Re: pgsql: Fix double-release of spinlock

Heikki Linnakangas <heikki(dot)linnakangas(at)iki(dot)fi> writes:
> Commit 9d9b9d46f3 added spinlocks to protect the fields in ProcSignal
> flags, but in EmitProcSignalBarrier(), the spinlock was released
> twice. With most spinlock implementations, releasing a lock that's not
> held is not easy to notice, because most of the time it does nothing,
> but if the spinlock was concurrently acquired by another process, it
> could lead to more serious issues. Fortunately, with the
> --disable-spinlocks emulation implementation, it caused more visible
> failures.

There was some recent discussion about getting rid of
--disable-spinlocks on the grounds that nobody would use
hardware that lacked native spinlocks. But now I wonder
if there is a testing/debugging reason to keep it.

regards, tom lane