mcr/shared_memories/Consumer_Diego.C

#include <Riostream.h>
#include "TROOT.h"
#include "TSystem.h"
#include "TCanvas.h"
#include "TH1F.h"
#include "TH2F.h"
#include "TProfile.h"
#include "TRandom.h"
#include "TMapFile.h"
#include "TSystem.h"
#include "TString.h"

#include <sys/types.h>
#include <sys/file.h>
#include <stdio.h>


//#include <unistd.h>
#include <fcntl.h>

Bool_t CheckProducerMessages(const Char_t *sh_msg_file){

  Bool_t can_act = kFALSE;
  

  FILE *f_sh = fopen(sh_msg_file,"r");
  if(!f_sh){
    cout << "Messages shared file not found...waiting" << endl;
    return kFALSE;
  }
  
  Char_t msg[10];
  Int_t scan = fscanf(f_sh,"%s",msg);
  cout << "scan: " << scan << " ---> msg: \"" << msg << "\"" << endl; 


  if(!strcmp(msg,"go")) can_act = kTRUE;
  else if(!strcmp(msg,"wait")) can_act = kFALSE;
  fclose(f_sh);

  return can_act;
}

void Consumer_Diego(){

  TString mnam = TString(gSystem->Getenv("FND_SHR"));
  mnam+="/hsimple.map";
 
  TString msgnam = TString(gSystem->Getenv("FND_SHR"));
  msgnam+="/shared_msg.txt";
  // Open the memory mapped file "hsimple.map" in "READ" (default) mode.

  

  // Create pointers to the objects in shared memory.
  TH1F *h1 = 0;

  TMapFile *mfile = 0;
  Int_t i = 0;
  while (1) {
    while(gSystem->AccessPathName(mnam.Data())){
      cout << "Shared memory not found! retrying..." << endl;
      gSystem->Sleep(100);
    }
    while(!CheckProducerMessages(msgnam.Data())){
      cout << "shared files busy...producer message" << endl;
      gSystem->Sleep(100);
    }
    mfile = TMapFile::Create(mnam.Data());

    // Print status of mapped file and list its contents
    if(i==0){
      cout << "mfile is: " << mfile << endl;
      mfile->Print();
      mfile->ls();
    }
    h1    = (TH1F *) mfile->Get("h1", h1);
    cout << "entries: " << h1->GetEntries() << endl; 
    
    gSystem->Sleep(10); 
    i++;
    //    cout << "Closing mapfile" << endl; 
    mfile->Close();
    //    cout << "done: setting pointer to zero" << endl; 
    mfile = 0;
    //    cout << "done." << endl; 
  }
}

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