src/simix/smx_network.c

   1 /* Copyright (c) 2009, 2010. The SimGrid Team.
   2  * All rights reserved.                                                     */
   3
   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. */
   6
   7 #include "private.h"
   8 #include "xbt/log.h"
   9 #include "mc/mc.h"
  10 #include "xbt/dict.h"
  11
  12 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(simix_network, simix,
  13                                 "Logging specific to SIMIX (network)");
  14
  15 static xbt_dict_t rdv_points = NULL;
  16
  17 static XBT_INLINE void SIMIX_comm_start(smx_action_t action);
  18 static void SIMIX_comm_finish(smx_action_t action);
  19 static void SIMIX_waitany_req_remove_from_actions(smx_req_t req);
  20 static void SIMIX_comm_copy_data(smx_action_t comm);
  21 static smx_action_t SIMIX_comm_new(e_smx_comm_type_t type);
  22 static XBT_INLINE void SIMIX_comm_wait_for_completion(smx_action_t comm,
  23                                                       double timeout);
  24 static XBT_INLINE void SIMIX_rdv_push(smx_rdv_t rdv, smx_action_t comm);
  25 static XBT_INLINE void SIMIX_rdv_remove(smx_rdv_t rdv, smx_action_t comm);
  26 static smx_action_t SIMIX_rdv_get_request(smx_rdv_t rdv, e_smx_comm_type_t type,
  27                                                                                   int (*match_fun)(void *, void *), void *);
  28 static void SIMIX_rdv_free(void *data);
  29
  30 void SIMIX_network_init(void)
  31 {
  32   rdv_points = xbt_dict_new();
  33 }
  34
  35 void SIMIX_network_exit(void)
  36 {
  37   xbt_dict_free(&rdv_points);
  38 }
  39
  40 /******************************************************************************/
  41 /*                           Rendez-Vous Points                               */
  42 /******************************************************************************/
  43
  44 smx_rdv_t SIMIX_rdv_create(const char *name)
  45 {
  46   /* two processes may have pushed the same rdv_create request at the same time */
  47   smx_rdv_t rdv = name ? xbt_dict_get_or_null(rdv_points, name) : NULL;
  48
  49   if (!rdv) {
  50     rdv = xbt_new0(s_smx_rvpoint_t, 1);
  51     rdv->name = name ? xbt_strdup(name) : NULL;
  52     rdv->comm_fifo = xbt_fifo_new();
  53
  54     if (rdv->name)
  55       xbt_dict_set(rdv_points, rdv->name, rdv, SIMIX_rdv_free);
  56   }
  57   return rdv;
  58 }
  59
  60 void SIMIX_rdv_destroy(smx_rdv_t rdv)
  61 {
  62   if (rdv->name)
  63     xbt_dict_remove(rdv_points, rdv->name);
  64 }
  65
  66 void SIMIX_rdv_free(void *data)
  67 {
  68   smx_rdv_t rdv = (smx_rdv_t) data;
  69   if (rdv->name)
  70     xbt_free(rdv->name);
  71   xbt_fifo_free(rdv->comm_fifo);
  72   xbt_free(rdv);
  73 }
  74
  75 smx_rdv_t SIMIX_rdv_get_by_name(const char *name)
  76 {
  77   return xbt_dict_get_or_null(rdv_points, name);
  78 }
  79
  80 int SIMIX_rdv_comm_count_by_host(smx_rdv_t rdv, smx_host_t host)
  81 {
  82   smx_action_t comm = NULL;
  83   xbt_fifo_item_t item = NULL;
  84   int count = 0;
  85
  86   xbt_fifo_foreach(rdv->comm_fifo, item, comm, smx_action_t) {
  87     if (comm->comm.src_proc->smx_host == host)
  88       count++;
  89   }
  90
  91   return count;
  92 }
  93
  94 smx_action_t SIMIX_rdv_get_head(smx_rdv_t rdv)
  95 {
  96   return xbt_fifo_get_item_content(xbt_fifo_get_first_item(rdv->comm_fifo));
  97 }
  98
  99 /**
 100  *  \brief Push a communication request into a rendez-vous point
 101  *  \param rdv The rendez-vous point
 102  *  \param comm The communication request
 103  */
 104 static XBT_INLINE void SIMIX_rdv_push(smx_rdv_t rdv, smx_action_t comm)
 105 {
 106   xbt_fifo_push(rdv->comm_fifo, comm);
 107   comm->comm.rdv = rdv;
 108 }
 109
 110 /**
 111  *  \brief Remove a communication request from a rendez-vous point
 112  *  \param rdv The rendez-vous point
 113  *  \param comm The communication request
 114  */
 115 static XBT_INLINE void SIMIX_rdv_remove(smx_rdv_t rdv, smx_action_t comm)
 116 {
 117   xbt_fifo_remove(rdv->comm_fifo, comm);
 118   comm->comm.rdv = NULL;
 119 }
 120
 121 /**
 122  *  \brief Checks if there is a communication action queued in a rendez-vous matching our needs
 123  *  \param type The type of communication we are looking for (comm_send, comm_recv)
 124  *  \return The communication action if found, NULL otherwise
 125  */
 126 smx_action_t SIMIX_rdv_get_request(smx_rdv_t rdv, e_smx_comm_type_t type,
 127                                    int (*match_fun)(void *, void *), void *data)
 128 {
 129   smx_action_t action;
 130   xbt_fifo_item_t item;
 131   void* req_data = NULL;
 132
 133   xbt_fifo_foreach(rdv->comm_fifo, item, action, smx_action_t){
 134     if (action->comm.type == SIMIX_COMM_SEND) {
 135       req_data = action->comm.src_data;
 136     } else if (action->comm.type == SIMIX_COMM_RECEIVE) {
 137       req_data = action->comm.dst_data;
 138     }
 139     if (action->comm.type == type && (!match_fun || match_fun(data, req_data))) {
 140       DEBUG1("Found a matching communication action %p", action);
 141       xbt_fifo_remove_item(rdv->comm_fifo, item);
 142       xbt_fifo_free_item(item);
 143       action->comm.refcount++;
 144       action->comm.rdv = NULL;
 145       return action;
 146     }
 147     DEBUG3("Sorry, communication action %p does not match our needs:"
 148            " its type is %d but we are looking for a comm of type %d",
 149            action, action->comm.type, type);
 150   }
 151   DEBUG0("No matching communication action found");
 152   return NULL;
 153 }
 154
 155 /******************************************************************************/
 156 /*                            Comunication Actions                            */
 157 /******************************************************************************/
 158
 159 /**
 160  *  \brief Creates a new comunicate action
 161  *  \param type The type of request (comm_send, comm_recv)
 162  *  \return The new comunicate action
 163  */
 164 smx_action_t SIMIX_comm_new(e_smx_comm_type_t type)
 165 {
 166   smx_action_t act;
 167
 168   /* alloc structures */
 169   act = xbt_new0(s_smx_action_t, 1);
 170   act->type = SIMIX_ACTION_COMMUNICATE;
 171   act->state = SIMIX_WAITING;
 172   act->request_list = xbt_fifo_new();
 173
 174   /* set communication */
 175   act->comm.type = type;
 176   act->comm.refcount = 1;
 177
 178 #ifdef HAVE_LATENCY_BOUND_TRACKING
 179   //initialize with unknown value
 180   act->latency_limited = -1;
 181 #endif
 182
 183 #ifdef HAVE_TRACING
 184   act->category = NULL;
 185 #endif
 186
 187   DEBUG1("Create communicate action %p", act);
 188
 189   return act;
 190 }
 191
 192 /**
 193  *  \brief Destroy a communicate action
 194  *  \param action The communicate action to be destroyed
 195  */
 196 void SIMIX_comm_destroy(smx_action_t action)
 197 {
 198   DEBUG2("Destroy action %p (refcount:%d)", action, action->comm.refcount);
 199
 200   if (action->comm.refcount <= 0)
 201     xbt_die(bprintf("the refcount of comm %p is already 0 before decreasing it. That's a bug!",action));
 202
 203   action->comm.refcount--;
 204   if (action->comm.refcount > 0)
 205     return;
 206   DEBUG2("Really free communication %p; refcount is now %d", action,
 207         action->comm.refcount);
 208
 209 #ifdef HAVE_LATENCY_BOUND_TRACKING
 210     action->latency_limited = SIMIX_comm_is_latency_bounded( action ) ;
 211 #endif
 212
 213 #ifdef HAVE_TRACING
 214   TRACE_smx_action_destroy(action);
 215 #endif
 216
 217   if (action->name)
 218     xbt_free(action->name);
 219
 220   xbt_fifo_free(action->request_list);
 221
 222   SIMIX_comm_destroy_internal_actions(action);
 223
 224   xbt_free(action);
 225 }
 226
 227 void SIMIX_comm_destroy_internal_actions(smx_action_t action)
 228 {
 229   if (action->comm.surf_comm){
 230 #ifdef HAVE_LATENCY_BOUND_TRACKING
 231     action->latency_limited = SIMIX_comm_is_latency_bounded(action);
 232 #endif
 233     action->comm.surf_comm->model_type->action_unref(action->comm.surf_comm);
 234     action->comm.surf_comm = NULL;
 235   }
 236
 237   if (action->comm.src_timeout){
 238     action->comm.src_timeout->model_type->action_unref(action->comm.src_timeout);
 239     action->comm.src_timeout = NULL;
 240   }
 241
 242   if (action->comm.dst_timeout){
 243     action->comm.dst_timeout->model_type->action_unref(action->comm.dst_timeout);
 244     action->comm.dst_timeout = NULL;
 245   }
 246 }
 247
 248 smx_action_t SIMIX_comm_isend(smx_process_t src_proc, smx_rdv_t rdv,
 249                               double task_size, double rate,
 250                               void *src_buff, size_t src_buff_size,
 251                               int (*match_fun)(void *, void *), void *data)
 252 {
 253   smx_action_t action;
 254
 255   /* Look for communication request matching our needs.
 256      If it is not found then create it and push it into the rendez-vous point */
 257   action = SIMIX_rdv_get_request(rdv, SIMIX_COMM_RECEIVE, match_fun, data);
 258
 259   if (!action) {
 260     action = SIMIX_comm_new(SIMIX_COMM_SEND);
 261     SIMIX_rdv_push(rdv, action);
 262   } else {
 263     action->state = SIMIX_READY;
 264     action->comm.type = SIMIX_COMM_READY;
 265   }
 266
 267   /* Setup the communication request */
 268   action->comm.src_proc = src_proc;
 269   action->comm.task_size = task_size;
 270   action->comm.rate = rate;
 271   action->comm.src_buff = src_buff;
 272   action->comm.src_buff_size = src_buff_size;
 273   action->comm.src_data = data;
 274
 275   if (MC_IS_ENABLED) {
 276     action->state = SIMIX_RUNNING;
 277     return action;
 278   }
 279
 280   SIMIX_comm_start(action);
 281   return action;
 282 }
 283
 284 smx_action_t SIMIX_comm_irecv(smx_process_t dst_proc, smx_rdv_t rdv,
 285                       void *dst_buff, size_t *dst_buff_size,
 286                       int (*match_fun)(void *, void *), void *data)
 287 {
 288   smx_action_t action;
 289
 290   /* Look for communication request matching our needs.
 291    * If it is not found then create it and push it into the rendez-vous point
 292    */
 293   action = SIMIX_rdv_get_request(rdv, SIMIX_COMM_SEND, match_fun, data);
 294
 295   if (!action) {
 296     action = SIMIX_comm_new(SIMIX_COMM_RECEIVE);
 297     SIMIX_rdv_push(rdv, action);
 298   } else {
 299     action->state = SIMIX_READY;
 300     action->comm.type = SIMIX_COMM_READY;
 301   }
 302
 303   /* Setup communication request */
 304   action->comm.dst_proc = dst_proc;
 305   action->comm.dst_buff = dst_buff;
 306   action->comm.dst_buff_size = dst_buff_size;
 307   action->comm.dst_data = data;
 308
 309   if (MC_IS_ENABLED) {
 310     action->state = SIMIX_RUNNING;
 311     return action;
 312   }
 313
 314   SIMIX_comm_start(action);
 315   return action;
 316 }
 317
 318 void SIMIX_pre_comm_wait(smx_req_t req)
 319 {
 320   smx_action_t action = req->comm_wait.comm;
 321   double timeout = req->comm_wait.timeout;
 322   surf_action_t sleep;
 323
 324   /* Associate this request to the action */
 325   xbt_fifo_push(action->request_list, req);
 326   req->issuer->waiting_action = action;
 327
 328   if (MC_IS_ENABLED){
 329     action->state = SIMIX_DONE;
 330     SIMIX_comm_finish(action);
 331     return;
 332   }
 333
 334   /* If the action has already finish perform the error handling, */
 335   /* otherwise set up a waiting timeout on the right side         */
 336   if (action->state != SIMIX_WAITING && action->state != SIMIX_RUNNING) {
 337     SIMIX_comm_finish(action);
 338   } else { /* if (timeout >= 0) { we need a surf sleep action even when there is no timeout, otherwise surf won't tell us when the host fails */
 339     sleep = surf_workstation_model->extension.workstation.sleep(req->issuer->smx_host->host, timeout);
 340     surf_workstation_model->action_data_set(sleep, action);
 341
 342     if (req->issuer == action->comm.src_proc)
 343       action->comm.src_timeout = sleep;
 344     else
 345       action->comm.dst_timeout = sleep;
 346   }
 347 }
 348
 349 void SIMIX_pre_comm_test(smx_req_t req)
 350 {
 351   smx_action_t action = req->comm_test.comm;
 352   req->comm_test.result = (action->state != SIMIX_WAITING && action->state != SIMIX_RUNNING);
 353
 354   if (req->comm_test.result) {
 355     xbt_fifo_push(action->request_list, req);
 356     SIMIX_comm_finish(action);
 357   } else {
 358     SIMIX_request_answer(req);
 359   }
 360 }
 361
 362 void SIMIX_pre_comm_testany(smx_req_t req, unsigned int idx)
 363 {
 364   unsigned int cursor;
 365   smx_action_t action;
 366   xbt_dynar_t actions = req->comm_testany.comms;
 367   req->comm_testany.result = -1;
 368
 369   if (MC_IS_ENABLED){
 370     if((int)idx == -1){
 371       SIMIX_request_answer(req);
 372     }else{
 373       action = xbt_dynar_get_as(actions, idx, smx_action_t);
 374       xbt_fifo_push(action->request_list, req);
 375       action->state = SIMIX_DONE;
 376       SIMIX_comm_finish(action);
 377     }
 378     return;
 379   }
 380
 381   xbt_dynar_foreach(req->comm_testany.comms,cursor,action) {
 382     if (action->state != SIMIX_WAITING && action->state != SIMIX_RUNNING) {
 383       req->comm_testany.result = cursor;
 384       xbt_fifo_push(action->request_list, req);
 385       SIMIX_comm_finish(action);
 386       return;
 387     }
 388   }
 389   SIMIX_request_answer(req);
 390 }
 391
 392 void SIMIX_pre_comm_waitany(smx_req_t req, unsigned int idx)
 393 {
 394   smx_action_t action;
 395   unsigned int cursor = 0;
 396   xbt_dynar_t actions = req->comm_waitany.comms;
 397
 398   if (MC_IS_ENABLED){
 399     action = xbt_dynar_get_as(actions, idx, smx_action_t);
 400     xbt_fifo_push(action->request_list, req);
 401     req->comm_waitany.result = idx;
 402     action->state = SIMIX_DONE;
 403     SIMIX_comm_finish(action);
 404     return;
 405   }
 406
 407   xbt_dynar_foreach(actions, cursor, action){
 408     /* Associate this request to the action */
 409     xbt_fifo_push(action->request_list, req);
 410     if (action->state != SIMIX_WAITING && action->state != SIMIX_RUNNING){
 411       SIMIX_comm_finish(action);
 412       break;
 413     }
 414   }
 415 }
 416
 417 void SIMIX_waitany_req_remove_from_actions(smx_req_t req)
 418 {
 419   smx_action_t action;
 420   unsigned int cursor = 0;
 421   xbt_dynar_t actions = req->comm_waitany.comms;
 422
 423   xbt_dynar_foreach(actions, cursor, action){
 424     xbt_fifo_remove(action->request_list, req);
 425   }
 426 }
 427
 428 /**
 429  *  \brief Start the simulation of a communication request
 430  *  \param action The communication action
 431  */
 432 static XBT_INLINE void SIMIX_comm_start(smx_action_t action)
 433 {
 434   /* If both the sender and the receiver are already there, start the communication */
 435   if (action->state == SIMIX_READY) {
 436     smx_host_t sender = action->comm.src_proc->smx_host;
 437     smx_host_t receiver = action->comm.dst_proc->smx_host;
 438
 439     DEBUG3("Starting communication %p from '%s' to '%s'", action,
 440            SIMIX_host_get_name(sender), SIMIX_host_get_name(receiver));
 441
 442     action->comm.surf_comm = surf_workstation_model->extension.workstation.
 443         communicate(sender->host, receiver->host, action->comm.task_size, action->comm.rate);
 444
 445     surf_workstation_model->action_data_set(action->comm.surf_comm, action);
 446
 447     action->state = SIMIX_RUNNING;
 448
 449 #ifdef HAVE_TRACING
 450     TRACE_smx_action_communicate(action, action->comm.src_proc);
 451 #endif
 452
 453     /* If a link is failed, detect it immediately */
 454     if (surf_workstation_model->action_state_get(action->comm.surf_comm) == SURF_ACTION_FAILED) {
 455       DEBUG2("Communication from '%s' to '%s' failed to start because of a link failure",
 456           SIMIX_host_get_name(sender), SIMIX_host_get_name(receiver));
 457       action->state = SIMIX_LINK_FAILURE;
 458       SIMIX_comm_destroy_internal_actions(action);
 459     }
 460
 461     /* If any of the process is suspend, create the action but stop its execution,
 462        it will be restarted when the sender process resume */
 463     if (SIMIX_process_is_suspended(action->comm.src_proc) ||
 464         SIMIX_process_is_suspended(action->comm.dst_proc)) {
 465       /* FIXME: check what should happen with the action state */
 466       surf_workstation_model->suspend(action->comm.surf_comm);
 467     }
 468   }
 469 }
 470
 471 void SIMIX_comm_finish(smx_action_t action)
 472 {
 473   smx_req_t req;
 474
 475   while ((req = xbt_fifo_shift(action->request_list))) {
 476
 477     /* If a waitany request is waiting for this action to finish, then remove
 478        it from the other actions in the waitany list. Afterwards, get the
 479        position of the actual action in the waitany request's actions dynar and
 480        return it as the result of the call */
 481     if (req->call == REQ_COMM_WAITANY) {
 482       SIMIX_waitany_req_remove_from_actions(req);
 483       if(!MC_IS_ENABLED)
 484         req->comm_waitany.result = xbt_dynar_search(req->comm_waitany.comms, &action);
 485     }
 486
 487     /* If the action is still in a rendez-vous point then remove from it */
 488     if (action->comm.rdv)
 489       SIMIX_rdv_remove(action->comm.rdv, action);
 490
 491     DEBUG1("SIMIX_comm_finish: action state = %d", action->state);
 492
 493     /* Check out for errors */
 494     switch (action->state) {
 495
 496       case SIMIX_DONE:
 497         DEBUG1("Communication %p complete!", action);
 498         SIMIX_comm_copy_data(action);
 499         break;
 500
 501       case SIMIX_SRC_TIMEOUT:
 502         TRY {
 503           THROW0(timeout_error, 0, "Communication timeouted because of sender");
 504         }
 505         CATCH(req->issuer->running_ctx->exception) {
 506           req->issuer->doexception = 1;
 507         }
 508         break;
 509
 510       case SIMIX_DST_TIMEOUT:
 511         TRY {
 512           THROW0(timeout_error, 0, "Communication timeouted because of receiver");
 513         }
 514         CATCH(req->issuer->running_ctx->exception) {
 515           req->issuer->doexception = 1;
 516         }
 517         break;
 518
 519       case SIMIX_SRC_HOST_FAILURE:
 520         TRY {
 521           if (req->issuer == action->comm.src_proc)
 522             THROW0(host_error, 0, "Host failed");
 523           else
 524             THROW0(network_error, 0, "Remote peer failed");
 525         }
 526         CATCH(req->issuer->running_ctx->exception) {
 527           req->issuer->doexception = 1;
 528         }
 529         break;
 530
 531       case SIMIX_DST_HOST_FAILURE:
 532         TRY {
 533           if (req->issuer == action->comm.dst_proc)
 534             THROW0(host_error, 0, "Host failed");
 535           else
 536             THROW0(network_error, 0, "Remote peer failed");
 537         }
 538         CATCH(req->issuer->running_ctx->exception) {
 539           req->issuer->doexception = 1;
 540         }
 541         break;
 542
 543       case SIMIX_LINK_FAILURE:
 544         TRY {
 545           DEBUG5("Link failure in action %p between '%s' and '%s': posting an exception to the issuer: %s (%p)",
 546               action, action->comm.src_proc->smx_host->name, action->comm.dst_proc->smx_host->name,
 547               req->issuer->name, req->issuer);
 548           THROW0(network_error, 0, "Link failure");
 549         }
 550         CATCH(req->issuer->running_ctx->exception) {
 551           req->issuer->doexception = 1;
 552         }
 553         break;
 554
 555       default:
 556         THROW_IMPOSSIBLE;
 557     }
 558
 559     /* if there is an exception during a waitany or a testany, indicate the position of the failed communication */
 560     if (req->issuer->doexception) {
 561       if (req->call == REQ_COMM_WAITANY) {
 562         req->issuer->running_ctx->exception.value = xbt_dynar_search(req->comm_waitany.comms, &action);
 563       }
 564       else if (req->call == REQ_COMM_TESTANY) {
 565         req->issuer->running_ctx->exception.value = xbt_dynar_search(req->comm_testany.comms, &action);
 566       }
 567     }
 568
 569     req->issuer->waiting_action = NULL;
 570     SIMIX_request_answer(req);
 571   }
 572 }
 573
 574 void SIMIX_post_comm(smx_action_t action)
 575 {
 576   /* Update action state */
 577   if (action->comm.src_timeout &&
 578      surf_workstation_model->action_state_get(action->comm.src_timeout) == SURF_ACTION_DONE)
 579      action->state = SIMIX_SRC_TIMEOUT;
 580   else if (action->comm.dst_timeout &&
 581           surf_workstation_model->action_state_get(action->comm.dst_timeout) == SURF_ACTION_DONE)
 582      action->state = SIMIX_DST_TIMEOUT;
 583   else if (action->comm.src_timeout &&
 584           surf_workstation_model->action_state_get(action->comm.src_timeout) == SURF_ACTION_FAILED)
 585      action->state = SIMIX_SRC_HOST_FAILURE;
 586   else if (action->comm.dst_timeout &&
 587           surf_workstation_model->action_state_get(action->comm.dst_timeout) == SURF_ACTION_FAILED)
 588      action->state = SIMIX_DST_HOST_FAILURE;
 589   else if (action->comm.surf_comm &&
 590           surf_workstation_model->action_state_get(action->comm.surf_comm) == SURF_ACTION_FAILED)
 591      action->state = SIMIX_LINK_FAILURE;
 592   else
 593     action->state = SIMIX_DONE;
 594
 595   DEBUG1("SIMIX_post_comm: action state = %d", action->state);
 596
 597   /* After this point the surf actions associated with the simix communicate
 598      action are no longer needed, thus we delete them. */
 599   SIMIX_comm_destroy_internal_actions(action);
 600
 601   /* If there are requests associated with the action, then answer them */
 602   if (xbt_fifo_size(action->request_list))
 603     SIMIX_comm_finish(action);
 604 }
 605
 606 void SIMIX_comm_cancel(smx_action_t action)
 607 {
 608   /* If the action is a waiting state means that it is still in a rdv */
 609   /* so remove from it and delete it */
 610   if (action->state == SIMIX_WAITING) {
 611     SIMIX_rdv_remove(action->comm.rdv, action);
 612     action->state = SIMIX_FAILED;
 613   } else {
 614     surf_workstation_model->action_cancel(action->comm.surf_comm);
 615   }
 616 }
 617
 618 void SIMIX_comm_suspend(smx_action_t action)
 619 {
 620   /*FIXME: shall we suspend also the timeout actions? */
 621   surf_workstation_model->suspend(action->comm.surf_comm);
 622 }
 623
 624 void SIMIX_comm_resume(smx_action_t action)
 625 {
 626   /*FIXME: check what happen with the timeouts */
 627   surf_workstation_model->resume(action->comm.surf_comm);
 628 }
 629
 630
 631 /************* Action Getters **************/
 632
 633 /**
 634  *  \brief get the amount remaining from the communication
 635  *  \param action The communication
 636  */
 637 double SIMIX_comm_get_remains(smx_action_t action)
 638 {
 639   double remains;
 640
 641   switch (action->state) {
 642
 643     case SIMIX_RUNNING:
 644       remains = surf_workstation_model->get_remains(action->comm.surf_comm);
 645       break;
 646
 647     case SIMIX_WAITING:
 648     case SIMIX_READY:
 649       remains = 0; /*FIXME: check what should be returned */
 650       break;
 651
 652     default:
 653       remains = 0; /*FIXME: is this correct? */
 654       break;
 655   }
 656   return remains;
 657 }
 658
 659 e_smx_state_t SIMIX_comm_get_state(smx_action_t action)
 660 {
 661   return action->state;
 662 }
 663
 664 /**
 665  *  \brief Return the user data associated to the sender of the communication
 666  *  \param action The communication
 667  *  \return the user data
 668  */
 669 void* SIMIX_comm_get_src_data(smx_action_t action)
 670 {
 671   return action->comm.src_data;
 672 }
 673
 674 /**
 675  *  \brief Return the user data associated to the receiver of the communication
 676  *  \param action The communication
 677  *  \return the user data
 678  */
 679 void* SIMIX_comm_get_dst_data(smx_action_t action)
 680 {
 681   return action->comm.dst_data;
 682 }
 683
 684 void* SIMIX_comm_get_src_buff(smx_action_t action)
 685 {
 686   return action->comm.src_buff;
 687 }
 688
 689 void* SIMIX_comm_get_dst_buff(smx_action_t action)
 690 {
 691   return action->comm.dst_buff;
 692 }
 693
 694 size_t SIMIX_comm_get_src_buff_size(smx_action_t action)
 695 {
 696   return action->comm.src_buff_size;
 697 }
 698
 699 size_t SIMIX_comm_get_dst_buff_size(smx_action_t action)
 700 {
 701   size_t buff_size;
 702
 703   if (action->comm.dst_buff_size)
 704     buff_size = *(action->comm.dst_buff_size);
 705   else
 706     buff_size = 0;
 707
 708   return buff_size;
 709 }
 710
 711 smx_process_t SIMIX_comm_get_src_proc(smx_action_t action)
 712 {
 713   return action->comm.src_proc;
 714 }
 715
 716 smx_process_t SIMIX_comm_get_dst_proc(smx_action_t action)
 717 {
 718   return action->comm.dst_proc;
 719 }
 720
 721 #ifdef HAVE_LATENCY_BOUND_TRACKING
 722 /**
 723  *  \brief verify if communication is latency bounded
 724  *  \param comm The communication
 725  */
 726 XBT_INLINE int SIMIX_comm_is_latency_bounded(smx_action_t action)
 727 {
 728   if (action->comm.surf_comm){
 729       DEBUG1("Getting latency limited for surf_action (%p)", action->comm.surf_comm);
 730       action->latency_limited = surf_workstation_model->get_latency_limited(action->comm.surf_comm);
 731       DEBUG1("Action limited is %d", action->latency_limited);
 732   }
 733   return action->latency_limited;
 734 }
 735 #endif
 736
 737 /******************************************************************************/
 738 /*                    SIMIX_comm_copy_data callbacks                       */
 739 /******************************************************************************/
 740 static void (*SIMIX_comm_copy_data_callback) (smx_action_t, size_t) =
 741     &SIMIX_comm_copy_pointer_callback;
 742
 743 void
 744 SIMIX_comm_set_copy_data_callback(void (*callback) (smx_action_t, size_t))
 745 {
 746   SIMIX_comm_copy_data_callback = callback;
 747 }
 748
 749 void SIMIX_comm_copy_pointer_callback(smx_action_t comm, size_t buff_size)
 750 {
 751   xbt_assert1((buff_size == sizeof(void *)),
 752               "Cannot copy %zu bytes: must be sizeof(void*)", buff_size);
 753   *(void **) (comm->comm.dst_buff) = comm->comm.src_buff;
 754 }
 755
 756 void SIMIX_comm_copy_buffer_callback(smx_action_t comm, size_t buff_size)
 757 {
 758   memcpy(comm->comm.dst_buff, comm->comm.src_buff, buff_size);
 759 }
 760
 761 /**
 762  *  \brief Copy the communication data from the sender's buffer to the receiver's one
 763  *  \param comm The communication
 764  */
 765 void SIMIX_comm_copy_data(smx_action_t comm)
 766 {
 767   size_t buff_size = comm->comm.src_buff_size;
 768   /* If there is no data to be copy then return */
 769   if (!comm->comm.src_buff || !comm->comm.dst_buff || comm->comm.copied == 1)
 770     return;
 771
 772   DEBUG6("Copying comm %p data from %s (%p) -> %s (%p) (%zu bytes)",
 773          comm,
 774          comm->comm.src_proc->smx_host->name, comm->comm.src_buff,
 775          comm->comm.dst_proc->smx_host->name, comm->comm.dst_buff, buff_size);
 776
 777   /* Copy at most dst_buff_size bytes of the message to receiver's buffer */
 778   if (comm->comm.dst_buff_size)
 779     buff_size = MIN(buff_size, *(comm->comm.dst_buff_size));
 780
 781   /* Update the receiver's buffer size to the copied amount */
 782   if (comm->comm.dst_buff_size)
 783     *comm->comm.dst_buff_size = buff_size;
 784
 785   if (buff_size == 0)
 786     return;
 787
 788   (*SIMIX_comm_copy_data_callback) (comm, buff_size);
 789
 790   /* Set the copied flag so we copy data only once */
 791   /* (this function might be called from both communication ends) */
 792   comm->comm.copied = 1;
 793 }