Hi Akira,
The issue is the ownership of the histogram object. The simplest fix is to use:
TCanvas can("can", "can");
TH2D h("h", "h", 100, -3, 3, 100, -3, 3);
h.FillRandom("gaus", 100000);
h.DrawCopy("col");
can.SaveAs("tmp.root");
The issue is that when you do h.Draw, it does associate the histogram with the Canvas but it __correctly__ (especially in your case) does not delegate ownership of the histogram to the Canvas. Since you did not delegate ownership of the histogram to the Canvas, the Canvas __must__ assume that you will store the histogram independently and thus upon reading the file, the Canvas does not take ownership of the histogram and do not delete it when you delete the Canvas.
By using DrawCopy you create a new histogram and delegate its ownership to the Canvas.
Note that you of course need to delete the Canvas in the reading loop in order to really get rid of the leak (this is because Canvas are __not__ owned by the TFile they are read from).
Cheers,
Philippe.
PS. A slightly more cpu efficient option is:
TCanvas can("can", "can");
TH2D *h = new TH2D("h", "h", 100, -3, 3, 100, -3, 3);
h->FillRandom("gaus", 100000);
On 9/9/10 10:34 AM, OKUMURA, Akira wrote:
> Hello all,
>
> Here is a minimum example. You don't need to download http://slac.stanford.edu/~oxon/tmp.tgz
>
> ==============================
> #include<TFile.h>
> #include<TCanvas.h>
> #include<TH2D.h>
> #include<iostream>
>
> int main(int argc, char** argv)
> {
> TCanvas can("can", "can");
> TH2D h("h", "h", 100, -3, 3, 100, -3, 3);
> h.FillRandom("gaus", 100000);
> h.Draw("col");
> can.SaveAs("tmp.root");
>
> const Int_t kN = 10000;
> for(Int_t i = 0; i< kN; i++){
> TFile f("tmp.root");
> std::cout<< "Reading "<< f.GetName()<< "...\n";
> TCanvas* c = (TCanvas*)f.Get("can");
> f.Close();
> } // i
>
> return 0;
> }
> ==============================
>
> I would like to know how to delete the allocated memory to TCanvas* c. C++'s delete does not work.
>
> Regards,
>
> --
> OKUMURA, Akira oxon@{astro.isas.jaxa.jp,stanford.edu}
> Institute of Space and Astronautical Science (ISAS/JAXA)
> Now at KIPAC/SLAC/Stanford
> Varian Physics #306
> 382 Via Pueblo Mall, MC 406 Stanford, CA94305
> TEL 650-736-0971/FAX 650-724-5065
> Skype : okumura.akira
>
> On 2010/09/09, at 8:20, OKUMURA, Akira wrote:
>
>> Hello John and all,
>>
>> I uploaded the log file here.
>> http://slac.stanford.edu/~oxon/valgrind.log
>>
>> Regards,
>>
>> --
>> OKUMURA, Akira oxon@{astro.isas.jaxa.jp,stanford.edu}
>> Institute of Space and Astronautical Science (ISAS/JAXA)
>> Now at KIPAC/SLAC/Stanford
>> Varian Physics #306
>> 382 Via Pueblo Mall, MC 406 Stanford, CA94305
>> TEL 650-736-0971/FAX 650-724-5065
>> Skype : okumura.akira
>>
>> On 2010/09/09, at 2:06, John Idarraga wrote:
>>
>>> Hello Akira
>>>
>>> Can you&> that to a log file and send it ?
>>>
>>> John
>>>
>>> OKUMURA, Akira wrote:
>>>> Hello Claudi and all,
>>>>
>>>> Thank you for your advice. I attach a part of the valgrind output. Even though this is a first time to use valgrind for me, the output seems that there is memory leak.
>>>>
>>>> ==17737== 5,189,819 (27,328 direct, 5,162,491 indirect) bytes in 61 blocks are definitely lost in loss record 45,809 of 45,811
>>>> ==17737== at 0x1000146CE: operator new(unsigned long) (vg_replace_malloc.c:261)
>>>> ==17737== by 0x1000386C9: TStorage::ObjectAlloc(unsigned long) (in /usr/local/root_svn/lib/libCore.so)
>>>> ==17737== by 0x100233BB4: TObject::operator new(unsigned long) (in /usr/local/root_svn/lib/libCore.so)
>>>> ==17737== by 0x102DE6955: ROOT::new_TPaletteAxis(void*) (in /usr/local/root_svn/lib/libHistPainter.so)
>>>> ==17737== by 0x10010AAA5: TClass::New(TClass::ENewType) const (in /usr/local/root_svn/lib/libCore.so)
>>>> ==17737== by 0x100FEB2BF: TBufferFile::ReadObjectAny(TClass const*) (in /usr/local/root_svn/lib/libRIO.so)
>>>> ==17737== by 0x1000EF390: TBuffer& operator>><TObject>(TBuffer&, TObject*&) (in /usr/local/root_svn/lib/libCore.so)
>>>> ==17737== by 0x1000F2C22: TList::Streamer(TBuffer&) (in /usr/local/root_svn/lib/libCore.so)
>>>> ==17737== by 0x100FE8A18: TBufferFile::ReadFastArray(void**, TClass const*, int, bool, TMemberStreamer*, TClass const*) (in /usr/local/root_svn/lib/libRIO.so)
>>>> ==17737== by 0x1010A1864: int TStreamerInfo::ReadBuffer<char**>(TBuffer&, char** const&, int, int, int, int) (in /usr/local/root_svn/lib/libRIO.so)
>>>> ==17737== by 0x100FE9C15: TBufferFile::ReadClassBuffer(TClass const*, void*, int, unsigned int, unsigned int, TClass const*) (in /usr/local/root_svn/lib/libRIO.so)
>>>> ==17737== by 0x101363C23: TH1::Streamer(TBuffer&) (in /usr/local/root_svn/lib/libHist.so)
>>>> ==17737== ==17737== 69,739,543 (823,176 direct, 68,916,367 indirect) bytes in 999 blocks are definitely lost in loss record 45,810 of 45,811
>>>> ==17737== at 0x1000146CE: operator new(unsigned long) (vg_replace_malloc.c:261)
>>>> ==17737== by 0x1000386C9: TStorage::ObjectAlloc(unsigned long) (in /usr/local/root_svn/lib/libCore.so)
>>>> ==17737== by 0x100233BB4: TObject::operator new(unsigned long) (in /usr/local/root_svn/lib/libCore.so)
>>>> ==17737== by 0x101A9EA7E: ROOT::new_TCanvas(void*) (in /usr/local/root_svn/lib/libGpad.so)
>>>> ==17737== by 0x10010AAA5: TClass::New(TClass::ENewType) const (in /usr/local/root_svn/lib/libCore.so)
>>>> ==17737== by 0x101013FBB: TKey::ReadObj() (in /usr/local/root_svn/lib/libRIO.so)
>>>> ==17737== by 0x100FF5AEE: TDirectoryFile::Get(char const*) (in /usr/local/root_svn/lib/libRIO.so)
>>>> ==17737== by 0x100000EFC: main (test.C:19)
>>>> ==17737== ==17737== LEAK SUMMARY:
>>>> ==17737== definitely lost: 859,176 bytes in 1,222 blocks
>>>> ==17737== indirectly lost: 85,444,368 bytes in 14,771 blocks
>>>> ==17737== possibly lost: 387,824 bytes in 1,534 blocks
>>>> ==17737== still reachable: 9,549,367 bytes in 84,421 blocks
>>>> ==17737== suppressed: 852,204 bytes in 23,733 blocks
>>>> ==17737== Reachable blocks (those to which a pointer was found) are not shown.
>>>> ==17737== To see them, rerun with: --leak-check=full --show-reachable=yes
>>>> ==17737== ==17737== For counts of detected and suppressed errors, rerun with: -v
>>>> ==17737== Use --track-origins=yes to see where uninitialised values come from
>>>> ==17737== ERROR SUMMARY: 705 errors from 705 contexts (suppressed: 1692 from 1692)
>>>>
>>>> Regards,
>>>>
>>>> --
>>>> OKUMURA, Akira oxon@{astro.isas.jaxa.jp,stanford.edu}
>>>> Institute of Space and Astronautical Science (ISAS/JAXA)
>>>> Now at KIPAC/SLAC/Stanford
>>>> Varian Physics #306
>>>> 382 Via Pueblo Mall, MC 406 Stanford, CA94305
>>>> TEL 650-736-0971/FAX 650-724-5065
>>>> Skype : okumura.akira
>>>>
>>>>
>>>> On 2010/09/08, at 14:31, Claudi Astres wrote:
>>>>
>>>>
>>>>> Hi Akira,
>>>>> You could use "valgrind" utility to check whether the problem is really a memory leak. Maybe you already knew it.
>>>>> Valgrind has become crucial for me: http://valgrind.org/
>>>>>
>>>>> Regards.
>>>>> Claudi
>>>>>
>>>>>
>>>>> El 08/09/2010, a las 22:14, OKUMURA, Akira escribió:
>>>>>
>>>>>
>>>>>> Hello ROOTers,
>>>>>>
>>>>>> This question may be a very basic one but I could not find similar questions on the web.
>>>>>>
>>>>>> http://slac.stanford.edu/~oxon/tmp.tgz
>>>>>>
>>>>>> This tgz file includes a .root file and a very simple script which opens TFile 10000 times. When I execute the script,
>>>>>>
>>>>>> root [0] .x test.C
>>>>>>
>>>>>> the memory usage of the process becomes more than 1 GB while all TFile instances are closed.
>>>>>>
>>>>>> The .root file was created via TPad::SaveAs, as follows.
>>>>>>
>>>>>> root [0] TCanvas can("can", "can")
>>>>>> root [1] TH2D* h = new TH2D("h", "h", 100, -3, 3, 100, -3, 3)
>>>>>> root [2] h->FillRandom("gaus", 1000000)
>>>>>> root [3] h->Draw()
>>>>>> root [4] can.SaveAs("aho.root")
>>>>>>
>>>>>> How can I suppress this large memory consumption? I am not sure if this is an intended behavior or memory leak.
>>>>>>
>>>>>> I am using svn trunk on Snow Leopard and SL 5.
>>>>>>
>>>>>> Regards,
>>>>>>
>>>>>> --
>>>>>> OKUMURA, Akira oxon@{astro.isas.jaxa.jp,stanford.edu}
>>>>>> Institute of Space and Astronautical Science (ISAS/JAXA)
>>>>>> Now at KIPAC/SLAC/Stanford
>>>>>> Varian Physics #306
>>>>>> 382 Via Pueblo Mall, MC 406 Stanford, CA94305
>>>>>> TEL 650-736-0971/FAX 650-724-5065
>>>>>> Skype : okumura.akira
>>>>>>
>>>>>>
>>>>
Received on Thu Sep 09 2010 - 19:32:10 CEST
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