include <stdlib.h>
#include <stdio.h>
#include <omp.h>
#include <time.h>
#include <sys/time.h>
static const long Num_To_Add = 1000000000;
static const double Scale = 10.0 / RAND_MAX;
long add_serial(const char *numbers) {
long sum = 0;
for (long i = 0; i < Num_To_Add; i++) {
sum += numbers[i];
}
return sum;
}
long add_parallel(const char *numbers) {
long sum = 0;
return sum;
}
int main() {
char *numbers = malloc(sizeof(long) * Num_To_Add);
long chunk_size = Num_To_Add / omp_get_max_threads();
#pragma omp parallel num_threads(omp_get_max_threads())
{
int p = omp_get_thread_num();
unsigned int seed = (unsigned int) time(NULL) + (unsigned int) p;
long chunk_start = p * chunk_size;
long chunk_end = chunk_start + chunk_size;
for (long i = chunk_start; i < chunk_end; i++) {
numbers[i] = (char) (rand_r(&seed) * Scale);
}
}
struct timeval start, end;
printf(“Timing sequential…n”);
gettimeofday(&start, NULL);
long sum_s = add_serial(numbers);
gettimeofday(&end, NULL);
printf(“Took %f secondsnn”, end.tv_sec – start.tv_sec + (double) (end.tv_usec – start.tv_usec) / 1000000);
printf(“Timing parallel…n”);
gettimeofday(&start, NULL);
long sum_p = add_parallel(numbers);
gettimeofday(&end, NULL);
printf(“Took %f secondsnn”, end.tv_sec – start.tv_sec + (double) (end.tv_usec – start.tv_usec) / 1000000);
printf(“Sum serial: %ldnSum parallel: %ld”, sum_s, sum_p);
free(numbers);
return 0;
}
