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#include "orte_config.h"
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <mpi.h>
int main(int argc, char* argv[])
{
int msg;
MPI_Comm parent, child;
int rank, size;
char hostname[OPAL_MAXHOSTNAMELEN];
pid_t pid;
int i;
char *cmds[2];
char *argv0[] = { "foo", NULL };
char *argv1[] = { "bar", NULL };
char **spawn_argv[2];
int maxprocs[] = { 1, 1 };
MPI_Info info[] = { MPI_INFO_NULL, MPI_INFO_NULL };
cmds[1] = cmds[0] = argv[0];
spawn_argv[0] = argv0;
spawn_argv[1] = argv1;
MPI_Init(NULL, NULL);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
MPI_Comm_size(MPI_COMM_WORLD, &size);
MPI_Comm_get_parent(&parent);
/* If we get COMM_NULL back, then we're the parent */
if (MPI_COMM_NULL == parent) {
pid = getpid();
printf("Parent [pid %ld] about to spawn!\n", (long)pid);
MPI_Comm_spawn_multiple(2, cmds, spawn_argv, maxprocs,
info, 0, MPI_COMM_WORLD,
&child, MPI_ERRCODES_IGNORE);
printf("Parent done with spawn\n");
if (0 == rank) {
msg = 38;
printf("Parent sending message to children\n");
MPI_Send(&msg, 1, MPI_INT, 0, 1, child);
MPI_Send(&msg, 1, MPI_INT, 1, 1, child);
}
MPI_Comm_disconnect(&child);
printf("Parent disconnected\n");
}
/* Otherwise, we're the child */
else {
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
MPI_Comm_size(MPI_COMM_WORLD, &size);
gethostname(hostname, sizeof(hostname));
pid = getpid();
printf("Hello from the child %d of %d on host %s pid %ld: argv[1] = %s\n", rank, size, hostname, (long)pid, argv[1]);
MPI_Recv(&msg, 1, MPI_INT, 0, 1, parent, MPI_STATUS_IGNORE);
printf("Child %d received msg: %d\n", rank, msg);
MPI_Comm_disconnect(&parent);
printf("Child %d disconnected\n", rank);
}
MPI_Finalize();
return 0;
}
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