Centre Blaise Pascal » Bench4GPU

/******************************************************************************

* FILE: hello.c

* DESCRIPTION:

*   A "hello world" Pthreads program.  Demonstrates thread creation and

*   termination.

* AUTHOR: Blaise Barney

* LAST REVISED: 08/09/11

******************************************************************************/

#include <pthread.h>

#include <stdio.h>

#include <stdlib.h>

#include <math.h>

#include <stdio.h>

#define NUM_THREADS        4

struct thread_data

{

  int thread_id;

  unsigned int seed_w;

  unsigned int seed_z;

  unsigned int iterations;

  unsigned int inside;

};

struct thread_data thread_data_array[NUM_THREADS];

// Marsaglia RNG very simple implementation

#define znew  ((z=36969*(z&65535)+(z>>16))<<16)

#define wnew  ((w=18000*(w&65535)+(w>>16))&65535)

#define MWC   (znew+wnew)

#define SHR3  (jsr=(jsr=(jsr=jsr^(jsr<<17))^(jsr>>13))^(jsr<<5))

#define CONG  (jcong=69069*jcong+1234567)

#define KISS  ((MWC^CONG)+SHR3)

#define MWCfp MWC * 2.328306435454494e-10f

#define KISSfp KISS * 2.328306435454494e-10f

#define ITERATIONS 1000000000

int MainLoopGlobal(unsigned int iterations,unsigned int seed_w,unsigned int seed_z)

{

   unsigned int z=seed_z;

   unsigned int w=seed_w;

   int total=0;

   for (unsigned int i=0;i<iterations;i++) {

      float x=MWCfp ;

      float y=MWCfp ;

      // Matching test

      int inside=((x*x+y*y) < 1.0f) ? 1:0;

      total+=inside;

   }

   return(total);

}

void *MainLoopThread(void *threadarg)

{

  int taskid;

  unsigned int iterations,z,w,total=0;

  struct thread_data *my_data;

  my_data=(struct thread_data *) threadarg;

  taskid = my_data->thread_id;

  iterations = my_data->iterations;

  z = my_data->seed_z;

  w = my_data->seed_w;

  iterations = my_data->iterations;

  printf("Hello World! It's me, thread #%ld, with seeds (%i,%i) and %i !\n", taskid,z,w,iterations);

   for (unsigned int i=0;i<iterations;i++) {

      float x=MWCfp ;

      float y=MWCfp ;

      // Matching test

      int inside=((x*x+y*y) < 1.0f) ? 1:0;

      total+=inside;

   }

   printf("In #%ld, found %i inside\n",taskid,total);

   my_data->inside=total;

   pthread_exit(NULL);

}

int main(int argc, char *argv[])

{

pthread_t threads[NUM_THREADS];

int *taskids[NUM_THREADS];

int rc, t, sum;

sum=0;

for(t=0;t<NUM_THREADS;t++) {

  thread_data_array[t].thread_id = t;

  thread_data_array[t].iterations = ITERATIONS/NUM_THREADS;

  thread_data_array[t].seed_w = (t+1)<<4;

  thread_data_array[t].seed_z = (1048576*(t+1))>>4;

  thread_data_array[t].inside = 0;

  printf("Creating thread %d\n", t);

  rc = pthread_create(&threads[t], NULL, MainLoopThread, (void *) 

       &thread_data_array[t]);

  printf("%i inside\n", thread_data_array[t].inside);

  if (rc) {

    printf("ERROR; return code from pthread_create() is %d\n", rc);

    exit(-1);

    }

  }

pthread_exit(NULL);

}