Experimental Physics and
Industrial Control System

"Wang, Andrew via Tech-talk" <tech-talk at aps.anl.gov> · Mon, 24 Jan 2022 08:18:08 +0000

Hi Dirk,

Since there isn't a function prototype for streamReload, do you recommend that I manually add it into devStream.h? gcc isn't liking the fact that I am calling to streamReload, because there is no prototype.

Thanks,
Andy

-----Original Message-----
From: Zimoch Dirk (PSI) <dirk.zimoch at psi.ch> 
Sent: Saturday, January 22, 2022 3:04 AM
To: EPICS tech-talk <tech-talk at aps.anl.gov>; Wang, Andrew <wang126 at llnl.gov>
Cc: Michael Davidsaver <mdavidsaver at gmail.com>
Subject: Re: Calling the streamReload IOC Shell function within C

Hi Andy

You can call extern „C“ long streamReload(const char* recordname) directly from C/C++. If NULL is passed for recordname, then all StreamDevice records reload. If a record is in the middle of processing, the running protocol is aborted and the record goes to INVALID alarm until the next processing.

It seems I have forgotten to put the function prototype into devStream.h. Will be done in the next release.

Dirk

> Am 22.01.2022 um 06:08 schrieb Michael Davidsaver via Tech-talk <tech-talk at aps.anl.gov>:
> On 1/21/22 19:39, Wang, Andrew via Tech-talk wrote:
>> This is a far-fetched question, but I was wondering whether there is a possibility of executing streamReload, or a similar functionality, within a C function. The reason why I ask is because I saw within this Github link (https://urldefense.us/v3/__https://github.com/epics-modules/ioczed/blob/master/zzzApp/Db/streamExample.db__;!!G2kpM7uM-TzIFchu!gjnSZo93VcnoDkmziao7QLSXtfmZDUg0hZ5hqdkj-M2oKQch9GQRdAvkPjUS4spw6a4$  <https://urldefense.us/v3/__https://github.com/epics-modules/ioczed/blob/master/zzzApp/Db/streamExample.db__;!!G2kpM7uM-TzIFchu!gjnSZo93VcnoDkmziao7QLSXtfmZDUg0hZ5hqdkj-M2oKQch9GQRdAvkPjUS4spw6a4$ >) that the SUB record calls streamReload. However, I couldn’t locate the source code for that, so I am not entirely sure how it is used and what its arguments are. Thoughts?
> 
> The registrar code adding both the function callable from subRecord as 
> well as iocsh.
> 
> https://urldefense.us/v3/__https://github.com/paulscherrerinstitute/St
> reamDevice/blob/dfbd308d4602e7cb99d7f60ddf35909a70f41c4f/src/StreamEpi
> cs.cc*L297-L307__;Iw!!G2kpM7uM-TzIFchu!gjnSZo93VcnoDkmziao7QLSXtfmZDUg
> 0hZ5hqdkj-M2oKQch9GQRdAvkPjUS5UlYp3c$
> 
> So you could do something like
> 
>> iocshCmd("streamReload");
> 
> cf. iocsh.h from Base.
> 
> Since it is already callable from a subRecord I assume it is 
> thread-safe.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System