Multiplica Matrizes (pthreads)

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multiplicamatrizes.c
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 1 /*
 2 * multiplicamatrizes.c
 3 *
 4 * Copyright 2012 Thassae Lander Silva dos Santos <thassae@hotmail.com>
 5 *
 6 * This program is free software; you can redistribute it and/or modify
 7 * it under the terms of the GNU General Public License as published by
 8 * the Free Software Foundation; either version 2 of the License, or
 9 * (at your option) any later version.
 10 *
 11 * This program is distributed in the hope that it will be useful,
 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 14 * GNU General Public License for more details.
 15 *
 16 * You should have received a copy of the GNU General Public License
 17 * along with this program; if not, write to the Free Software
 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 19 * MA 02110-1301, USA.
 20 *
 21 *
 22 */
 23 
 24 #include <stdio.h>
 25 #include <stdlib.h>
 26 #include <pthread.h>
 27 
 28 #define MAX_THREADS 10 // Define o número máximo de threads
 29 #define N 10 // Define o "N" da matriz quadrada
 30 
 31 int A[N][N], B[N][N], C[N][N]; // Declaraçã o das matrizes que eu vou utiliz
ar
 32 
 33 void *multiplica(void *id) // Funçã o que eu quero paralelizar
 34 {
 35 int threadId = (int)id;
 36 int i,j,k;
 37 for (i = (threadId*(N/MAX_THREADS)); i < ((threadId+1)*(N/MAX_THREADS))
; i++)
 38 for (j = 0; j < N; j++)
 39 {
 40 C[i][j] = 0;
 41 for (k = 0; k < N; k++)
 42 C[i][j] += A[i][k] * B[k][j];
 43 }
 44 pthread_exit(NULL);
 45 }
 46 
 47 void preenche(int A[N][N], int m, int n) // Preenche matriz com '1'
 48 {
 49 int i,j;
 50 for (i = 0; i < m; i++)
 51 for (j = 0; j < n; j++)
 52 A[i][j] = 1;
 53 }
 54 
 55 void imprime(int A[N][N], int m, int n) // Exibe a matriz na tela
 56 {
 57 int i,j;
 58 for (i = 0; i < m; i++)
 59 {
 60 for (j = 0; j < n; j++)
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multiplicamatrizes.c
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 61 {
 62 printf("|%d|\t", A[i][j]);
 63 }
 64 printf("\n");
 65 }
 66 printf("-----------------------------------------------------\n");
 67 }
 68 
 69 int main(int argc, char **argv)
 70 {
 71 // Declaraçã o dos parâmetros do pthread
 72 pthread_t threads[MAX_THREADS];
 73 pthread_attr_t atributos;
 74 pthread_attr_init(&atributos);
 75 pthread_attr_setdetachstate(&atributos, PTHREAD_CREATE_JOINABLE);
 76 pthread_attr_setscope(&atributos,PTHREAD_SCOPE_SYSTEM);
 77 
 78 int i,flag;
 79 preenche(A,N,N); //Preenche toda a matriz A[N][N] com '1'
 80 preenche(B,N,N); //Preenche toda a matriz B[N][N] com '1'
 81 
 82 // Criaçã o das threads. Se houver erro de criaçã o, o programa para de e
xecutar.
 83 for (i = 0; i < MAX_THREADS; i++)
 84 flag = pthread_create(&threads[i], &atributos, multiplica, (void *)
i);
 85 if (flag)
 86 exit(-1);
 87 
 88 // Junçã o dos resultados obtidos por cada thread
 89 for (i = 0; i < MAX_THREADS; i++)
 90 pthread_join(threads[i], NULL);
 91 
 92 //Imprime as matrizes na tela 
 93 imprime(A,N,N);
 94 imprime(B,N,N);
 95 imprime(C,N,N);
 96 
 97 pthread_exit(NULL);
 98 }
 99 
100 
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