Experimental Physics and
Industrial Control System

David Maden <[email protected]> · Tue, 22 Jan 2008 09:16:08 +0100

Hi,
I also have a CA connection management problem similar to the recent thread:
         Re: CA connection management problem
but hopefully different enough to warrant a slightly different name.
I'm trying to convert a vxWorks channel access C program from EPICS 3.13.10
to 3.14.8. The program is intended to run once after iocInit and then exit.
I get an exception in ca_context_destroy if the channel connection times out.
Reducing the program to its bare essentials, it does the following:
 1) Set up ca context with preemptive callbacks enabled:
 ca_context_create (ca_enable_preemptive_callback)
 2) Call ca_create_channel specifying channel name and callback function.
  3) Wait for callback function to get called:
       If callback function is called, goto step 5.
       If there is a time-out, go to step 4.
 4) On time-out, call ca_context_destroy and return with error.
  5) If callback function gets called, continue with calls
     to ca_get, ca_pend_io, ca_context_destroy and return with success.
This runs fine if I specify a PV which is valid.
If I specify an invalid channel name, I get:
    0x15d0250 (tShell): Unhandled C++ exception resulted
                        in call to terminate
The program runs fine under Linux. Is there some problem with
ca_context_destroy under vxWorks, which I couldn't find in the Channel
Access Reference Manuel or the tech-talk archives? I note, for example,
that snl programs under 3.14 are no longer able to exit. Is this related?
Regards, David
--
[email protected]
SLS Project
--

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System