Don't use positive tags for internal messages.

They could interfere with receives posted with MPI_ANY_TAG in user's code

diff --git a/src/smpi/colls/bcast/bcast-arrival-scatter.cpp b/src/smpi/colls/bcast/bcast-arrival-scatter.cpp
index 7d51422..7891c76 100644 (file)
--- a/src/smpi/colls/bcast/bcast-arrival-scatter.cpp
+++ b/src/smpi/colls/bcast/bcast-arrival-scatter.cpp
@@ -21,7 +21,7 @@ int Coll_bcast_arrival_scatter::bcast(void *buf, int count,
                                           MPI_Comm comm)
 {
   int tag = -COLL_TAG_BCAST;//in order to use ANY_TAG, make this one positive
-  int header_tag = 10;
+  int header_tag = -10;
   MPI_Status status;
 
   int curr_remainder;

diff --git a/src/smpi/mpi/smpi_comm.cpp b/src/smpi/mpi/smpi_comm.cpp
index 5bdf88d..7f51e7e 100644 (file)
--- a/src/smpi/mpi/smpi_comm.cpp
+++ b/src/smpi/mpi/smpi_comm.cpp
@@ -212,7 +212,7 @@ MPI_Comm Comm::split(int color, int key)
 {
   if (this == MPI_COMM_UNINITIALIZED)
     return smpi_process()->comm_world()->split(color, key);
-  int system_tag = 123;
+  int system_tag = -123;
   int* recvbuf;
 
   MPI_Group group_root = nullptr;