I’m writing an online monitor to watch over some of our signals for the benefit of people on shift. The code polls a rootfile whose TTrees are “AutoSave”'d every 5 seconds (in a separately running program). It seems to run well, but I’m watching “top” (on Fedora Core 1, ROOT 4.00/03)… as the program runs, and the items under “SIZE”, “RSS”, and “%MEM” steadily increase as the program runs. I took this as an indicator that it was using up more and more of my system’s physical memory.
I decided to make a very basic version of my code (without having an updating rootfile), to see if I could track down the problem… here it is (run after the rootfile loaded up):
void curious() {
TCanvas *c1 = new TCanvas("c1","Whatever");
c1->Divide(2,2);
TTimer *timer = new TTimer();
timer->SetCommand("dodraw()");
timer->Start(2000);
}
void dodraw() {
c1->cd(1);
R->Draw("adc22_0:ev_num");
c1->cd(2);
R->Draw("adc22_1:ev_num");
c1->cd(3);
R->Draw("adc22_2:ev_num");
c1->cd(4);
R->Draw("adc22_3:ev_num");
c1->cd();
c1->Update();
}When started… top tells me “SIZE” is around 32M. My rootfile size is 200M. After running this CINT macro for 3 hours, “SIZE” is now 220M… and climbing. This is the same behavior that I’m seeing in my more complicated code.
Ideally… we’d need a code like this to run for quite a long time (at least 1 week straight). I’m a bit worried that I’m going to run out of physical memory here… Is there something I should add to aleviate this problem? Or perhaps I’m just misinterpretting top’s output…
Thanks.