Fred,
> The first one is that the channel acccess still calls my connection event handler
> and access right handler after I call the ca_clear_event() and ca_clear_channel().
>
> The above unexpected callbacks only happen when you call ca_clear_event() and
> ca_clear_channel() during the IOC reboot but before the channel access prints
> out the lost connection message.
This is a bug. It will show up under the following circumstances:
o The client has a valid connection to an IOC
o The client deletes a channel on that IOC
o The IOC disconnects prior to returning its delete confirm message
> Calling ca_change_connection_event() with a NULL handler solves the first problem but
> calling ca_replace_access_right_event() with a NUll handler results as a segmentation
> fault.
This is also a bug.
It will occur only if you attempt to set the access rights handler to NULL.
>
> The second one is that the channel access calls my event handler with args.dbr = NULL.
> This happens during I am doing a lot of connections, disconnections, ca_add_event()
> and ca_get_callback(). The debugger shows args.dbr = NULL.
>
This isnt a bug.
This would occur during normal operation if the status in struct event_handler_args
wasnt ECA_NORMAL (indicating the the requested operation failed in the IOC) or if
there isnt any data returned (ie put call back).
An example of an operation failing in the IOC would be attempting to
read an ai PV that is in INVALID alarm because the hardware isnt present.
You would also be called back with a NULL dbr pointer and status equal to
ECA_DISCONN if a get call back was outstanding and the IOC disconnected.
There are omissions in the document in this area and I have eliminated
them (but not updated the web yet).
Code changes for all of the above will show up in EPICS 3.12.2.
Thanks for your assistance tracking down these problems.
Jeff
______________________________________________________________________
Jeffrey O. Hill Internet [email protected]
LANL MS H820 Voice 505 665 1831
Los Alamos, NM 87545 USA FAX 505 665 5107
- Navigate by Date:
- Prev:
RE: ezca under VMS? Mark Rivers
- Next:
Re: question: GPIB-SUPPORT FOR EPICS Tim Mooney
- Index:
1994
<1995>
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
- Navigate by Thread:
- Prev:
RE: ezca under VMS? Mark Rivers
- Next:
Re: question: GPIB-SUPPORT FOR EPICS Tim Mooney
- Index:
1994
<1995>
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
|