From 267ca781cdffc0c7006a848bb3467b6d176eaccd Mon Sep 17 00:00:00 2001
From: Joost VandeVondele <Joost.VandeVondele@gmail.com>
Date: Sat, 29 Dec 2018 19:01:10 +0100
Subject: [PATCH] Always wait before posting the next call in _sync.

---
 src/cluster.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/cluster.cpp b/src/cluster.cpp
index 40f5aae4..d01a05e5 100644
--- a/src/cluster.cpp
+++ b/src/cluster.cpp
@@ -191,10 +191,11 @@ void signals_sync() {
   uint64_t globalCounter;
   MPI_Allreduce(&signalsCallCounter, &globalCounter, 1, MPI_UINT64_T, MPI_MAX, MoveComm); // MoveComm needed
   if (signalsCallCounter < globalCounter)
+  {
+      MPI_Wait(&reqSignals, MPI_STATUS_IGNORE);
       signals_send();
-
+  }
   assert(signalsCallCounter == globalCounter);
-
   MPI_Wait(&reqSignals, MPI_STATUS_IGNORE);
 
   signals_process();
@@ -204,12 +205,14 @@ void signals_sync() {
   if (gathersPosted < globalCounter)
   {
      size_t recvBuffPerRankSize = Threads.size() * TTCacheSize;
+     MPI_Wait(&reqGather, MPI_STATUS_IGNORE);
      MPI_Iallgather(MPI_IN_PLACE, 0, MPI_DATATYPE_NULL,
                     TTRecvBuff.data(), recvBuffPerRankSize * sizeof(KeyedTTEntry), MPI_BYTE,
                     TTComm, &reqGather);
      ++gathersPosted;
   }
   assert(gathersPosted == globalCounter);
+  MPI_Wait(&reqGather, MPI_STATUS_IGNORE);
 
 }