//+ Example of a simple script creating 3 threads.
// This script can only be executed via ACliC: .x threads.C++.
// Before executing the script, load the Thread library with:
//   gSystem->Load("libThread");
// This is not needed anymore due to the rootmap facility which
// automatically loads the needed libraries.
//Author: Victor Perevovchikov

#include "TThread.h"
#include <Riostream.h>
#include <TStopwatch.h>
#include <TRandom.h>
#include <TRandom3.h>
#include <TGraph.h>
#include <TAxis.h>
#include <TCanvas.h>

TCanvas *c1;
TGraph *gr;

double pi(long int pHodu, double jehla=1, double pruh=1)
{
    TRandom3 uhel(0);
    TRandom3 centrum(0);
    const double x=acos(0);
    int abc=0;
    double c, phi;
    int vyhovujici=0;
    for(abc=0; abc<pHodu; abc++)
    {
	c=pruh*centrum.Rndm();
	phi=0.5*jehla*cos(uhel.Uniform(-x,x));
	if(((c-phi)<=0)||((c+phi)>=1))
		vyhovujici++;
    }
if(vyhovujici==0)
return 0;
else
	return (2*(double)pHodu/(double)vyhovujici); //Odhad pi
	//return ((double)vyhovujici/(double)pHodu); //Odhad pravdepodobnosti
}

struct hodnoty
{
  int N;
  double *x;
  double *b;
  hodnoty(int n){
			N=n;
			b= new double[N];
			x= new double[N];
		for(int i=0; i<N; i++)
			x[i]=i;
		}
  hodnoty(const hodnoty &druhy)
  {
	for(int p=0; p<N; p++)
		{b[p]=druhy.b[p];
		x[p]=druhy.x[p];}  	
  }
};


void *handle1(void *a)
{
   hodnoty *tady = (hodnoty*) a;
   for (int i = 0; i < tady->N; i+=2) {

      tady->b[i]=pi(i);

   }
   return 0;
}

void *handle2(void *c)
{
   hodnoty *tady = (hodnoty*) c;
   for (int k = 1; k < tady->N; k+=2) {
      tady->b[k]=pi(k);
   }
   return 0;
}

void threads()
{
   TStopwatch stopky;
   stopky.ResetRealTime();
   hodnoty test(100000);
   cout<<test.N<<endl;
#ifdef __CINT__
   printf("This script can only be executed via ACliC: .x threads.C++\n");
   return;
#endif

   gDebug = 1;
   stopky.Start();
   printf("Starting Thread 1\n");
   TThread *h1 = new TThread("h1", handle1, (void*)&test);
   h1->Run();
   printf("Starting Thread 2\n");
   TThread *h2 = new TThread("h2", handle2, (void*)&test);
   h2->Run();
   TThread::Ps();
   h1->Join();
   TThread::Ps();
   h2->Join();
   TThread::Ps();
   TThread::Lock();
   stopky.Stop();
c1 = new TCanvas("c1","",1024,800);
gr = new TGraph(test.N,test.x,test.b);
gr->GetXaxis()->SetTitle("N[-]");
//gr->Fit("pol1"); //fit pro presny odhad hodnoty pi, pouze u stejneho poctu hodu..
gr->Draw("ap");
c1->Modified();
c1->SaveAs("abc.pdf");
cout<<stopky.RealTime()<<endl;
delete h1;
delete h2;
delete h3;
delete h4;
}