osc/pt2pt: disable osc/pt2pt for THREAD_MULTIPLE scenarios

As a workaround for issue open-mpi#2614 for the v2.0.2 release,
do not allow for selection of the OSC PT2PT when
creating an MPI RMA window.  Print a hopefully helpful
message and return an not-supported error.

This PR should be reverted once a fix for open-mpi#2614
is in place.

Signed-off-by: Howard Pritchard <[email protected]>
(cherry picked from commit d0ffd66)

The original commit message is shown above.  Followup: as of this
writing (26 Mar 2018), we do not plan to fix this issue for the v2.0.x
or v2.x.  Hence, the osc/pt2pt component will continue to disable
itself in THREAD_MULTIPLE scenarios for the life of all v2.x series.
It is possible (likely?) that this will be fixed in a v3.0.x release
(where x>1).

Author: hppritcha

ompi/mca/osc/pt2pt/Makefile.am

@@ -18,6 +18,8 @@
 # $HEADER$
 #
 
+dist_ompidata_DATA = help-osc-pt2pt.txt
+
 pt2pt_sources = \
 	osc_pt2pt.h \
 	osc_pt2pt_module.c \

ompi/mca/osc/pt2pt/help-osc-pt2pt.txt

@@ -0,0 +1,15 @@
+# -*- text -*-
+#
+# Copyright (c) 2016 Los Alamos National Security, LLC. All rights
+#                    reserved.
+#
+# $COPYRIGHT$
+#
+# Additional copyrights may follow
+#
+# $HEADER$
+#
+[mpi-thread-multiple-not-supported]
+The OSC pt2pt component does not support MPI_THREAD_MULTIPLE in this release.
+Workarounds are to run on a single node, or to use a system with an RDMA
+capable network such as Infiniband.

ompi/mca/osc/pt2pt/osc_pt2pt_component.c

@@ -24,6 +24,7 @@
  */
 
 #include "ompi_config.h"
+#include "opal/util/show_help.h"
 
 #include <string.h>
 
@@ -110,6 +111,7 @@ ompi_osc_pt2pt_module_t ompi_osc_pt2pt_module_template = {
 };
 
 bool ompi_osc_pt2pt_no_locks = false;
+static bool using_thread_multiple = false;
 
 /* look up parameters for configuring this window.  The code first
    looks in the info structure passed by the user, then through mca
@@ -208,6 +210,10 @@ component_init(bool enable_progress_threads,
 {
     int ret;
 
+    if (enable_mpi_threads) {
+        using_thread_multiple = true;
+    }
+
     OBJ_CONSTRUCT(&mca_osc_pt2pt_component.lock, opal_mutex_t);
     OBJ_CONSTRUCT(&mca_osc_pt2pt_component.pending_operations, opal_list_t);
     OBJ_CONSTRUCT(&mca_osc_pt2pt_component.pending_operations_lock, opal_mutex_t);
@@ -304,6 +310,15 @@ component_select(struct ompi_win_t *win, void **base, size_t size, int disp_unit
        component */
     if (MPI_WIN_FLAVOR_SHARED == flavor) return OMPI_ERR_NOT_SUPPORTED;
 
+    /*
+     * workaround for issue https://github.com/open-mpi/ompi/issues/2614
+     * The following check needs to be removed once 2614 is addressed.
+     */
+    if (using_thread_multiple) {
+        opal_show_help("help-osc-pt2pt.txt", "mpi-thread-multiple-not-supported", true);
+        return OMPI_ERR_NOT_SUPPORTED;
+    }
+
     /* create module structure with all fields initialized to zero */
     module = (ompi_osc_pt2pt_module_t*)
         calloc(1, sizeof(ompi_osc_pt2pt_module_t));