src/s4u/s4u_Comm.cpp

   1 /* Copyright (c) 2006-2023. The SimGrid Team. All rights reserved.          */
   2
   3 /* This program is free software; you can redistribute it and/or modify it
   4  * under the terms of the license (GNU LGPL) which comes with this package. */
   5
   6 #include <cmath>
   7 #include <simgrid/Exception.hpp>
   8 #include <simgrid/comm.h>
   9 #include <simgrid/s4u/Comm.hpp>
  10 #include <simgrid/s4u/Engine.hpp>
  11 #include <simgrid/s4u/Mailbox.hpp>
  12
  13 #include "src/kernel/activity/CommImpl.hpp"
  14 #include "src/kernel/actor/ActorImpl.hpp"
  15 #include "src/kernel/actor/SimcallObserver.hpp"
  16 #include "src/mc/mc.h"
  17 #include "src/mc/mc_replay.hpp"
  18
  19 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(s4u_comm, s4u_activity, "S4U asynchronous communications");
  20
  21 namespace simgrid::s4u {
  22 xbt::signal<void(Comm const&)> Comm::on_send;
  23 xbt::signal<void(Comm const&)> Comm::on_recv;
  24 xbt::signal<void(Comm const&)> Comm::on_start;
  25
  26 CommPtr Comm::set_copy_data_callback(const std::function<void(kernel::activity::CommImpl*, void*, size_t)>& callback)
  27 {
  28   copy_data_function_ = callback;
  29   return this;
  30 }
  31
  32 void Comm::copy_buffer_callback(kernel::activity::CommImpl* comm, void* buff,
  33                                 size_t buff_size) // XBT_ATTRIB_DEPRECATED_v337
  34 {
  35   XBT_DEBUG("Copy the data over");
  36   memcpy(comm->dst_buff_, buff, buff_size);
  37   if (comm->is_detached()) { // if this is a detached send, the source buffer was duplicated by SMPI sender to make the
  38                              // original buffer available to the application ASAP
  39     xbt_free(buff);
  40     comm->src_buff_ = nullptr;
  41   }
  42 }
  43
  44 void Comm::copy_pointer_callback(kernel::activity::CommImpl* comm, void* buff,
  45                                  size_t buff_size) // XBT_ATTRIB_DEPRECATED_v337
  46 {
  47   xbt_assert((buff_size == sizeof(void*)), "Cannot copy %zu bytes: must be sizeof(void*)", buff_size);
  48   *(void**)(comm->dst_buff_) = buff;
  49 }
  50
  51 Comm::~Comm()
  52 {
  53   if (state_ == State::STARTED && not detached_ &&
  54       (pimpl_ == nullptr || pimpl_->get_state() == kernel::activity::State::RUNNING)) {
  55     XBT_INFO("Comm %p freed before its completion. Did you forget to detach it? (state: %s)", this, get_state_str());
  56     if (pimpl_ != nullptr)
  57       XBT_INFO("pimpl_->state: %s", pimpl_->get_state_str());
  58     else
  59       XBT_INFO("pimpl_ is null");
  60     xbt_backtrace_display_current();
  61   }
  62 }
  63
  64 void Comm::send(kernel::actor::ActorImpl* sender, const Mailbox* mbox, double task_size, double rate, void* src_buff,
  65                 size_t src_buff_size,
  66                 const std::function<bool(void*, void*, simgrid::kernel::activity::CommImpl*)>& match_fun,
  67                 const std::function<void(simgrid::kernel::activity::CommImpl*, void*, size_t)>& copy_data_fun,
  68                 void* data, double timeout)
  69 {
  70   /* checking for infinite values */
  71   xbt_assert(std::isfinite(task_size), "task_size is not finite!");
  72   xbt_assert(std::isfinite(rate), "rate is not finite!");
  73   xbt_assert(std::isfinite(timeout), "timeout is not finite!");
  74
  75   xbt_assert(mbox, "No rendez-vous point defined for send");
  76
  77   if (MC_is_active() || MC_record_replay_is_active()) {
  78     /* the model-checker wants two separate simcalls, and wants comm to be nullptr during the simcall */
  79     simgrid::kernel::activity::ActivityImplPtr comm = nullptr;
  80
  81     simgrid::kernel::actor::CommIsendSimcall send_observer{
  82         sender,  mbox->get_impl(), task_size, rate, static_cast<unsigned char*>(src_buff), src_buff_size, match_fun,
  83         nullptr, copy_data_fun,    data,      false};
  84     comm = simgrid::kernel::actor::simcall_answered(
  85         [&send_observer] { return simgrid::kernel::activity::CommImpl::isend(&send_observer); }, &send_observer);
  86
  87     if (simgrid::kernel::actor::ActivityWaitSimcall wait_observer{sender, comm.get(), timeout};
  88         simgrid::kernel::actor::simcall_blocking(
  89             [&wait_observer] {
  90               wait_observer.get_activity()->wait_for(wait_observer.get_issuer(), wait_observer.get_timeout());
  91             },
  92             &wait_observer)) {
  93       throw simgrid::TimeoutException(XBT_THROW_POINT, "Timeouted");
  94     }
  95     comm = nullptr;
  96   } else {
  97     simgrid::kernel::actor::CommIsendSimcall observer(sender, mbox->get_impl(), task_size, rate,
  98                                                       static_cast<unsigned char*>(src_buff), src_buff_size, match_fun,
  99                                                       nullptr, copy_data_fun, data, false);
 100     simgrid::kernel::actor::simcall_blocking([&observer, timeout] {
 101       simgrid::kernel::activity::ActivityImplPtr comm = simgrid::kernel::activity::CommImpl::isend(&observer);
 102       comm->wait_for(observer.get_issuer(), timeout);
 103     });
 104   }
 105 }
 106
 107 void Comm::recv(kernel::actor::ActorImpl* receiver, const Mailbox* mbox, void* dst_buff, size_t* dst_buff_size,
 108                 const std::function<bool(void*, void*, simgrid::kernel::activity::CommImpl*)>& match_fun,
 109                 const std::function<void(simgrid::kernel::activity::CommImpl*, void*, size_t)>& copy_data_fun,
 110                 void* data, double timeout, double rate)
 111 {
 112   xbt_assert(std::isfinite(timeout), "timeout is not finite!");
 113   xbt_assert(mbox, "No rendez-vous point defined for recv");
 114
 115   if (MC_is_active() || MC_record_replay_is_active()) {
 116     /* the model-checker wants two separate simcalls, and wants comm to be nullptr during the simcall */
 117     simgrid::kernel::activity::ActivityImplPtr comm = nullptr;
 118
 119     simgrid::kernel::actor::CommIrecvSimcall observer{receiver,
 120                                                       mbox->get_impl(),
 121                                                       static_cast<unsigned char*>(dst_buff),
 122                                                       dst_buff_size,
 123                                                       match_fun,
 124                                                       copy_data_fun,
 125                                                       data,
 126                                                       rate};
 127     comm = simgrid::kernel::actor::simcall_answered(
 128         [&observer] { return simgrid::kernel::activity::CommImpl::irecv(&observer); }, &observer);
 129
 130     if (simgrid::kernel::actor::ActivityWaitSimcall wait_observer{receiver, comm.get(), timeout};
 131         simgrid::kernel::actor::simcall_blocking(
 132             [&wait_observer] {
 133               wait_observer.get_activity()->wait_for(wait_observer.get_issuer(), wait_observer.get_timeout());
 134             },
 135             &wait_observer)) {
 136       throw simgrid::TimeoutException(XBT_THROW_POINT, "Timeouted");
 137     }
 138     comm = nullptr;
 139   } else {
 140     simgrid::kernel::actor::CommIrecvSimcall observer(receiver, mbox->get_impl(), static_cast<unsigned char*>(dst_buff),
 141                                                       dst_buff_size, match_fun, copy_data_fun, data, rate);
 142     simgrid::kernel::actor::simcall_blocking([&observer, timeout] {
 143       simgrid::kernel::activity::ActivityImplPtr comm = simgrid::kernel::activity::CommImpl::irecv(&observer);
 144       comm->wait_for(observer.get_issuer(), timeout);
 145     });
 146   }
 147 }
 148
 149 CommPtr Comm::sendto_init()
 150 {
 151   CommPtr res(new Comm());
 152   res->pimpl_ = kernel::activity::CommImplPtr(new kernel::activity::CommImpl());
 153   boost::static_pointer_cast<kernel::activity::CommImpl>(res->pimpl_)->detach();
 154   res->sender_ = kernel::actor::ActorImpl::self();
 155   return res;
 156 }
 157
 158 CommPtr Comm::sendto_init(Host* from, Host* to)
 159 {
 160   auto res = Comm::sendto_init()->set_source(from)->set_destination(to);
 161   res->set_state(State::STARTING);
 162   return res;
 163 }
 164
 165 CommPtr Comm::sendto_async(Host* from, Host* to, uint64_t simulated_size_in_bytes)
 166 {
 167   return Comm::sendto_init()->set_payload_size(simulated_size_in_bytes)->set_source(from)->set_destination(to);
 168 }
 169
 170 void Comm::sendto(Host* from, Host* to, uint64_t simulated_size_in_bytes)
 171 {
 172   sendto_async(from, to, simulated_size_in_bytes)->wait();
 173 }
 174
 175 CommPtr Comm::set_source(Host* from)
 176 {
 177   xbt_assert(state_ == State::INITED || state_ == State::STARTING,
 178              "Cannot change the source of a Comm once it's started (state: %s)", to_c_str(state_));
 179   boost::static_pointer_cast<kernel::activity::CommImpl>(pimpl_)->set_source(from);
 180   // Setting 'source' may allow to start the activity, let's try
 181   if (state_ == State::STARTING && remains_ <= 0)
 182     XBT_DEBUG("This communication has a payload size of 0 byte. It cannot start yet");
 183   else
 184     start();
 185
 186   return this;
 187 }
 188 Host* Comm::get_source() const
 189 {
 190   return pimpl_ ? boost::static_pointer_cast<kernel::activity::CommImpl>(pimpl_)->get_source() : nullptr;
 191 }
 192
 193 CommPtr Comm::set_destination(Host* to)
 194 {
 195   xbt_assert(state_ == State::INITED || state_ == State::STARTING,
 196              "Cannot change the destination of a Comm once it's started (state: %s)", to_c_str(state_));
 197   boost::static_pointer_cast<kernel::activity::CommImpl>(pimpl_)->set_destination(to);
 198   // Setting 'destination' may allow to start the activity, let's try
 199   if (state_ == State::STARTING && remains_ <= 0)
 200     XBT_DEBUG("This communication has a payload size of 0 byte. It cannot start yet");
 201   else
 202     start();
 203
 204   return this;
 205 }
 206
 207 Host* Comm::get_destination() const
 208 {
 209   return pimpl_ ? boost::static_pointer_cast<kernel::activity::CommImpl>(pimpl_)->get_destination() : nullptr;
 210 }
 211
 212 CommPtr Comm::set_rate(double rate)
 213 {
 214   xbt_assert(state_ == State::INITED, "You cannot use %s() once your communication started (not implemented)",
 215              __FUNCTION__);
 216   rate_ = rate;
 217   return this;
 218 }
 219
 220 CommPtr Comm::set_mailbox(Mailbox* mailbox)
 221 {
 222   xbt_assert(state_ == State::INITED, "You cannot use %s() once your communication started (not implemented)",
 223              __FUNCTION__);
 224   mailbox_ = mailbox;
 225   return this;
 226 }
 227
 228 CommPtr Comm::set_src_data(void* buff)
 229 {
 230   xbt_assert(state_ == State::INITED, "You cannot use %s() once your communication started (not implemented)",
 231              __FUNCTION__);
 232   xbt_assert(dst_buff_ == nullptr, "Cannot set the src and dst buffers at the same time");
 233   src_buff_ = buff;
 234   return this;
 235 }
 236
 237 CommPtr Comm::set_src_data_size(size_t size)
 238 {
 239   xbt_assert(state_ == State::INITED, "You cannot use %s() once your communication started (not implemented)",
 240              __FUNCTION__);
 241   src_buff_size_ = size;
 242   return this;
 243 }
 244
 245 CommPtr Comm::set_src_data(void* buff, size_t size)
 246 {
 247   xbt_assert(state_ == State::INITED, "You cannot use %s() once your communication started (not implemented)",
 248              __FUNCTION__);
 249
 250   xbt_assert(dst_buff_ == nullptr, "Cannot set the src and dst buffers at the same time");
 251   src_buff_      = buff;
 252   src_buff_size_ = size;
 253   return this;
 254 }
 255
 256 CommPtr Comm::set_dst_data(void** buff)
 257 {
 258   xbt_assert(state_ == State::INITED, "You cannot use %s() once your communication started (not implemented)",
 259              __FUNCTION__);
 260   xbt_assert(src_buff_ == nullptr, "Cannot set the src and dst buffers at the same time");
 261   dst_buff_ = buff;
 262   return this;
 263 }
 264
 265 CommPtr Comm::set_dst_data(void** buff, size_t size)
 266 {
 267   xbt_assert(state_ == State::INITED, "You cannot use %s() once your communication started (not implemented)",
 268              __FUNCTION__);
 269
 270   xbt_assert(src_buff_ == nullptr, "Cannot set the src and dst buffers at the same time");
 271   dst_buff_      = buff;
 272   dst_buff_size_ = size;
 273   return this;
 274 }
 275
 276 CommPtr Comm::set_payload_size(uint64_t bytes)
 277 {
 278   set_remaining(bytes);
 279   if (pimpl_) {
 280     boost::static_pointer_cast<kernel::activity::CommImpl>(pimpl_)->set_size(bytes);
 281   }
 282   return this;
 283 }
 284
 285 Actor* Comm::get_sender() const
 286 {
 287   kernel::actor::ActorImplPtr sender = nullptr;
 288   if (pimpl_)
 289     sender = boost::static_pointer_cast<kernel::activity::CommImpl>(pimpl_)->src_actor_;
 290   return sender ? sender->get_ciface() : nullptr;
 291 }
 292
 293 Actor* Comm::get_receiver() const
 294 {
 295   kernel::actor::ActorImplPtr receiver = nullptr;
 296   if (pimpl_)
 297     receiver = boost::static_pointer_cast<kernel::activity::CommImpl>(pimpl_)->dst_actor_;
 298   return receiver ? receiver->get_ciface() : nullptr;
 299 }
 300
 301 bool Comm::is_assigned() const
 302 {
 303   return (pimpl_ && boost::static_pointer_cast<kernel::activity::CommImpl>(pimpl_)->is_assigned()) ||
 304          mailbox_ != nullptr;
 305 }
 306
 307 Comm* Comm::do_start()
 308 {
 309   xbt_assert(get_state() == State::INITED || get_state() == State::STARTING,
 310              "You cannot use %s() once your communication started (not implemented)", __FUNCTION__);
 311   if (get_source() != nullptr || get_destination() != nullptr) {
 312     xbt_assert(is_assigned(), "When either from_ or to_ is specified, both must be.");
 313     xbt_assert(src_buff_ == nullptr && dst_buff_ == nullptr,
 314                "Direct host-to-host communications cannot carry any data.");
 315     XBT_DEBUG("host-to-host Comm. Pimpl already created and set, just start it.");
 316     on_send(*this);
 317     on_recv(*this);
 318     kernel::actor::simcall_answered([this] {
 319       pimpl_->set_state(kernel::activity::State::READY);
 320       boost::static_pointer_cast<kernel::activity::CommImpl>(pimpl_)->start();
 321     });
 322   } else if (src_buff_ != nullptr) { // Sender side
 323     on_send(*this);
 324     kernel::actor::CommIsendSimcall observer{sender_,
 325                                              mailbox_->get_impl(),
 326                                              remains_,
 327                                              rate_,
 328                                              static_cast<unsigned char*>(src_buff_),
 329                                              src_buff_size_,
 330                                              match_fun_,
 331                                              clean_fun_,
 332                                              copy_data_function_,
 333                                              get_data<void>(),
 334                                              detached_};
 335     pimpl_ = kernel::actor::simcall_answered([&observer] { return kernel::activity::CommImpl::isend(&observer); },
 336                                              &observer);
 337   } else if (dst_buff_ != nullptr) { // Receiver side
 338     xbt_assert(not detached_, "Receive cannot be detached");
 339     on_recv(*this);
 340     kernel::actor::CommIrecvSimcall observer{receiver_,
 341                                              mailbox_->get_impl(),
 342                                              static_cast<unsigned char*>(dst_buff_),
 343                                              &dst_buff_size_,
 344                                              match_fun_,
 345                                              copy_data_function_,
 346                                              get_data<void>(),
 347                                              rate_};
 348     pimpl_ = kernel::actor::simcall_answered([&observer] { return kernel::activity::CommImpl::irecv(&observer); },
 349                                              &observer);
 350   } else {
 351     xbt_die("Cannot start a communication before specifying whether we are the sender or the receiver");
 352   }
 353
 354   if (suspended_)
 355     pimpl_->suspend();
 356
 357   if (not detached_) {
 358     pimpl_->set_iface(this);
 359     pimpl_->set_actor(sender_);
 360     // Only throw the signal when both sides are here and the status is READY
 361     if (pimpl_->get_state() != kernel::activity::State::WAITING)
 362       on_start(*this);
 363   }
 364
 365   state_ = State::STARTED;
 366   return this;
 367 }
 368
 369 Comm* Comm::detach()
 370 {
 371   xbt_assert(state_ == State::INITED || state_ == State::STARTING,
 372              "You cannot use %s() once your communication is %s (not implemented)", __FUNCTION__, get_state_str());
 373   xbt_assert(dst_buff_ == nullptr && dst_buff_size_ == 0, "You can only detach sends, not recvs");
 374   detached_ = true;
 375   start();
 376   return this;
 377 }
 378
 379 ssize_t Comm::test_any(const std::vector<CommPtr>& comms)
 380 {
 381   std::vector<ActivityPtr> activities;
 382   for (const auto& comm : comms)
 383     activities.push_back(boost::dynamic_pointer_cast<Activity>(comm));
 384   return Activity::test_any(activities);
 385 }
 386
 387 /** @brief Block the calling actor until the communication is finished, or until timeout
 388  *
 389  * On timeout, an exception is thrown and the communication is invalidated.
 390  *
 391  * @param timeout the amount of seconds to wait for the comm termination.
 392  *                Negative values denote infinite wait times. 0 as a timeout returns immediately. */
 393 Comm* Comm::wait_for(double timeout)
 394 {
 395   XBT_DEBUG("Calling Comm::wait_for with state %s", get_state_str());
 396   kernel::actor::ActorImpl* issuer = nullptr;
 397   switch (state_) {
 398     case State::FINISHED:
 399       break;
 400     case State::FAILED:
 401       throw NetworkFailureException(XBT_THROW_POINT, "Cannot wait for a failed communication");
 402     case State::INITED:
 403     case State::STARTING: // It's not started yet. Do it in one simcall if it's a regular communication
 404       if (get_source() != nullptr || get_destination() != nullptr) {
 405         return start()->wait_for(timeout); // In the case of host2host comm, do it in two simcalls
 406       } else if (src_buff_ != nullptr) {
 407         on_send(*this);
 408         send(sender_, mailbox_, remains_, rate_, src_buff_, src_buff_size_, match_fun_, copy_data_function_,
 409              get_data<void>(), timeout);
 410
 411       } else { // Receiver
 412         on_recv(*this);
 413         recv(receiver_, mailbox_, dst_buff_, &dst_buff_size_, match_fun_, copy_data_function_, get_data<void>(),
 414              timeout, rate_);
 415       }
 416       break;
 417     case State::STARTED:
 418       try {
 419         issuer = kernel::actor::ActorImpl::self();
 420         kernel::actor::ActivityWaitSimcall observer{issuer, pimpl_.get(), timeout};
 421         if (kernel::actor::simcall_blocking(
 422                 [&observer] { observer.get_activity()->wait_for(observer.get_issuer(), observer.get_timeout()); },
 423                 &observer)) {
 424           throw TimeoutException(XBT_THROW_POINT, "Timeouted");
 425         }
 426       } catch (const NetworkFailureException& e) {
 427         issuer->simcall_.observer_ = nullptr; // Comm failed on network failure, reset the observer to nullptr
 428         complete(State::FAILED);
 429         e.rethrow_nested(XBT_THROW_POINT, boost::core::demangle(typeid(e).name()) + " raised in kernel mode.");
 430       }
 431       break;
 432
 433     case State::CANCELED:
 434       throw CancelException(XBT_THROW_POINT, "Communication canceled");
 435
 436     default:
 437       THROW_IMPOSSIBLE;
 438   }
 439   complete(State::FINISHED);
 440   return this;
 441 }
 442
 443 ssize_t Comm::wait_any_for(const std::vector<CommPtr>& comms, double timeout)
 444 {
 445   std::vector<ActivityPtr> activities;
 446   for (const auto& comm : comms)
 447     activities.push_back(boost::dynamic_pointer_cast<Activity>(comm));
 448   ssize_t changed_pos;
 449   try {
 450     changed_pos = Activity::wait_any_for(activities, timeout);
 451   } catch (const NetworkFailureException& e) {
 452     changed_pos = -1;
 453     for (auto c : comms) {
 454       if (c->pimpl_->get_state() == kernel::activity::State::FAILED) {
 455         c->complete(State::FAILED);
 456       }
 457     }
 458     e.rethrow_nested(XBT_THROW_POINT, boost::core::demangle(typeid(e).name()) + " raised in kernel mode.");
 459   }
 460   return changed_pos;
 461 }
 462
 463 void Comm::wait_all(const std::vector<CommPtr>& comms)
 464 {
 465   // TODO: this should be a simcall or something
 466   for (auto& comm : comms)
 467     comm->wait();
 468 }
 469
 470 size_t Comm::wait_all_for(const std::vector<CommPtr>& comms, double timeout)
 471 {
 472   if (timeout < 0.0) {
 473     wait_all(comms);
 474     return comms.size();
 475   }
 476
 477   double deadline = Engine::get_clock() + timeout;
 478   std::vector<CommPtr> waited_comm(1, nullptr);
 479   for (size_t i = 0; i < comms.size(); i++) {
 480     double wait_timeout = std::max(0.0, deadline - Engine::get_clock());
 481     waited_comm[0]      = comms[i];
 482     // Using wait_any_for() here (and not wait_for) because we don't want comms to be invalidated on timeout
 483     if (wait_any_for(waited_comm, wait_timeout) == -1) {
 484       XBT_DEBUG("Timeout (%g): i = %zu", wait_timeout, i);
 485       return i;
 486     }
 487   }
 488   return comms.size();
 489 }
 490 } // namespace simgrid::s4u
 491 /* **************************** Public C interface *************************** */
 492 void sg_comm_detach(sg_comm_t comm, void (*clean_function)(void*))
 493 {
 494   comm->detach(clean_function);
 495   comm->unref();
 496 }
 497 void sg_comm_unref(sg_comm_t comm)
 498 {
 499   comm->unref();
 500 }
 501 int sg_comm_test(sg_comm_t comm)
 502 {
 503   bool finished = comm->test();
 504   if (finished)
 505     comm->unref();
 506   return finished;
 507 }
 508
 509 sg_error_t sg_comm_wait(sg_comm_t comm)
 510 {
 511   return sg_comm_wait_for(comm, -1);
 512 }
 513
 514 sg_error_t sg_comm_wait_for(sg_comm_t comm, double timeout)
 515 {
 516   sg_error_t status = SG_OK;
 517
 518   simgrid::s4u::CommPtr s4u_comm(comm, false);
 519   try {
 520     s4u_comm->wait_for(timeout);
 521   } catch (const simgrid::TimeoutException&) {
 522     status = SG_ERROR_TIMEOUT;
 523   } catch (const simgrid::CancelException&) {
 524     status = SG_ERROR_CANCELED;
 525   } catch (const simgrid::NetworkFailureException&) {
 526     status = SG_ERROR_NETWORK;
 527   }
 528   return status;
 529 }
 530
 531 void sg_comm_wait_all(sg_comm_t* comms, size_t count)
 532 {
 533   sg_comm_wait_all_for(comms, count, -1);
 534 }
 535
 536 size_t sg_comm_wait_all_for(sg_comm_t* comms, size_t count, double timeout)
 537 {
 538   std::vector<simgrid::s4u::CommPtr> s4u_comms;
 539   for (size_t i = 0; i < count; i++)
 540     s4u_comms.emplace_back(comms[i], false);
 541
 542   size_t pos = simgrid::s4u::Comm::wait_all_for(s4u_comms, timeout);
 543   for (size_t i = pos; i < count; i++)
 544     s4u_comms[i]->add_ref();
 545   return pos;
 546 }
 547
 548 ssize_t sg_comm_wait_any(sg_comm_t* comms, size_t count)
 549 {
 550   return sg_comm_wait_any_for(comms, count, -1);
 551 }
 552
 553 ssize_t sg_comm_wait_any_for(sg_comm_t* comms, size_t count, double timeout)
 554 {
 555   std::vector<simgrid::s4u::CommPtr> s4u_comms;
 556   for (size_t i = 0; i < count; i++)
 557     s4u_comms.emplace_back(comms[i], false);
 558
 559   ssize_t pos = simgrid::s4u::Comm::wait_any_for(s4u_comms, timeout);
 560   for (size_t i = 0; i < count; i++) {
 561     if (pos != -1 && static_cast<size_t>(pos) != i)
 562       s4u_comms[i]->add_ref();
 563   }
 564   return pos;
 565 }