MPI_DOORBELL_STATE
if (mpi_wait_ne(sc, MPI_DOORBELL, MPI_DOORBELL_STATE,
switch (db & MPI_DOORBELL_STATE) {
if (mpi_wait_ne(sc, MPI_DOORBELL, MPI_DOORBELL_STATE,
if (mpi_wait_eq(sc, MPI_DOORBELL, MPI_DOORBELL_STATE,
if (mpi_wait_eq(sc, MPI_DOORBELL, MPI_DOORBELL_STATE,
mpi_read_db(sc) & MPI_DOORBELL_STATE);