mutex_own calls instead of ut_ad(mutex

Bug #96401	No-op mutex_own calls instead of ut_ad(mutex_own)
Submitted:	1 Aug 2019 13:32	Modified:	5 Aug 2019 14:00
Reporter:	Laurynas Biveinis (OCA)	Email Updates:
Status:	Verified	Impact on me:	None
Category:	MySQL Server: InnoDB storage engine	Severity:	S6 (Debug Builds)
Version:	8.0.17	OS:	Any
Assigned to:		CPU Architecture:	Any

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Description:
If one converts mutex_own macro to a function and adds [[nodiscard]] / __attribute__((warn_unused_result)), a few places pop up where an unwrapped mutex_own call sits - i.e. read the mutex status and don't do anything about it. All of them are missing ut_ad wrapper:

clone0snapshot.h:350: Clone_snapshot::in_transit_state:     mutex_own(&m_snapshot_mutex);
buf0buf.cc:987: buf_chunk_init:  mutex_own(&buf_pool->chunks_mutex);

How to repeat:
See above

Suggested fix:
Add missing ut_ad
Convert mutex_own to an inline function with [[nodiscard]]

Hello Mr. Biveinis,

Thank you very much for your bug report.

I agree fully with your analysis.

Verified as reported.