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openmpi/ompi/mca/coll/basic/coll_basic_exscan.c
George Bosilca 4d00c59b2e Cleanup the memory handling for temporary buffers in
some of the collective modules. Added a new function
opan_datatype_span, to compute the memory span of
count number of datatype, excluding the gaps in the
beginning and at the end. If a memory allocation is
made using the returned value, the gap (also returned)
should be removed from the allocated pointer.
2015-12-02 20:42:18 -05:00

136 строки
4.5 KiB
C

/*
* Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2014 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 (c) 2011 NVIDIA Corporation. All rights reserved.
* Copyright (c) 2015 Research Organization for Information Science
* and Technology (RIST). 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/constants.h"
#include "ompi/op/op.h"
#include "ompi/datatype/ompi_datatype.h"
#include "ompi/mca/pml/pml.h"
#include "ompi/mca/coll/coll.h"
#include "ompi/mca/coll/base/coll_tags.h"
#include "coll_basic.h"
/*
* exscan_intra
*
* Function: - basic exscan operation
* Accepts: - same arguments as MPI_Exscan()
* Returns: - MPI_SUCCESS or error code
*/
int
mca_coll_basic_exscan_intra(const void *sbuf, void *rbuf, int count,
struct ompi_datatype_t *dtype,
struct ompi_op_t *op,
struct ompi_communicator_t *comm,
mca_coll_base_module_t *module)
{
int size, rank, err;
ptrdiff_t dsize, gap;
char *free_buffer = NULL;
char *reduce_buffer = NULL;
rank = ompi_comm_rank(comm);
size = ompi_comm_size(comm);
/* For MPI_IN_PLACE, just adjust send buffer to point to
* receive buffer. */
if (MPI_IN_PLACE == sbuf) {
sbuf = rbuf;
}
/* If we're rank 0, then just send our sbuf to the next rank, and
* we are done. */
if (0 == rank) {
return MCA_PML_CALL(send(sbuf, count, dtype, rank + 1,
MCA_COLL_BASE_TAG_EXSCAN,
MCA_PML_BASE_SEND_STANDARD, comm));
}
/* If we're the last rank, then just receive the result from the
* prior rank, and we are done. */
else if ((size - 1) == rank) {
return MCA_PML_CALL(recv(rbuf, count, dtype, rank - 1,
MCA_COLL_BASE_TAG_EXSCAN, comm,
MPI_STATUS_IGNORE));
}
/* Otherwise, get the result from the prior rank, combine it with my
* data, and send it to the next rank */
/* Get a temporary buffer to perform the reduction into. Rationale
* for malloc'ing this size is provided in coll_basic_reduce.c. */
dsize = opal_datatype_span(&dtype->super, count, &gap);
free_buffer = (char*)malloc(dsize);
if (NULL == free_buffer) {
return OMPI_ERR_OUT_OF_RESOURCE;
}
reduce_buffer = free_buffer - gap;
err = ompi_datatype_copy_content_same_ddt(dtype, count,
reduce_buffer, (char*)sbuf);
/* Receive the reduced value from the prior rank */
err = MCA_PML_CALL(recv(rbuf, count, dtype, rank - 1,
MCA_COLL_BASE_TAG_EXSCAN, comm, MPI_STATUS_IGNORE));
if (MPI_SUCCESS != err) {
goto error;
}
/* Now reduce the prior rank's result with my source buffer. The source
* buffer had been previously copied into the temporary reduce_buffer. */
ompi_op_reduce(op, rbuf, reduce_buffer, count, dtype);
/* Send my result off to the next rank */
err = MCA_PML_CALL(send(reduce_buffer, count, dtype, rank + 1,
MCA_COLL_BASE_TAG_EXSCAN,
MCA_PML_BASE_SEND_STANDARD, comm));
/* Error */
error:
free(free_buffer);
/* All done */
return err;
}
/*
* exscan_inter
*
* Function: - basic exscan operation
* Accepts: - same arguments as MPI_Exscan()
* Returns: - MPI_SUCCESS or error code
*/
int
mca_coll_basic_exscan_inter(const void *sbuf, void *rbuf, int count,
struct ompi_datatype_t *dtype,
struct ompi_op_t *op,
struct ompi_communicator_t *comm,
mca_coll_base_module_t *module)
{
return OMPI_ERR_NOT_IMPLEMENTED;
}