[ROOT] problem filling TTrees in a standalone program

From: FECHNER Maximilien (mfechner@hep.saclay.cea.fr)
Date: Mon Feb 17 2003 - 17:06:21 MET 

Dear ROOTers,

I use a linux computer with the following compiler

gcc version 2.96 20000731 (Red Hat Linux 7.1 2.96-81).

I have encountered segfaults crashes in the program enclosed in the
attachment when I used the ROOT binaries present on the system (dec 2002
version).
THe program crashed in method TTree::Fill, TTree::Print and
TObject::Write().
So I decided to upgrade to ROOT 3.05.02.I have done so,the programs compiles
fine, but it now segfaults
almost immediately at a different location.

The stack trace is :
*** Break *** segmentation violation
 Generating stack trace...
 0x4021338f in TUnixSystem::StackTrace(void) + 0x25b from
/home/daplxa119/mnt/mfechner/root/lib/libCore.so
 0x40211f82 in TUnixSystem::DispatchSignals(ESignals) + 0xb2 from
/home/daplxa119/mnt/mfechner/root/lib/libCore.so
 0x4021112b in TWebFile::GetSize(void) const + 0x9b from
/home/daplxa119/mnt/mfechner/root/lib/libCore.so
 0x40214c61 in TUnixSystem::GetSockOpt(int, int, int *) + 0x339 from
/home/daplxa119/mnt/mfechner/root/lib/libCore.so
 0x415b9935 in sigaction at
/usr/src/bs/BUILD/glibc-2.2.2/linuxthreads/signals.c:97 from
/lib/i686/libpthread.so.0
 0x413bd648 in killpg at
/usr/src/bs/BUILD/glibc-2.2.2/signal/../sysdeps/posix/killpg.c:34 from
/lib/i686/libc.so.6
 0x08048feb in main + 0xdb from ./Range.exe
 0x413ac177 in __libc_start_main at
/usr/src/bs/BUILD/glibc-2.2.2/csu/../sysdeps/generic/libc-start.c:129 from
/lib/i686/libc.so.6
 0x08048ad1 in _start + 0x21 from ./Range.exe
Abandon (core dumped)



Analysis of the core dump gives the following output with gbd's
'backtrace' command :
(gdb) bt
#0  0x413bd801 in __kill () from /lib/i686/libc.so.6
#1  0x413bd5da in raise (sig=6) at ../sysdeps/posix/raise.c:27
#2  0x413bed82 in abort () at ../sysdeps/generic/abort.c:88
#3  0x40213134 in TUnixSystem::StackTrace () from
/home/daplxa119/mnt/mfechner/root/lib/libCore.so
#4  0x40212028 in TUnixSystem::DispatchSignals () from
/home/daplxa119/mnt/mfechner/root/lib/libCore.so
#5  0x4021112b in SigHandler () from
/home/daplxa119/mnt/mfechner/root/lib/libCore.so
#6  0x40214c61 in sighandler () from
/home/daplxa119/mnt/mfechner/root/lib/libCore.so
#7  0x415b9935 in pthread_sighandler (signo=11, ctx=
      {gs = 7, __gsh = 0, fs = 0, __fsh = 0, es = 43, __esh = 0, ds = 43,
__dsh = 0, edi = 3221222460, esi = 1073834852, ebp = 3221222248, esp =
3221222080, ebx = 134522336, edx = 1635282324, ecx = 4, eax = 134517747,
trapno = 14, err = 4, eip = 134516109, cs = 35, __csh = 0, eflags = 66050,
esp_at_signal = 3221222080, ss = 43, __ssh = 0, fpstate = 0xbffff040,
oldmask = 2147483648, cr2 = 1635282324}) at signals.c:97
#8  <signal handler called>
#9  0x08048d8d in DataFill (Arb=0x8698a40, typ=0x804938d "e") at
Range.cpp:53
#10 0x08048feb in main () at Range.cpp:77
#11 0x413ac177 in __libc_start_main (main=0x8048f10 <main>, argc=1,
ubp_av=0xbffff43c, init=0x8048930 <_init>, fini=0x8049290 <_fini>,
    rtld_fini=0x4000e184 <_dl_fini>, stack_end=0xbffff42c) at
../sysdeps/generic/libc-start.c:129

My source code is ( see attachments) :


struct EnergyLossData {
  double energy;
  double dedx;
  double range;
};

void DataFill(TTree* Arb, const char* typ)
{
  static char* MCPATH = "MCPATH";
  char* datapath = getenv(MCPATH);
  char* filename;char line[45];
  EnergyLossData ElData; double a1,a2;
  FILE* dat;

  if (datapath == NULL) {
    fprintf(stderr,"Environment variable %s is not defined.\n",MCPATH);
    fprintf(stderr,"Make %s point to the directory which holds all data
tables for de/dx, etc..\n",MCPATH);
    exit(2);
  }
  if ( strcmp(typ,"e") == 0 ) {
    sprintf(filename,"%s/electron_loss.dat",datapath);a2=
ELEC_MASS;printf("%s\n",filename);fflush(stdout);}
  else if ( strcmp(typ,"m")  == 0) {
    sprintf(filename,"%s/muon_loss.dat",datapath);a2 =
MUON_MASS;printf("%s\n",filename); fflush(stdout);}
  else {
    fprintf(stderr,"Option %s not recognized\n",typ);
    fprintf(stderr,"Exiting to system\n");
    exit(2);
  }
  dat = fopen(filename,"r");
  Arb->Branch("Energy",&ElData.energy,"Energy/D");
  Arb->Branch("Dedx",&ElData.dedx,"Dedx/D");
  Arb->Branch("Range",&ElData.range,"Range/D");
  if (dat != NULL)
    {
      while ( fgets(line,45,dat)) {
        sscanf(&line[0],"%lG",&a1);
        ElData.energy = a1 + a2;
        sscanf(&line[9],"%lG",&ElData.dedx);
        sscanf(&line[19],"%lG",&ElData.range);
        printf("%lG %lG %lG\n",ElData.energy,ElData.dedx,ElData.range);
        fflush(stdout);
        Arb->Fill();
      }
      Arb->Print();
      //Arb->Write();
      fclose(dat);
    }
}

int main()
{
  TFile* f1 = new TFile("elec.root","recreate");
  TTree* t1 = new TTree("elec_loss","Energy loss table for electrons");
  DataFill(t1,"e");
  t1->Write();
  f1->Write();
  f1->Close();
  TFile* f2 = new TFile("muon.root","recreate");
  TTree* t2 = new TTree("muon_loss","Energy loss table for muons");
  DataFill(t2,"m");
  t2->Write();
  f2->Write();
  f2->Close();
  return 0;
}


I am quite puzzled (problem with pthread ?).
Do you have any idea what I am doing wrong ?

Thanking you in advance,

Yours

Maximilien Fechner

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