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Entry  20 Aug 2007, Konstantin Olchanski, Bug Report, how to handle end of run? 
    Reply  03 Sep 2007, Stefan Ritt, Bug Report, how to handle end of run? 
Message ID: 401     Entry time: 20 Aug 2007     Reply to this: 405
Author: Konstantin Olchanski 
Topic: Bug Report 
Subject: how to handle end of run? 
I am having problems with handling the end-of-run situation in my midas
frontend. I have a device that continuously sends data (over USB) and I read
this data in my "read_event" function.

Everything is good until the end-of-run, at which time this happens:
0) mfe.c calls my read_event() to read the data (loop until the end-of-run
transition)
1) mfe.c calls my end_of_run()
2) here, I tell the device "please stop sending data"
3) all seems good, but wait!!!
4) there is all this data generated between step 0 and step 2 still sitting
inside the device and it has nowhere to go: the run is ended, the output file is
closed, my read_event() will never be called ever again (well, until the next run).

It seems to me mfe.c needs to have one more function, something like
"pre_end_of_run()" that works like this:
0) mfe.c calls my read_event() to read the data (loop until the end-of-run
transition)
1) mfe.c calls pre_end_of_run(), here I tell the device to stop sending data
2) mfe.c calls read_event() for the very last time, to give me the opportunity
to read and send away any data I still may have.
3) mfe.c calls the end_of_run(). The run is truely finished.

Any thoughts?

K.O.
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