Experimental Physics and
Industrial Control System

Kazuro FURUKAWA <[email protected]> · Thu, 18 Mar 2010 06:04:12 +0900

Hello Ben, 

Some of the old vxi11.x implementations were designed assuming 
long=32bit.  If I remember correctly, VXI-11 document was one of 
them.  I had to modify it for 64bit architecture some time ago.  
As we didn't modify AsynDriver, I hope this is not the issue :-).  

We run ~30 oscilloscopes of DPO7104/7254 at KEKB and KEK linac.  
As they have good CPUs inside (~3GHz), we run embedded IOCs on 
all of them.  While VXI-11 on DPO7000 is relatively fast, an 
embedded IOC with a dedicated (synchronous) device-support is 
faster and more reliable.  

(Before this implementation I was afraid of the stability of 
Windows.  However, this embedded IOC turned out to be rather 
reliable.) 

Cheers,
Kazuro.

>>> On Wed, 17 Mar 2010 13:09:33 JST,  Benjamin Franksen <[email protected]> wrote;
> On Wednesday 17 March 2010, Benjamin Franksen wrote:
> > I'm trying to talk to the mentioned scope via asyn/stream and get
> >  mysterious crashes the first time the IOC tries to communicate over the
> >  link. Below is a trace of the IOC shell up to the crash. I am using the
> >  latest and greatest versions of everything except EPICS base:
> >  base-3.14.8.2, asyn-4.11a (supposedly the last version that works with
> >  base-3.14.8), StreamDevice-2- snapshot20081007. The crash happens on the
> >  latest ubuntu version as well as on a debian stable system. I should
> >  point out that with the exact same setup I can talk fine with e.g. a
> >  GPIB controller.
> 
> Ok I did dome more research. G$BC6(Btz suggested valgrind and indeed I got 
> interesting results:
> 
> (1) When I run the IOC under valgrind it doesn't crash, it even talks to the 
> device. Nice.
> 
> (2) Valgrind complains about StreamDevice doing "Mismatched free() / delete 
> / delete []". See below for a transcript.
> 
> My current theory is that these mismatched calls cause the memory free list 
> to become corrupted. Note that VXI-11 is based on RPC which heavily uses 
> malloc/free internally during runtime, so there is some probability that a 
> corrupted free list will lead to a crash inside the RPC library.
> 
> Dirk, could you look into this?
> 
> Cheers
> Ben
> 
> PS: this is a log of the IOC shell run under valgrind:

(* log removed *)

-----
Kazuro FURUKAWA <[email protected]>
 Linac&KEKB,  High Energy Accelerator Research Organization (KEK), Japan
 Telephone: +81-29-864-5200 x4316,  Facsimile: +81-29-864-0321

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System