datawizard: add a new field 'rank' to starpu_data_handle

src/datawizard/coherency.h

@@ -185,6 +185,9 @@ struct starpu_data_state_t {
 	starpu_data_handle reduction_tmp_handles[STARPU_NMAXWORKERS];
 
 	unsigned lazy_unregister;
+
+        /* Used for MPI */
+        int rank;
 };
 
 void _starpu_display_msi_stats(void);

src/datawizard/interfaces/data_interface.c

@@ -183,6 +183,17 @@ void starpu_data_register(starpu_data_handle *handleptr, uint32_t home_node,
 	_starpu_register_new_data(handle, home_node, 0);
 }
 
+int starpu_data_get_rank(starpu_data_handle handle)
+{
+	return handle->rank;
+}
+
+int starpu_data_set_rank(starpu_data_handle handle, int rank)
+{
+        handle->rank = rank;
+        return 0;
+}
+
 /* 
  * Stop monitoring a piece of data
  */