How to solve or debug "zsh: segmentation fault"

Particles, Track, Event, Run and Biasing
1

Dear all,
I want to simulate 0vbb and record the coordinates and energy for each step of all events using bxdecay0, so my code is based on the example “bxdecay0_g4_ex01”
To manage the data for each step, I added SteppingAction.cc to get the informations and DataManager.cc to create a tree and fill it.

#include "SteppingAction.hh"
#include "G4Step.hh"
#include "G4Track.hh"
#include "G4ParticleDefinition.hh"
#include "G4SystemOfUnits.hh"
#include "EventAction.hh"

SteppingAction::SteppingAction(EventAction* eventAction)
: fEventAction(eventAction) {}

void SteppingAction::UserSteppingAction(const G4Step* step) {
  G4double edep = step->GetTotalEnergyDeposit();
  if (edep <= 0.) return;
    G4StepPoint* prePoint = step->GetPreStepPoint();
    G4ThreeVector pos = prePoint->GetPosition();

G4cout << "Step at x=" << pos.x()
         << ", y=" << pos.y()
         << ", z=" << pos.z()
         << ", edep=" << edep << G4endl;


    fEventAction->AddStep(pos.x(), pos.y(), pos.z(), edep);
  G4cout << "Step at x=" << pos.x() << ", edep=" << edep << G4endl;

}


DataManager* DataManager::fInstance = nullptr;
DataManager::DataManager():
  fFile(0),fTree(0)
{}


void DataManager::Book() {
  fFile = new TFile("event_tree.root", "RECREATE");
  fTree = new TTree("T", "Step info per event");
  fTree->Branch("x", &fX);
  fTree->Branch("y", &fY);
  fTree->Branch("z", &fZ);
  fTree->Branch("edep", &fEdep);
}

DataManager::~DataManager() {
 if (fTree)
        delete fTree;
  if (fFile){
        fFile ->Close();
        delete fFile;
        }

}

DataManager* DataManager::GetInstance() {
  if (!fInstance) fInstance = new DataManager();
  return fInstance;
}

void DataManager::AddStep(double x, double y, double z, double edep) {
  fX.push_back(x);
  fY.push_back(y);
  fZ.push_back(z);
  fEdep.push_back(edep);
}

void DataManager::FillEvent() {
  fTree->Fill();
  fX.clear(); fY.clear(); fZ.clear(); fEdep.clear();
}
void DataManager::WriteEvent() {
  if (fTree) fFile->Write();
}

And then fix the EventAction and RunAction

EventAction::EventAction()
  : G4UserEventAction()
{
  // Set default print level 
  G4RunManager::GetRunManager()->SetPrintProgress(500);
  //return;

}


EventAction::~EventAction()
{
  return;

}


void EventAction::BeginOfEventAction(const G4Event*)
{
  return;
}


void EventAction::EndOfEventAction(const G4Event* evt)
{
  G4int evtID = evt->GetEventID();
  G4int printProgress = G4RunManager::GetRunManager()->GetPrintProgress();
  // Printing survey:
  if (evtID % printProgress == 0) {
    G4cout << "End of event #" << evtID << "." << G4endl << G4endl;
  }

  DataManager::GetInstance()->FillEvent();
}

void EventAction::AddStep(G4double x, G4double y, G4double z, G4double edep) {
DataManager::GetInstance()->AddStep(x, y, z, edep);
}


void RunAction::BeginOfRunAction(const G4Run*)
{
  auto dataManager = DataManager::GetInstance();
  dataManager ->DataManager::Book();
  return;
}
void RunAction::EndOfRunAction(const G4Run*)
{
  auto dataManager = DataManager::GetInstance();
  dataManager ->DataManager::WriteEvent();
  return;

}

When running the simulation, the output of terminal is normal just like

======================== run summary ======================
 The run was 1 geantino of 1 GeV
 ===========================================================

 Nb of generated particles: 

               e-:       2  Emean =  1.499 MeV	( 658.5 keV --> 2.34 MeV)

So I’m sure the simulation works well.
But
sh: segmentation fault ./bxdecay0_g4_ex01 Se82_debug.mac
was showed finally and the root file I created was not filled.

Could anyone show some suggestions?

_Geant4 Version:_v11.2.0
_Operating System:_MacOS M1
_Compiler/Version:_clang version 15.0.0
_CMake Version:_3.29.3

2

I am not familiar with the bxdecay library but could you post the macro Se82_debug.mac?

This is also a way to saving events I am unfamiliar with but do you need to flush the file as you are writing to it before you clear the data? I am not sure what this will do in multithreaded mode.

3

Just three lines

/run/initialize
/bxdecay0/generator/dbd Se82 1 1 0
/run/beamOn 1

But the multithreaded was forbidden.

4

I know what’s wrong. Some functions were destroyed when a run is finished. It’s from the example.