openmpi/src/mca/coll/basic/src/coll_basic_scatterv.c

/*
 * $HEADER$
 */

#include "ompi_config.h"
#include "coll_basic.h"

#include "constants.h"
#include "mpi.h"
#include "mca/coll/coll.h"
#include "mca/coll/base/coll_tags.h"
#include "coll_basic.h"


/*
 *	scatterv
 *
 *	Function:	- scatterv operation
 *	Accepts:	- same arguments as MPI_Scatter()
 *	Returns:	- MPI_SUCCESS or error code
 */
int mca_coll_basic_scatterv(void *sbuf, int *scounts,
                            int *disps, MPI_Datatype sdtype,
                            void *rbuf, int rcount,
                            MPI_Datatype rdtype, int root,
                            MPI_Comm comm)
{
#if 1
  return OMPI_ERR_NOT_IMPLEMENTED;
#else
  int i;
  int rank;
  int size;
  int err;
  char *ptmp;
  MPI_Aint extent;

  MPI_Comm_rank(comm, &rank);
  MPI_Comm_size(comm, &size);

  /* If not root, receive data. */

  if (rank != root) {
#if 0
    /* JMS Need to replace this with negative tags and direct PML calls */
    err = MPI_Recv(rbuf, rcount, rdtype,
		   root, BLKMPISCATTERV, comm, MPI_STATUS_IGNORE);
#endif
    return err;
  }

  /* I am the root, loop sending data. */

  MPI_Type_extent(sdtype, &extent);
  for (i = 0; i < size; ++i) {
    ptmp = ((char *) sbuf) + (extent * disps[i]);

    /* simple optimization */

    if (i == rank) {
#if 0
      /* JMS Need to replace this with ompi_datatype_*() functions */
      err = ompi_dtsndrcv(ptmp, scounts[i], sdtype, rbuf,
			 rcount, rdtype, BLKMPISCATTERV, comm);
#endif
    } else {
#if 0
    /* JMS Need to replace this with negative tags and direct PML calls */
      err = MPI_Send(ptmp, scounts[i], sdtype, i, BLKMPISCATTERV, comm);
#endif
    }
    if (MPI_SUCCESS != err) {
      return err;
    }
  }

  /* All done */

  return MPI_SUCCESS;
#endif
}