NAME

       MPI_Neighbor_alltoallw  -   Like  MPI_Neighbor_alltoallv  but  it  allows  one  to  send and receive with
       different types to and from each neighbor.

SYNOPSIS

       int MPI_Neighbor_alltoallw(const void *sendbuf, const int sendcounts[], const MPI_Aint sdispls[],
       const MPI_Datatype sendtypes[], void *recvbuf, const int recvcounts[],
       const MPI_Aint rdispls[], const MPI_Datatype recvtypes[], MPI_Comm comm)

INPUT PARAMETERS

       sendbuf
              - starting address of the send buffer (choice)
       sendcounts
              - non-negative integer array (of length outdegree) specifying the number of elements  to  send  to
              each neighbor
       sdispls
              -  integer  array (of length outdegree).  Entry j specifies the displacement in bytes (relative to
              sendbuf) from which to take the outgoing data destined for neighbor j (array of integers)
       sendtypes
              - array of datatypes (of length outdegree).  Entry j  specifies  the  type  of  data  to  send  to
              neighbor j (array of handles)
       recvcounts
              -  non-negative  integer  array  (of  length  indegree) specifying the number of elements that are
              received from each neighbor
       rdispls
              - integer array (of length indegree).  Entry i specifies the displacement in  bytes  (relative  to
              recvbuf) at which to place the incoming data from neighbor i (array of integers).
       recvtypes
              -  array  of  datatypes  (of  length  indegree).  Entry i specifies the type of data received from
              neighbor i (array of handles).
       comm   - communicator with topology structure (handle)

OUTPUT PARAMETERS

       recvbuf
              - starting address of the receive buffer (choice)

THREAD AND INTERRUPT SAFETY

       This routine is thread-safe.  This means that this routine may be safely used by multiple threads without
       the need for any user-provided thread locks.  However, the routine is  not  interrupt  safe.   Typically,
       this  is  due to the use of memory allocation routines such as malloc or other non-MPICH runtime routines
       that are themselves not interrupt-safe.

NOTES FOR FORTRAN

       All MPI routines in Fortran (except for MPI_WTIME and MPI_WTICK ) have an additional argument ierr at the
       end of the argument list.  ierr is an integer and has the same meaning as the return value of the routine
       in C.  In Fortran, MPI routines are subroutines, and are invoked with the call statement.

       All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in Fortran.

ERRORS

       All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error value; C routines as the value of  the
       function  and Fortran routines in the last argument.  Before the value is returned, the current MPI error
       handler is called.  By default, this error handler aborts the MPI job.  The error handler may be  changed
       with    MPI_Comm_set_errhandler   (for   communicators),   MPI_File_set_errhandler   (for   files),   and
       MPI_Win_set_errhandler (for RMA windows).  The MPI-1 routine MPI_Errhandler_set may be used but  its  use
       is  deprecated.   The  predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be
       returned.  Note that MPI does not guarentee that an MPI program can continue past an error; however,  MPI
       implementations will attempt to continue whenever possible.

                                                   11/12/2019                          MPI_Neighbor_alltoallw(3)