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openmpi/ompi/mca/coll/libnbc/nbc_neighbor_helpers.c
Nathan Hjelm c5596548b2 MPI-3: Add support for neighborhood collectives
Blocking versions are simple linear algorithms implemented in coll/basic. Non-
blocking versions are from libnbc 1.1.1. All algorithms have been tested with
simple test cases.

cmr=v1.7.4:reviewer=jsquyres

This commit was SVN r29265.
2013-09-26 21:55:08 +00:00

107 строки
3.7 KiB
C

/*
* Copyright (c) 2006 The Trustees of Indiana University and Indiana
* University Research and Technology
* Corporation. All rights reserved.
* Copyright (c) 2006 The Technical University of Chemnitz. All
* rights reserved.
*
* Author(s): Torsten Hoefler <htor@cs.indiana.edu>
*
*/
#include "nbc_internal.h"
int NBC_Comm_neighbors_count(MPI_Comm comm, int *indegree, int *outdegree, int *weighted) {
int topo, res;
res = MPI_Topo_test(comm, &topo);
if (MPI_SUCCESS != res) { printf("MPI Error in MPI_Topo_test() (%i)\n", res); return res; }
switch(topo) {
case MPI_CART: /* cartesian */
{
int ndims;
res = MPI_Cartdim_get(comm, &ndims) ;
if (MPI_SUCCESS != res) { printf("MPI Error in MPI_Cartdim_get() (%i)\n", res); return res; }
/* outdegree is always 2*ndims because we need to iterate over empty buffers for MPI_PROC_NULL */
*outdegree = *indegree = 2*ndims;
*weighted = 0;
}
break;
case MPI_GRAPH: /* graph */
{
int rank, nneighbors;
MPI_Comm_rank(comm, &rank);
res = MPI_Graph_neighbors_count(comm, rank, &nneighbors);
if (MPI_SUCCESS != res) { printf("MPI Error in MPI_Graph_neighbors_count() (%i)\n", res); return res; }
*outdegree = *indegree = nneighbors;
*weighted = 0;
}
break;
case MPI_DIST_GRAPH: /* graph */
{
res = MPI_Dist_graph_neighbors_count(comm, indegree, outdegree, weighted);
if (MPI_SUCCESS != res) { printf("MPI Error in MPI_Dist_graph_neighbors_count() (%i)\n", res); return res; }
}
break;
case MPI_UNDEFINED:
return NBC_INVALID_TOPOLOGY_COMM;
break;
default:
return NBC_INVALID_PARAM;
break;
}
return NBC_OK;
}
int NBC_Comm_neighbors(MPI_Comm comm, int maxindegree, int sources[], int sourceweights[], int maxoutdegree, int destinations[], int destweights[]) {
int topo, res;
int index = 0;
int indeg, outdeg, wgtd;
res = NBC_Comm_neighbors_count(comm, &indeg, &outdeg, &wgtd);
if(indeg > maxindegree && outdeg > maxoutdegree) return NBC_INVALID_PARAM; /* we want to return *all* neighbors */
res = MPI_Topo_test(comm, &topo);
if (MPI_SUCCESS != res) { printf("MPI Error in MPI_Topo_test() (%i)\n", res); return res; }
switch(topo) {
case MPI_CART: /* cartesian */
{
int ndims, i, rpeer, speer;
res = MPI_Cartdim_get(comm, &ndims);
if (MPI_SUCCESS != res) { printf("MPI Error in MPI_Cartdim_get() (%i)\n", res); return res; }
for(i = 0; i<ndims; i++) {
res = MPI_Cart_shift(comm, i, 1, &rpeer, &speer);
if (MPI_SUCCESS != res) { printf("MPI Error in MPI_Cart_shift() (%i)\n", res); return res; }
sources[index] = destinations[index] = rpeer; index++;
sources[index] = destinations[index] = speer; index++;
}
}
break;
case MPI_GRAPH: /* graph */
{
int rank;
MPI_Comm_rank(comm, &rank);
res = MPI_Graph_neighbors(comm, rank, maxindegree, sources);
if (MPI_SUCCESS != res) { printf("MPI Error in MPI_Graph_neighbors_count() (%i)\n", res); return res; }
for(int i=0; i<maxindegree; i++) destinations[i] = sources[i];
}
break;
case MPI_DIST_GRAPH: /* dist graph */
{
res = MPI_Dist_graph_neighbors(comm, maxindegree, sources, sourceweights, maxoutdegree, destinations, destweights);
if (MPI_SUCCESS != res) { printf("MPI Error in MPI_Graph_neighbors_count() (%i)\n", res); return res; }
}
break;
case MPI_UNDEFINED:
return NBC_INVALID_TOPOLOGY_COMM;
break;
default:
return NBC_INVALID_PARAM;
break;
}
return NBC_OK;
}