L5_Ex2_Pthread

# include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
#include <string.h>
#include <math.h>
#include <omp.h>

void *Exercitiul_2 (void *);
int n = 1024;
int p = 2;
int mod = 0;
int max_rep = 1;
float **a, *b, *c;

int main(int argc, char *argv[]) {
    int i, j, k, q, rep;
    int* params;
    pthread_t *ids;
    struct timeval t1, t2;
    if (argc >= 2) n = atoi(argv[1]);
    if (argc >= 3) p = atoi(argv[2]);
    if (argc >= 4) mod = atoi(argv[3]);
    if (argc >= 5) max_rep = atoi(argv[4]);
    a = (float**)malloc(sizeof(float)*n);
    b = (float*)malloc(sizeof(float)*n);
    c = (float*)malloc(sizeof(float)*n);

    for (i = 0; i < n; i++)
    {
        a[i] = (float*)malloc(sizeof(float)*n);
    }
    for (i = 0; i < n; i++) {
        b[i] = rand()/(float)RAND_MAX;
        c[i] = 0;
        for(j = 0; j < n; j++)
        {
            a[i][j] = rand()/(float)RAND_MAX;
        }
    }
    params = (int*)malloc(sizeof(int)*p);
    ids = (pthread_t*)malloc(sizeof(pthread_t)*p);
    gettimeofday(&t1, NULL);
    for (q = 0; q < p; q++)
    {
        params[q] = q;
        pthread_create(&ids[q], 0, Exercitiul_2, (void*)&params[q]);
    }
    for (q = 0; q < p; q++)
    {
        pthread_join(ids[q], 0);
    }

    gettimeofday(&t2, NULL);

    float tp = (t2.tv_sec - t1.tv_sec + 0.000001*(t2.tv_usec - t1.tv_usec));
    for (i = 0; i < n; i++)
        printf(" %f ", c[i]);
    printf("\n");
    printf("n=%d\np=%d\nTimp executie: %f\n", n, p, (float)tp);
    return 0;
}

void *Exercitiul_2(void *param)
{
    int i, j, k, first, last;
    int q = *(int*)param;
    int s = (int) n/p;
    first = q*s;
    last = first + s;
    for (i = first; i < last; i++)
        for(j = 0; j < n; j++)
        {
            c[i] += a[i][j]*b[j];
        }
    return 0;
}