Event display exits when reloading.
Dear LArSoft Experts,
I am having a strange problem with event display. If I reconstruct one event, look at it in event display and hit reload button, the event display would exit.
Here is how to reproduce this problem on a dunegpvm machine.
source /grid/fermiapp/products/dune/setup_dune.sh setup dunetpc v06_05_00 -q e10:prof lar -c standard_reco_dune10kt_1x2x6.fcl /pnfs/dune/scratch/dunepro/v06_04_01/detsim/prod_muminus_0.1-5.0GeV_isotropic_dune10kt_1x2x6/13289364_0/prod_muminus_0.1-5.0GeV_isotropic_dune10kt_1x2x6_7_20160826T215719_gen_6b914fe0-09c3-469e-b1f0-056dad368a1b_g4_detsim.root -n 1 lar -c evd_dunefd.fcl prod_muminus_0.1-5.0GeV_isotropic_dune10kt_1x2x6_7_20160826T215719_gen_6b914fe0-09c3-469e-b1f0-056dad368a1b_g4_detsim_reco.root
click Reload, event display will exit.
However, if I run event display on the file with all reconstructed events (from production):
lar -c evd_dunefd.fcl /pnfs/dune/scratch/dunepro/v06_04_01/reco/prod_muminus_0.1-5.0GeV_isotropic_dune10kt_1x2x6/10111991_0/prod_muminus_0.1-5.0GeV_isotropic_dune10kt_1x2x6_44_20160826T215741_gen_d40d2d5c-caa1-4a3f-b716-4e62843057dd_g4_detsim_reco.root
Clicking Reload does not exit.
I am having the same problem with argoneut as well. This is annoying because every time I change event display configuration (e.g. track module label), the display would refresh and quite. I suspect this is an art problem and I started to seeing this problem since moving to art2 (larsoft v06).
#2 Updated by Gianluca Petrillo almost 4 years ago
- Description updated (diff)
- Occurs In v06_03_00 added
- Occurs In deleted (
- Experiment LArSoft added
- Experiment deleted (
I can reproduce the problem.
Bisection shows that the problem was introduced between LArSoft
LArSoft event display relies on nutools for driving the event loop, via
EventDisplay service. When the action Tingjun reports is performed, the service attempts a
RootInput::seekToEvent() call with the same event as the current one.
The differences in dependencies are:
lareventdisplay and in nutools pertaining event display are naught. There are quite some changes in
Bouncing the ball to art experts.
#3 Updated by Gianluca Petrillo almost 4 years ago
Simplified steps to reproduce:
setup larsoft v06_03_00 -q e10:prof lar -c prodsingle.fcl -n 1 lar -c evd.fcl single_gen.root
and then follow Tingjun instructions (either hit
[Reload]button or edit a parameter, e.g. menu
RawDrawinfOptions, click on the "RawDataLabel" box that says
<Enter>and then click on
#6 Updated by Kyle Knoepfel almost 4 years ago
The problem is understood.
[N.B. The following explanation is technical.]
In the context of the
EventDisplay service, the
seekToEvent function ultimately controls which state-machine events are emitted. In
art 2.01.00 and later, event-processing (and calls to all
postProcessEvent callbacks) occur as an exit action from the
HandleEvents state (which, in the
boost::statechart implementation, is a call to the state's destructor). At the point when the destructor is called, the next signal has already been emitted and posted. If there is only one event in the file, this means that by the time the user has a chance to (e.g.) press the
Reload button on the
EventDisplay window, the
Stop signal has already been registered as the next state-machine event. Any attempt at adjusting the signal, by calling
seekToEvent, will be too late.
There are several considerations in pursuing a solution:
- Moving the
postProcessEventfunctionality to become part of the
preProcessEventcallback is a possibility, but it is not obvious to me what the side-effects would be.
- Putting the event-processing step back in the
NewEventstate will result in processing (but not writing) one-too-many events per output-file switch, if the new output-file switching is enabled.
- Fundamentally, the state machine should probably be adjusted, like adding a
ProcessEventstage. However, it is not obvious to me to what extent that can be done cleanly. More analysis is required at this stage.
#8 Updated by Kyle Knoepfel almost 4 years ago
- Category set to Event Loop
- % Done changed from 0 to 60
- SSI Package art added
- SSI Package deleted (
The problem has been solved: by adding a
ProcessEvent state to the state machine, I have been able to move the event-processing outside of the
HandleEvents destructor. This allows the
seekToEvent function call to guide the emission of the correct state-machine event before the
nextItemType() function is called in the
EventProcessor::runToCompletion event loop.
Incidentally, by adding the
ProcessEvent state as a sub-state of the
HandleEvents composite state, I have restored the symmetry of the state machine with respect to
What remains: some code cleanup, adjusted documentation of the state machine, and a suitable regression/integration test within
#9 Updated by Kyle Knoepfel almost 4 years ago
- Status changed from Assigned to Resolved
- % Done changed from 60 to 100
Code polished, and a test added to
art that will catch this problem in the future. I have verified that the event display works correctly with the pushed changes.
Implemented with commit art:7e7e8d2f.