/*D
   MPI_T_event_register_callback - Associates a user-defined function with an allocated event-registration handle

Synopsis:
.vb
int MPI_T_event_register_callback(MPI_T_event_registration event_registration,
                                  MPI_T_cb_safety cb_safety, MPI_Info info,
                                  void *user_data,
                                  MPI_T_event_cb_function event_cb_function)
.ve

Input Parameters:
+ event_registration - event registration (handle)
. cb_safety - maximum callback safety level (integer)
. info - info object (handle)
. user_data - pointer to a user-controlled buffer (None)
- event_cb_function - pointer to user-defined callback function (function)

.N ThreadSafe

.N Errors
.N MPI_SUCCESS
.N MPI_ERR_INFO
.N MPI_T_ERR_INVALID_HANDLE
.N MPI_T_ERR_NOT_INITIALIZED
.N MPI_ERR_OTHER

D*/

