Geant4EventSeed.cpp

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//==========================================================================
//  AIDA Detector description implementation 
//--------------------------------------------------------------------------
// Copyright (C) Organisation europeenne pour la Recherche nucleaire (CERN)
// All rights reserved.
//
// For the licensing terms see $DD4hepINSTALL/LICENSE.
// For the list of contributors see $DD4hepINSTALL/doc/CREDITS.
//
// Author     : A.Sailer
//
//=========================================================================
 
// Class include file
#include "Geant4EventSeed.h"
 
// Framework include files
#include <DD4hep/InstanceCount.h>
#include <DD4hep/Printout.h>
 
#include <DDG4/Geant4EventAction.h>
#include <DDG4/Geant4StackingAction.h>
#include <DDG4/Geant4Random.h>
#include <DDG4/Factories.h>
 
#include <CLHEP/Random/EngineFactory.h>
 
//Geant includes
#include <G4Run.hh>
#include <G4Event.hh>
#include <G4EventManager.hh>
#include <G4StackManager.hh>
 
using namespace dd4hep::sim;
 
Geant4EventSeed::Geant4EventSeed(Geant4Context* c, const std::string& typ) : Geant4RunAction(c, typ),
                                         m_initialSeed(0),
                                         m_runID(0),
                                         m_type(typ),
                                         m_initialised(false)
{
  Geant4Action::runAction().callAtBegin(this,&Geant4EventSeed::begin);
  Geant4Action::eventAction().callAtBegin(this,&Geant4EventSeed::beginEvent);
  // Re-seed after GeneratePrimaries so file-based generators' SetEventID is visible.
  Geant4Action::stackingAction().callAtPrepare(this,&Geant4EventSeed::prepareEvent);
  InstanceCount::increment(this);
}
 
Geant4EventSeed::~Geant4EventSeed() {
  InstanceCount::decrement(this);
}
 
void Geant4EventSeed::begin(const G4Run* run) {
 
  if(not m_initialised){
    m_initialised = true;
    m_initialSeed = Geant4Random::instance()->engine()->getSeed();
  }
 
  m_runID = run->GetRunID();
 
  dd4hep::printout( dd4hep::INFO, m_type, "Get RunID: runID=%u", m_runID );
 
}
 
void Geant4EventSeed::beginEvent(const G4Event* evt) {
 
  Geant4Random *rndm = Geant4Random::instance();
 
  unsigned int eventID = evt->GetEventID();
  unsigned int newSeed = hash( m_initialSeed, eventID, m_runID );
 
  dd4hep::printout( dd4hep::INFO, m_type,
            "At beginEvent: eventID=%u, runID=%u initialSeed=%u, newSeed=%u" ,
            evt->GetEventID(),  m_runID, m_initialSeed, newSeed );
 
  rndm->setSeed( newSeed );
 
  if ( dd4hep::printLevel() <= dd4hep::DEBUG ) {
    rndm->showStatus();
  }
 
}
 
void Geant4EventSeed::prepareEvent(G4StackManager* /* stackMgr */) {
 
  const G4Event* evt = G4EventManager::GetEventManager()->GetConstCurrentEvent();
  if ( !evt ) return;
 
  Geant4Random *rndm = Geant4Random::instance();
 
  unsigned int eventID = evt->GetEventID();
  unsigned int newSeed = hash( m_initialSeed, eventID, m_runID );
 
  dd4hep::printout( dd4hep::INFO, m_type,
            "At prepareEvent: eventID=%u, runID=%u initialSeed=%u, newSeed=%u",
            eventID, m_runID, m_initialSeed, newSeed );
 
  rndm->setSeed( newSeed );
 
}
 
DECLARE_GEANT4ACTION(Geant4EventSeed)