Make this test capable of running more than "-np 1". If you run with

"-np X", it will launch X parents and then MPI_COMM_SPAWN X additional
children.

This commit was SVN r13466.

orte/test/mpi/simple_spawn.c

@@ -12,17 +12,21 @@ int main(int argc, char* argv[])
     pid_t pid;
 
     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(argv[0], MPI_ARGV_NULL, 1, MPI_INFO_NULL, 
+        MPI_Comm_spawn(argv[0], MPI_ARGV_NULL, size, MPI_INFO_NULL, 
                        0, MPI_COMM_WORLD, &child, MPI_ERRCODES_IGNORE);
         printf("Parent done with spawn\n");
-        msg = 38;
-        printf("Parent sending message to child\n");
-        MPI_Send(&msg, 1, MPI_INT, 0, 1, child);
+        if (0 == rank) {
+            msg = 38;
+            printf("Parent sending message to child\n");
+            MPI_Send(&msg, 1, MPI_INT, 0, 1, child);
+        }
         MPI_Comm_disconnect(&child);
         printf("Parent disconnected\n");
     } 
@@ -33,8 +37,10 @@ int main(int argc, char* argv[])
         gethostname(hostname, 512);
         pid = getpid();
         printf("Hello from the child %d of %d on host %s pid %ld\n", rank, size, hostname, (long)pid);
-        MPI_Recv(&msg, 1, MPI_INT, 0, 1, parent, MPI_STATUS_IGNORE);
-        printf("Child %d received msg: %d\n", rank, msg);
+        if (0 == rank) {
+            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);
     }