Following a suggestion by Sander, I am reposting a mail about memory leaks
with a different subject title. See below
I take once more this opportunity to repeat some very basic rules
when sending mails to roottalk:
- always specify a meaningfull subsject title. This facilitates the search
with tools such as google, yahoo, etc.
- always specify the version of Root that you are using
- if you submit a problem, provide enough information such that it is not
necessary to send another mail asking for more details.
- when submitting a problem, try to reproduce the problem in a small
script. The time to solve the problem is often proportional to the size
of the script.
Rene Brun
ORIGINAL MAIL ABOUT MEMORY LEAKS
================================
Hi Ruben,
Two solutions to your problem
- solution1 (recommended) in testwrite
Set the ownership of your top level TObjArray.
detectors = new TObjArray(nsens);
detectors->SetOwner(kTRUE); //<======add this line
- solution 2 (if you do not want to rewrite your data set) in testread
for (int i=0;i<nev;i++) {
// Read the branch for this detector
branch->GetEntry(i);
if (!(i%100)) {
printf("Ev. %5d : %7s %7s
%s\n",i,"Sensor","NDigits","&TClonesArray");
int nsens = detectors->GetLast()+1;
for (int j=0;j<nsens;j++) {
TClonesArray *arr = (TClonesArray*)detectors->At(j);
printf(" %7d %7d %p |\n",j,arr->GetLast()+1,arr);
}
}
detectors->Delete(); //<======add this line
}
Rene Brun
Ruben Shahoian wrote:
>
> Hello,
> I need to write and read the branc of the tree, which constists of the
> TObjArray of TClonesArray (TObjArray being collector of data
> (TClonesArray) of different sensor).
> So, I do
>
> detectors = new TObjArray(nsens);
> for (int i=0;i<nsens;i++) {
> TClonesArray *arr = new TClonesArray("TObject",3000);
> detectors->AddAt(arr,i);
> }
> file = new TFile("tree.root","RECREATE");
> tree = new TTree("DataTree","Tree");
> branch = tree->Branch("Det1","TObjArray",&detectors,32000,0);
>
> It works fine for writing.
> But then, in the reading method, I do
> TObjArray *detectors=0;
> branch->SetAddress(&detectors);
> ...
> branch->GetEntry(i);
>
> It reads back everything correctly but it appears that for each event
> it creates new TClonesArrays and attaches it to TObjArray (without even
> deleting the previous TClonesArrays, although, I would expect that they
> simply should be reused).
> I've tried both splitting the tree and setting SetAutoDelete(kTRUE),
> very soon it swallows up all RAM and starts swapping ...
> Is this normal behavoiur?
> I attach short macros (run .x testrw.C, demonstrating the problem)
>
> Best regards,
> Ruben
On Wed, 23 Oct 2002, Sander Klous wrote:
> Hi,
> Can you please resubmit this message to the mailing list with something
> like 'memory leak using TTree with TObjArray' in the title?
>
> http://root.cern.ch/root/roottalk/roottalk02/0444.html
>
> As a courtesy to the people that encoutner this problem in the future...
> I could only find the mail after I solved the problem myself because of
> the worthless title.
> Thanks,
> Sander
>
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