#include <Riostream.h>
#include "TH1F.h"
#include "TH2F.h"
#include "TProfile.h"
#include "TRandom.h"
#include "TMapFile.h"

void Producer1(){
  // Histogram producer script. This script creates a memory mapped
  // file and stores three histogram objects in it (a TH1F, a TH2F and a
  // TProfile). It then fills, in an infinite loop (so use ctrl-c to
  // stop this script), the three histogram objects with random numbers.
  // Every 10 fills the objects are updated in shared memory.
  // Use the hcons.C script to map this file and display the histograms.
  
  gROOT->Reset();
  
  // Create a new memory mapped file. The memory mapped file can be
  // opened in an other process on the same machine and the objects
  // stored in it can be accessed.
  
  TMapFile *mfile = TMapFile::Create("hsimple.map","RECREATE", 100000,
			   "Demo memory mapped file with histograms");
  
  cout << "mfile is: " << mfile << endl;
  // Create a 1d, a 2d and a profile histogram. These objects will
  // be automatically added to the current directory, i.e. mfile.
  TH1F *hpx    = new TH1F("hpx","This is the px distribution",100,-4,4);
  TH2F *hpxpy  = new TH2F("hpxpy","py vs px",40,-4,4,40,-4,4);
  TProfile *hprof  = new TProfile("hprof","Profile of pz versus px",100,-4,4,0,20);
  
  // Set a fill color for the TH1F
  hpx->SetFillColor(48);
  // Print status of mapped file
  mfile->Print();
  mfile->ls();
  
  // Endless loop filling histograms with random numbers
  Float_t px, py, pz;
  int ii = 0;
  while (1) {
    gRandom->Rannor(px,py);
    pz = px*px + py*py;
    hpx->Fill(px);
    hpxpy->Fill(px,py);
    hprof->Fill(px,pz);
    if (!(ii % 10)) {
      mfile->Update();       // updates all objects in shared memory
      if (!ii) mfile->ls();  // print contents of mapped file after
    }                         // first update
    ii++;
   }
}