//
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//
// $Id: G4Scheduler.cc 60494 2012-07-12 14:49:30Z gcosmo $
//
// Author: Mathieu Karamitros (kara (AT) cenbg . in2p3 . fr)
//
// History:
// -----------
// 10 Oct 2011 M.Karamitros created
//
// -------------------------------------------------------------------

#include <G4AllITFinder.hh>
#include <G4Scheduler.hh>
#include <G4SchedulerMessenger.hh>

#include "G4SystemOfUnits.hh"
#include "G4ITModelProcessor.hh"
#include "G4ITStepProcessor.hh"
#include "G4IT.hh"
#include "G4ITReactionChange.hh"
#include "G4ITModelHandler.hh"
#include "G4VITStepModel.hh"
#include "G4UserTimeStepAction.hh"
#include "G4ITTrackingManager.hh"
#include "G4ITTrackingInteractivity.hh"
#include "G4TrackingInformation.hh"
#include "G4UnitsTable.hh"
#include "G4ITStepStatus.hh"
#include "G4ITGun.hh"
#include "G4StateManager.hh"
#include "G4Timer.hh"
#include "G4IosFlagsSaver.hh"
#include <sstream>

//#include "G4Phenomenon.hh"
//#include "G4MIWorkspace.hh"

//#define DEBUG_MEM 1
#define DEBUG_MEM_STEPPING
#define DEBUG_MEM_DETAILED_STEPPING
//#define DEBUG_MEM_DOIT

#ifdef DEBUG_MEM
#include "G4MemStat.hh"
using namespace G4MemStat;
using G4MemStat::MemStat;
#endif

//COLOR FOR DEBUGING
//#define USE_COLOR 1

#ifdef USE_COLOR
#define RED  "\033[0;31m"
#define LIGHT_RED  "\33[1;31m"
#define GREEN "\033[32;40m"
#define GREEN_ON_BLUE "\033[1;32;44m"
#define RESET_COLOR "\033[0m"
#else
#define RED  ""
#define LIGHT_RED  ""
#define GREEN ""
#define GREEN_ON_BLUE ""
#define RESET_COLOR ""
#endif

using namespace std;

G4ThreadLocal G4Scheduler* G4Scheduler::fgScheduler(0);

template<typename T>
  inline bool IsInf(T value)
  {
    return std::numeric_limits<T>::has_infinity
        && value == std::numeric_limits<T>::infinity();
  }
//_________________________________________________________________________

G4Scheduler* G4Scheduler::Instance()
{
  if(fgScheduler == 0) fgScheduler = new G4Scheduler();
  return fgScheduler;
}
//_________________________________________________________________________

G4bool G4Scheduler::Notify(G4ApplicationState requestedState)
{
  if(requestedState == G4State_Quit)
  {
    if(fVerbose >= 4)
    {
      G4cout << "G4Scheduler received G4State_Quit" << G4endl;
    }
    Clear();
    //DeleteInstance();
  }
  return true;
}
//_________________________________________________________________________

void G4Scheduler::DeleteInstance()
{
  if(fgScheduler)
  {
    delete fgScheduler;
  }
}
//_________________________________________________________________________

G4Scheduler::G4Scheduler() :
    G4VScheduler(), G4VStateDependent(),
    fTrackContainer((G4ITTrackHolder&) *G4ITTrackHolder::Instance())
{
  Create();
}

void G4Scheduler::Create()
{
  fUseDefaultTimeSteps = true;
  fUserUpperTimeLimit = -1;
  fpGun = 0;
  fContinue = true;
//  fpMainList = 0;
//  fpWaitingList = 0;
  fpTrackingInteractivity = 0;

  fITStepStatus = eUndefined;

  fpUserTimeSteps = 0;

  fTimeStep = DBL_MAX;
  fTSTimeStep = DBL_MAX;
  fILTimeStep = DBL_MAX;
  fPreviousTimeStep = DBL_MAX;

  fZeroTimeCount = 0;
  fMaxNZeroTimeStepsAllowed = 10;

  fStartTime = 0;
  fTimeTolerance = 1 * picosecond;
  fEndTime = 1 * microsecond;
  fGlobalTime = -1;
  fInteractionStep = true;
  fUsePreDefinedTimeSteps = false;

  fDefaultMinTimeStep = 1 * picosecond;

  fpStepProcessor = 0;
  fpModelProcessor = 0;

  fNbSteps = 0;
  fMaxSteps = -1;

  fRunning = false;
  fInitialized = false;

  fpUserTimeStepAction = 0;
  fpModelHandler = new G4ITModelHandler();
  fpTrackingManager = new G4ITTrackingManager();

  fVerbose = 0;
  fWhyDoYouStop = false;
  fDefinedMinTimeStep = -1.;
  fReachedUserTimeLimit = false;
  fStopTime = -1.;
  fTmpGlobalTime = -1.;

  fpMessenger = new G4SchedulerMessenger(this);

  fReactionSet = G4ITReactionSet::Instance();
  fMaxTimeStep = DBL_MAX;

  G4ITTypeManager::Instance()->ReserveRessource();
}

//_________________________________________________________________________

G4Scheduler::~G4Scheduler()
{

  if(fpMessenger) // is used as a flag to know whether the manager was cleared
  {
    Clear();
  }

  fgScheduler = 0;

//  if (fVerbose >= 1)
//  {
//    G4cout << "G4Scheduler is being deleted. Bye :) !" << G4endl;
//  }
}

void G4Scheduler::Clear()
{
//  if (fVerbose) G4cout << "*** G4Scheduler is being cleared ***" << G4endl;

  if(fpMessenger)
  {
    delete fpMessenger;
    fpMessenger = 0;
  }
  if(fpStepProcessor)
  {
    delete fpStepProcessor;
    fpStepProcessor = 0;
  }
  if(fpModelProcessor)
  {
    delete fpModelProcessor;
    fpModelProcessor = 0;
  }

  G4ITTypeManager::Instance()->ReleaseRessource();
  ClearList();
  if(fpTrackingManager)
  {
    delete fpTrackingManager;
    fpTrackingManager = 0;
  }

  if(fReactionSet)
  {
    delete fReactionSet;
    fReactionSet = 0;
  }

  if(fpModelHandler)
  {
    delete fpModelHandler;
    fpModelHandler = 0;
  }

   //* DEBUG
   //* assert(G4StateManager::GetStateManager()->
   //* DeregisterDependent(this) == true);

}

//_________________________________________________________________________

void G4Scheduler::ClearList()
{
//  if (fNbTracks == 0) return;

  fTrackContainer.Clear();

  G4AllITFinder::DeleteInstance();
}

//_________________________________________________________________________
void G4Scheduler::RegisterModel(G4VITStepModel* model, double time)
{
  fpModelHandler->RegisterModel(model, time);
}

//_________________________________________________________________________

void G4Scheduler::Initialize()
{
  if(fpStepProcessor)
  {
    delete fpStepProcessor;
  }
  if(fpModelProcessor)
  {
    delete fpModelProcessor;
  }
  // if(fpMasterModelProcessor)
  // {
  //     delete fpMasterModelProcessor;
  // }

  //______________________________________________________________

  fpModelProcessor = new G4ITModelProcessor();
  fpModelProcessor->SetModelHandler(fpModelHandler);
  fpModelProcessor->SetTrackingManager(fpTrackingManager);

  // fpMasterModelProcessor = new G4ITModelProcessor();
  // fpMasterModelProcessor->SetModelHandler(fpModelHandler);
  // fpModelProcessor      = fpMasterModelProcessor;

  //______________________________________________________________

  fpStepProcessor = new G4ITStepProcessor();
  fpStepProcessor->SetTrackingManager(fpTrackingManager);

  fpTrackingManager->SetInteractivity(fpTrackingInteractivity);

  // fpMasterStepProcessor = new G4ITStepProcessor();
  // fpMasterStepProcessor->SetTrackingManager(fpTrackingManager);
  // fpStepProcessor = fpMasterStepProcessor ;
  //______________________________________________________________

  if(fUsePreDefinedTimeSteps)
  {
    if(fpUserTimeSteps == 0) // Extra checking, is it necessary ?
    {
      G4ExceptionDescription exceptionDescription;
      exceptionDescription
          << "You are asking to use user defined steps but you did not give any.";
      G4Exception("G4Scheduler::FindUserPreDefinedTimeStep",
                  "Scheduler004",
                  FatalErrorInArgument,
                  exceptionDescription);
      return; // makes coverity happy
    }
  }

//  if (fComputeTimeStep)
//  {
//    if (fpModelProcessor == 0)
//    {
//      G4ExceptionDescription exceptionDescription;
//      exceptionDescription
//          << "There is no G4ITModelProcessor to handle IT reaction. ";
//      exceptionDescription
//          << "You probably did not initialize the G4Scheduler. ";
//      exceptionDescription
//          << "Just do G4Scheduler::Instance()->Initialize(); ";
//      exceptionDescription << " but only after initializing the run manager.";
//      G4Exception("G4Scheduler::CalculateMinStep", "ITScheduler005",
//                  FatalErrorInArgument, exceptionDescription);
//      return; // makes coverity happy
//    }
//  }

  fInitialized = true;
}

//_________________________________________________________________________

void G4Scheduler::Reset()
{
  fStartTime = 0;
  fUserUpperTimeLimit = -1;
  fTimeStep = DBL_MAX;
  fTSTimeStep = DBL_MAX;
  fILTimeStep = DBL_MAX;
  fPreviousTimeStep = DBL_MAX;
  fGlobalTime = -1;
  fInteractionStep = true;
  fITStepStatus = eUndefined;
  fZeroTimeCount = 0;

  fNbSteps = 0;
  fContinue = true;
  // fReactingTracks.clear();
  fReactionSet->CleanAllReaction();
}
//_________________________________________________________________________

void G4Scheduler::Process()
{

#ifdef G4VERBOSE
  if(fVerbose)
  {
    G4cout << "*** G4Scheduler starts processing " << G4endl;
    if(fVerbose > 2)
    G4cout << "___________________________________________"
    "___________________________" << G4endl;
  }
#endif

  if (fInitialized == false) Initialize();

  // fpTrackingManager->Initialize();
  fpModelProcessor->Initialize();
  fpStepProcessor->Initialize();

  // TODO
  // fpMasterModelProcessor->Initialize();
  // fpMasterStepProcessor->Initialize();

  if (fpGun) fpGun->DefineTracks();

  if (fpTrackingInteractivity) fpTrackingInteractivity->Initialize();

  // ___________________
  fRunning = true;
  Reset();

  if (fpUserTimeStepAction) fpUserTimeStepAction->StartProcessing();

#ifdef G4VERBOSE
  G4bool trackFound = false;
  G4IosFlagsSaver iosfs(G4cout);
  G4cout.precision(5);
#endif

  //===========================================================================
  // By default, before the G4Scheduler is launched, the tracks are pushed to
  // the delayed lists
  //===========================================================================

  if(fTrackContainer.DelayListsNOTEmpty())
  {
    fStartTime = fTrackContainer.GetNextTime();
#ifdef G4VERBOSE
    trackFound = true;
    G4Timer localtimer;
    if(fVerbose>1)
    {
      localtimer.Start();
    }
#endif
    SynchronizeTracks();
#ifdef G4VERBOSE
    if(fVerbose>1)
    {
      localtimer.Stop();
      G4cout << "G4Scheduler: process time= "<< localtimer << G4endl;
    }
#endif
  }

//  //---------------------------------
//  // TODO: This could be removed ?
//  if(fTrackContainer.MainListsNOTEmpty()
//      && (fMaxSteps == -1 ? true : fNbSteps < fMaxSteps)
//      && fGlobalTime < fEndTime
//      && fContinue == true)
//{
//#ifdef G4VERBOSE
//    trackFound = true;
//#endif
//    DoProcess();
//}
//  //---------------------------------

#ifdef G4VERBOSE
  if(fVerbose)
  {
    if(trackFound)
    {
      G4cout << "*** G4Scheduler ends at time : "
      << G4BestUnit(fGlobalTime,"Time") << G4endl;
      G4cout << "___________________________________" << G4endl;
    }
    else
    {
      G4cout << "*** G4Scheduler did not start because no "
      "track was found to be processed"<< G4endl;
      G4cout << "___________________________________" << G4endl;
    }
  }
#endif

  fRunning = false;

  if (fpUserTimeStepAction) fpUserTimeStepAction->EndProcessing();

  // ___________________
  EndTracking();
  ClearList();

  Reset();

  if (fpTrackingInteractivity) fpTrackingInteractivity->Finalize();
}

//_________________________________________________________________________

double G4Scheduler::GetNextWatchedTime() const
{
  std::set<double>::const_iterator up = fWatchedTimes.upper_bound(fGlobalTime);
  if(up == fWatchedTimes.end()) return DBL_MAX;
  return *up;
}

//_________________________________________________________________________

void G4Scheduler::SynchronizeTracks()
{
//  if(fTrackContainer.WaitingListsNOTEmpty())
//   {
//    G4ExceptionDescription exceptionDescription;
//    exceptionDescription
//        << "There is a waiting track list (fpWaitingList != 0).";
//    exceptionDescription
//        << " When G4Scheduler::SynchronizeTracks() is called, ";
//    exceptionDescription
//        << "no more tracks should remain in the fpWaitingList.";
//    G4Exception("G4Scheduler::SynchronizeTracks", "ITScheduler002",
//                FatalErrorInArgument, exceptionDescription);
//  }

  // Backup main list and time feature
  // Reminder : the main list here, should
  // have the biggest global time
  //  fTrackContainer.MoveMainToWaitingList();
  // TODO: not yet supported

  fTmpGlobalTime = fGlobalTime;
  //fTmpEndTime = fEndTime;

  fGlobalTime = fTrackContainer.GetNextTime();
  G4double tmpGlobalTime = fGlobalTime;

  double nextWatchedTime = -1;
  bool carryOn = true;

  while(fTrackContainer.MergeNextTimeToMainList(tmpGlobalTime) && carryOn)
  {
//    assert(tmpGlobalTime == fGlobalTime);
    fStopTime = min(fTrackContainer.GetNextTime(), fEndTime);
    while((nextWatchedTime = GetNextWatchedTime()) < fTrackContainer.GetNextTime()
        && (carryOn = CanICarryOn()))
    {
      fStopTime = min(nextWatchedTime, fEndTime);
      DoProcess();
    }

    carryOn = CanICarryOn();

    if(nextWatchedTime > fEndTime && carryOn)
    {
      fStopTime = min(fTrackContainer.GetNextTime(), fEndTime);
      DoProcess();
    }
  }
}

//_________________________________________________________________________

bool G4Scheduler::CanICarryOn()
{
  return fGlobalTime < fEndTime && (fMaxSteps == -1 ? true : fNbSteps < fMaxSteps)
      && fContinue == true;
}

//_________________________________________________________________________

void G4Scheduler::PrintWhyDoYouStop()
{
#ifdef G4VERBOSE
  if(fWhyDoYouStop)
  {
    G4cout << "G4Scheduler has reached a stage: it might be"
           " a transition or the end"
           << G4endl;

    G4bool normalStop = false;

    if(fGlobalTime >= fStopTime)
    {
      G4cout << "== G4Scheduler: I stop because I reached the stop time : "
      << G4BestUnit(fStopTime,"Time") << " =="<< G4endl;
      normalStop = true;
    }
    if(fTrackContainer.MainListsNOTEmpty() == false) // is empty
    {
      G4cout << "G4Scheduler: I stop because the current main list of tracks "
      "is empty"
      << G4endl;
      normalStop = true;
    }
    if(fMaxSteps == -1 ? false : fNbSteps >= fMaxSteps)
    {
      G4cout << "G4Scheduler: I stop because I reached the maximum allowed "
      "number of steps=" << fMaxSteps
      << G4endl;
      normalStop = true;
    }
    if(fContinue && normalStop == false)
    {
      G4cout << "G4Scheduler: It might be that I stop because "
      "I have been told so. You may check "
      "member fContinue and usage of the method G4Scheduler::Stop()."
      << G4endl;
    }
  }
#endif
}

//_________________________________________________________________________

void G4Scheduler::DoProcess()
// We split it from the Process() method to avoid repeating code in SynchronizeTracks
{
  if(fpUserTimeStepAction) fpUserTimeStepAction->NewStage();

#if defined (DEBUG_MEM) && defined (DEBUG_MEM_STEPPING)
  MemStat mem_first, mem_second, mem_diff;
#endif

#if defined (DEBUG_MEM) && defined (DEBUG_MEM_STEPPING)
  mem_first = MemoryUsage();
#endif

  while (fGlobalTime < fStopTime
         && fTrackContainer.MainListsNOTEmpty()
         && (fMaxSteps == -1 ? true : fNbSteps < fMaxSteps)
         && fContinue == true)
  {
//    G4cout << "Mainlist size : " << fTrackContainer.GetMainList()->size()
//        << G4endl;

    Stepping();

#if defined (DEBUG_MEM) && defined (DEBUG_MEM_STEPPING)
    mem_second = MemoryUsage();
    mem_diff = mem_second-mem_first;
    G4cout << "\t || MEM || After step " << fNbSteps << ", diff is : "
    << mem_diff << G4endl;
#endif
  }

  PrintWhyDoYouStop();

#if defined (DEBUG_MEM) && defined (DEBUG_MEM_STEPPING)
  mem_second = MemoryUsage();
  mem_diff = mem_second-mem_first;
  G4cout << "\t || MEM || After stepping, diff is : " << mem_diff << G4endl;
#endif

#ifdef G4VERBOSE
  if(fVerbose > 2)
    G4cout << "*** G4Scheduler has finished processing a track list at time : "
           << G4BestUnit(fGlobalTime, "Time") << G4endl;
#endif
}
//_________________________________________________________________________

void G4Scheduler::Stepping()
{
  fTimeStep = fMaxTimeStep;

  fTSTimeStep = DBL_MAX;
  fILTimeStep = DBL_MAX;

  fInteractionStep = false;
  fReachedUserTimeLimit = false;

  fITStepStatus = eUndefined;

  // Start of step
#ifdef G4VERBOSE
  if (fVerbose > 2)
  {
#ifdef USE_COLOR
    G4cout << LIGHT_RED;
#endif
    G4cout << "*** Start Of Step N°" << fNbSteps + 1 << " ***" << G4endl;
    G4cout << "Current Global time : " << G4BestUnit(fGlobalTime, "Time")
           <<G4endl;
#ifdef USE_COLOR
    G4cout << RESET_COLOR;
#endif
  }
#endif

#if defined (DEBUG_MEM) && defined (DEBUG_MEM_DETAILED_STEPPING)
  MemStat mem_first, mem_second, mem_diff;
#endif

#if defined (DEBUG_MEM) && defined (DEBUG_MEM_DETAILED_STEPPING)
  mem_first = MemoryUsage();
#endif

  fDefinedMinTimeStep = GetLimitingTimeStep();

  if (fUsePreDefinedTimeSteps)
  {
#ifdef G4VERBOSE
    if (fVerbose > 2)
    {
#ifdef USE_COLOR
      G4cout << LIGHT_RED;
#endif
      G4cout << "*** At time : " << G4BestUnit(fGlobalTime, "Time")
             << " the chosen user time step is : "
             << G4BestUnit(fDefinedMinTimeStep, "Time") << " ***" << G4endl;
#ifdef USE_COLOR
      G4cout << RESET_COLOR;
#endif
    }
#endif
  }

  if (fpModelProcessor->GetComputeTimeStep()) // fComputeTimeStep)
  {
    fTSTimeStep = fpModelProcessor->CalculateMinTimeStep(fGlobalTime,
                                                         fDefinedMinTimeStep);
    // => at least N (N = nb of tracks) loops
  }
  else if(fUseDefaultTimeSteps)
  {
    fTSTimeStep = fDefinedMinTimeStep;
  }

#if defined (DEBUG_MEM) && defined (DEBUG_MEM_DETAILED_STEPPING)
  mem_second = MemoryUsage();
  mem_diff = mem_second-mem_first;
  G4cout << "|| MEM || After computing TS, diff is : " << mem_diff << G4endl;
#endif

#ifdef G4VERBOSE
  if (fVerbose > 2)
  {
#ifdef USE_COLOR
    G4cout << LIGHT_RED;
#endif
    G4cout << "*** Time stepper returned : " << G4BestUnit(fTSTimeStep, "Time")
           << " ***" << G4endl;
#ifdef USE_COLOR
    G4cout << RESET_COLOR;
#endif
  }
#endif

#if defined (DEBUG_MEM) && defined (DEBUG_MEM_DETAILED_STEPPING)
  mem_first = MemoryUsage();
#endif

  // Call IL even if fTSTimeStep == 0
  // if fILTimeStep == 0 give the priority to DoIt processes

  fILTimeStep =
    fpStepProcessor->ComputeInteractionLength(fPreviousTimeStep);
  // => at least N loops
  // All process returns the physical step of interaction
  // The transportation process calculates the corresponding
  // time step

#if defined (DEBUG_MEM) && defined (DEBUG_MEM_DETAILED_STEPPING)
  mem_second = MemoryUsage();
  mem_diff = mem_second-mem_first;
  G4cout << "|| MEM || After IL, diff is : " << mem_diff << G4endl;
#endif

#ifdef G4VERBOSE
  if (fVerbose > 2)
  {
#ifdef USE_COLOR
    G4cout << LIGHT_RED;
#endif
    G4cout << "*** The minimum time returned by the processes is : "
           << G4BestUnit(fILTimeStep, "Time") << " ***" << G4endl;
#ifdef USE_COLOR
    G4cout << RESET_COLOR;
#endif
  }
#endif

#if defined (DEBUG_MEM) && defined (DEBUG_MEM_DETAILED_STEPPING)
  mem_first = MemoryUsage();
#endif

  if (fILTimeStep <= fTSTimeStep)
    // Give the priority to the IL
  {
    fInteractionStep = true;
    fReactionSet->CleanAllReaction();
    fTimeStep = fILTimeStep;
    fITStepStatus = eInteractionWithMedium;
    fpStepProcessor->PrepareLeadingTracks();
  }
  else
  {
    fInteractionStep = false;
    fpStepProcessor->ResetLeadingTracks();
    fTimeStep = fTSTimeStep;
    fITStepStatus = eCollisionBetweenTracks;
  }

  if (fGlobalTime + fTimeStep > fStopTime)
    // This check is done at every time step
  {
    fTimeStep = fStopTime - fGlobalTime;
    fITStepStatus = eInteractionWithMedium; // ie: transportation
    fInteractionStep = true;
    fReactionSet->CleanAllReaction();
    fpStepProcessor->ResetLeadingTracks();
  }

  if (fTimeStep == 0) // < fTimeTolerance)
  {
    ++fZeroTimeCount;
    if (fZeroTimeCount >= fMaxNZeroTimeStepsAllowed)
    {
      G4ExceptionDescription exceptionDescription;

      exceptionDescription << "Too many zero time steps were detected. ";
      exceptionDescription << "The simulation is probably stuck. ";
      exceptionDescription
          << "The maximum number of zero time steps is currently : "
          << fMaxNZeroTimeStepsAllowed;
      exceptionDescription << ".";

      G4Exception("G4Scheduler::Stepping",
                  "SchedulerNullTimeSteps",
                  FatalErrorInArgument,
                  exceptionDescription);
    }
  }
  else
  {
    fZeroTimeCount = 0;
  }

  fReachedUserTimeLimit =
      ((fTimeStep <= fDefinedMinTimeStep) || ((fTimeStep > fDefinedMinTimeStep)
          && fabs(fTimeStep - fDefinedMinTimeStep) < fTimeTolerance)) ?
          true : false;

  if (fpUserTimeStepAction) fpUserTimeStepAction->UserPreTimeStepAction();
  // TODO: pre/post

#if defined (DEBUG_MEM) && defined (DEBUG_MEM_DETAILED_STEPPING)
  mem_second = MemoryUsage();
  mem_diff = mem_second-mem_first;
  G4cout << "|| MEM || After LeadingTracks and UserPreTimeStepAction: "
         << mem_diff << G4endl;
#endif

#if defined (DEBUG_MEM) && defined (DEBUG_MEM_DETAILED_STEPPING)
  mem_first = MemoryUsage();
#endif


  fGlobalTime += fTimeStep;

  // if fTSTimeStep > 0 => still need to call the transportation process
  // if fILTimeStep < fTSTimeStep => call only DoIt processes, no reactions
  // if fILTimeStep == fTSTimeStep => give the priority to the DoIt processes
  if (fTSTimeStep > 0 || fILTimeStep <= fTSTimeStep)
  {
    //        G4cout << "Will call DoIT" << G4endl;
    fpStepProcessor->DoIt(fTimeStep);
    //  fTrackContainer.MergeSecondariesWithMainList();
    //  fTrackContainer.KillTracks(); // remove ?
  }
  // else
  // {
  //   G4cout << "fTSTimeStep : " << fTSTimeStep << G4endl;
  //   G4cout << "fILTimeStep : " << fILTimeStep << G4endl;
  // }

#if defined (DEBUG_MEM) && defined (DEBUG_MEM_DETAILED_STEPPING)
  mem_second = MemoryUsage();
  mem_diff = mem_second-mem_first;
  G4cout << "|| MEM || After DoIT, diff is : " << mem_diff << G4endl;
#endif

#if defined (DEBUG_MEM) && defined (DEBUG_MEM_DETAILED_STEPPING)
  mem_first = MemoryUsage();
#endif

  fpModelProcessor->ComputeTrackReaction(fITStepStatus,
                                         fGlobalTime,
                                         fTimeStep,
                                         fPreviousTimeStep,
                                         fReachedUserTimeLimit,
                                         fTimeTolerance,
                                         fpUserTimeStepAction,
                                         fVerbose);

  ++fNbSteps;

  if (fpUserTimeStepAction)
  {
    fpUserTimeStepAction->UserPostTimeStepAction();
  }

  fPreviousTimeStep = fTimeStep;

#if defined (DEBUG_MEM) && defined (DEBUG_MEM_DETAILED_STEPPING)
  mem_second = MemoryUsage();
  mem_diff = mem_second-mem_first;
  G4cout << "|| MEM || After computing reactions + UserPostTimeStepAction, "
  "diff is : " << mem_diff << G4endl;
#endif

  // End of step
#ifdef G4VERBOSE
    if (fVerbose >= 2)
    {
#ifdef USE_COLOR
      G4cout << LIGHT_RED;
#endif

      G4String interactionType;
      GetCollisionType(interactionType);

      std::stringstream finalOutput;

      finalOutput << "*** End of step N°" << fNbSteps
             << "\t T_i= " << G4BestUnit(fGlobalTime-fTimeStep, "Time")
             << "\t dt= " << G4BestUnit(fTimeStep, "Time")
             << "\t T_f= " << G4BestUnit(fGlobalTime, "Time")
             << "\t " << interactionType
             << G4endl;

      if(fVerbose>2)
      {
        if(fReachedUserTimeLimit)
        {
          finalOutput << "It has also reached the user time limit" << G4endl;
        }
        finalOutput << "_______________________________________________________________"
            "_______"<< G4endl;
      }

      G4cout << finalOutput.str();

#ifdef USE_COLOR
      G4cout << RESET_COLOR;
#endif
    }
#endif

}
//_________________________________________________________________________

double G4Scheduler::GetLimitingTimeStep() const
{
  if (fpUserTimeSteps == 0) return fDefaultMinTimeStep;
  if (fabs(fGlobalTime - fUserUpperTimeLimit) < fTimeTolerance)
    return fDefinedMinTimeStep;

  map<double, double>::const_iterator it_fpUserTimeSteps_i = fpUserTimeSteps
      ->upper_bound(fGlobalTime);
  map<double, double>::const_iterator it_fpUserTimeSteps_low = fpUserTimeSteps
      ->lower_bound(fGlobalTime);

  // DEBUG
  // G4cout << "fGlobalTime : " << G4BestUnit(fGlobalTime,"Time")
  //            << G4endl;
  // G4cout << "fpUserTimeSteps_i : "
  //        <<"<"<<G4BestUnit(it_fpUserTimeSteps->first,"Time")
  //        <<", "<< G4BestUnit(it_fpUserTimeSteps->second,"Time")<<">"
  //        << "\t fpUserTimeSteps_low : "
  //        <<"<"<<G4BestUnit(fpUserTimeSteps_low->first,"Time")<<", "*
  //        << G4BestUnit(fpUserTimeSteps_low->second,"Time")<<">"
  //        << G4endl;

  if (it_fpUserTimeSteps_i == fpUserTimeSteps->end())
  {
    it_fpUserTimeSteps_i--;
    fUserUpperTimeLimit = fStopTime;
  }
  else if (fabs(fGlobalTime - it_fpUserTimeSteps_low->first) < fTimeTolerance)
  {
    // Case : fGlobalTime = X picosecond
    // and fpUserTimeSteps_low->first = X picosecond
    // but the precision is not good enough
    it_fpUserTimeSteps_i = it_fpUserTimeSteps_low;
    map<double, double>::const_iterator tmp_it = it_fpUserTimeSteps_low;
    ++tmp_it;
    if (tmp_it == fpUserTimeSteps->end())
    {
      fUserUpperTimeLimit = fStopTime;
    }
    else
    {
      fUserUpperTimeLimit = tmp_it->first;
    }
  }
  else if (it_fpUserTimeSteps_i == it_fpUserTimeSteps_low)
  {
    // "Normal" cases
    fUserUpperTimeLimit = it_fpUserTimeSteps_i->first;
//    it_fpUserTimeSteps_i++;
//    G4cout << "Global time = " << fGlobalTime << G4endl;
//    G4cout << "Is begin = "
//    << (it_fpUserTimeSteps_i == fpUserTimeSteps->begin())<< G4endl;

    if(it_fpUserTimeSteps_i != fpUserTimeSteps->begin()) it_fpUserTimeSteps_i--;
  }
  else
  {
    fUserUpperTimeLimit = it_fpUserTimeSteps_i->first;
    it_fpUserTimeSteps_i = it_fpUserTimeSteps_low;
  }

  return it_fpUserTimeSteps_i->second;
}

//_________________________________________________________________________

void G4Scheduler::FindUserPreDefinedTimeStep()
{

  if(fpUserTimeSteps == 0)
  {
    G4ExceptionDescription exceptionDescription;
    exceptionDescription
        << "You are asking to use user defined steps but you did not give any.";
    G4Exception("G4Scheduler::FindUserPreDefinedTimeStep",
                "Scheduler004",
                FatalErrorInArgument,
                exceptionDescription);
    return; // makes coverity happy
  }
  map<double, double>::iterator fpUserTimeSteps_i =
      fpUserTimeSteps->upper_bound(fGlobalTime);
  map<double, double>::iterator fpUserTimeSteps_low = fpUserTimeSteps
      ->lower_bound(fGlobalTime);

  // DEBUG
  // G4cout << "fGlobalTime : " << G4BestUnit(fGlobalTime,"Time") << G4endl;
  // G4cout << "fpUserTimeSteps_i : "
  // <<"<"<<G4BestUnit(fpUserTimeSteps_i->first,"Time")<<", "
  // << G4BestUnit(fpUserTimeSteps_i->second,"Time")<<">"
  // << "\t fpUserTimeSteps_low : "
  // <<"<"<<G4BestUnit(fpUserTimeSteps_low->first,"Time")<<", "
  // << G4BestUnit(fpUserTimeSteps_low->second,"Time")<<">"
  // << G4endl;

  if(fpUserTimeSteps_i == fpUserTimeSteps->end())
  {
    fpUserTimeSteps_i--;
  }
  else if(fabs(fGlobalTime - fpUserTimeSteps_low->first) < fTimeTolerance)
  {
    // Case : fGlobalTime = X picosecond
    // and fpUserTimeSteps_low->first = X picosecond
    // but the precision is not good enough
    fpUserTimeSteps_i = fpUserTimeSteps_low;
  }
  else if(fpUserTimeSteps_i == fpUserTimeSteps_low)
  {
    // "Normal" cases
    fpUserTimeSteps_i--;
  }
  else
  {
    fpUserTimeSteps_i = fpUserTimeSteps_low;
  }

  fDefinedMinTimeStep = fpUserTimeSteps_i->second;
}

//_________________________________________________________________________

void G4Scheduler::EndTracking()
{
  if(fRunning)
  {
    G4ExceptionDescription exceptionDescription;
    exceptionDescription
        << "End tracking is called while G4Scheduler is still running."
        << G4endl;

    G4Exception("G4Scheduler::EndTracking",
                "Scheduler017",
                FatalErrorInArgument,
                exceptionDescription);
  }

  fTrackContainer.MergeSecondariesWithMainList();

  if (fTrackContainer.MainListsNOTEmpty())
  {
    G4TrackManyList* mainList = fTrackContainer.GetMainList();
    G4TrackManyList::iterator it = mainList->begin();
    G4TrackManyList::iterator end = mainList->end();
    for (; it != end; ++it)
    {
      fpTrackingManager->EndTrackingWOKill(*it);
    }
  }

  if (fTrackContainer.SecondaryListsNOTEmpty()) // should be empty
  {
    G4TrackManyList* secondaries = fTrackContainer.GetSecondariesList();
    G4TrackManyList::iterator it = secondaries->begin();
    G4TrackManyList::iterator end = secondaries->end();

    for (; it != end; ++it)
    {
      fpTrackingManager->EndTrackingWOKill(*it);
    }
  }
}

//_________________________________________________________________________
void G4Scheduler::SetInteractivity(G4ITTrackingInteractivity* interactivity)
{
  fpTrackingInteractivity = interactivity;
  if(fpTrackingManager)
  {
    fpTrackingManager->SetInteractivity(fpTrackingInteractivity);
  }

  //G4MIWorkspace::GetWorldWorkspace()->SetTrackingInteractivity(interactivity);
}

//_________________________________________________________________________
void G4Scheduler::ForceReinitialization()
{
  fInitialized = false;
  Initialize();
}

//_________________________________________________________________________
G4Scheduler::G4Scheduler(const G4Scheduler&) :
    G4VScheduler(), G4VStateDependent(),
    fTrackContainer((G4ITTrackHolder&) *G4ITTrackHolder::Instance())

{
  Create();
}

//_________________________________________________________________________
G4Scheduler& G4Scheduler::operator=(const G4Scheduler& right)
{
  if(this != &right)
  {
    Create();
  }
  return *this;
}

size_t G4Scheduler::GetNTracks()
{
  return fTrackContainer.GetNTracks();
}
//_________________________________________________________________________

void G4Scheduler::GetCollisionType(G4String& interactionType)
{
  switch(fITStepStatus)
  {
    case eInteractionWithMedium:
      interactionType = "eInteractionWithMedium";
      break;
    case eCollisionBetweenTracks:
      interactionType = "eCollisionBetweenTracks";
      break;
    default:
      interactionType = "eCollisionBetweenTracks";
      break;
  }
}