Dear RootTalk,
This is a follow-up question to an earlier post:
http://root.cern.ch/phpBB2/viewtopic.php?t=9685
I would like to make a tree with a branch that holds TClonesArrays. The TClonesArrays contain a class that derives from TNamed and this time contain two new data members: a float (_value) and a TTimeStamp pointer (*_timeStamp).
Below, I show code that writes/reads the TTree. Again, I modeled this code after $ROOTSYS/tutorials/tree/tcl.C. The tree creation step appears to run correctly (doesn’t crash). The code to read the tree compiles, but seg-faults at runtime on tree->GetEvent(0) executes.
Any suggestions as to why this code fails? Perhaps the problem relates to streaming pointer data members? Apologies if this answer is in the User Guide. I was not able to find it there.
Also, a few other questions:
-
In the tree writing step, is the TClonesArray->BypassStreamer() required (it was in the tutorial example)? From the TCA class documentation, it seems that this is only important when using different split levels (not the case here).
-
In the tree reading step, is the Branch()->SetAutoDelete(kFALSE) required?
-
In the MyClass.hh file, should I have included a //-> after TTimeStamp declaration:
TTimeStamp *_timeStamp; //->
I tried this as well, but still got the seg fault when reading the tree.
MyClass.hh[code]
#ifndef MYCLASS_HH
#define MYCLASS_HH
#include “TROOT.h”
#include “TNamed.h”
#include “TTimeStamp.h”
class TString;
class MyClass : public TNamed {
public:
MyClass();
MyClass(TString name, TString title);
MyClass(const MyClass &other);
virtual ~MyClass();
virtual void SetValue(Float_t newVal) {_value = newVal; }
virtual void SetTimeStamp(TTimeStamp newTime) { _timeStamp = newTime; }
virtual Float_t GetValue() { return _value; }
virtual TTimeStamp GetTimeStamp() { return _timeStamp; }
void print();
private:
Float_t _value; // value of parameter
TTimeStamp *_timeStamp; // time the value was obtained
ClassDef(MyClass,1)
};
#endif[/code]
MyClass.cc[code]#include “MyClass.hh”
#include “TROOT.h”
#include
using std::cout;
using std::endl;
ClassImp(MyClass)
MyClass::MyClass(TString name, TString title) : TNamed(name, title) {}
MyClass::MyClass(const MyClass &other) : TNamed(other), _value(other._value) {
//cout << “copy ctor” << endl;
//cout << "other._value = " << other._value << endl;
//cout << "_value = " << _value << endl;
}
MyClass::MyClass() { cout << “def ctor” << endl; }
MyClass::~MyClass() {}
void MyClass::print() {
cout << "MyClass: name, title, value, timestamp = "
<< GetName() << ", " << GetTitle() << ", "
<< GetValue() << ", " << GetTimeStamp()->GetTime() << endl;
}[/code]
testtcaptr.cxx[code]
#include
#include “TClonesArray.h”
#include “TFile.h”
#include “TTree.h”
#include “TBranch.h”
#include “TString.h”
#include “TTimeStamp.h”
#include “…/MyClass.hh”
using namespace std;
void testtcawrite() {
TFile *logfile = new TFile(“junk.root”, “RECREATE”);
logfile->SetCompressionLevel(1); // is this required?
TTree *logtree = new TTree(“logtree”, “environment”);
TClonesArray *tca_ptr = new TClonesArray(“MyClass”);
logtree->Branch(“myBranch”, “TClonesArray”, &tca_ptr, 32000, 0);
tca_ptr->BypassStreamer(); // is this necessary? (taken from tutorial…)
for (Int_t ev=0; ev<5; ev++) {
tca_ptr->Clear();
Int_t nentries = 3;
for (Int_t ii=0; ii<nentries; ii++) {
MyClass myClass(“myClass”, “myClass entry”);
myClass.SetValue(ii+1);
TTimeStamp *myTime = new TTimeStamp();
myClass.SetTimeStamp(myTime);
new ( (*tca_ptr)[ii] ) MyClass(myClass);
}
logtree->Fill();
}
logtree->Print();
logtree->Write();
logfile->Close();
}
void testtcaread() {
TFile *f = new TFile(“junk.root”);
TTree t = (TTree)f->Get(“logtree”);
TClonesArray *tca = new TClonesArray(“MyClass”);
t->GetBranch(“myBranch”)->SetAutoDelete(kFALSE); // from tutorial…
t->SetBranchAddress(“myBranch”, &tca);
Int_t nentries = (Int_t)(t->GetEntries());
cout << "t->GetEntries() = " << nentries << endl;
tca->Clear();
cout << “t->GetEvent(0)” << endl;
t->GetEvent(0); // crashes…
}[/code]
Here’s the output I get:
root [0] .L testtcaptr.cxx+
root [1] testtcawrite()
def ctor
******************************************************************************
*Tree :logtree : environment *
*Entries : 5 : Total = 1942 bytes File Size = 0 *
* : : Tree compression factor = 1.00 *
******************************************************************************
*Br 0 :myBranch : *
*Entries : 5 : Total Size= 1649 bytes One basket in memory *
*Baskets : 0 : Basket Size= 32000 bytes Compression= 1.00 *
*............................................................................*
root [2] testtcaread()
t->GetEntries() = 5
t->GetEvent(0)
def ctor
def ctor
def ctor
*** Break *** segmentation violation
(no debugging symbols found)
Attaching to program: /proc/26837/exe, process 26837
(no debugging symbols found)...done.
(no debugging symbols found)...done.
(no debugging symbols found)...done.
(no debugging symbols found)...done.
[Thread debugging using libthread_db enabled]
[New Thread 0xb7f438e0 (LWP 26837)]
(no debugging symbols found)...done.
(no debugging symbols found)...done.
(no debugging symbols found)...done.
(no debugging symbols found)...done.
(no debugging symbols found)...done.
(no debugging symbols found)...done.
0x007a8402 in __kernel_vsyscall ()
#1 0x0608bdf3 in __waitpid_nocancel () from /lib/libc.so.6
#2 0x0603106b in do_system () from /lib/libc.so.6
#3 0x0544687d in system () from /lib/libpthread.so.0
#4 0x00cdfb2b in TUnixSystem::Exec () from /usr/local/cern/root/lib/libCore.so
#5 0x00ce469b in TUnixSystem::StackTrace () from /usr/local/cern/root/lib/libCore.so
#6 0x00ce3695 in TUnixSystem::DispatchSignals () from /usr/local/cern/root/lib/libCore.so
#7 0x00ce3827 in SigHandler () from /usr/local/cern/root/lib/libCore.so
#8 0x00cdcc5d in sighandler () from /usr/local/cern/root/lib/libCore.so
#9 <signal handler called>
#10 0x00f07976 in ROOT::delete_TTimeStamp () from /usr/local/cern/root/lib/libCore.so
#11 0x00c556c5 in TClass::Destructor () from /usr/local/cern/root/lib/libCore.so
#12 0x00b8cf36 in TBuffer::ReadFastArray () from /usr/local/cern/root/lib/libCore.so
#13 0x00cb164d in TStreamerInfo::ReadBuffer<char**> () from /usr/local/cern/root/lib/libCore.so
#14 0x00c7ee59 in TStreamerInfo::ReadBufferClones () from /usr/local/cern/root/lib/libCore.so
#15 0x00c2f3bf in TClonesArray::Streamer () from /usr/local/cern/root/lib/libCore.so
#16 0x02ddfd58 in TLeafObject::ReadBasket () from /usr/local/cern/root/lib/libTree.so
#17 0x02db18af in TBranch::ReadLeaves () from /usr/local/cern/root/lib/libTree.so
#18 0x02db2fa8 in TBranch::GetEntry () from /usr/local/cern/root/lib/libTree.so
#19 0x02dc5918 in TBranchObject::GetEntry () from /usr/local/cern/root/lib/libTree.so
#20 0x02df8a31 in TTree::GetEntry () from /usr/local/cern/root/lib/libTree.so
#21 0x06a1e2fa in testtcaread () from /home/jbattat/projects/DarkMatter/MaxCam/examples/./testtcaptr_cxx.so
#22 0x06a1e319 in G__fileuOEB8A__0_1650 ()
from /home/jbattat/projects/DarkMatter/MaxCam/examples/./testtcaptr_cxx.so
#23 0x0014d825 in Cint::G__ExceptionWrapper () from /usr/local/cern/root/lib/libCint.so
#24 0x00222d66 in G__call_cppfunc () from /usr/local/cern/root/lib/libCint.so
#25 0x001fbf58 in G__interpret_func () from /usr/local/cern/root/lib/libCint.so
#26 0x001f0525 in G__getfunction () from /usr/local/cern/root/lib/libCint.so
#27 0x001c76ae in G__getitem () from /usr/local/cern/root/lib/libCint.so
#28 0x001d6d38 in G__getexpr () from /usr/local/cern/root/lib/libCint.so
#29 0x00230bd8 in G__exec_function () from /usr/local/cern/root/lib/libCint.so
#30 0x00236080 in G__exec_statement () from /usr/local/cern/root/lib/libCint.so
#31 0x001b3d45 in G__exec_tempfile_core () from /usr/local/cern/root/lib/libCint.so
#32 0x001b4003 in G__exec_tempfile_fp () from /usr/local/cern/root/lib/libCint.so
#33 0x0024327f in G__process_cmd () from /usr/local/cern/root/lib/libCint.so
#34 0x00c53d64 in TCint::ProcessLine () from /usr/local/cern/root/lib/libCore.so
#35 0x00b7e224 in TApplication::ProcessLine () from /usr/local/cern/root/lib/libCore.so
#36 0x007836d0 in TRint::HandleTermInput () from /usr/local/cern/root/lib/libRint.so
#37 0x00782d3d in TTermInputHandler::Notify () from /usr/local/cern/root/lib/libRint.so
#38 0x00784cb6 in TTermInputHandler::ReadNotify () from /usr/local/cern/root/lib/libRint.so
#39 0x00ce335c in TUnixSystem::CheckDescriptors () from /usr/local/cern/root/lib/libCore.so
#40 0x00ce3970 in TUnixSystem::DispatchOneEvent () from /usr/local/cern/root/lib/libCore.so
#41 0x00c023b3 in TSystem::InnerLoop () from /usr/local/cern/root/lib/libCore.so
#42 0x00c038c7 in TSystem::Run () from /usr/local/cern/root/lib/libCore.so
#43 0x00b7d37c in TApplication::Run () from /usr/local/cern/root/lib/libCore.so
#44 0x00784ab9 in TRint::Run () from /usr/local/cern/root/lib/libRint.so
#45 0x08048d20 in main ()
The program is running. Quit anyway (and detach it)? (y or n) [answered Y; input not from terminal]
Detaching from program: /proc/26837/exe, process 26837
Root > Thank you,
James