From 68407587ba598a09ac6f63458a080040eeaaf7a9 Mon Sep 17 00:00:00 2001
From: Brian Barrett <brbarret@open-mpi.org>
Date: Wed, 22 Sep 2004 16:05:33 +0000
Subject: [PATCH] * Make it easier to get just the number of peer processes by
 allowing NULL   to be passed for the first argument of ompi_rte_get_peers(). 
 Also   cleaned up the documentation for that function.

This commit was SVN r2801.
---
 src/runtime/ompi_rte_pcm.c | 13 ++++++++++++-
 src/runtime/runtime.h      | 18 ++++++++++++++++--
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/src/runtime/ompi_rte_pcm.c b/src/runtime/ompi_rte_pcm.c
index 6cde592967..8f1a9f9cf5 100644
--- a/src/runtime/ompi_rte_pcm.c
+++ b/src/runtime/ompi_rte_pcm.c
@@ -142,11 +142,22 @@ ompi_rte_get_self(void)
 int
 ompi_rte_get_peers(ompi_process_name_t **peers, size_t *npeers)
 {
+    ompi_process_name_t *useless;
+    ompi_process_name_t **peers_p;
+
     if (NULL == mca_pcmclient.pcmclient_get_peers) {
         return OMPI_ERR_NOT_IMPLEMENTED;
     }
 
-    return mca_pcmclient.pcmclient_get_peers(peers, npeers);
+    if (NULL == peers) {
+        /* the returned value is a pointer to a static buffer, so no
+           free is neeeded.  This is therefore completely safe.  Yay */
+        peers_p = &useless;
+    } else {
+        peers_p = peers;
+    }
+
+    return mca_pcmclient.pcmclient_get_peers(peers_p, npeers);
 }
 
 
diff --git a/src/runtime/runtime.h b/src/runtime/runtime.h
index eee5d5f4ce..eb7acc1d03 100644
--- a/src/runtime/runtime.h
+++ b/src/runtime/runtime.h
@@ -212,8 +212,22 @@ extern "C" {
     /**
      * Get names of peer processes which have been launched
      *
-     * @param Nothing
-     * @return An array of peer names, including me
+     * @param peers (OUT) Pointer to a pointer of
+     *                    ompi_process_name_t. \c *peers will be set
+     *                    to point to a statically allocated buffer
+     *                    containing the array of peer processes
+     *                    started with the current process.  If \c
+     *                    peers is NULL, then only \c npeers is
+     *                    updated.
+     * @param npeers (OUT) pointer to an integer that will be updated
+     *                    with the total number of peers started with
+     *                    the current process.  Also the length of \c
+     *                    *peers array if \c peers is not \c NULL
+     *
+     * @return OMPI_SUCCESS on success
+     *         OMPI_ERR_NOT_IMPLEMENTED if the underlying module is
+     *                     not properly loaded.
+     *
      */
     int ompi_rte_get_peers(ompi_process_name_t **peers, size_t *npeers);