1 /* Copyright (c) 2010-2014. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
10 #include "smpi_mpi_dt_private.h"
12 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(smpi_comm, smpi,
13 "Logging specific to SMPI (comm)");
17 /* Support for cartesian topology was added, but there are 2 other types of
18 * topology, graph et dist graph. In order to support them, we have to add a
19 * field MPIR_Topo_type, and replace the MPI_Topology field by an union. */
21 typedef struct s_smpi_mpi_communicator {
23 MPIR_Topo_type topoType;
24 MPI_Topology topo; // to be replaced by an union
26 } s_smpi_mpi_communicator_t;
28 static int smpi_compare_rankmap(const void *a, const void *b)
30 const int* x = (const int*)a;
31 const int* y = (const int*)b;
48 MPI_Comm smpi_comm_new(MPI_Group group, MPI_Topology topo)
52 comm = xbt_new(s_smpi_mpi_communicator_t, 1);
54 smpi_group_use(comm->group);
60 void smpi_comm_destroy(MPI_Comm comm)
62 if (comm == MPI_COMM_UNINITIALIZED)
63 comm = smpi_process_comm_world();
64 smpi_group_unuse(comm->group);
65 smpi_topo_destroy(comm->topo); // there's no use count on topos
66 smpi_comm_unuse(comm);
69 MPI_Group smpi_comm_group(MPI_Comm comm)
71 if (comm == MPI_COMM_UNINITIALIZED)
72 comm = smpi_process_comm_world();
77 MPI_Topology smpi_comm_topo(MPI_Comm comm) {
78 if (comm != MPI_COMM_NULL)
83 int smpi_comm_size(MPI_Comm comm)
85 if (comm == MPI_COMM_UNINITIALIZED)
86 comm = smpi_process_comm_world();
88 return smpi_group_size(smpi_comm_group(comm));
91 int smpi_comm_rank(MPI_Comm comm)
93 if (comm == MPI_COMM_UNINITIALIZED)
94 comm = smpi_process_comm_world();
95 return smpi_group_rank(smpi_comm_group(comm), smpi_process_index());
98 void smpi_comm_get_name (MPI_Comm comm, char* name, int* len)
100 if (comm == MPI_COMM_UNINITIALIZED)
101 comm = smpi_process_comm_world();
102 if(comm == MPI_COMM_WORLD) {
103 strcpy(name, "WORLD");
106 *len = snprintf(name, MPI_MAX_NAME_STRING, "%p", comm);
110 MPI_Comm smpi_comm_split(MPI_Comm comm, int color, int key)
112 if (comm == MPI_COMM_UNINITIALIZED)
113 comm = smpi_process_comm_world();
114 int system_tag = 123;
115 int index, rank, size, i, j, count, reqs;
119 MPI_Group group, group_root, group_out;
120 MPI_Request* requests;
122 group_root = group_out = NULL;
123 group = smpi_comm_group(comm);
124 rank = smpi_comm_rank(comm);
125 size = smpi_comm_size(comm);
126 /* Gather all colors and keys on rank 0 */
127 sendbuf = xbt_new(int, 2);
131 recvbuf = xbt_new(int, 2 * size);
135 smpi_mpi_gather(sendbuf, 2, MPI_INT, recvbuf, 2, MPI_INT, 0, comm);
137 /* Do the actual job */
139 rankmap = xbt_new(int, 2 * size);
140 for(i = 0; i < size; i++) {
141 if(recvbuf[2 * i] == MPI_UNDEFINED) {
145 for(j = i + 1; j < size; j++) {
146 if(recvbuf[2 * i] == recvbuf[2 * j]) {
147 recvbuf[2 * j] = MPI_UNDEFINED;
148 rankmap[2 * count] = j;
149 rankmap[2 * count + 1] = recvbuf[2 * j + 1];
153 /* Add self in the group */
154 recvbuf[2 * i] = MPI_UNDEFINED;
155 rankmap[2 * count] = i;
156 rankmap[2 * count + 1] = recvbuf[2 * i + 1];
158 qsort(rankmap, count, 2 * sizeof(int), &smpi_compare_rankmap);
159 group_out = smpi_group_new(count);
161 group_root = group_out; /* Save root's group */
163 for(j = 0; j < count; j++) {
164 //increment refcounter in order to avoid freeing the group too quick before copy
165 index = smpi_group_index(group, rankmap[2 * j]);
166 smpi_group_set_mapping(group_out, index, j);
168 requests = xbt_new(MPI_Request, count);
170 for(j = 0; j < count; j++) {
171 if(rankmap[2 * j] != 0) {
172 requests[reqs] = smpi_isend_init(&group_out, 1, MPI_PTR, rankmap[2 * j], system_tag, comm);
176 smpi_mpi_startall(reqs, requests);
177 smpi_mpi_waitall(reqs, requests, MPI_STATUS_IGNORE);
181 group_out = group_root; /* exit with root's group */
183 if(color != MPI_UNDEFINED) {
184 smpi_mpi_recv(&group_out, 1, MPI_PTR, 0, system_tag, comm, MPI_STATUS_IGNORE);
186 group_out=smpi_group_copy(group_out);
188 } /* otherwise, exit with group_out == NULL */
190 return group_out ? smpi_comm_new(group_out, NULL) : MPI_COMM_NULL;
193 void smpi_comm_use(MPI_Comm comm){
194 if (comm == MPI_COMM_UNINITIALIZED)
195 comm = smpi_process_comm_world();
199 void smpi_comm_unuse(MPI_Comm comm){
200 if (comm == MPI_COMM_UNINITIALIZED)
201 comm = smpi_process_comm_world();
203 if(comm->refcount==0)