Argonne National Laboratory

Experimental Physics and
Industrial Control System

1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  <20112012  2013  2014  2015  2016  2017  2018  2019  Index 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  <20112012  2013  2014  2015  2016  2017  2018  2019 
<== Date ==> <== Thread ==>

Subject: RE: EPICS on RTEMS crashing on CA access, due to GNU readline?!?
From: "Mark Rivers" <rivers@cars.uchicago.edu>
To: "Angus Gratton" <angus.gratton@anu.edu.au>, "tech-talk" <tech-talk@aps.anl.gov>
Date: Tue, 3 May 2011 21:59:07 -0500
I had a similar problem with readline when using the Prosilica GigE camera library on Linux.  The Prosilica camera library uses the Posix timer functions (timer_create, etc.), which use SIGALARM signals.
 
I added the following to the constructor in my Prosilica areaDetector driver to disable signal handling in readline.
 
    /* There is a conflict with readline use of signals, don't use readline signal handlers */
#ifdef linux
    rl_catch_signals = 0;
#endif
 
That can be done at run-time, you don't need to rebuild readline.
 
When I originally had this problem there was also a bug in EPICS base that was causing it to call the timer functions signal handlers incorrectly.  That code has since been removed from EPICS.  I don't think I have revisited the readline problem since then, so perhaps it is no longer an issue?
 
Mark
 

________________________________

From: tech-talk-bounces@aps.anl.gov on behalf of Angus Gratton
Sent: Tue 5/3/2011 9:41 PM
To: tech-talk
Subject: Re: EPICS on RTEMS crashing on CA access, due to GNU readline?!?



On Tue, 2011-05-03 at 16:07 +1000, Angus Gratton wrote:
> I have a _very_ unusual bug that I'm currently working through.
>
> *snip*

Against all intuition, it looks like my bug has something to do with
POSIX signal handlers for RTEMS.

Readline wraps several POSIX signals by default while waiting on
standard input, something in that process trips the bug. Disabling
HANDLE_SIGNALS in rlconf.h before building readline fixes the problem.

I've done some more extensive debugging, enabling and disabling the
different signal handlers, but I can't seem to nail it down to any
particular signal. It feels to me like an internal RTEMS bug at this
point, although it's hard to tell.

I can't afford much more time on it, so I'm just building readline
without HANDLE_SIGNALS for now.

- Angus






Replies:
RE: EPICS on RTEMS crashing on CA access, due to GNU readline?!? Angus Gratton
References:
EPICS on RTEMS crashing on CA access, due to GNU readline?!? Angus Gratton
Re: EPICS on RTEMS crashing on CA access, due to GNU readline?!? Angus Gratton

Navigate by Date:
Prev: Re: EPICS on RTEMS crashing on CA access, due to GNU readline?!? Angus Gratton
Next: RE: EPICS on RTEMS crashing on CA access, due to GNU readline?!? Angus Gratton
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  <20112012  2013  2014  2015  2016  2017  2018  2019 
Navigate by Thread:
Prev: Re: EPICS on RTEMS crashing on CA access, due to GNU readline?!? Angus Gratton
Next: RE: EPICS on RTEMS crashing on CA access, due to GNU readline?!? Angus Gratton
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  <20112012  2013  2014  2015  2016  2017  2018  2019 
ANJ, 18 Nov 2013 Valid HTML 4.01! · Home · News · About · Base · Modules · Extensions · Distributions · Download ·
· Search · EPICS V4 · IRMIS · Talk · Bugs · Documents · Links · Licensing ·