Unnecessary use of SkipListAccessor in TPRequestHandler::periodic_data_transmission() ?

[wesketchum]

trigger/src/TPRequestHandler.cpp

Line 65 in 6b62c0c

SkipListAcc acc(inherited2::m_latency_buffer->get_skip_list());

My understanding of SkipList node removal is that it is done lazily, removing nodes that have been marked for removal only after all SkipListAccessors, so creating accessors more than needed induces some overhead and may reduce some ability to get cleanup done.

I don't know if removing this will help much with the performance issue noted here DUNE-DAQ/datahandlinglibs#62, but I don't think the accessor created here is really necessary: get_fragment_pieces() will create an accessor when it gets its lower_bound iterator, and so if we only need to get the best understanding of the timestamps, then we should be able to call front() and back() here (as is done in other datahandling places).

If others agree, we might try to remove this here, and then see if that helps (or at least doesn't hurt) the cleanup situation.

[ArturSztuc]

I don't know enough about SkipListAcc object, but you can certainly try: I imagine faulty logic would be catastrophical here, so it would be very easy to see whether removing SkipListAcc here is fine. This is probably something that someone from the core software team will know more about.