[G14_run] Bug in rootbeer.

[Franz Klein]

Dao,
thanks for pointing out the missing initialization of fError (in 
src/TDST.cxx).
I added this statement in /home/clasg14/rootbeer2.1/src and recompiled 
rootbeer and the dstmakers used for pass1/v1.

Those who used the tarball in /home/clasg14/rootbeer2.1.1.tar.gz, this 
was already corrected (some time ago);
others might reinstall their own rootbeer or correct the line in 
src/TDST.cxx.

The observed problems with skimmed DSTs from pass1/v1 cooking are not 
due to this bug. I reran dstmaker_n2pi over the files Irene sent me last 
night and got no zombie. There are more zombies in other skims (I will 
see to that shortly using a script to recreate the skims, of course it 
would be better if I can reproduce the crash in an interactive session ...).

If there is no objection, I'd like to continue the cooking this weekend.

Greetings,
Franz

On 04/09/2014 12:19 PM, daoh at andrew.cmu.edu wrote:
> Dear collaborators,
>
> If you are using rootbeer for analysis, your code probably has a small
> bug. The bug causes your code to terminate because it thinks the current
> DST root file is a zombie file. The problem lies inside a very innocent
> lines of code:
>
>
> if((rootbeer=createBeerObject(inFile))==NULL) return;   // create rootbeer
> object, should use continue, not return.
>
> if you go to src/RootBeerUtil.cxx (this folder inside rootbeer), you would
> see the how the createBeerObject function defined.
> If you see the followings, then we have the same version:
>
>
> //************************* createBeerObject()
> ********************************
> TRootBeer *createBeerObject(char *bankFileName){
>    Int_t error=0;
>
>    //work out whether it's a bos file or a root file and create the
>    //appropriate object
>    if((strstr(bankFileName,".root"))!=NULL){
>      rootbeer = new TDST(bankFileName,bankAddress,nBankTypes); //<--problem
> is here
>    }
>    else{
>      rootbeer = new TBos(bankFileName,bankAddress,nBankTypes);
>    }
>    error=rootbeer->GetError(); //<--problem is here
>    if(error){
>      delete rootbeer;
>      return NULL;
>    }
>    else  return rootbeer;
> }
>
>
> The variable error is used as a flag to indicate whether the current root
> file is Zombile or not.
> Open the file TDST.cxx (the same directory), you would see that
> rootbeer->GetError() returns fError.  For some reasons, fError can have a
> non zero value, even though the file is NOT zombie. The problem is that
> the fError needs to be initialized before it can be used (the below
> function is a constructor). So just add this line fError=0; //-->ADDING
> THIS LINE to the function below.
>
> TDST::TDST(const char *bosFile, void* addresses, int total)
> {
> // Create one TDST object and open the 1st data file
>
>    fError=0; //-->ADDING THIS LINE
>    fBankAddr = (struct addressBanks_t*)addresses;        //all info about
> bank variables
>    fBankTotal = total;                                   //total no of
> defined banks
>    fDSTfile = new TFile(bosFile);                        //open DST input file
>    if(fDSTfile->IsZombie()){                             //if failed return
> error
>      fprintf(stderr,"Zombie file? \n");
>      fError=1;
>      return;
>    }
>    fBankTree = (TTree*)gDirectory->Get("bankTree");      //get the tree
>    if(fBankTree==NULL){
>      fprintf(stderr,"failed to open banktree \n");
>      return;
>    }
>    fBigBuff = new char[100000];          //create a 100k buffer to hold the
> event
>    fDataStartAddr = fBigBuff;            //init the data pointer
>    fDataAddr = fBigBuff;                 //ditto
>    fServedBankNo=0;                      //init the no of banks being handled
>    fEntry=0;
>    fMaxEntry=(int)fBankTree->GetEntries(); //get the no of events in the
> DST file
>    for(int n=0;n<fBankTotal;n++){        //init the status of all banks to
> zero
>        fBankStatus[n]=0;
>    }
> }
>
>
>
> If you still have same problems, then the root file is truely a zombie!
> But it is a good practice to initialize variables before using them. Btw,
> you need to reinstall rootbeer.
>
> Sincerely,
> Dao Ho
>
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> G14_run at jlab.org
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-- 
===============================================================
                   Franz J. Klein, Associate Professor
                   CUA, Department of Physics
                   Washington, DC 20064
   office: Hannan Hall 206          phone: 202-319-6190
   or: Jefferson Lab,CC F-243       phone: 757-269-6672
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