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//
// Merge G4analysis histogram objects via MPI
//
// History:
// Jun 27, 2015 : Ivana Hrivnacova - new implementation using g4analysis

#include "G4MPIhistoMerger.hh"
#include "G4ios.hh"
#include "tools/mpi/hmpi"
#include <mpi.h>
#include "G4VAnalysisManager.hh"

G4MPIhistoMerger::G4MPIhistoMerger() :
manager(0),destination(G4MPImanager::kRANK_MASTER),
verboseLevel(0) {}

G4MPIhistoMerger::G4MPIhistoMerger(G4VAnalysisManager* m,
    G4int dest, G4int v) : manager(m), destination(dest),verboseLevel(v) {}

void G4MPIhistoMerger::Merge()
{
  if ( verboseLevel > 0 ) {
    G4cout << "Starting merging of histograms" << G4endl;
  }

  MPI::Intracomm comm = MPI::COMM_WORLD.Dup();

  G4bool verbose = ( verboseLevel > 1 );
  G4int tag = G4MPImanager::kTAG_HISTO;
  //const MPI::Intracomm* comm = &COMM_G4COMMAND_;
  tools::mpi::hmpi* hmpi = new tools::mpi::hmpi(G4cout, destination, tag,
                                                                            comm, verbose);
  if ( ! manager->Merge(hmpi) ) {
      G4cout<<" Merge FAILED"<<G4endl;
  }

  delete hmpi;

  if ( verboseLevel > 0 ) {
    G4cout << "End merging of histograms" << G4endl;
  }
  comm.Free();
}
