mp_recv_d Subroutine

      SUBROUTINE mp_recv_d (msg, source, tag, gid)
      !! Receive one datum from another process
      !!
      !! MPI mapping
      !! mpi_send

         REAL(kind=real_8), INTENT(INOUT)                 :: msg
         !! Place received data into this variable
         INTEGER, INTENT(INOUT)                   :: source, tag
         !! Process to receive from
         !! Transfer identifier
         TYPE(mp_comm_type), INTENT(IN)                      :: gid
         !! Message passing environment identifier

         CHARACTER(LEN=*), PARAMETER :: routineN = 'mp_recv_d'

         INTEGER                                  :: handle, ierr, msglen
#if defined(__parallel)
         MPI_STATUS_TYPE                          :: status
#endif

         ierr = 0
         CALL timeset(routineN, handle)

         msglen = 1
#if defined(__parallel)
         CALL mpi_recv(msg, msglen, MPI_DOUBLE_PRECISION, source, tag, gid%handle, status, ierr)
         IF (ierr /= 0) CALL mp_stop(ierr, "mpi_recv @ "//routineN)
         CALL add_perf(perf_id=14, msg_size=msglen*real_8_size)
         source = status MPI_STATUS_EXTRACT(MPI_SOURCE)
         tag = status MPI_STATUS_EXTRACT(MPI_TAG)
#else
         MARK_USED(msg)
         MARK_USED(source)
         MARK_USED(tag)
         MARK_USED(gid)
         ! only defined in parallel
         DBCSR_ABORT("not in parallel mode")
#endif
         CALL timestop(handle)
      END SUBROUTINE mp_recv_d