TChain Loop Error


I use TChain to loop over my tree files with TChain::GetEntry(int). It runs for a while and then crashes with:

My code:

#define AMPT_cxx
#include "AMPT.h"
#include <TString.h>
#include <TRandom3.h>
#include <TSystem.h>
#include <TFile.h>
#include <TChain.h>
#include <TTree.h>
#include <TMath.h>
#include <TH1.h>
#include <TH2.h>
#include <TGraph.h>
#include <TStopwatch.h>
#include <iostream>
#include <fstream>
using namespace std;

void test()

  ifstream in_stream;"list.txt");
  if(     cout << "Input file opening failed" << endl;
  char inFile[800];

  TChain *chain = new TChain("AMPT");
  while(in_stream >> inFile)

  AMPT *Eve = new AMPT(chain);
  Int_t nEvents = chain->GetEntries();
  cout<<"# of Events :"  <<nEvents<<endl;

  for(int ievt = 0; ievt<nEvents; ievt++) {

      if(ievt%10000==0) cout<< ievt << endl;

‘list.txt’ is the input tree files list.

‘AMPT.h’ is from the MakeClass() of the tree file:

// This class has been automatically generated on
// Sat Jun  1 19:53:35 2013 by ROOT version 5.30/00
// from TTree AMPT/AMPT DST Tree
// found on file: ampt_afterART.root

#ifndef AMPT_h
#define AMPT_h

#include <TROOT.h>
#include <TChain.h>
#include <TFile.h>

class AMPT {
public :
   TTree          *fChain;   //!pointer to the analyzed TTree or TChain
   Int_t           fCurrent; //!current Tree number in a TChain

   // Declaration of leaf types
   Int_t           Event_nevent;
   Int_t           Event_nrun;
   Int_t           Event_multi;
   Float_t         Event_impactpar;
   Int_t           Event_NpartP;
   Int_t           Event_NpartT;
   Int_t           Event_NELP;
   Int_t           Event_NINP;
   Int_t           Event_NELT;
   Int_t           Event_NINT;
   Float_t         Event_px_trig1;
   Float_t         Event_py_trig1;
   Float_t         Event_pz_trig1;
   Float_t         Event_energy_trig1;
   Float_t         Event_mass_trig1;
   Int_t           Event_id_trig1;
   Float_t         Event_px_trig2;
   Float_t         Event_py_trig2;
   Float_t         Event_pz_trig2;
   Float_t         Event_energy_trig2;
   Float_t         Event_mass_trig2;
   Int_t           Event_id_trig2;
   Float_t         Event_VVX;
   Float_t         Event_VVY;
   Int_t           Indx[636];   //[multi]
   Int_t           ID[636];   //[multi]
   Float_t         Px[636];   //[multi]
   Float_t         Py[636];   //[multi]
   Float_t         Pz[636];   //[multi]
   Float_t         Mass[636];   //[multi]
   Float_t         X[636];   //[multi]
   Float_t         Y[636];   //[multi]
   Float_t         Z[636];   //[multi]
   Float_t         Time[636];   //[multi]

   // List of branches
   TBranch        *b_Event;   //!
   TBranch        *b_Indx;   //!
   TBranch        *b_ID;   //!
   TBranch        *b_Px;   //!
   TBranch        *b_Py;   //!
   TBranch        *b_Pz;   //!
   TBranch        *b_Mass;   //!
   TBranch        *b_X;   //!
   TBranch        *b_Y;   //!
   TBranch        *b_Z;   //!
   TBranch        *b_Time;   //!

   AMPT(TTree *tree=0);
   virtual ~AMPT();
   virtual Int_t    Cut(Long64_t entry);
   virtual Int_t    GetEntry(Long64_t entry);
   virtual Long64_t LoadTree(Long64_t entry);
   virtual void     Init(TTree *tree);
   virtual void     Loop();
   virtual Bool_t   Notify();
   virtual void     Show(Long64_t entry = -1);


#ifdef AMPT_cxx
AMPT::AMPT(TTree *tree)
// if parameter tree is not specified (or zero), connect the file
// used to generate this class and read the Tree.
   if (tree == 0) {
      TFile *f = (TFile*)gROOT->GetListOfFiles()->FindObject("ampt_afterART.root");
      if (!f || !f->IsOpen()) {
         f = new TFile("ampt_afterART.root");


   if (!fChain) return;
   delete fChain->GetCurrentFile();

Int_t AMPT::GetEntry(Long64_t entry)
// Read contents of entry.
   if (!fChain) return 0;
   return fChain->GetEntry(entry);
Long64_t AMPT::LoadTree(Long64_t entry)
// Set the environment to read one entry
   if (!fChain) return -5;
   Long64_t centry = fChain->LoadTree(entry);
   if (centry < 0) return centry;
   if (fChain->GetTreeNumber() != fCurrent) {
      fCurrent = fChain->GetTreeNumber();
   return centry;

void AMPT::Init(TTree *tree)
   // The Init() function is called when the selector needs to initialize
   // a new tree or chain. Typically here the branch addresses and branch
   // pointers of the tree will be set.
   // It is normally not necessary to make changes to the generated
   // code, but the routine can be extended by the user if needed.
   // Init() will be called many times when running on PROOF
   // (once per file to be processed).

   // Set branch addresses and branch pointers
   if (!tree) return;
   fChain = tree;
   fCurrent = -1;

   fChain->SetBranchAddress("Event", &Event_nevent, &b_Event);
   fChain->SetBranchAddress("Indx", Indx, &b_Indx);
   fChain->SetBranchAddress("ID", ID, &b_ID);
   fChain->SetBranchAddress("Px", Px, &b_Px);
   fChain->SetBranchAddress("Py", Py, &b_Py);
   fChain->SetBranchAddress("Pz", Pz, &b_Pz);
   fChain->SetBranchAddress("Mass", Mass, &b_Mass);
   fChain->SetBranchAddress("X", X, &b_X);
   fChain->SetBranchAddress("Y", Y, &b_Y);
   fChain->SetBranchAddress("Z", Z, &b_Z);
   fChain->SetBranchAddress("Time", Time, &b_Time);

Bool_t AMPT::Notify()
   // The Notify() function is called when a new file is opened. This
   // can be either for a new TTree in a TChain or when when a new TTree
   // is started when using PROOF. It is normally not necessary to make changes
   // to the generated code, but the routine can be extended by the
   // user if needed. The return value is currently not used.

   return kTRUE;

void AMPT::Show(Long64_t entry)
// Print contents of entry.
// If entry is not specified, print current entry
   if (!fChain) return;
Int_t AMPT::Cut(Long64_t entry)
// This function may be called from Loop.
// returns  1 if entry is accepted.
// returns -1 otherwise.
   return 1;
void AMPT::Loop()
//   In a ROOT session, you can do:
//      Root > .L AMPT.C
//      Root > AMPT t
//      Root > t.GetEntry(12); // Fill t data members with entry number 12
//      Root > t.Show();       // Show values of entry 12
//      Root > t.Show(16);     // Read and show values of entry 16
//      Root > t.Loop();       // Loop on all entries

//     This is the loop skeleton where:
//    jentry is the global entry number in the chain
//    ientry is the entry number in the current Tree
//  Note that the argument to GetEntry must be:
//    jentry for TChain::GetEntry
//    ientry for TTree::GetEntry and TBranch::GetEntry
//       To read only selected branches, Insert statements like:
//    fChain->SetBranchStatus("*",0);  // disable all branches
//    fChain->SetBranchStatus("branchname",1);  // activate branchname
// METHOD2: replace line
//    fChain->GetEntry(jentry);       //read all branches
//by  b_branchname->GetEntry(ientry); //read only this branch
   if (fChain == 0) return;

   Long64_t nentries = fChain->GetEntriesFast();

   Long64_t nbytes = 0, nb = 0;
   for (Long64_t jentry=0; jentry<nentries;jentry++) {
      Long64_t ientry = LoadTree(jentry);
      if (ientry < 0) break;
      nb = fChain->GetEntry(jentry);   nbytes += nb;
      // if (Cut(ientry) < 0) continue;
#endif // #ifdef AMPT_cxx

When running a few files, it works fine. However, it can not finish all files.
If GetEntry is not called and TChain::Draw() is called directly, it works fine.

The full error message is: (The beginning numbers is the event counting.)

Valgrind gives thing:

Thank you for discussion,