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openmpi/ompi/mpi/c/reduce_scatter.c
Jeff Squyres 3e2031e0e3 Finally commit something that has been sitting around in one of my
development trees since last year (had to wait for some intel tests to
run yesterday, so I finally took the time to finish this work):

 * Improve MPI API argument checking by also checking for NULL values
   (especially helps when invalid Fortran MPI handles are passed,
   because the various MPI_*f2c functions are supposed to return an
   "invalid" MPI handle [meaning NULL] when this happens).  So now
   OMPI will generate an MPI exception rather than a segv.
 * Removed a few redundant DATATYPE_NULL checks.
 * Also check for some other forms of "invalid" handles (e.g., already
   been freed, etc.) in some cases.  We could probably be a bit more
   stringent in this regard if we really wanted to.
 * Change MPI_Get_processor_name to zero out the string up to
   MPI_MAX_PROCESSOR_NAME characters, because the MPI spec says that
   the string must be at least that long.  We were already passing
   that length to gethostname(), anyway.

This commit was SVN r14100.
2007-03-21 11:10:42 +00:00

103 строки
3.4 KiB
C

/*
* Copyright (c) 2004-2007 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2004-2005 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) 2006 Cisco Systems, Inc. All rights reserved.
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
#include "ompi_config.h"
#include <stdio.h>
#include "ompi/mpi/c/bindings.h"
#include "ompi/datatype/datatype.h"
#include "ompi/op/op.h"
#if OMPI_HAVE_WEAK_SYMBOLS && OMPI_PROFILING_DEFINES
#pragma weak MPI_Reduce_scatter = PMPI_Reduce_scatter
#endif
#if OMPI_PROFILING_DEFINES
#include "ompi/mpi/c/profile/defines.h"
#endif
static const char FUNC_NAME[] = "MPI_Reduce_scatter";
int MPI_Reduce_scatter(void *sendbuf, void *recvbuf, int *recvcounts,
MPI_Datatype datatype, MPI_Op op, MPI_Comm comm)
{
int i, err, size, count;
OPAL_CR_TEST_CHECKPOINT_READY();
if (MPI_PARAM_CHECK) {
char *msg;
err = MPI_SUCCESS;
OMPI_ERR_INIT_FINALIZE(FUNC_NAME);
if (ompi_comm_invalid(comm)) {
return OMPI_ERRHANDLER_INVOKE(MPI_COMM_WORLD, MPI_ERR_COMM,
FUNC_NAME);
}
/* Unrooted operation; same checks for all ranks on both
intracommunicators and intercommunicators */
else if (MPI_OP_NULL == op || NULL == op) {
err = MPI_ERR_OP;
} else if (!ompi_op_is_valid(op, datatype, &msg, FUNC_NAME)) {
int ret = OMPI_ERRHANDLER_INVOKE(comm, MPI_ERR_OP, msg);
free(msg);
return ret;
} else if (NULL == recvcounts) {
err = MPI_ERR_COUNT;
} else if (MPI_IN_PLACE == recvbuf) {
err = MPI_ERR_ARG;
}
OMPI_ERRHANDLER_CHECK(err, comm, err, FUNC_NAME);
/* We always define the remote group to be the same as the
local group in the case of an intracommunicator, so it's
safe to get the size of the remote group here for both
intra- and intercommunicators */
size = ompi_comm_size(comm);
for (i = 0; i < size; ++i) {
OMPI_CHECK_DATATYPE_FOR_SEND(err, datatype, recvcounts[i]);
OMPI_ERRHANDLER_CHECK(err, comm, err, FUNC_NAME);
}
}
/* MPI-1, p114, says that each process must supply at least one
element. But at least the Pallas benchmarks call MPI_REDUCE
with a count of 0. So be sure to handle it. Grrr... */
size = ompi_comm_size(comm);
for (count = i = 0; i < size; ++i) {
if (0 == recvcounts[i]) {
++count;
}
}
if (size == count) {
return MPI_SUCCESS;
}
/* Invoke the coll component to perform the back-end operation */
OBJ_RETAIN(op);
err = comm->c_coll.coll_reduce_scatter(sendbuf, recvbuf, recvcounts,
datatype, op, comm);
OBJ_RELEASE(op);
OMPI_ERRHANDLER_RETURN(err, comm, err, FUNC_NAME);
}