src/smpi/colls/smpi_coll.cpp

   1 /* smpi_coll.c -- various optimized routing for collectives                 */
   2
   3 /* Copyright (c) 2009-2019. The SimGrid Team. All rights reserved.          */
   4
   5 /* This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the license (GNU LGPL) which comes with this package. */
   7
   8 #include "smpi_coll.hpp"
   9 #include "private.hpp"
  10 #include "smpi_comm.hpp"
  11 #include "smpi_datatype.hpp"
  12 #include "smpi_op.hpp"
  13 #include "smpi_request.hpp"
  14 #include "xbt/config.hpp"
  15
  16 #include <map>
  17
  18 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(smpi_coll, smpi, "Logging specific to SMPI collectives.");
  19
  20 namespace simgrid {
  21 namespace smpi {
  22
  23 std::map<std::string, std::vector<s_mpi_coll_description_t>> smpi_coll_descriptions(
  24     {{std::string("gather"),
  25       {{"default", "gather default collective", (void*)gather__default},
  26        {"ompi", "gather ompi collective", (void*)gather__ompi},
  27        {"ompi_basic_linear", "gather ompi_basic_linear collective", (void*)gather__ompi_basic_linear},
  28        {"ompi_binomial", "gather ompi_binomial collective", (void*)gather__ompi_binomial},
  29        {"ompi_linear_sync", "gather ompi_linear_sync collective", (void*)gather__ompi_linear_sync},
  30        {"mpich", "gather mpich collective", (void*)gather__mpich},
  31        {"mvapich2", "gather mvapich2 collective", (void*)gather__mvapich2},
  32        {"mvapich2_two_level", "gather mvapich2_two_level collective", (void*)gather__mvapich2_two_level},
  33        {"impi", "gather impi collective", (void*)gather__impi},
  34        {"automatic", "gather automatic collective", (void*)gather__automatic}}},
  35
  36      {"allgather",
  37       {{"default", "allgather default collective", (void*)allgather__default},
  38        {"2dmesh", "allgather 2dmesh collective", (void*)allgather__2dmesh},
  39        {"3dmesh", "allgather 3dmesh collective", (void*)allgather__3dmesh},
  40        {"bruck", "allgather bruck collective", (void*)allgather__bruck},
  41        {"GB", "allgather GB collective", (void*)allgather__GB},
  42        {"loosely_lr", "allgather loosely_lr collective", (void*)allgather__loosely_lr},
  43        {"NTSLR", "allgather NTSLR collective", (void*)allgather__NTSLR},
  44        {"NTSLR_NB", "allgather NTSLR_NB collective", (void*)allgather__NTSLR_NB},
  45        {"pair", "allgather pair collective", (void*)allgather__pair},
  46        {"rdb", "allgather rdb collective", (void*)allgather__rdb},
  47        {"rhv", "allgather rhv collective", (void*)allgather__rhv},
  48        {"ring", "allgather ring collective", (void*)allgather__ring},
  49        {"SMP_NTS", "allgather SMP_NTS collective", (void*)allgather__SMP_NTS},
  50        {"smp_simple", "allgather smp_simple collective", (void*)allgather__smp_simple},
  51        {"spreading_simple", "allgather spreading_simple collective", (void*)allgather__spreading_simple},
  52        {"ompi", "allgather ompi collective", (void*)allgather__ompi},
  53        {"ompi_neighborexchange", "allgather ompi_neighborexchange collective", (void*)allgather__ompi_neighborexchange},
  54        {"mvapich2", "allgather mvapich2 collective", (void*)allgather__mvapich2},
  55        {"mvapich2_smp", "allgather mvapich2_smp collective", (void*)allgather__mvapich2_smp},
  56        {"mpich", "allgather mpich collective", (void*)allgather__mpich},
  57        {"impi", "allgather impi collective", (void*)allgather__impi},
  58        {"automatic", "allgather automatic collective", (void*)allgather__automatic}}},
  59
  60      {"allgatherv",
  61       {{"default", "allgatherv default collective", (void*)allgatherv__default},
  62        {"GB", "allgatherv GB collective", (void*)allgatherv__GB},
  63        {"pair", "allgatherv pair collective", (void*)allgatherv__pair},
  64        {"ring", "allgatherv ring collective", (void*)allgatherv__ring},
  65        {"ompi", "allgatherv ompi collective", (void*)allgatherv__ompi},
  66        {"ompi_neighborexchange", "allgatherv ompi_neighborexchange collective",
  67         (void*)allgatherv__ompi_neighborexchange},
  68        {"ompi_bruck", "allgatherv ompi_bruck collective", (void*)allgatherv__ompi_bruck},
  69        {"mpich", "allgatherv mpich collective", (void*)allgatherv__mpich},
  70        {"mpich_rdb", "allgatherv mpich_rdb collective", (void*)allgatherv__mpich_rdb},
  71        {"mpich_ring", "allgatherv mpich_ring collective", (void*)allgatherv__mpich_ring},
  72        {"mvapich2", "allgatherv mvapich2 collective", (void*)allgatherv__mvapich2},
  73        {"impi", "allgatherv impi collective", (void*)allgatherv__impi},
  74        {"automatic", "allgatherv automatic collective", (void*)allgatherv__automatic}}},
  75
  76      {"allreduce",
  77       {{"default", "allreduce default collective", (void*)allreduce__default},
  78        {"lr", "allreduce lr collective", (void*)allreduce__lr},
  79        {"rab1", "allreduce rab1 collective", (void*)allreduce__rab1},
  80        {"rab2", "allreduce rab2 collective", (void*)allreduce__rab2},
  81        {"rab_rdb", "allreduce rab_rdb collective", (void*)allreduce__rab_rdb},
  82        {"rdb", "allreduce rdb collective", (void*)allreduce__rdb},
  83        {"smp_binomial", "allreduce smp_binomial collective", (void*)allreduce__smp_binomial},
  84        {"smp_binomial_pipeline", "allreduce smp_binomial_pipeline collective", (void*)allreduce__smp_binomial_pipeline},
  85        {"smp_rdb", "allreduce smp_rdb collective", (void*)allreduce__smp_rdb},
  86        {"smp_rsag", "allreduce smp_rsag collective", (void*)allreduce__smp_rsag},
  87        {"smp_rsag_lr", "allreduce smp_rsag_lr collective", (void*)allreduce__smp_rsag_lr},
  88        {"smp_rsag_rab", "allreduce smp_rsag_rab collective", (void*)allreduce__smp_rsag_rab},
  89        {"redbcast", "allreduce redbcast collective", (void*)allreduce__redbcast},
  90        {"ompi", "allreduce ompi collective", (void*)allreduce__ompi},
  91        {"ompi_ring_segmented", "allreduce ompi_ring_segmented collective", (void*)allreduce__ompi_ring_segmented},
  92        {"mpich", "allreduce mpich collective", (void*)allreduce__mpich},
  93        {"mvapich2", "allreduce mvapich2 collective", (void*)allreduce__mvapich2},
  94        {"mvapich2_rs", "allreduce mvapich2_rs collective", (void*)allreduce__mvapich2_rs},
  95        {"mvapich2_two_level", "allreduce mvapich2_two_level collective", (void*)allreduce__mvapich2_two_level},
  96        {"impi", "allreduce impi collective", (void*)allreduce__impi},
  97        {"rab", "allreduce rab collective", (void*)allreduce__rab},
  98        {"automatic", "allreduce automatic collective", (void*)allreduce__automatic}}},
  99
 100      {"reduce_scatter",
 101       {{"default", "reduce_scatter default collective", (void*)reduce_scatter__default},
 102        {"ompi", "reduce_scatter ompi collective", (void*)reduce_scatter__ompi},
 103        {"ompi_basic_recursivehalving", "reduce_scatter ompi_basic_recursivehalving collective",
 104         (void*)reduce_scatter__ompi_basic_recursivehalving},
 105        {"ompi_ring", "reduce_scatter ompi_ring collective", (void*)reduce_scatter__ompi_ring},
 106        {"mpich", "reduce_scatter mpich collective", (void*)reduce_scatter__mpich},
 107        {"mpich_pair", "reduce_scatter mpich_pair collective", (void*)reduce_scatter__mpich_pair},
 108        {"mpich_rdb", "reduce_scatter mpich_rdb collective", (void*)reduce_scatter__mpich_rdb},
 109        {"mpich_noncomm", "reduce_scatter mpich_noncomm collective", (void*)reduce_scatter__mpich_noncomm},
 110        {"mvapich2", "reduce_scatter mvapich2 collective", (void*)reduce_scatter__mvapich2},
 111        {"impi", "reduce_scatter impi collective", (void*)reduce_scatter__impi},
 112        {"automatic", "reduce_scatter automatic collective", (void*)reduce_scatter__automatic}}},
 113
 114      {"scatter",
 115       {{"default", "scatter default collective", (void*)scatter__default},
 116        {"ompi", "scatter ompi collective", (void*)scatter__ompi},
 117        {"ompi_basic_linear", "scatter ompi_basic_linear collective", (void*)scatter__ompi_basic_linear},
 118        {"ompi_binomial", "scatter ompi_binomial collective", (void*)scatter__ompi_binomial},
 119        {"mpich", "scatter mpich collective", (void*)scatter__mpich},
 120        {"mvapich2", "scatter mvapich2 collective", (void*)scatter__mvapich2},
 121        {"mvapich2_two_level_binomial", "scatter mvapich2_two_level_binomial collective",
 122         (void*)scatter__mvapich2_two_level_binomial},
 123        {"mvapich2_two_level_direct", "scatter mvapich2_two_level_direct collective",
 124         (void*)scatter__mvapich2_two_level_direct},
 125        {"impi", "scatter impi collective", (void*)scatter__impi},
 126        {"automatic", "scatter automatic collective", (void*)scatter__automatic}}},
 127
 128      {"barrier",
 129       {{"default", "barrier default collective", (void*)barrier__default},
 130        {"ompi", "barrier ompi collective", (void*)barrier__ompi},
 131        {"ompi_basic_linear", "barrier ompi_basic_linear collective", (void*)barrier__ompi_basic_linear},
 132        {"ompi_two_procs", "barrier ompi_two_procs collective", (void*)barrier__ompi_two_procs},
 133        {"ompi_tree", "barrier ompi_tree collective", (void*)barrier__ompi_tree},
 134        {"ompi_bruck", "barrier ompi_bruck collective", (void*)barrier__ompi_bruck},
 135        {"ompi_recursivedoubling", "barrier ompi_recursivedoubling collective", (void*)barrier__ompi_recursivedoubling},
 136        {"ompi_doublering", "barrier ompi_doublering collective", (void*)barrier__ompi_doublering},
 137        {"mpich_smp", "barrier mpich_smp collective", (void*)barrier__mpich_smp},
 138        {"mpich", "barrier mpich collective", (void*)barrier__mpich},
 139        {"mvapich2_pair", "barrier mvapich2_pair collective", (void*)barrier__mvapich2_pair},
 140        {"mvapich2", "barrier mvapich2 collective", (void*)barrier__mvapich2},
 141        {"impi", "barrier impi collective", (void*)barrier__impi},
 142        {"automatic", "barrier automatic collective", (void*)barrier__automatic}}},
 143
 144      {"alltoall",
 145       {{"default", "alltoall default collective", (void*)alltoall__default},
 146        {"2dmesh", "alltoall 2dmesh collective", (void*)alltoall__2dmesh},
 147        {"3dmesh", "alltoall 3dmesh collective", (void*)alltoall__3dmesh},
 148        {"basic_linear", "alltoall basic_linear collective", (void*)alltoall__basic_linear},
 149        {"bruck", "alltoall bruck collective", (void*)alltoall__bruck},
 150        {"pair", "alltoall pair collective", (void*)alltoall__pair},
 151        {"pair_rma", "alltoall pair_rma collective", (void*)alltoall__pair_rma},
 152        {"pair_light_barrier", "alltoall pair_light_barrier collective", (void*)alltoall__pair_light_barrier},
 153        {"pair_mpi_barrier", "alltoall pair_mpi_barrier collective", (void*)alltoall__pair_mpi_barrier},
 154        {"pair_one_barrier", "alltoall pair_one_barrier collective", (void*)alltoall__pair_one_barrier},
 155        {"rdb", "alltoall rdb collective", (void*)alltoall__rdb},
 156        {"ring", "alltoall ring collective", (void*)alltoall__ring},
 157        {"ring_light_barrier", "alltoall ring_light_barrier collective", (void*)alltoall__ring_light_barrier},
 158        {"ring_mpi_barrier", "alltoall ring_mpi_barrier collective", (void*)alltoall__ring_mpi_barrier},
 159        {"ring_one_barrier", "alltoall ring_one_barrier collective", (void*)alltoall__ring_one_barrier},
 160        {"mvapich2", "alltoall mvapich2 collective", (void*)alltoall__mvapich2},
 161        {"mvapich2_scatter_dest", "alltoall mvapich2_scatter_dest collective", (void*)alltoall__mvapich2_scatter_dest},
 162        {"ompi", "alltoall ompi collective", (void*)alltoall__ompi},
 163        {"mpich", "alltoall mpich collective", (void*)alltoall__mpich},
 164        {"impi", "alltoall impi collective", (void*)alltoall__impi},
 165        {"automatic", "alltoall automatic collective", (void*)alltoall__automatic}}},
 166
 167      {"alltoallv",
 168       {{"default", "alltoallv default collective", (void*)alltoallv__default},
 169        {"bruck", "alltoallv bruck collective", (void*)alltoallv__bruck},
 170        {"pair", "alltoallv pair collective", (void*)alltoallv__pair},
 171        {"pair_light_barrier", "alltoallv pair_light_barrier collective", (void*)alltoallv__pair_light_barrier},
 172        {"pair_mpi_barrier", "alltoallv pair_mpi_barrier collective", (void*)alltoallv__pair_mpi_barrier},
 173        {"pair_one_barrier", "alltoallv pair_one_barrier collective", (void*)alltoallv__pair_one_barrier},
 174        {"ring", "alltoallv ring collective", (void*)alltoallv__ring},
 175        {"ring_light_barrier", "alltoallv ring_light_barrier collective", (void*)alltoallv__ring_light_barrier},
 176        {"ring_mpi_barrier", "alltoallv ring_mpi_barrier collective", (void*)alltoallv__ring_mpi_barrier},
 177        {"ring_one_barrier", "alltoallv ring_one_barrier collective", (void*)alltoallv__ring_one_barrier},
 178        {"ompi", "alltoallv ompi collective", (void*)alltoallv__ompi},
 179        {"mpich", "alltoallv mpich collective", (void*)alltoallv__mpich},
 180        {"ompi_basic_linear", "alltoallv ompi_basic_linear collective", (void*)alltoallv__ompi_basic_linear},
 181        {"mvapich2", "alltoallv mvapich2 collective", (void*)alltoallv__mvapich2},
 182        {"impi", "alltoallv impi collective", (void*)alltoallv__impi},
 183        {"automatic", "alltoallv automatic collective", (void*)alltoallv__automatic}}},
 184
 185      {"bcast",
 186       {{"default", "bcast default collective", (void*)bcast__default},
 187        {"arrival_pattern_aware", "bcast arrival_pattern_aware collective", (void*)bcast__arrival_pattern_aware},
 188        {"arrival_pattern_aware_wait", "bcast arrival_pattern_aware_wait collective",
 189         (void*)bcast__arrival_pattern_aware_wait},
 190        {"arrival_scatter", "bcast arrival_scatter collective", (void*)bcast__arrival_scatter},
 191        {"binomial_tree", "bcast binomial_tree collective", (void*)bcast__binomial_tree},
 192        {"flattree", "bcast flattree collective", (void*)bcast__flattree},
 193        {"flattree_pipeline", "bcast flattree_pipeline collective", (void*)bcast__flattree_pipeline},
 194        {"NTSB", "bcast NTSB collective", (void*)bcast__NTSB},
 195        {"NTSL", "bcast NTSL collective", (void*)bcast__NTSL},
 196        {"NTSL_Isend", "bcast NTSL_Isend collective", (void*)bcast__NTSL_Isend},
 197        {"scatter_LR_allgather", "bcast scatter_LR_allgather collective", (void*)bcast__scatter_LR_allgather},
 198        {"scatter_rdb_allgather", "bcast scatter_rdb_allgather collective", (void*)bcast__scatter_rdb_allgather},
 199        {"SMP_binary", "bcast SMP_binary collective", (void*)bcast__SMP_binary},
 200        {"SMP_binomial", "bcast SMP_binomial collective", (void*)bcast__SMP_binomial},
 201        {"SMP_linear", "bcast SMP_linear collective", (void*)bcast__SMP_linear},
 202        {"ompi", "bcast ompi collective", (void*)bcast__ompi},
 203        {"ompi_split_bintree", "bcast ompi_split_bintree collective", (void*)bcast__ompi_split_bintree},
 204        {"ompi_pipeline", "bcast ompi_pipeline collective", (void*)bcast__ompi_pipeline},
 205        {"mpich", "bcast mpich collective", (void*)bcast__mpich},
 206        {"mvapich2", "bcast mvapich2 collective", (void*)bcast__mvapich2},
 207        {"mvapich2_inter_node", "bcast mvapich2_inter_node collective", (void*)bcast__mvapich2_inter_node},
 208        {"mvapich2_intra_node", "bcast mvapich2_intra_node collective", (void*)bcast__mvapich2_intra_node},
 209        {"mvapich2_knomial_intra_node", "bcast mvapich2_knomial_intra_node collective",
 210         (void*)bcast__mvapich2_knomial_intra_node},
 211        {"impi", "bcast impi collective", (void*)bcast__impi},
 212        {"automatic", "bcast automatic collective", (void*)bcast__automatic}}},
 213
 214      {"reduce",
 215       {{"default", "reduce default collective", (void*)reduce__default},
 216        {"arrival_pattern_aware", "reduce arrival_pattern_aware collective", (void*)reduce__arrival_pattern_aware},
 217        {"binomial", "reduce binomial collective", (void*)reduce__binomial},
 218        {"flat_tree", "reduce flat_tree collective", (void*)reduce__flat_tree},
 219        {"NTSL", "reduce NTSL collective", (void*)reduce__NTSL},
 220        {"scatter_gather", "reduce scatter_gather collective", (void*)reduce__scatter_gather},
 221        {"ompi", "reduce ompi collective", (void*)reduce__ompi},
 222        {"ompi_chain", "reduce ompi_chain collective", (void*)reduce__ompi_chain},
 223        {"ompi_pipeline", "reduce ompi_pipeline collective", (void*)reduce__ompi_pipeline},
 224        {"ompi_basic_linear", "reduce ompi_basic_linear collective", (void*)reduce__ompi_basic_linear},
 225        {"ompi_in_order_binary", "reduce ompi_in_order_binary collective", (void*)reduce__ompi_in_order_binary},
 226        {"ompi_binary", "reduce ompi_binary collective", (void*)reduce__ompi_binary},
 227        {"ompi_binomial", "reduce ompi_binomial collective", (void*)reduce__ompi_binomial},
 228        {"mpich", "reduce mpich collective", (void*)reduce__mpich},
 229        {"mvapich2", "reduce mvapich2 collective", (void*)reduce__mvapich2},
 230        {"mvapich2_knomial", "reduce mvapich2_knomial collective", (void*)reduce__mvapich2_knomial},
 231        {"mvapich2_two_level", "reduce mvapich2_two_level collective", (void*)reduce__mvapich2_two_level},
 232        {"impi", "reduce impi collective", (void*)reduce__impi},
 233        {"rab", "reduce rab collective", (void*)reduce__rab},
 234        {"automatic", "reduce automatic collective", (void*)reduce__automatic}}}});
 235
 236 // Needed by the automatic selector weird implementation
 237 std::vector<s_mpi_coll_description_t>* colls::get_smpi_coll_descriptions(const std::string& name)
 238 {
 239   if (smpi_coll_descriptions.find(name) == smpi_coll_descriptions.end())
 240     xbt_die("No collective named %s. This is a bug.", name.c_str());
 241   return &smpi_coll_descriptions[name];
 242 }
 243
 244 static s_mpi_coll_description_t* find_coll_description(const std::string& collective, const std::string& algo)
 245 {
 246   std::vector<s_mpi_coll_description_t>* table = colls::get_smpi_coll_descriptions(collective);
 247   if (table->empty())
 248     xbt_die("No registered algorithm for collective '%s'! This is a bug.", collective.c_str());
 249
 250   for (unsigned long i = 0; i < table->size(); i++) {
 251     auto desc = &table->at(i);
 252     if (algo == desc->name) {
 253       if (desc->name != "default")
 254         XBT_INFO("Switch to algorithm %s for collective %s", desc->name.c_str(), collective.c_str());
 255       return desc;
 256     }
 257   }
 258
 259   std::string name_list = table->at(0).name;
 260   for (unsigned long i = 1; i < table->size(); i++)
 261     name_list = name_list + ", " + table->at(i).name;
 262   xbt_die("Collective '%s' has no algorithm '%s'! Valid algorithms: %s.", collective.c_str(), algo.c_str(), name_list.c_str());
 263 }
 264
 265 int (*colls::gather)(const void* send_buff, int send_count, MPI_Datatype send_type, void* recv_buff, int recv_count,
 266                      MPI_Datatype recv_type, int root, MPI_Comm comm);
 267 int (*colls::allgather)(const void* send_buff, int send_count, MPI_Datatype send_type, void* recv_buff, int recv_count,
 268                         MPI_Datatype recv_type, MPI_Comm comm);
 269 int (*colls::allgatherv)(const void* send_buff, int send_count, MPI_Datatype send_type, void* recv_buff,
 270                          const int* recv_count, const int* recv_disps, MPI_Datatype recv_type, MPI_Comm comm);
 271 int (*colls::alltoall)(const void* send_buff, int send_count, MPI_Datatype send_type, void* recv_buff, int recv_count,
 272                        MPI_Datatype recv_type, MPI_Comm comm);
 273 int (*colls::alltoallv)(const void* send_buff, const int* send_counts, const int* send_disps, MPI_Datatype send_type,
 274                         void* recv_buff, const int* recv_counts, const int* recv_disps, MPI_Datatype recv_type,
 275                         MPI_Comm comm);
 276 int (*colls::bcast)(void* buf, int count, MPI_Datatype datatype, int root, MPI_Comm comm);
 277 int (*colls::reduce)(const void* buf, void* rbuf, int count, MPI_Datatype datatype, MPI_Op op, int root, MPI_Comm comm);
 278 int (*colls::allreduce)(const void* sbuf, void* rbuf, int rcount, MPI_Datatype dtype, MPI_Op op, MPI_Comm comm);
 279 int (*colls::reduce_scatter)(const void* sbuf, void* rbuf, const int* rcounts, MPI_Datatype dtype, MPI_Op op,
 280                              MPI_Comm comm);
 281 int (*colls::scatter)(const void* sendbuf, int sendcount, MPI_Datatype sendtype, void* recvbuf, int recvcount,
 282                       MPI_Datatype recvtype, int root, MPI_Comm comm);
 283 int (*colls::barrier)(MPI_Comm comm);
 284
 285 void (*colls::smpi_coll_cleanup_callback)();
 286
 287 #define COLL_SETTER(cat, ret, args, args2)                                                                             \
 288   void colls::_XBT_CONCAT(set_, cat)(const std::string& name)                                                          \
 289   {                                                                                                                    \
 290     auto desc = find_coll_description(_XBT_STRINGIFY(cat), name);                                                      \
 291     cat       = reinterpret_cast<ret(*) args>(desc->coll);                                                             \
 292     if (cat == nullptr)                                                                                                \
 293       xbt_die("Collective " _XBT_STRINGIFY(cat) " set to nullptr!");                                                   \
 294   }
 295 COLL_APPLY(COLL_SETTER, COLL_GATHER_SIG, "")
 296 COLL_APPLY(COLL_SETTER,COLL_ALLGATHER_SIG,"")
 297 COLL_APPLY(COLL_SETTER,COLL_ALLGATHERV_SIG,"")
 298 COLL_APPLY(COLL_SETTER,COLL_REDUCE_SIG,"")
 299 COLL_APPLY(COLL_SETTER,COLL_ALLREDUCE_SIG,"")
 300 COLL_APPLY(COLL_SETTER,COLL_REDUCE_SCATTER_SIG,"")
 301 COLL_APPLY(COLL_SETTER,COLL_SCATTER_SIG,"")
 302 COLL_APPLY(COLL_SETTER,COLL_BARRIER_SIG,"")
 303 COLL_APPLY(COLL_SETTER,COLL_BCAST_SIG,"")
 304 COLL_APPLY(COLL_SETTER,COLL_ALLTOALL_SIG,"")
 305 COLL_APPLY(COLL_SETTER,COLL_ALLTOALLV_SIG,"")
 306
 307 void colls::set_collectives()
 308 {
 309   std::string selector_name = simgrid::config::get_value<std::string>("smpi/coll-selector");
 310   if (selector_name.empty())
 311     selector_name = "default";
 312
 313   std::pair<std::string, std::function<void(std::string)>> setter_callbacks[] = {
 314       {"gather", &colls::set_gather},         {"allgather", &colls::set_allgather},
 315       {"allgatherv", &colls::set_allgatherv}, {"allreduce", &colls::set_allreduce},
 316       {"alltoall", &colls::set_alltoall},     {"alltoallv", &colls::set_alltoallv},
 317       {"reduce", &colls::set_reduce},         {"reduce_scatter", &colls::set_reduce_scatter},
 318       {"scatter", &colls::set_scatter},       {"bcast", &colls::set_bcast},
 319       {"barrier", &colls::set_barrier}};
 320
 321   for (auto& elem : setter_callbacks) {
 322     std::string name = simgrid::config::get_value<std::string>(("smpi/" + elem.first).c_str());
 323     if (name.empty())
 324       name = selector_name;
 325
 326     (elem.second)(name);
 327   }
 328 }
 329
 330 //Implementations of the single algorithm collectives
 331
 332 int colls::gatherv(const void* sendbuf, int sendcount, MPI_Datatype sendtype, void* recvbuf, const int* recvcounts,
 333                    const int* displs, MPI_Datatype recvtype, int root, MPI_Comm comm)
 334 {
 335   MPI_Request request;
 336   colls::igatherv(sendbuf, sendcount, sendtype, recvbuf, recvcounts, displs, recvtype, root, comm, &request, 0);
 337   return Request::wait(&request, MPI_STATUS_IGNORE);
 338 }
 339
 340 int colls::scatterv(const void* sendbuf, const int* sendcounts, const int* displs, MPI_Datatype sendtype, void* recvbuf,
 341                     int recvcount, MPI_Datatype recvtype, int root, MPI_Comm comm)
 342 {
 343   MPI_Request request;
 344   colls::iscatterv(sendbuf, sendcounts, displs, sendtype, recvbuf, recvcount, recvtype, root, comm, &request, 0);
 345   return Request::wait(&request, MPI_STATUS_IGNORE);
 346 }
 347
 348 int colls::scan(const void* sendbuf, void* recvbuf, int count, MPI_Datatype datatype, MPI_Op op, MPI_Comm comm)
 349 {
 350   int system_tag = -888;
 351   MPI_Aint lb      = 0;
 352   MPI_Aint dataext = 0;
 353
 354   int rank = comm->rank();
 355   int size = comm->size();
 356
 357   datatype->extent(&lb, &dataext);
 358
 359   // Local copy from self
 360   Datatype::copy(sendbuf, count, datatype, recvbuf, count, datatype);
 361
 362   // Send/Recv buffers to/from others
 363   MPI_Request* requests = new MPI_Request[size - 1];
 364   unsigned char** tmpbufs = new unsigned char*[rank];
 365   int index = 0;
 366   for (int other = 0; other < rank; other++) {
 367     tmpbufs[index] = smpi_get_tmp_sendbuffer(count * dataext);
 368     requests[index] = Request::irecv_init(tmpbufs[index], count, datatype, other, system_tag, comm);
 369     index++;
 370   }
 371   for (int other = rank + 1; other < size; other++) {
 372     requests[index] = Request::isend_init(sendbuf, count, datatype, other, system_tag, comm);
 373     index++;
 374   }
 375   // Wait for completion of all comms.
 376   Request::startall(size - 1, requests);
 377
 378   if(op != MPI_OP_NULL && op->is_commutative()){
 379     for (int other = 0; other < size - 1; other++) {
 380       index = Request::waitany(size - 1, requests, MPI_STATUS_IGNORE);
 381       if(index == MPI_UNDEFINED) {
 382         break;
 383       }
 384       if(index < rank) {
 385         // #Request is below rank: it's a irecv
 386         op->apply( tmpbufs[index], recvbuf, &count, datatype);
 387       }
 388     }
 389   }else{
 390     //non commutative case, wait in order
 391     for (int other = 0; other < size - 1; other++) {
 392       Request::wait(&(requests[other]), MPI_STATUS_IGNORE);
 393       if(index < rank && op!=MPI_OP_NULL) {
 394         op->apply( tmpbufs[other], recvbuf, &count, datatype);
 395       }
 396     }
 397   }
 398   for(index = 0; index < rank; index++) {
 399     smpi_free_tmp_buffer(tmpbufs[index]);
 400   }
 401   for(index = 0; index < size-1; index++) {
 402     Request::unref(&requests[index]);
 403   }
 404   delete[] tmpbufs;
 405   delete[] requests;
 406   return MPI_SUCCESS;
 407 }
 408
 409 int colls::exscan(const void* sendbuf, void* recvbuf, int count, MPI_Datatype datatype, MPI_Op op, MPI_Comm comm)
 410 {
 411   int system_tag = -888;
 412   MPI_Aint lb         = 0;
 413   MPI_Aint dataext    = 0;
 414   int recvbuf_is_empty=1;
 415   int rank = comm->rank();
 416   int size = comm->size();
 417
 418   datatype->extent(&lb, &dataext);
 419
 420   // Send/Recv buffers to/from others
 421   MPI_Request* requests = new MPI_Request[size - 1];
 422   unsigned char** tmpbufs = new unsigned char*[rank];
 423   int index = 0;
 424   for (int other = 0; other < rank; other++) {
 425     tmpbufs[index] = smpi_get_tmp_sendbuffer(count * dataext);
 426     requests[index] = Request::irecv_init(tmpbufs[index], count, datatype, other, system_tag, comm);
 427     index++;
 428   }
 429   for (int other = rank + 1; other < size; other++) {
 430     requests[index] = Request::isend_init(sendbuf, count, datatype, other, system_tag, comm);
 431     index++;
 432   }
 433   // Wait for completion of all comms.
 434   Request::startall(size - 1, requests);
 435
 436   if(op != MPI_OP_NULL && op->is_commutative()){
 437     for (int other = 0; other < size - 1; other++) {
 438       index = Request::waitany(size - 1, requests, MPI_STATUS_IGNORE);
 439       if(index == MPI_UNDEFINED) {
 440         break;
 441       }
 442       if(index < rank) {
 443         if(recvbuf_is_empty){
 444           Datatype::copy(tmpbufs[index], count, datatype, recvbuf, count, datatype);
 445           recvbuf_is_empty=0;
 446         } else
 447           // #Request is below rank: it's a irecv
 448           op->apply( tmpbufs[index], recvbuf, &count, datatype);
 449       }
 450     }
 451   }else{
 452     //non commutative case, wait in order
 453     for (int other = 0; other < size - 1; other++) {
 454      Request::wait(&(requests[other]), MPI_STATUS_IGNORE);
 455       if(index < rank) {
 456         if (recvbuf_is_empty) {
 457           Datatype::copy(tmpbufs[other], count, datatype, recvbuf, count, datatype);
 458           recvbuf_is_empty = 0;
 459         } else
 460           if(op!=MPI_OP_NULL)
 461             op->apply( tmpbufs[other], recvbuf, &count, datatype);
 462       }
 463     }
 464   }
 465   for(index = 0; index < rank; index++) {
 466     smpi_free_tmp_buffer(tmpbufs[index]);
 467   }
 468   for(index = 0; index < size-1; index++) {
 469     Request::unref(&requests[index]);
 470   }
 471   delete[] tmpbufs;
 472   delete[] requests;
 473   return MPI_SUCCESS;
 474 }
 475
 476 int colls::alltoallw(const void* sendbuf, const int* sendcounts, const int* senddisps, const MPI_Datatype* sendtypes,
 477                      void* recvbuf, const int* recvcounts, const int* recvdisps, const MPI_Datatype* recvtypes,
 478                      MPI_Comm comm)
 479 {
 480   MPI_Request request;
 481   colls::ialltoallw(sendbuf, sendcounts, senddisps, sendtypes, recvbuf, recvcounts, recvdisps, recvtypes, comm,
 482                     &request, 0);
 483   return Request::wait(&request, MPI_STATUS_IGNORE);
 484 }
 485
 486 }
 487 }