Add a check for now that invokes an MPI exception if you try to

SPAWN[_MULTIPLE] from a singleton (and displays a pretty help message
explaining that you need to use mpirun).  This can be removed when
fixes for ORTE come over that allow SPAWN[_MULTIPLE] from singletons. 

This commit was SVN r10898.

ompi/mpi/Makefile.am

@@ -9,6 +9,7 @@
 #                         University of Stuttgart.  All rights reserved.
 # Copyright (c) 2004-2005 The Regents of the University of California.
 #                         All rights reserved.
+# Copyright (c) 2006      Cisco Systems, Inc.  All rights reserved.
 # $COPYRIGHT$
 # 
 # Additional copyrights may follow
@@ -16,6 +17,6 @@
 # $HEADER$
 #
 
-
-
 SUBDIRS = c cxx f77 f90
+
+dist_pkgdata_DATA = help-mpi-api.txt

ompi/mpi/c/comm_spawn.c

@@ -19,9 +19,9 @@
 #include "ompi_config.h"
 #include <stdio.h>
 
-#include "ompi/mpi/c/bindings.h"
-#include "orte/mca/oob/oob.h"
+#include "opal/util/show_help.h"
 #include "ompi/info/info.h"
+#include "ompi/mpi/c/bindings.h"
 
 #if OMPI_HAVE_WEAK_SYMBOLS && OMPI_PROFILING_DEFINES
 #pragma weak MPI_Comm_spawn = PMPI_Comm_spawn
@@ -68,6 +68,17 @@ int MPI_Comm_spawn(char *command, char **argv, int maxprocs, MPI_Info info,
           return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_INFO,
                                         FUNC_NAME);
         }
+
+        /* Do not allow MPI_COMM_SPAWN from a singleton.  This check
+           will be removed when the ORTE 2.0 stuff comes over and
+           Makes This All Better(tm) */
+        if (orte_process_info.singleton) {
+            if (ompi_comm_rank(comm) == root) {
+                opal_show_help("help-mpi-api.txt", "spawn-from-singleton", 
+                               true, FUNC_NAME);
+            }
+            return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_ARG, FUNC_NAME);
+        }
     }
    
    rank = ompi_comm_rank ( comm );

ompi/mpi/c/comm_spawn_multiple.c

@@ -19,6 +19,7 @@
 #include "ompi_config.h"
 #include <stdio.h>
 
+#include "opal/util/show_help.h"
 #include "ompi/mpi/c/bindings.h"
 #include "ompi/info/info.h"
 
@@ -75,6 +76,17 @@ int MPI_Comm_spawn_multiple(int count, char **array_of_commands, char ***array_o
                                           FUNC_NAME);
           }
         }
+
+        /* Do not allow MPI_COMM_SPAWN from a singleton.  This check
+           will be removed when the ORTE 2.0 stuff comes over and
+           Makes This All Better(tm) */
+        if (orte_process_info.singleton) {
+            if (ompi_comm_rank(comm) == root) {
+                opal_show_help("help-mpi-api.txt", "spawn-from-singleton", 
+                               true, FUNC_NAME);
+            }
+            return OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_ARG, FUNC_NAME);
+        }
     }
    
    rank = ompi_comm_rank ( comm );

ompi/mpi/help-mpi-api.txt

@@ -0,0 +1,22 @@
+# -*- text -*-
+#
+# Copyright (c) 2006      Cisco Systems, Inc.  All rights reserved.
+# $COPYRIGHT$
+# 
+# Additional copyrights may follow
+# 
+# $HEADER$
+#
+# This is the US/English general help file for Open MPI.
+#
+[spawn-from-singleton]
+This version of Open MPI does not support %s from a 
+"singleton" application.  Specifically, you cannot invoke an MPI
+application like this:
+
+    shell$ ./a.out
+
+and then have a.out use the MPI-2 dynamic spawn functions.  Instead,
+you must start your MPI application via mpirun:
+
+    shell: mpirun -np 1 ./a.out