furnace/extern/fftw/mpi/wisdom-api.c

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/*
* Copyright (c) 2003, 2007-14 Matteo Frigo
* Copyright (c) 2003, 2007-14 Massachusetts Institute of Technology
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include "fftw3-mpi.h"
#include "ifftw-mpi.h"
#include <string.h>
#if SIZEOF_SIZE_T == SIZEOF_UNSIGNED_INT
# define FFTW_MPI_SIZE_T MPI_UNSIGNED
#elif SIZEOF_SIZE_T == SIZEOF_UNSIGNED_LONG
# define FFTW_MPI_SIZE_T MPI_UNSIGNED_LONG
#elif SIZEOF_SIZE_T == SIZEOF_UNSIGNED_LONG_LONG
# define FFTW_MPI_SIZE_T MPI_UNSIGNED_LONG_LONG
#else
# error MPI type for size_t is unknown
# define FFTW_MPI_SIZE_T MPI_UNSIGNED_LONG
#endif
/* Import wisdom from all processes to process 0, as prelude to
exporting a single wisdom file (this is convenient when we are
running on identical processors, to avoid the annoyance of having
per-process wisdom files). In order to make the time for this
operation logarithmic in the number of processors (rather than
linear), we employ a tree reduction algorithm. This means that the
wisdom is modified on processes other than root, which shouldn't
matter in practice. */
void XM(gather_wisdom)(MPI_Comm comm_)
{
MPI_Comm comm, comm2;
int my_pe, n_pes;
char *wis;
size_t wislen;
MPI_Status status;
MPI_Comm_dup(comm_, &comm);
MPI_Comm_rank(comm, &my_pe);
MPI_Comm_size(comm, &n_pes);
if (n_pes > 2) { /* recursively split into even/odd processes */
MPI_Comm_split(comm, my_pe % 2, my_pe, &comm2);
XM(gather_wisdom)(comm2);
MPI_Comm_free(&comm2);
}
if (n_pes > 1 && my_pe < 2) { /* import process 1 -> 0 */
if (my_pe == 1) {
wis = X(export_wisdom_to_string)();
wislen = strlen(wis) + 1;
MPI_Send(&wislen, 1, FFTW_MPI_SIZE_T, 0, 111, comm);
MPI_Send(wis, wislen, MPI_CHAR, 0, 222, comm);
free(wis);
}
else /* my_pe == 0 */ {
MPI_Recv(&wislen, 1, FFTW_MPI_SIZE_T, 1, 111, comm, &status);
wis = (char *) MALLOC(wislen * sizeof(char), OTHER);
MPI_Recv(wis, wislen, MPI_CHAR, 1, 222, comm, &status);
if (!X(import_wisdom_from_string)(wis))
MPI_Abort(comm, 1);
X(ifree)(wis);
}
}
MPI_Comm_free(&comm);
}
/* broadcast wisdom from process 0 to all other processes; this
is useful so that we can import wisdom once and not worry
about parallel I/O or process-specific wisdom, although of
course it assumes that all the processes have identical
performance characteristics (i.e. identical hardware). */
void XM(broadcast_wisdom)(MPI_Comm comm_)
{
MPI_Comm comm;
int my_pe;
char *wis;
size_t wislen;
MPI_Comm_dup(comm_, &comm);
MPI_Comm_rank(comm, &my_pe);
if (my_pe != 0) {
MPI_Bcast(&wislen, 1, FFTW_MPI_SIZE_T, 0, comm);
wis = (char *) MALLOC(wislen * sizeof(char), OTHER);
MPI_Bcast(wis, wislen, MPI_CHAR, 0, comm);
if (!X(import_wisdom_from_string)(wis))
MPI_Abort(comm, 1);
X(ifree)(wis);
}
else /* my_pe == 0 */ {
wis = X(export_wisdom_to_string)();
wislen = strlen(wis) + 1;
MPI_Bcast(&wislen, 1, FFTW_MPI_SIZE_T, 0, comm);
MPI_Bcast(wis, wislen, MPI_CHAR, 0, comm);
X(free)(wis);
}
MPI_Comm_free(&comm);
}