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openmpi/ompi/mca/coll/basic/coll_basic_gather.c
2015-06-23 20:59:57 -07:00

85 строки
2.6 KiB
C

/*
* Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2015 The University of Tennessee and The University
* of Tennessee Research Foundation. 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 "mpi.h"
#include "ompi/constants.h"
#include "coll_basic.h"
#include "ompi/datatype/ompi_datatype.h"
#include "ompi/mca/coll/coll.h"
#include "ompi/mca/coll/base/coll_tags.h"
#include "ompi/mca/pml/pml.h"
/*
* gather_inter
*
* Function: - basic gather operation
* Accepts: - same arguments as MPI_Gather()
* Returns: - MPI_SUCCESS or error code
*/
int
mca_coll_basic_gather_inter(void *sbuf, int scount,
struct ompi_datatype_t *sdtype,
void *rbuf, int rcount,
struct ompi_datatype_t *rdtype,
int root, struct ompi_communicator_t *comm,
mca_coll_base_module_t *module)
{
int i;
int err;
int size;
char *ptmp;
MPI_Aint incr;
MPI_Aint extent;
MPI_Aint lb;
size = ompi_comm_remote_size(comm);
if (MPI_PROC_NULL == root) {
/* do nothing */
err = OMPI_SUCCESS;
} else if (MPI_ROOT != root) {
/* Everyone but root sends data and returns. */
err = MCA_PML_CALL(send(sbuf, scount, sdtype, root,
MCA_COLL_BASE_TAG_GATHER,
MCA_PML_BASE_SEND_STANDARD, comm));
} else {
/* I am the root, loop receiving the data. */
err = ompi_datatype_get_extent(rdtype, &lb, &extent);
if (OMPI_SUCCESS != err) {
return OMPI_ERROR;
}
incr = extent * rcount;
for (i = 0, ptmp = (char *) rbuf; i < size; ++i, ptmp += incr) {
err = MCA_PML_CALL(recv(ptmp, rcount, rdtype, i,
MCA_COLL_BASE_TAG_GATHER,
comm, MPI_STATUS_IGNORE));
if (MPI_SUCCESS != err) {
return err;
}
}
}
/* All done */
return err;
}