From: degomme <augustin.degomme@unibas.ch>
Date: Thu, 16 Feb 2017 11:08:44 +0000 (+0100)
Subject: Avoid doing things when there is nothing to do.
X-Git-Tag: v3_15~344^2
X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/63c411f773b06e9adb04479d4943efaf9838bf9f

Avoid doing things when there is nothing to do.
---

diff --git a/src/smpi/smpi_rma.cpp b/src/smpi/smpi_rma.cpp
index 68d8507b8d..6edbee3e47 100644
--- a/src/smpi/smpi_rma.cpp
+++ b/src/smpi/smpi_rma.cpp
@@ -117,13 +117,16 @@ int smpi_mpi_win_fence( int assert,  MPI_Win win){
     std::vector<MPI_Request> *reqs = win->requests;
     int size = static_cast<int>(reqs->size());
     // start all requests that have been prepared by another process
-    for(auto req: *reqs){
-      if (req && (req->flags & PREPARED))
-        smpi_mpi_start(req);
-    }
+    if(size>0){
+        for(auto req: *reqs){
+          if (req && (req->flags & PREPARED))
+            smpi_mpi_start(req);
+        }
+
+        MPI_Request* treqs = &(*reqs)[0];
 
-    MPI_Request* treqs = &(*reqs)[0];
-    smpi_mpi_waitall(size,treqs,MPI_STATUSES_IGNORE);
+        smpi_mpi_waitall(size,treqs,MPI_STATUSES_IGNORE);
+    }
     win->count=0;
   }
   win->assert = assert;