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openmpi/ompi/mca/coll/basic/coll_basic_scan.c
Jeff Squyres 5dca18f903 First cut of handling MPI_IN_PLACE:
- added relevant logic for everything except
  mca_coll_basic_reduce_log_intra() -- need some help from George /
  Edgar on this one...
- replaced ompi_ddt_sndrcv() with ompi_ddt_copy_content_same_ddt()
  where relevant
- removed some "if (size > 1)" conditionals, because the self coll
  module will always be chosen for collectives where size==1

Waiting for BA's tests to check the validity of this IN_PLACE stuff.
We'll see how it goes!

This commit was SVN r7351.
2005-09-13 20:06:54 +00:00

131 строка
3.5 KiB
C

/*
* Copyright (c) 2004-2005 The Trustees of Indiana University.
* All rights reserved.
* Copyright (c) 2004-2005 The Trustees of the University of Tennessee.
* All rights reserved.
* Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
* University of Stuttgart. All rights reserved.
* Copyright (c) 2004-2005 The Regents of the University of California.
* All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "ompi_config.h"
#include "coll_basic.h"
#include <stdio.h>
#include "mpi.h"
#include "ompi/include/constants.h"
#include "ompi/op/op.h"
#include "ompi/mca/coll/coll.h"
#include "ompi/mca/coll/base/coll_tags.h"
#include "coll_basic.h"
/*
* scan
*
* Function: - basic scan operation
* Accepts: - same arguments as MPI_Scan()
* Returns: - MPI_SUCCESS or error code
*/
int
mca_coll_basic_scan_intra(void *sbuf, void *rbuf, int count,
struct ompi_datatype_t *dtype,
struct ompi_op_t *op,
struct ompi_communicator_t *comm)
{
int size;
int rank;
int err;
long true_lb, true_extent, lb, extent;
char *free_buffer = NULL;
char *pml_buffer = NULL;
/* Initialize */
rank = ompi_comm_rank(comm);
size = ompi_comm_size(comm);
/* If I'm rank 0, just copy into the receive buffer */
if (0 == rank) {
if (MPI_IN_PLACE != sbuf) {
err = ompi_ddt_copy_content_same_ddt(dtype, count, rbuf, sbuf);
if (MPI_SUCCESS != err) {
return err;
}
} else {
return MPI_SUCCESS;
}
}
/* Otherwise receive previous buffer and reduce. */
else {
/* Allocate a temporary buffer. Rationale for this size is
* listed in coll_basic_reduce.c. Use this temporary buffer to
* receive into, later. */
ompi_ddt_get_extent(dtype, &lb, &extent);
ompi_ddt_get_true_extent(dtype, &true_lb, &true_extent);
free_buffer = malloc(true_extent + (count - 1) * extent);
if (NULL == free_buffer) {
return OMPI_ERR_OUT_OF_RESOURCE;
}
pml_buffer = free_buffer - lb;
/* Copy the send buffer into the receive buffer. */
if (MPI_IN_PLACE != sbuf) {
err = ompi_ddt_copy_content_same_ddt(dtype, count, rbuf, sbuf);
if (MPI_SUCCESS != err) {
if (NULL != free_buffer) {
free(free_buffer);
}
return err;
}
}
/* Receive the prior answer */
err = MCA_PML_CALL(recv(pml_buffer, count, dtype,
rank - 1, MCA_COLL_BASE_TAG_SCAN, comm,
MPI_STATUS_IGNORE));
if (MPI_SUCCESS != err) {
if (NULL != free_buffer) {
free(free_buffer);
}
return err;
}
/* Perform the operation */
ompi_op_reduce(op, pml_buffer, rbuf, count, dtype);
/* All done */
if (NULL != free_buffer) {
free(free_buffer);
}
}
/* Send result to next process. */
if (rank < (size - 1)) {
return MCA_PML_CALL(send(rbuf, count, dtype, rank + 1,
MCA_COLL_BASE_TAG_SCAN,
MCA_PML_BASE_SEND_STANDARD, comm));
}
/* All done */
return MPI_SUCCESS;
}