Re: Detect double-release of spinlock - Mailing list pgsql-hackers

From Andres Freund
Subject Re: Detect double-release of spinlock
Date
Msg-id 20240729174853.uo5qjqkxlacjg6vv@awork3.anarazel.de
Whole thread Raw
In response to Re: Detect double-release of spinlock  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Detect double-release of spinlock
Re: Detect double-release of spinlock
List pgsql-hackers
Hi,

On 2024-07-29 13:25:22 -0400, Tom Lane wrote:
> Heikki Linnakangas <hlinnaka@iki.fi> writes:
> > Yeah I'm not worried about that at all. Also, the assert is made when 
> > you have already released the spinlock; you are already out of the 
> > critical section.
> 
> Not in the patch Andres posted.

Which seems fairly fundamental - once outside of the critical section, we
can't actually assert that the lock isn't acquired, somebody else *validly*
might have acquired it by then.

However, I still don't think it's a problem to assert that the lock is held in
in the unlock "routine". As mentioned before, the spinlock implementation
itself has never followed the "just straight line code" rule that users of
spinlocks are supposed to follow.

Greetings,

Andres Freund



pgsql-hackers by date:

Previous
From: Heikki Linnakangas
Date:
Subject: Re: Remove dead code generation tools in src/backend/utils/mb/
Next
From: Tom Lane
Date:
Subject: Re: Detect double-release of spinlock