src/simix/smx_network.cpp

   1 /* Copyright (c) 2009-2019. 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 "mc/mc.h"
   7 #include "simgrid/Exception.hpp"
   8 #include "src/kernel/activity/MailboxImpl.hpp"
   9 #include "src/mc/mc_replay.hpp"
  10 #include "src/simix/smx_network_private.hpp"
  11 #include "src/simix/smx_private.hpp"
  12 #include "src/surf/cpu_interface.hpp"
  13 #include "src/surf/network_interface.hpp"
  14
  15 #include <boost/circular_buffer.hpp>
  16 #include <boost/range/algorithm.hpp>
  17
  18 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_network, simix, "SIMIX network-related synchronization");
  19
  20 static void SIMIX_waitany_remove_simcall_from_actions(smx_simcall_t simcall);
  21
  22 /**
  23  *  @brief Checks if there is a communication activity queued in a deque matching our needs
  24  *  @param deque where to search into
  25  *  @param type The type of communication we are looking for (comm_send, comm_recv)
  26  *  @param match_fun the function to apply
  27  *  @param this_user_data additional parameter to the match_fun
  28  *  @param my_synchro what to compare against
  29  *  @param remove_matching whether or not to clean the found object from the queue
  30  *  @return The communication activity if found, nullptr otherwise
  31  */
  32 static simgrid::kernel::activity::CommImplPtr
  33 _find_matching_comm(boost::circular_buffer_space_optimized<smx_activity_t>* deque, e_smx_comm_type_t type,
  34                     int (*match_fun)(void*, void*, simgrid::kernel::activity::CommImpl*), void* this_user_data,
  35                     simgrid::kernel::activity::CommImplPtr my_synchro, bool remove_matching)
  36 {
  37   void* other_user_data = nullptr;
  38
  39   for(auto it = deque->begin(); it != deque->end(); it++){
  40     simgrid::kernel::activity::CommImplPtr comm =
  41         boost::dynamic_pointer_cast<simgrid::kernel::activity::CommImpl>(std::move(*it));
  42
  43     if (comm->type == SIMIX_COMM_SEND) {
  44       other_user_data = comm->src_data_;
  45     } else if (comm->type == SIMIX_COMM_RECEIVE) {
  46       other_user_data = comm->dst_data_;
  47     }
  48     if (comm->type == type && (match_fun == nullptr || match_fun(this_user_data, other_user_data, comm.get())) &&
  49         (not comm->match_fun || comm->match_fun(other_user_data, this_user_data, my_synchro.get()))) {
  50       XBT_DEBUG("Found a matching communication synchro %p", comm.get());
  51       if (remove_matching)
  52         deque->erase(it);
  53 #if SIMGRID_HAVE_MC
  54       comm->mbox_cpy = comm->mbox;
  55 #endif
  56       comm->mbox = nullptr;
  57       return comm;
  58     }
  59     XBT_DEBUG("Sorry, communication synchro %p does not match our needs:"
  60               " its type is %d but we are looking for a comm of type %d (or maybe the filtering didn't match)",
  61               comm.get(), (int)comm->type, (int)type);
  62   }
  63   XBT_DEBUG("No matching communication synchro found");
  64   return nullptr;
  65 }
  66
  67 /******************************************************************************/
  68 /*                          Communication synchros                            */
  69 /******************************************************************************/
  70 XBT_PRIVATE void simcall_HANDLER_comm_send(smx_simcall_t simcall, smx_actor_t src, smx_mailbox_t mbox, double task_size,
  71                                            double rate, void* src_buff, size_t src_buff_size,
  72                                            int (*match_fun)(void*, void*, simgrid::kernel::activity::CommImpl*),
  73                                            void (*copy_data_fun)(smx_activity_t, void*, size_t), void* data,
  74                                            double timeout)
  75 {
  76   smx_activity_t comm = simcall_HANDLER_comm_isend(simcall, src, mbox, task_size, rate,
  77                            src_buff, src_buff_size, match_fun, nullptr, copy_data_fun,
  78                data, 0);
  79   SIMCALL_SET_MC_VALUE(simcall, 0);
  80   simcall_HANDLER_comm_wait(simcall, comm, timeout);
  81 }
  82 XBT_PRIVATE smx_activity_t simcall_HANDLER_comm_isend(
  83     smx_simcall_t /*simcall*/, smx_actor_t src_proc, smx_mailbox_t mbox, double task_size, double rate, void* src_buff,
  84     size_t src_buff_size, int (*match_fun)(void*, void*, simgrid::kernel::activity::CommImpl*),
  85     void (*clean_fun)(void*), // used to free the synchro in case of problem after a detached send
  86     void (*copy_data_fun)(smx_activity_t, void*, size_t), // used to copy data if not default one
  87     void* data, int detached)
  88 {
  89   XBT_DEBUG("send from mailbox %p", mbox);
  90
  91   /* Prepare a synchro describing us, so that it gets passed to the user-provided filter of other side */
  92   simgrid::kernel::activity::CommImplPtr this_comm =
  93       simgrid::kernel::activity::CommImplPtr(new simgrid::kernel::activity::CommImpl(SIMIX_COMM_SEND));
  94
  95   /* Look for communication synchro matching our needs. We also provide a description of
  96    * ourself so that the other side also gets a chance of choosing if it wants to match with us.
  97    *
  98    * If it is not found then push our communication into the rendez-vous point */
  99   simgrid::kernel::activity::CommImplPtr other_comm =
 100       _find_matching_comm(&mbox->comm_queue_, SIMIX_COMM_RECEIVE, match_fun, data, this_comm, /*remove_matching*/ true);
 101
 102   if (not other_comm) {
 103     other_comm = std::move(this_comm);
 104
 105     if (mbox->permanent_receiver_ != nullptr) {
 106       //this mailbox is for small messages, which have to be sent right now
 107       other_comm->state_  = SIMIX_READY;
 108       other_comm->dst_actor_ = mbox->permanent_receiver_.get();
 109       mbox->done_comm_queue_.push_back(other_comm);
 110       XBT_DEBUG("pushing a message into the permanent receive list %p, comm %p", mbox, other_comm.get());
 111
 112     }else{
 113       mbox->push(other_comm);
 114     }
 115   } else {
 116     XBT_DEBUG("Receive already pushed");
 117
 118     other_comm->state_ = SIMIX_READY;
 119     other_comm->type = SIMIX_COMM_READY;
 120   }
 121   src_proc->comms.push_back(other_comm);
 122
 123   if (detached) {
 124     other_comm->detached = true;
 125     other_comm->clean_fun = clean_fun;
 126   } else {
 127     other_comm->clean_fun = nullptr;
 128   }
 129
 130   /* Setup the communication synchro */
 131   other_comm->src_actor_     = src_proc;
 132   other_comm->task_size_     = task_size;
 133   other_comm->rate_          = rate;
 134   other_comm->src_buff_      = src_buff;
 135   other_comm->src_buff_size_ = src_buff_size;
 136   other_comm->src_data_      = data;
 137
 138   other_comm->match_fun = match_fun;
 139   other_comm->copy_data_fun = copy_data_fun;
 140
 141
 142   if (MC_is_active() || MC_record_replay_is_active()) {
 143     other_comm->state_ = SIMIX_RUNNING;
 144     return (detached ? nullptr : other_comm);
 145   }
 146
 147   other_comm->start();
 148
 149   return (detached ? nullptr : other_comm);
 150 }
 151
 152 XBT_PRIVATE void simcall_HANDLER_comm_recv(smx_simcall_t simcall, smx_actor_t receiver, smx_mailbox_t mbox,
 153                                            void* dst_buff, size_t* dst_buff_size,
 154                                            int (*match_fun)(void*, void*, simgrid::kernel::activity::CommImpl*),
 155                                            void (*copy_data_fun)(smx_activity_t, void*, size_t), void* data,
 156                                            double timeout, double rate)
 157 {
 158   smx_activity_t comm = SIMIX_comm_irecv(receiver, mbox, dst_buff, dst_buff_size, match_fun, copy_data_fun, data, rate);
 159   SIMCALL_SET_MC_VALUE(simcall, 0);
 160   simcall_HANDLER_comm_wait(simcall, comm, timeout);
 161 }
 162
 163 XBT_PRIVATE smx_activity_t simcall_HANDLER_comm_irecv(smx_simcall_t /*simcall*/, smx_actor_t receiver,
 164                                                       smx_mailbox_t mbox, void* dst_buff, size_t* dst_buff_size,
 165                                                       simix_match_func_t match_fun,
 166                                                       void (*copy_data_fun)(smx_activity_t, void*, size_t), void* data,
 167                                                       double rate)
 168 {
 169   return SIMIX_comm_irecv(receiver, mbox, dst_buff, dst_buff_size, match_fun, copy_data_fun, data, rate);
 170 }
 171
 172 smx_activity_t
 173 SIMIX_comm_irecv(smx_actor_t dst_proc, smx_mailbox_t mbox, void* dst_buff, size_t* dst_buff_size,
 174                  int (*match_fun)(void*, void*, simgrid::kernel::activity::CommImpl*),
 175                  void (*copy_data_fun)(smx_activity_t, void*, size_t), // used to copy data if not default one
 176                  void* data, double rate)
 177 {
 178   simgrid::kernel::activity::CommImplPtr this_synchro =
 179       simgrid::kernel::activity::CommImplPtr(new simgrid::kernel::activity::CommImpl(SIMIX_COMM_RECEIVE));
 180   XBT_DEBUG("recv from mbox %p. this_synchro=%p", mbox, this_synchro.get());
 181
 182   simgrid::kernel::activity::CommImplPtr other_comm;
 183   //communication already done, get it inside the list of completed comms
 184   if (mbox->permanent_receiver_ != nullptr && not mbox->done_comm_queue_.empty()) {
 185
 186     XBT_DEBUG("We have a comm that has probably already been received, trying to match it, to skip the communication");
 187     //find a match in the list of already received comms
 188     other_comm = _find_matching_comm(&mbox->done_comm_queue_, SIMIX_COMM_SEND, match_fun, data, this_synchro,
 189                                      /*remove_matching*/ true);
 190     //if not found, assume the receiver came first, register it to the mailbox in the classical way
 191     if (not other_comm) {
 192       XBT_DEBUG("We have messages in the permanent receive list, but not the one we are looking for, pushing request into list");
 193       other_comm = std::move(this_synchro);
 194       mbox->push(other_comm);
 195     } else {
 196       if (other_comm->surf_action_ && other_comm->remains() < 1e-12) {
 197         XBT_DEBUG("comm %p has been already sent, and is finished, destroy it", other_comm.get());
 198         other_comm->state_ = SIMIX_DONE;
 199         other_comm->type = SIMIX_COMM_DONE;
 200         other_comm->mbox = nullptr;
 201       }
 202     }
 203   } else {
 204     /* Prepare a comm describing us, so that it gets passed to the user-provided filter of other side */
 205
 206     /* Look for communication activity matching our needs. We also provide a description of
 207      * ourself so that the other side also gets a chance of choosing if it wants to match with us.
 208      *
 209      * If it is not found then push our communication into the rendez-vous point */
 210     other_comm = _find_matching_comm(&mbox->comm_queue_, SIMIX_COMM_SEND, match_fun, data, this_synchro,
 211                                      /*remove_matching*/ true);
 212
 213     if (other_comm == nullptr) {
 214       XBT_DEBUG("Receive pushed first (%zu comm enqueued so far)", mbox->comm_queue_.size());
 215       other_comm = std::move(this_synchro);
 216       mbox->push(other_comm);
 217     } else {
 218       XBT_DEBUG("Match my %p with the existing %p", this_synchro.get(), other_comm.get());
 219
 220       other_comm->state_ = SIMIX_READY;
 221       other_comm->type = SIMIX_COMM_READY;
 222     }
 223     dst_proc->comms.push_back(other_comm);
 224   }
 225
 226   /* Setup communication synchro */
 227   other_comm->dst_actor_     = dst_proc;
 228   other_comm->dst_buff_      = dst_buff;
 229   other_comm->dst_buff_size_ = dst_buff_size;
 230   other_comm->dst_data_      = data;
 231
 232   if (rate > -1.0 && (other_comm->rate_ < 0.0 || rate < other_comm->rate_))
 233     other_comm->rate_ = rate;
 234
 235   other_comm->match_fun = match_fun;
 236   other_comm->copy_data_fun = copy_data_fun;
 237
 238   if (MC_is_active() || MC_record_replay_is_active()) {
 239     other_comm->state_ = SIMIX_RUNNING;
 240     return other_comm;
 241   }
 242   other_comm->start();
 243   return other_comm;
 244 }
 245
 246 smx_activity_t SIMIX_comm_iprobe(smx_mailbox_t mbox, int type, simix_match_func_t match_fun, void* data)
 247 {
 248   XBT_DEBUG("iprobe from %p %p", mbox, &mbox->comm_queue_);
 249   simgrid::kernel::activity::CommImplPtr this_comm;
 250   int smx_type;
 251   if(type == 1){
 252     this_comm = simgrid::kernel::activity::CommImplPtr(new simgrid::kernel::activity::CommImpl(SIMIX_COMM_SEND));
 253     smx_type = SIMIX_COMM_RECEIVE;
 254   } else{
 255     this_comm = simgrid::kernel::activity::CommImplPtr(new simgrid::kernel::activity::CommImpl(SIMIX_COMM_RECEIVE));
 256     smx_type = SIMIX_COMM_SEND;
 257   }
 258   smx_activity_t other_synchro=nullptr;
 259   if (mbox->permanent_receiver_ != nullptr && not mbox->done_comm_queue_.empty()) {
 260     XBT_DEBUG("first check in the permanent recv mailbox, to see if we already got something");
 261     other_synchro = _find_matching_comm(&mbox->done_comm_queue_, (e_smx_comm_type_t)smx_type, match_fun, data,
 262                                         this_comm, /*remove_matching*/ false);
 263   }
 264   if (not other_synchro) {
 265     XBT_DEBUG("check if we have more luck in the normal mailbox");
 266     other_synchro = _find_matching_comm(&mbox->comm_queue_, (e_smx_comm_type_t)smx_type, match_fun, data, this_comm,
 267                                         /*remove_matching*/ false);
 268   }
 269
 270   return other_synchro;
 271 }
 272
 273 void simcall_HANDLER_comm_wait(smx_simcall_t simcall, smx_activity_t synchro, double timeout)
 274 {
 275   /* Associate this simcall to the wait synchro */
 276   XBT_DEBUG("simcall_HANDLER_comm_wait, %p", synchro.get());
 277
 278   synchro->simcalls_.push_back(simcall);
 279   simcall->issuer->waiting_synchro = synchro;
 280
 281   if (MC_is_active() || MC_record_replay_is_active()) {
 282     int idx = SIMCALL_GET_MC_VALUE(simcall);
 283     if (idx == 0) {
 284       synchro->state_ = SIMIX_DONE;
 285     } else {
 286       /* If we reached this point, the wait simcall must have a timeout */
 287       /* Otherwise it shouldn't be enabled and executed by the MC */
 288       if (timeout < 0.0)
 289         THROW_IMPOSSIBLE;
 290
 291       simgrid::kernel::activity::CommImplPtr comm =
 292           boost::static_pointer_cast<simgrid::kernel::activity::CommImpl>(synchro);
 293       if (comm->src_actor_ == simcall->issuer)
 294         comm->state_ = SIMIX_SRC_TIMEOUT;
 295       else
 296         comm->state_ = SIMIX_DST_TIMEOUT;
 297     }
 298
 299     SIMIX_comm_finish(synchro);
 300     return;
 301   }
 302
 303   /* If the synchro has already finish perform the error handling, */
 304   /* otherwise set up a waiting timeout on the right side          */
 305   if (synchro->state_ != SIMIX_WAITING && synchro->state_ != SIMIX_RUNNING) {
 306     SIMIX_comm_finish(synchro);
 307   } else { /* we need a sleep action (even when there is no timeout) to be notified of host failures */
 308     simgrid::kernel::resource::Action* sleep = simcall->issuer->host_->pimpl_cpu->sleep(timeout);
 309     sleep->set_data(synchro.get());
 310
 311     simgrid::kernel::activity::CommImplPtr comm =
 312         boost::static_pointer_cast<simgrid::kernel::activity::CommImpl>(synchro);
 313     if (simcall->issuer == comm->src_actor_)
 314       comm->src_timeout_ = sleep;
 315     else
 316       comm->dst_timeout_ = sleep;
 317   }
 318 }
 319
 320 void simcall_HANDLER_comm_test(smx_simcall_t simcall, smx_activity_t synchro)
 321 {
 322   simgrid::kernel::activity::CommImplPtr comm =
 323       boost::static_pointer_cast<simgrid::kernel::activity::CommImpl>(synchro);
 324
 325   int res;
 326
 327   if (MC_is_active() || MC_record_replay_is_active()){
 328     res = comm->src_actor_ && comm->dst_actor_;
 329     if (res)
 330       synchro->state_ = SIMIX_DONE;
 331   } else {
 332     res = synchro->state_ != SIMIX_WAITING && synchro->state_ != SIMIX_RUNNING;
 333   }
 334
 335   simcall_comm_test__set__result(simcall, res);
 336   if (simcall_comm_test__get__result(simcall)) {
 337     synchro->simcalls_.push_back(simcall);
 338     SIMIX_comm_finish(synchro);
 339   } else {
 340     SIMIX_simcall_answer(simcall);
 341   }
 342 }
 343
 344 void simcall_HANDLER_comm_testany(smx_simcall_t simcall, simgrid::kernel::activity::ActivityImplPtr comms[],
 345                                   size_t count)
 346 {
 347   // The default result is -1 -- this means, "nothing is ready".
 348   // It can be changed below, but only if something matches.
 349   simcall_comm_testany__set__result(simcall, -1);
 350
 351   if (MC_is_active() || MC_record_replay_is_active()){
 352     int idx = SIMCALL_GET_MC_VALUE(simcall);
 353     if(idx == -1){
 354       SIMIX_simcall_answer(simcall);
 355     }else{
 356       simgrid::kernel::activity::ActivityImplPtr synchro = comms[idx];
 357       simcall_comm_testany__set__result(simcall, idx);
 358       synchro->simcalls_.push_back(simcall);
 359       synchro->state_ = SIMIX_DONE;
 360       SIMIX_comm_finish(synchro);
 361     }
 362     return;
 363   }
 364
 365   for (std::size_t i = 0; i != count; ++i) {
 366     simgrid::kernel::activity::ActivityImplPtr synchro = comms[i];
 367     if (synchro->state_ != SIMIX_WAITING && synchro->state_ != SIMIX_RUNNING) {
 368       simcall_comm_testany__set__result(simcall, i);
 369       synchro->simcalls_.push_back(simcall);
 370       SIMIX_comm_finish(synchro);
 371       return;
 372     }
 373   }
 374   SIMIX_simcall_answer(simcall);
 375 }
 376
 377 void simcall_HANDLER_comm_waitany(smx_simcall_t simcall, xbt_dynar_t synchros, double timeout)
 378 {
 379   if (MC_is_active() || MC_record_replay_is_active()){
 380     if (timeout > 0.0)
 381       xbt_die("Timeout not implemented for waitany in the model-checker");
 382     int idx = SIMCALL_GET_MC_VALUE(simcall);
 383     smx_activity_t synchro = xbt_dynar_get_as(synchros, idx, smx_activity_t);
 384     synchro->simcalls_.push_back(simcall);
 385     simcall_comm_waitany__set__result(simcall, idx);
 386     synchro->state_ = SIMIX_DONE;
 387     SIMIX_comm_finish(synchro);
 388     return;
 389   }
 390
 391   if (timeout < 0.0){
 392     simcall->timer = NULL;
 393   } else {
 394     simcall->timer = SIMIX_timer_set(SIMIX_get_clock() + timeout, [simcall]() {
 395       SIMIX_waitany_remove_simcall_from_actions(simcall);
 396       simcall_comm_waitany__set__result(simcall, -1);
 397       SIMIX_simcall_answer(simcall);
 398     });
 399   }
 400
 401   unsigned int cursor;
 402   simgrid::kernel::activity::ActivityImpl* ptr;
 403   xbt_dynar_foreach(synchros, cursor, ptr){
 404     smx_activity_t synchro = simgrid::kernel::activity::ActivityImplPtr(ptr);
 405     /* associate this simcall to the the synchro */
 406     synchro->simcalls_.push_back(simcall);
 407
 408     /* see if the synchro is already finished */
 409     if (synchro->state_ != SIMIX_WAITING && synchro->state_ != SIMIX_RUNNING) {
 410       SIMIX_comm_finish(synchro);
 411       break;
 412     }
 413   }
 414 }
 415
 416 void SIMIX_waitany_remove_simcall_from_actions(smx_simcall_t simcall)
 417 {
 418   unsigned int cursor = 0;
 419   xbt_dynar_t synchros = simcall_comm_waitany__get__comms(simcall);
 420
 421   simgrid::kernel::activity::ActivityImpl* ptr;
 422   xbt_dynar_foreach(synchros, cursor, ptr){
 423     smx_activity_t synchro = simgrid::kernel::activity::ActivityImplPtr(ptr);
 424
 425     // Remove the first occurence of simcall:
 426     auto i = boost::range::find(synchro->simcalls_, simcall);
 427     if (i != synchro->simcalls_.end())
 428       synchro->simcalls_.erase(i);
 429   }
 430 }
 431
 432 /**
 433  * @brief Answers the SIMIX simcalls associated to a communication synchro.
 434  * @param synchro a finished communication synchro
 435  */
 436 void SIMIX_comm_finish(smx_activity_t synchro)
 437 {
 438   simgrid::kernel::activity::CommImplPtr comm =
 439       boost::static_pointer_cast<simgrid::kernel::activity::CommImpl>(synchro);
 440
 441   while (not synchro->simcalls_.empty()) {
 442     smx_simcall_t simcall = synchro->simcalls_.front();
 443     synchro->simcalls_.pop_front();
 444
 445     /* If a waitany simcall is waiting for this synchro to finish, then remove it from the other synchros in the waitany
 446      * list. Afterwards, get the position of the actual synchro in the waitany dynar and return it as the result of the
 447      * simcall */
 448
 449     if (simcall->call == SIMCALL_NONE) //FIXME: maybe a better way to handle this case
 450       continue; // if process handling comm is killed
 451     if (simcall->call == SIMCALL_COMM_WAITANY) {
 452       SIMIX_waitany_remove_simcall_from_actions(simcall);
 453       if (simcall->timer) {
 454         SIMIX_timer_remove(simcall->timer);
 455         simcall->timer = nullptr;
 456       }
 457       if (not MC_is_active() && not MC_record_replay_is_active())
 458         simcall_comm_waitany__set__result(simcall,
 459                                           xbt_dynar_search(simcall_comm_waitany__get__comms(simcall), &synchro));
 460     }
 461
 462     /* If the synchro is still in a rendez-vous point then remove from it */
 463     if (comm->mbox)
 464       comm->mbox->remove(comm);
 465
 466     XBT_DEBUG("SIMIX_comm_finish: synchro state = %d", (int)synchro->state_);
 467
 468     /* Check out for errors */
 469
 470     if (not simcall->issuer->host_->is_on()) {
 471       simcall->issuer->context_->iwannadie = true;
 472       simcall->issuer->exception =
 473           std::make_exception_ptr(simgrid::HostFailureException(XBT_THROW_POINT, "Host failed"));
 474     } else {
 475       switch (comm->state_) {
 476
 477         case SIMIX_DONE:
 478           XBT_DEBUG("Communication %p complete!", synchro.get());
 479           comm->copy_data();
 480           break;
 481
 482         case SIMIX_SRC_TIMEOUT:
 483           simcall->issuer->exception = std::make_exception_ptr(
 484               simgrid::TimeoutError(XBT_THROW_POINT, "Communication timeouted because of the sender"));
 485           break;
 486
 487         case SIMIX_DST_TIMEOUT:
 488           simcall->issuer->exception = std::make_exception_ptr(
 489               simgrid::TimeoutError(XBT_THROW_POINT, "Communication timeouted because of the receiver"));
 490           break;
 491
 492         case SIMIX_SRC_HOST_FAILURE:
 493           if (simcall->issuer == comm->src_actor_)
 494             simcall->issuer->context_->iwannadie = true;
 495           else
 496             simcall->issuer->exception =
 497                 std::make_exception_ptr(simgrid::NetworkFailureException(XBT_THROW_POINT, "Remote peer failed"));
 498           break;
 499
 500         case SIMIX_DST_HOST_FAILURE:
 501           if (simcall->issuer == comm->dst_actor_)
 502             simcall->issuer->context_->iwannadie = true;
 503           else
 504             simcall->issuer->exception =
 505                 std::make_exception_ptr(simgrid::NetworkFailureException(XBT_THROW_POINT, "Remote peer failed"));
 506           break;
 507
 508         case SIMIX_LINK_FAILURE:
 509           XBT_DEBUG("Link failure in synchro %p between '%s' and '%s': posting an exception to the issuer: %s (%p) "
 510                     "detached:%d",
 511                     synchro.get(), comm->src_actor_ ? comm->src_actor_->host_->get_cname() : nullptr,
 512                     comm->dst_actor_ ? comm->dst_actor_->host_->get_cname() : nullptr, simcall->issuer->get_cname(),
 513                     simcall->issuer, comm->detached);
 514           if (comm->src_actor_ == simcall->issuer) {
 515             XBT_DEBUG("I'm source");
 516           } else if (comm->dst_actor_ == simcall->issuer) {
 517             XBT_DEBUG("I'm dest");
 518           } else {
 519             XBT_DEBUG("I'm neither source nor dest");
 520           }
 521           simcall->issuer->throw_exception(
 522               std::make_exception_ptr(simgrid::NetworkFailureException(XBT_THROW_POINT, "Link failure")));
 523           break;
 524
 525         case SIMIX_CANCELED:
 526           if (simcall->issuer == comm->dst_actor_)
 527             SMX_EXCEPTION(simcall->issuer, cancel_error, 0, "Communication canceled by the sender");
 528           else
 529             SMX_EXCEPTION(simcall->issuer, cancel_error, 0, "Communication canceled by the receiver");
 530           break;
 531
 532         default:
 533           xbt_die("Unexpected synchro state in SIMIX_comm_finish: %d", (int)synchro->state_);
 534       }
 535     }
 536
 537     /* if there is an exception during a waitany or a testany, indicate the position of the failed communication */
 538     if (simcall->issuer->exception &&
 539         (simcall->call == SIMCALL_COMM_WAITANY || simcall->call == SIMCALL_COMM_TESTANY)) {
 540       // First retrieve the rank of our failing synchro
 541       int rank = -1;
 542       if (simcall->call == SIMCALL_COMM_WAITANY) {
 543         rank = xbt_dynar_search(simcall_comm_waitany__get__comms(simcall), &synchro);
 544       } else if (simcall->call == SIMCALL_COMM_TESTANY) {
 545         rank         = -1;
 546         auto* comms  = simcall_comm_testany__get__comms(simcall);
 547         auto count   = simcall_comm_testany__get__count(simcall);
 548         auto element = std::find(comms, comms + count, synchro);
 549         if (element == comms + count)
 550           rank = -1;
 551         else
 552           rank = element - comms;
 553       }
 554
 555       // In order to modify the exception we have to rethrow it:
 556       try {
 557         std::rethrow_exception(simcall->issuer->exception);
 558       } catch (simgrid::TimeoutError& e) {
 559         e.value                    = rank;
 560         simcall->issuer->exception = std::make_exception_ptr(e);
 561       } catch (simgrid::NetworkFailureException& e) {
 562         e.value                    = rank;
 563         simcall->issuer->exception = std::make_exception_ptr(e);
 564       } catch (xbt_ex& e) {
 565         if (e.category == cancel_error) {
 566           e.value                    = rank;
 567           simcall->issuer->exception = std::make_exception_ptr(e);
 568         } else {
 569           xbt_die("Unexpected xbt_ex(%s). Please enhance this code", xbt_ex_catname(e.category));
 570         }
 571       }
 572     }
 573
 574     simcall->issuer->waiting_synchro = nullptr;
 575     simcall->issuer->comms.remove(synchro);
 576     if(comm->detached){
 577       if (simcall->issuer == comm->src_actor_) {
 578         if (comm->dst_actor_)
 579           comm->dst_actor_->comms.remove(synchro);
 580       } else if (simcall->issuer == comm->dst_actor_) {
 581         if (comm->src_actor_)
 582           comm->src_actor_->comms.remove(synchro);
 583       }
 584       else{
 585         comm->dst_actor_->comms.remove(synchro);
 586         comm->src_actor_->comms.remove(synchro);
 587       }
 588     }
 589
 590     if (simcall->issuer->host_->is_on())
 591       SIMIX_simcall_answer(simcall);
 592     else
 593       simcall->issuer->context_->iwannadie = true;
 594   }
 595 }
 596
 597
 598 void SIMIX_comm_copy_buffer_callback(smx_activity_t synchro, void* buff, size_t buff_size)
 599 {
 600   simgrid::kernel::activity::CommImplPtr comm =
 601       boost::static_pointer_cast<simgrid::kernel::activity::CommImpl>(synchro);
 602
 603   XBT_DEBUG("Copy the data over");
 604   memcpy(comm->dst_buff_, buff, buff_size);
 605   if (comm->detached) { // if this is a detached send, the source buffer was duplicated by SMPI sender to make the original buffer available to the application ASAP
 606     xbt_free(buff);
 607     comm->src_buff_ = nullptr;
 608   }
 609 }