ex2_mpi.c

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <pthread.h>
#include <float.h>
#include <time.h>
#include <mpi.h>
#define  MASTER    0
#define  N_TAREFAS 5

/*
Crie um programa em MPI com N processos, onde o processo n ́umero 0 crie uma lista de tarefas (5
conjunto de opera ̃oes matem ́aticas) e envie para cada 2 processos a mesma definindo o in ́ıcio e fim das
opera ̧c ̃oes.
*/

MPI_Status status;
int operacao1();
int operacao2();
int operacao3();
int operacao4();
int operacao5();

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

	int numtasks,taskid,rc,numworkers,source,dest,offset,i,j;

	MPI_Init(&argc, &argv);
	MPI_Comm_rank(MPI_COMM_WORLD, &taskid);
	MPI_Comm_size(MPI_COMM_WORLD, &numtasks);

	if (numtasks < 2 ) {
		printf("Need at least two MPI tasks. Quitting...\n");
		MPI_Abort(MPI_COMM_WORLD, rc);
		exit(1);
	}
	numworkers = numtasks-1;

	int nprocessos=numworkers;
	int listatarefas[nprocessos][N_TAREFAS];

	/*---------------------------- master ----------------------------*/
	if (taskid == MASTER) {

		//Initiate the timer
		clock_t begin = clock();

		offset = 0;
		
		for (dest=1; dest<=numworkers; dest++)
		{
			MPI_Send(&offset, 1, MPI_INT, dest, 1, MPI_COMM_WORLD);
			offset = offset + 1;
		}

		/* wait for results from all worker tasks */
		for (i=1; i<=numworkers; i++)
		{
			source = i;
			MPI_Recv(&offset, 1, MPI_INT, source, 2, MPI_COMM_WORLD, &status);
			MPI_Recv(&listatarefas[offset][0], N_TAREFAS, MPI_INT, source, 2, MPI_COMM_WORLD, &status);
		}

		//end the timer and calculate
		clock_t end = clock();
		double time_spent = (double)(end - begin) / CLOCKS_PER_SEC;

		for (i=0; i<nprocessos; i++) {
			for (j=0; j<N_TAREFAS; j++)
				printf("resultado do processo %i, tarefa %i: %i \n", i, j, listatarefas[i][j]);
		}

		printf("\n\n----This process took %f ----\n\n", time_spent);

	}
	/*---------------------------- worker----------------------------*/
	if (taskid > MASTER) {

		source = 0;
		MPI_Recv(&offset, 1, MPI_INT, source, 1, MPI_COMM_WORLD, &status);

		listatarefas[offset][0] = operacao1();
		listatarefas[offset][1] = operacao2();
		listatarefas[offset][2] = operacao3();
		listatarefas[offset][3] = operacao4();
		listatarefas[offset][4] = operacao5();


		MPI_Send(&offset, 1, MPI_INT, 0, 2, MPI_COMM_WORLD);
		MPI_Send(&listatarefas, N_TAREFAS, MPI_INT, 0, 2, MPI_COMM_WORLD);

	}
	MPI_Finalize();
}

int operacao1(){
	int a = 16, b = 8, c;
	c = a + b;
	return c;
}

int operacao2(){
	int a = 16, b = 8, c;
	c = a - b;
	return c;
}

int operacao3(){
	int a = 16, b = 8, c;
	c = a * b;
	return c;
}

int operacao4(){
	int a = 16, b = 8, c;
	c = a / b;
	return c;
}

int operacao5(){
	int a = 16, b = 8, c;
	c = a % b;
	return c;
}