Problem with collection

ROOT
1

Hello,
please help with this macro (attach). What is wrong ?

#include <TList.h>
#include <TH1.h>

TList *histograms = new TList();

TH1 *FindHis(const char *name) { return (TH1 *)histograms->FindObject(name); }

void HistoManager(TH1 *his, Option_t *option)
{
  if (!his) return;
  TString action = option;
  action.ToLower();

  if (action == "add") {
    TH1 *prev = FindHis(his->GetName()); // find previous histo with same name
    if (prev) {
      Printf("%s replaced", prev->GetName());
      delete prev;
    }
    his->SetDirectory(0);
    his->SetBit(kMustCleanup);
    histograms->Add(his);
  }
}

[quote]
root [0] .L problem.C+
Info in TUnixSystem::ACLiC: creating shared library /home/musinsky/./problem_C.so
root [1] TH1F *h1 = new TH1F(“nameA”, “”, 10, 0, 10)
root [2] HistoManager(h1, “add”)
root [3] TH1F *h2 = new TH1F(“nameA”, “”, 10, 0, 10)
root [4] HistoManager(h2, “add”)
nameA replaced
root [5] TH1F *h3 = new TH1F(“nameB”, “”, 10, 0, 10)
root [6] HistoManager(h3, “add”)
nameB replaced

*** Break *** segmentation violation
(no debugging symbols found)
[/quote] FC9, gcc version 4.1.2 20070925 (Red Hat 4.1.2-33), ROOT 5.19/02
Thanks, Jan
problem.C (547 Bytes)

2

Jan,

deleting prev is not enough, you must also remove it from your TlLst* histograms.

Rene

3

but object prev kMustCleanup bit is set => after deleting prev is remove (automatically) from list histograms.

I forgot: gROOT->GetListOfCleanups()->Add(histograms), solve this problem
Jan

4

Yes adding your list to the list of cleanups solve your problem, otherwise ROOT has no way to find out in which list(s) your histogram is referenced.

Rene