[ROOT] compiled/interpreted class inheritance

From: Michael Alan Mazur (mazur@SLAC.stanford.edu)
Date: Mon Mar 31 2003 - 00:59:05 MEST 

hi all,

i'm running root 3.02.07 (also tried 3.03.05) on RHL7.2... i have a class
representing a particle which inherits from TObject, and i run my code in
CINT. i always get (and usually ignore) the warning:

"!!!There are some limitations regarding compiled/interpreted class
inheritance"

is one of these known limitations that creating a TIter to iterate over a
TList of these objects causes memory problems?

i have a TList containing my particle class, *leptonList, and i have two
TH1* hpe and hpmu. these objects have all been created, and the pointers
point to valid memory locations at the start of this code.

in my main loop, i have the following code, which creates a TIter and
dumps all the pointers for debugging:

cout << "    before creating TIter " << (void*)hpmu <<" "<<
  (void*)hpe << endl;
cout << "    before, leptonList =  " << (void*)leptonList << endl;
TIter iterLep(leptonList);
cout << "    after  creating TIter " << (void*)hpmu <<" "<<
  (void*)hpe << endl;
cout << "    after,  leptonList =  " << (void*)leptonList << endl;
cout << "    &iterLep =            " << (void*)&iterLep << endl;



and, when i run this, i get the output below... the first time through the
loop is okay, but the second time through, creating the TIter changes the
pointers to the list itself and to two TH1 objects which have no
connection to the TList or the interpreted class at all... it then crashes
when i try to access one of the corrupt TH1 pointers.

is this something people have seen before? any suggestions on what to do
in this case?

thanks,
-michael


root [3] t.Loop("test.root",10)
beginning event 0
  examining B+ 1 of 2
    before creating TIter 0x91f4160 0x91e7850
    before, leptonList =  0x9129ac0
    after  creating TIter 0x91f4160 0x91e7850
    after,  leptonList =  0x9129ac0
    &iterLep =            0x8f85e48
  examining B+ 2 of 2
    before creating TIter 0x91f4160 0x91e7850
    before, leptonList =  0x9129ac0
    after  creating TIter 0x22 0x87eecf8
    after,  leptonList =  0x4050fae4
    &iterLep =            0x8d58df0

 *** Break *** segmentation violation
Root > Function Loop() busy flag cleared

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