Geant4 Background

G4UserTrackingAction

• http://geant4.slac.stanford.edu/Tips/event/5.html

G4EventManager allows setting the G4UserTrackingAction on the G4TrackingManager:

[blyth@cms01 source]$ pwd
/data/env/local/dyb/trunk/external/build/LCG/geant4.9.2.p01/source
[blyth@cms01 source]$ vi event/src/G4EventManager.cc

308 void G4EventManager::SetUserAction(G4UserEventAction* userAction)
309 {
310   userEventAction = userAction;
311   if(userEventAction) userEventAction->SetEventManager(this);
312 }
313
314 void G4EventManager::SetUserAction(G4UserStackingAction* userAction)
315 {
316   userStackingAction = userAction;
317   trackContainer->SetUserStackingAction(userAction);
318 }
319
320 void G4EventManager::SetUserAction(G4UserTrackingAction* userAction)
321 {
322   userTrackingAction = userAction;
323   trackManager->SetUserAction(userAction);
324 }
325
326 void G4EventManager::SetUserAction(G4UserSteppingAction* userAction)
327 {
328   userSteppingAction = userAction;
329   trackManager->SetUserAction(userAction);
330 }

The G4UserTrackingAction::PreUserTrackingAction is invoked at G4TrackingManager::ProcessOneTrack(G4Track* apValueG4Track) allowing track status changes, like kills:

91
92   // Pre tracking user intervention process.
93   fpTrajectory = 0;
94   if( fpUserTrackingAction != NULL ) {
95      fpUserTrackingAction->PreUserTrackingAction(fpTrack);
96   }

[blyth@cms01 source]$ find . -name '*.cc' -exec grep -H G4UserTrackingAction {} \;
./error_propagation/src/G4ErrorPropagator.cc:  const G4UserTrackingAction* fpUserTrackingAction =
./error_propagation/src/G4ErrorPropagator.cc:    const_cast<G4UserTrackingAction*>(fpUserTrackingAction)
./error_propagation/src/G4ErrorPropagator.cc:  const G4UserTrackingAction* fpUserTrackingAction =
./error_propagation/src/G4ErrorPropagator.cc:    const_cast<G4UserTrackingAction*>(fpUserTrackingAction)
./error_propagation/src/G4ErrorPropagatorManager.cc:void G4ErrorPropagatorManager::SetUserAction(G4UserTrackingAction* userAction)
./error_propagation/src/G4ErrorRunManagerHelper.cc:void G4ErrorRunManagerHelper::SetUserAction(G4UserTrackingAction* userAction)
./event/src/G4EventManager.cc:void G4EventManager::SetUserAction(G4UserTrackingAction* userAction)
./tracking/src/G4UserTrackingAction.cc:// $Id: G4UserTrackingAction.cc,v 1.10 2006/06/29 21:16:19 gunter Exp $
./tracking/src/G4UserTrackingAction.cc:// G4UserTrackingAction.cc
./tracking/src/G4UserTrackingAction.cc:#include "G4UserTrackingAction.hh"
./tracking/src/G4UserTrackingAction.cc:G4UserTrackingAction::G4UserTrackingAction()
./tracking/src/G4UserTrackingAction.cc:   msg =  " You are instantiating G4UserTrackingAction BEFORE your\n";
./tracking/src/G4UserTrackingAction.cc:   msg += "such as G4UserTrackingAction.";
./tracking/src/G4UserTrackingAction.cc:   G4Exception("G4UserTrackingAction::G4UserTrackingAction()",
./tracking/src/G4UserTrackingAction.cc:G4UserTrackingAction::~G4UserTrackingAction()
./tracking/src/G4UserTrackingAction.cc:void G4UserTrackingAction::
[blyth@cms01 source]$ pwd
/data/env/local/dyb/trunk/external/build/LCG/geant4.9.2.p01/source

[blyth@cms01 source]$ find . -name '*.cc' -exec grep -H PreUserTrackingAction {} \;
./visualization/management/src/G4VisCommandsSceneAdd.cc:     "\nin PreUserTrackingAction.");
./visualization/RayTracer/src/G4RTTrackingAction.cc:void G4RTTrackingAction :: PreUserTrackingAction(const G4Track*)
./error_propagation/src/G4ErrorPropagator.cc:  InvokePreUserTrackingAction( theG4Track );
./error_propagation/src/G4ErrorPropagator.cc:void G4ErrorPropagator::InvokePreUserTrackingAction( G4Track* fpTrack )
./error_propagation/src/G4ErrorPropagator.cc:      ->PreUserTrackingAction((fpTrack) );
./tracking/src/G4TrackingManager.cc:     fpUserTrackingAction->PreUserTrackingAction(fpTrack);

G4TrackStatus

track/include/G4Track.hh

174   // track status, flags for tracking
175    G4TrackStatus GetTrackStatus() const;
176    void SetTrackStatus(const G4TrackStatus aTrackStatus);

Curious, more states accessible cf StackAction classification:

track/include/G4TrackStatus.hh

49 //////////////////
50 enum G4TrackStatus
51 //////////////////
52 {
53
54   fAlive,             // Continue the tracking
55   fStopButAlive,      // Invoke active rest physics processes and
56                       // and kill the current track afterward
57   fStopAndKill,       // Kill the current track
58
59   fKillTrackAndSecondaries,
60                       // Kill the current track and also associated
61                       // secondaries.
62   fSuspend,           // Suspend the current track
63   fPostponeToNextEvent
64                       // Postpones the tracking of thecurrent track
65                       // to the next event.
66
67 };