Re: 'CAS-client' failed in ../db/dbEvent.c line 540

[Michael Davidsaver via Tech-talk <tech-talk at aps.anl.gov>]

On 9/6/22 15:57, Oleg Makarov wrote:
> Michael, see my answers below.
>
> On 9/6/2022 4:48 PM, Michael Davidsaver wrote:
> > On 9/6/22 13:19, Makarov, Oleg A. via Tech-talk wrote:
> > > Hi Jeffrey and Ralph,
> > >
> > >
> > > I am observing occasional/intermittent error in the vxWorks EPICS IOC. Error occurs during connection from CA client to the PVs in the IOC.
> > > mvme6100 IOC is running on EPICS version 7.0.6.1. We have CA clients using Java JCA library 2.4.1 and pyepics 3.5.0.
Also, standard question.

What drivers and/or support modules are loaded into this IOC?


> > Does this IOC have an access security file (ACF) loaded?
> *No.*
Next time this happens, please try to collect a stack trace.  With this additional
information, we may be able to distinguish between the other two call sites.

While this crash appears differently than lp:541371 (link below), my suspicion is
the same.  Some kind of race condition in the CA server (RSRV) on client disconnect.

So you might be able to provoke the crash with a lot of very short lived clients.
(eg. maybe some script is crashing in a tight loop?)


> > If so, does are any dynamic rules used?
> >
> >
> > Does it have any external CA links, connected or otherwise?
> *Yes.*
Never mind about this.  I was confused.  I don't think CA links from this IOC
have anything to do with this issue.


> > > dbcar "" 2
> > *see attached "dbcar.txt" file*
> >
> > > A call to 'assert(status == epicsMutexLockOK)'
> > >      by thread 'CAS-client' failed in ../db/dbEvent.c line 540.
> > > EPICS Release EPICS R7.0.6.1.
> > fyi.
> >
> > https://github.com/epics-base/epics-base/blob/abfe30ef13ad60b43ae6f257994c8e7a503d4f3a/modules/database/src/ioc/db/dbEvent.c#L540
> >
> > This is a different location than:
> >
> > https://bugs.launchpad.net/epics-base/+bug/541371