[ROOT] problem with read of TNamed objects from ROOT TTree

From: Susan Kasahara (schubert@physics.umn.edu)
Date: Thu Jan 17 2002 - 22:26:23 MET 

Hi rooters,
I am having trouble reading TNamed objects from a ROOT TTree.  I attach two
simple programs, one which writes the TNamed objects to a tree,
and one which reads the objects back.   The program which writes the
TNamed objects to tree works successfully, but the program which reads
the objects core dumps after the first 20 entries or so.
  This problem seems to be tied to the frequency of branch basket dumps,
and so I have set the basket size quite small in this example when creating
the TNamed branch to illustrate the problem.  I do not have trouble reading
and writing other classes that I've tested, only TNamed or a class
that inherits from TNamed.
  I am working with cvs ROOT (upgraded last on 13-Jan-2002) on rh
linux using gcc version 2.95.2.
  Any ideas?
-Sue

**************** program to fill and write TNamed objects to TTree ***********

#include <iostream.h>
#include "TROOT.h"
#include "TFile.h"
#include "TTree.h"
#include "TNamed.h"

TROOT test("test","test program");

int main(int argc, char **argv) {

  TFile* file = new TFile("test.root","RECREATE","test root file");
  TTree* tree = new TTree("testTree","test tree");

  TNamed* name = 0;
  // basket buffer size is set to 100 to enforce frequent basket dumps
  tree -> Branch("TNamed","TNamed",&name,100,99);

  // Begin entry loop
  for (Int_t ient=0; ient < 100; ient++) {
    name = new TNamed("Sue","Kasahara");
    tree -> Fill();
    delete name; name = 0;
  }

  file -> Write();
  tree -> Print();
  file -> Close();

  return 0;
}

**************** program to retrieve TNamed objects from ROOT TTree ***********

#include <iostream.h>
#include "TROOT.h"
#include "TFile.h"
#include "TTree.h"

TROOT test("test","Test program");

int main(int argc, char **argv) {

  TFile *file = new TFile("test.root","READ");
  TTree *tree = dynamic_cast<TTree*>(file -> Get("testTree"));

  Int_t nent = (Int_t)tree -> GetEntries();

  for (Int_t ient=0; ient < nent; ient++) {
    TNamed *name = 0;
    tree -> SetBranchAddress("TNamed",&name);

    Int_t nb = tree -> GetEntry(ient);
    cout << "Retrieved entry " << ient << " with " << nb << " bytes." << endl;
    if(name)delete name; name = 0;
  }

  // Finished all entries
  cout << "Total entries in tree = " << nent << endl;

  return 0;

}

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