root/orte/test/mpi/spawn_multiple.c

DEFINITIONS

1. main

   1 #include "orte_config.h"
   2 
   3 #include <stdio.h>
   4 #include <sys/types.h>
   5 #include <unistd.h>
   6 
   7 #include <mpi.h>
   8 
   9 int main(int argc, char* argv[])
  10 {
  11     int msg;
  12     MPI_Comm parent, child;
  13     int rank, size;
  14     char hostname[OPAL_MAXHOSTNAMELEN];
  15     pid_t pid;
  16     int i;
  17     char *cmds[2];
  18     char *argv0[] = { "foo", NULL };
  19     char *argv1[] = { "bar", NULL };
  20     char **spawn_argv[2];
  21     int maxprocs[] = { 1, 1 };
  22     MPI_Info info[] = { MPI_INFO_NULL, MPI_INFO_NULL };
  23 
  24     cmds[1] = cmds[0] = argv[0];
  25     spawn_argv[0] = argv0;
  26     spawn_argv[1] = argv1;
  27 
  28     MPI_Init(NULL, NULL);
  29     MPI_Comm_rank(MPI_COMM_WORLD, &rank);
  30     MPI_Comm_size(MPI_COMM_WORLD, &size);
  31     MPI_Comm_get_parent(&parent);
  32     /* If we get COMM_NULL back, then we're the parent */
  33     if (MPI_COMM_NULL == parent) {
  34         pid = getpid();
  35         printf("Parent [pid %ld] about to spawn!\n", (long)pid);
  36         MPI_Comm_spawn_multiple(2, cmds, spawn_argv, maxprocs,
  37                                 info, 0, MPI_COMM_WORLD,
  38                                 &child, MPI_ERRCODES_IGNORE);
  39         printf("Parent done with spawn\n");
  40         if (0 == rank) {
  41             msg = 38;
  42             printf("Parent sending message to children\n");
  43             MPI_Send(&msg, 1, MPI_INT, 0, 1, child);
  44             MPI_Send(&msg, 1, MPI_INT, 1, 1, child);
  45         }
  46         MPI_Comm_disconnect(&child);
  47         printf("Parent disconnected\n");
  48     }
  49     /* Otherwise, we're the child */
  50     else {
  51         MPI_Comm_rank(MPI_COMM_WORLD, &rank);
  52         MPI_Comm_size(MPI_COMM_WORLD, &size);
  53         gethostname(hostname, sizeof(hostname));
  54         pid = getpid();
  55         printf("Hello from the child %d of %d on host %s pid %ld: argv[1] = %s\n", rank, size, hostname, (long)pid, argv[1]);
  56         MPI_Recv(&msg, 1, MPI_INT, 0, 1, parent, MPI_STATUS_IGNORE);
  57         printf("Child %d received msg: %d\n", rank, msg);
  58         MPI_Comm_disconnect(&parent);
  59         printf("Child %d disconnected\n", rank);
  60     }
  61 
  62     MPI_Finalize();
  63     return 0;
  64 }