Невозможно запустить код MPI, написанный на C, на терминале с использованием Ubuntu
karim@karim:~/Desktop/greetings$ mpicc main.c -o test
karim@karim:~/Desktop/greetings$ mpirun -np 3 test
mpiexec_karim: cannot connect to local mpd (/tmp/mpd2.console_karim); possible causes:
1. no mpd is running on this host
2. an mpd is running but was started without a "console" (-n option)
In case 1, you can start an mpd on this host with:
mpd &
and you will be able to run jobs just on this host.
For more details on starting mpds on a set of hosts, see
the MPICH2 Installation Guide.
#include <stdio.h>
#include <string.h>
#include "mpi.h"
int main(int argc , char * argv[])
{
int my_rank; /* rank of process */
int p; /* number of process */
int source; /* rank of sender */
int dest; /* rank of reciever */
int tag = 0; /* tag for messages */
char message[100]; /* storage for message */
MPI_Status status; /* return status for recieve */
/* Start up MPI */
MPI_Init( &argc , &argv );
/* Find out process rank */
MPI_Comm_rank(MPI_COMM_WORLD, &my_rank);
/* Find out number of process */
MPI_Comm_size(MPI_COMM_WORLD, &p);
if( my_rank != 0)
{
/* create message */
sprintf( message, "Greetings from process %d !",my_rank);
dest = 0;
/* use Strlen+1 to transmit /0 */
MPI_Send( message, strlen(message)+1, MPI_CHAR, dest, tag,
MPI_COMM_WORLD);
}else
{
for( source = 1; source < p ; source++)
{
MPI_Recv(message, 100, MPI_CHAR, source, tag, MPI_COMM_WORLD,
&status);
printf("%s\n" , message);
}
}
/* shutdown MPI */
MPI_Finalize();
return 0;
}
Вывод:
Greetings from process 1 !
Greetings from process 2 !
Greetings from process 3 !