c_cpp threads.c

Posted 2021-05-14

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <zconf.h>


#define LEN 4
pthread_t tid[LEN];

struct Mat {
    double **macierz;
    int r;
    int c;
};

struct Result {
    struct Mat *mat1;
    struct Mat *mat2;
    struct Mat *result;
    int id;
    int poczatek[LEN];
    int koniec[LEN];
};

void print_matrix(double **A, int m, int n) {
    int i, j;
    printf("[");
    for (i = 0; i < m; i++) {
        for (j = 0; j < n; j++) {
            printf("%f ", A[i][j]);
        }
        printf("\n");
    }
    printf("]\n");
}

void *multiply(void *arg) {
    pthread_t id = pthread_self();

    struct Result *res = (struct Result *) arg;

    int i, j, k;
    double s;
    for (i = res->poczatek[res->id]; i < res->koniec[res->id]; i++) {
        for (j = 0; j < res->mat2->r; j++) {
            s = 0;
            for (k = 0; k < res->mat2->c; k++) {
                s += res->mat1->macierz[i][k] * res->mat2->macierz[k][j];
            }
            res->result->macierz[i][j] = s;
        }
    }
    print_matrix(res->result->macierz, res->result->r, res->result->c);
}



struct Mat *wczytaj(char *filename) {
    FILE *fpa;
    double **A;
    int ma, na;
    int i, j;
    double x;

    fpa = fopen(filename, "r");
    if (fpa == NULL) {
        perror("błąd otwarcia pliku");
        exit(-10);
    }

    fscanf(fpa, "%d", &ma);
    fscanf(fpa, "%d", &na);


    printf("pierwsza macierz ma wymiar %d x %d, a druga ", ma, na);


    /*Alokacja pamięci*/
    A = malloc(ma * sizeof(double));
    for (i = 0; i < ma; i++) {
        A[i] = malloc(na * sizeof(double));
    }

    for (i = 0; i < ma; i++) {
        for (j = 0; j < na; j++) {
            fscanf(fpa, "%lf", &x);
            A[i][j] = x;
        }
    }

    printf("A:\n");
    print_matrix(A, ma, na);

    struct Mat *result = (struct Mat *) malloc(sizeof(struct Mat));
    result->macierz = A;
    result->r = ma;
    result->c = na;

    return result;
}

int main(void) {
    struct Mat *m1 = wczytaj("A.txt");
    struct Mat *m2 = wczytaj("B.txt");
    struct Mat *results = (struct Mat *) malloc(sizeof(struct Mat));

    double **C;
    int i = 0;
    int err;

    /*Macierz na wynik*/
    C = malloc(m1->c * sizeof(double));
    for (i = 0; i < m1->c; i++) {
        C[i] = malloc(m2->r * sizeof(double));
    }
    results->macierz = C;
    results->r = m1->c;
    results->c = m2->r;

    struct Result *result = (struct Result *) malloc(sizeof(struct Result));
    result->mat1 = m1;
    result->mat2 = m2;
    result->result = results;

    for (int j = 0; j < LEN; ++j) {
        result->poczatek[j] = (result->mat1->r / LEN * j);
        result->koniec[j] = result->mat1->r / LEN + (result->mat1->r / LEN * j) - 1;
        printf("Poczatek %d, koniec %d\n", result->poczatek[j], result->koniec[j]);
    }

    while (i < LEN) {
        result->id = i;
        err = pthread_create(&(tid[i]), NULL, &multiply, (void *) result);
        if (err != 0)
            printf("\ncan't create thread :[]");
        else
            printf("\n Thread created successfully\n");

        i++;
    }

    for(i= 0; i < LEN; i++){
        pthread_join(tid[i], NULL);
    }

    print_matrix(result->result->macierz, result->result->r, result->result->c);



    sleep(5);
    return 0;
}