[libvirt PATCH 6/7] virMutex*: Warn on error

[Daniel P. Berrangé]

On Thu, Aug 05, 2021 at 05:29:24PM +0200, Peter Krempa wrote:
> On Thu, Aug 05, 2021 at 16:11:15 +0100, Daniel P. Berrangé wrote:
> > On Thu, Aug 05, 2021 at 02:58:03PM +0100, Daniel P. Berrangé wrote:
> > > On Thu, Aug 05, 2021 at 03:33:57PM +0200, Tim Wiederhake wrote:
> > > > On Thu, 2021-08-05 at 14:24 +0100, Daniel P. Berrangé wrote:
> > > > > On Thu, Aug 05, 2021 at 03:08:50PM +0200, Tim Wiederhake wrote:
> 
> [...]
> 
> > The pthread_mutex_destroy call is the only one that I see
> > returning errors with PTHREAD_MUTEX_NORMAL. So I don't think
> > there's benefit to adding the code to lock/unlock paths.
> 
> And as noted I'd be very careful with that one too. I've got at least
> one counterexample of a code path which effectively does the same on a
> very common code path.
> 
> Namely 'virDomainObjParseXML' uses:
> 
> g_autoptr(virDomainObj) obj = NULL;
> 
> and then returns directly on common failures such as XML parsing errors,
> post-parse callback errors or even errors from the validation callbacks.
> 
> Spamming logs in such a common code path is definitely not acceptable.

Destroying a locked mutex though is a clear bug that should be fixed
though, not a false positive. If it is a commonly triggered bug that
is even worse and more reason to fix it.

Regards,
Daniel
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