From 5f30f31253629200892746ad9d086d03bbec48a5 Mon Sep 17 00:00:00 2001
From: Augustin Degomme <degomme@idpann.imag.fr>
Date: Mon, 8 Jul 2013 14:28:07 +0200
Subject: [PATCH] add a reference counter in order to avoide deleting MPI_Comm,
 and MPI_Group, too soon

---
 src/smpi/private.h   |  2 ++
 src/smpi/smpi_base.c |  3 +++
 src/smpi/smpi_comm.c | 17 ++++++++++++++++-
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/smpi/private.h b/src/smpi/private.h
index 9c40250103..1e2a3c2142 100644
--- a/src/smpi/private.h
+++ b/src/smpi/private.h
@@ -173,6 +173,8 @@ int smpi_comm_size(MPI_Comm comm);
 void smpi_comm_get_name(MPI_Comm comm, char* name, int* len);
 int smpi_comm_rank(MPI_Comm comm);
 MPI_Comm smpi_comm_split(MPI_Comm comm, int color, int key);
+void smpi_comm_use(MPI_Comm comm);
+void smpi_comm_unuse(MPI_Comm comm);
 
 MPI_Request smpi_mpi_send_init(void *buf, int count, MPI_Datatype datatype,
                                int dst, int tag, MPI_Comm comm);
diff --git a/src/smpi/smpi_base.c b/src/smpi/smpi_base.c
index ee947cc2ef..df76fc2b0e 100644
--- a/src/smpi/smpi_base.c
+++ b/src/smpi/smpi_base.c
@@ -327,6 +327,7 @@ void smpi_mpi_start(MPI_Request request)
     // we make a copy here, as the size is modified by simix, and we may reuse the request in another receive later
     request->real_size=request->size;
     smpi_datatype_use(request->old_type);
+    smpi_comm_use(request->comm);
     request->action = simcall_comm_irecv(mailbox, request->buf, &request->real_size, &match_recv, request);
 
     //integrate pseudo-timing for buffering of small messages, do not bother to execute the simcall if 0
@@ -375,6 +376,7 @@ void smpi_mpi_start(MPI_Request request)
     // we make a copy here, as the size is modified by simix, and we may reuse the request in another receive later
     request->real_size=request->size;
     smpi_datatype_use(request->old_type);
+    smpi_comm_use(request->comm);
 
     //if we are giving back the control to the user without waiting for completion, we have to inject timings
     double sleeptime =0.0;
@@ -582,6 +584,7 @@ static void finish_wait(MPI_Request * request, MPI_Status * status)
       }
       if(req->detached == 0) free(req->buf);
     }
+    smpi_comm_unuse(req->comm);
     smpi_datatype_unuse(datatype);
 
   }
diff --git a/src/smpi/smpi_comm.c b/src/smpi/smpi_comm.c
index 611690a5e4..dac6ac341e 100644
--- a/src/smpi/smpi_comm.c
+++ b/src/smpi/smpi_comm.c
@@ -14,6 +14,7 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(smpi_comm, smpi,
 
 typedef struct s_smpi_mpi_communicator {
   MPI_Group group;
+  int refcount;
 } s_smpi_mpi_communicator_t;
 
 static int smpi_compare_rankmap(const void *a, const void *b)
@@ -43,12 +44,14 @@ MPI_Comm smpi_comm_new(MPI_Group group)
   comm = xbt_new(s_smpi_mpi_communicator_t, 1);
   comm->group = group;
   smpi_group_use(comm->group);
+  smpi_comm_use(comm);
   return comm;
 }
 
 void smpi_comm_destroy(MPI_Comm comm)
 {
-  xbt_free(comm);
+  smpi_group_unuse(comm->group);
+  smpi_comm_unuse(comm);
 }
 
 MPI_Group smpi_comm_group(MPI_Comm comm)
@@ -152,3 +155,15 @@ MPI_Comm smpi_comm_split(MPI_Comm comm, int color, int key)
   }
   return group_out ? smpi_comm_new(group_out) : MPI_COMM_NULL;
 }
+
+void smpi_comm_use(MPI_Comm comm){
+  comm->refcount++;
+  smpi_group_use(comm->group);
+}
+
+void smpi_comm_unuse(MPI_Comm comm){
+  comm->refcount--;
+  smpi_group_unuse(comm->group);
+  if(comm->refcount==0)
+    xbt_free(comm);
+}
-- 
2.20.1