WCudaMSE/Student_OMP/src/cpp/core/omp/02_pi/04_pi_entrelacer_atomic.cpp

   1 #include <omp.h>
   2 #include "00_pi_tools.h"
   3 #include "OmpTools.h"
   4
   5 /*----------------------------------------------------------------------*\
   6  |*                     Declaration                                     *|
   7  \*---------------------------------------------------------------------*/
   8
   9 /*--------------------------------------*\
  10  |*             Imported                *|
  11  \*-------------------------------------*/
  12
  13
  14 /*--------------------------------------*\
  15  |*             Public                  *|
  16  \*-------------------------------------*/
  17
  18 bool isPiOMPEntrelacerAtomic_Ok(int n);
  19
  20 /*--------------------------------------*\
  21  |*             Private                 *|
  22  \*-------------------------------------*/
  23
  24 static double piOMPEntrelacerAtomic(int n);
  25
  26 /*----------------------------------------------------------------------*\
  27  |*                     Implementation                                  *|
  28  \*---------------------------------------------------------------------*/
  29
  30 /*--------------------------------------*\
  31  |*             Public                  *|
  32  \*-------------------------------------*/
  33
  34 bool isPiOMPEntrelacerAtomic_Ok(int n)
  35     {
  36     return isAlgoPI_OK(piOMPEntrelacerAtomic,  n, "Pi OMP Entrelacer atomic");
  37     }
  38
  39 /*--------------------------------------*\
  40  |*             Private                 *|
  41  \*-------------------------------------*/
  42
  43 /**
  44  * Bonne performance, si!
  45  */
  46 double piOMPEntrelacerAtomic(int n)
  47     {
  48     const int NB_THREAD = OmpTools::setAndGetNaturalGranularity();
  49     const double DX = 1.0/(double)n;
  50     double sum = 0;
  51
  52     #pragma omp parallel
  53         {
  54         double xs;
  55         double sumLocalThread = 0;
  56         const int TID = OmpTools::getTid();
  57         int s = TID;
  58
  59         while (s < n)
  60             {
  61             xs = s * DX;
  62             sumLocalThread += fpi(xs);
  63             s += NB_THREAD;
  64             }
  65
  66         #pragma omp atomic
  67             sum += sumLocalThread;
  68
  69         }
  70
  71     return sum * DX;
  72     }
  73
  74 /*----------------------------------------------------------------------*\
  75  |*                     End                                             *|
  76  \*---------------------------------------------------------------------*/
  77