static void finish_wait(MPI_Request* request, MPI_Status* status);
static void unref(MPI_Request* request);
static int wait(MPI_Request* req, MPI_Status* status);
static void finish_wait(MPI_Request* request, MPI_Status* status);
static void unref(MPI_Request* request);
static int wait(MPI_Request* req, MPI_Status* status);