From 5b7c866f59d9d148166f6a7157772790fab7dbec Mon Sep 17 00:00:00 2001
From: Howard Pritchard <howardp@lanl.gov>
Date: Thu, 22 Dec 2016 10:14:34 -0700
Subject: [PATCH] osc/pt2pt: disable when THREAD_MULTIPLE.

Per discussion at
https://github.com/open-mpi/ompi/issues/2614#issuecomment-392815654,
do not allow for selection of the OSC PT2PT when creating an MPI RMA
window when THREAD_MULTIPLE is active.  Print a helpful message and
return a not-supported error.

Signed-off-by: Howard Pritchard <howardp@lanl.gov>
Signed-off-by: Jeff Squyres <jsquyres@cisco.com>

(cherry picked from commit d0ffd660841623c02d1dfa3151e7f7afd3327698)
Signed-off-by: Jeff Squyres <jsquyres@cisco.com>
---
 ompi/mca/osc/pt2pt/Makefile.am           |  2 ++
 ompi/mca/osc/pt2pt/help-osc-pt2pt.txt    | 15 +++++++++++++++
 ompi/mca/osc/pt2pt/osc_pt2pt_component.c | 15 +++++++++++++++
 3 files changed, 32 insertions(+)
 create mode 100644 ompi/mca/osc/pt2pt/help-osc-pt2pt.txt

diff --git a/ompi/mca/osc/pt2pt/Makefile.am b/ompi/mca/osc/pt2pt/Makefile.am
index 37ba3ab6f26..244f9b7d2c2 100644
--- a/ompi/mca/osc/pt2pt/Makefile.am
+++ b/ompi/mca/osc/pt2pt/Makefile.am
@@ -19,6 +19,8 @@
 # $HEADER$
 #
 
+dist_ompidata_DATA = help-osc-pt2pt.txt
+
 pt2pt_sources = \
 	osc_pt2pt.h \
 	osc_pt2pt_module.c \
diff --git a/ompi/mca/osc/pt2pt/help-osc-pt2pt.txt b/ompi/mca/osc/pt2pt/help-osc-pt2pt.txt
new file mode 100644
index 00000000000..9b57ac20b72
--- /dev/null
+++ b/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.
diff --git a/ompi/mca/osc/pt2pt/osc_pt2pt_component.c b/ompi/mca/osc/pt2pt/osc_pt2pt_component.c
index c8ac4e73f98..acb08fee54c 100644
--- a/ompi/mca/osc/pt2pt/osc_pt2pt_component.c
+++ b/ompi/mca/osc/pt2pt/osc_pt2pt_component.c
@@ -25,6 +25,7 @@
  */
 
 #include "ompi_config.h"
+#include "opal/util/show_help.h"
 
 #include <string.h>
 
@@ -108,6 +109,7 @@ 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
@@ -206,6 +208,10 @@ 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);
@@ -302,6 +308,15 @@ 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));