src/simdag/sd_task.c

   1 /* Copyright (c) 2007-2009 Da 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 "private.h"
   7 #include "simdag/simdag.h"
   8 #include "xbt/sysdep.h"
   9 #include "xbt/dynar.h"
  10
  11 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(sd_task, sd,
  12                                 "Logging specific to SimDag (task)");
  13
  14 static void __SD_task_remove_dependencies(SD_task_t task);
  15 static void __SD_task_destroy_scheduling_data(SD_task_t task);
  16
  17 /**
  18  * \brief Creates a new task.
  19  *
  20  * \param name the name of the task (can be \c NULL)
  21  * \param data the user data you want to associate with the task (can be \c NULL)
  22  * \param amount amount of the task
  23  * \return the new task
  24  * \see SD_task_destroy()
  25  */
  26 SD_task_t SD_task_create(const char *name, void *data, double amount)
  27 {
  28
  29   SD_task_t task;
  30   SD_CHECK_INIT_DONE();
  31
  32   task = xbt_new(s_SD_task_t, 1);
  33
  34   /* general information */
  35   task->data = data;            /* user data */
  36   task->name = xbt_strdup(name);
  37   task->kind = 0;
  38   task->state_hookup.prev = NULL;
  39   task->state_hookup.next = NULL;
  40   task->state_set = sd_global->not_scheduled_task_set;
  41   task->state = SD_NOT_SCHEDULED;
  42   xbt_swag_insert(task, task->state_set);
  43
  44   task->amount = amount;
  45   task->remains = amount;
  46   task->start_time = -1.0;
  47   task->finish_time = -1.0;
  48   task->surf_action = NULL;
  49   task->watch_points = 0;
  50
  51   /* dependencies */
  52   task->tasks_before = xbt_dynar_new(sizeof(SD_dependency_t), NULL);
  53   task->tasks_after = xbt_dynar_new(sizeof(SD_dependency_t), NULL);
  54
  55   /* scheduling parameters */
  56   task->workstation_nb = 0;
  57   task->workstation_list = NULL;
  58   task->computation_amount = NULL;
  59   task->communication_amount = NULL;
  60   task->rate = 0;
  61
  62   sd_global->task_number++;
  63
  64   return task;
  65 }
  66
  67 /**
  68  * \brief Returns the user data of a task
  69  *
  70  * \param task a task
  71  * \return the user data associated with this task (can be \c NULL)
  72  * \see SD_task_set_data()
  73  */
  74 void *SD_task_get_data(SD_task_t task)
  75 {
  76   SD_CHECK_INIT_DONE();
  77   xbt_assert0(task != NULL, "Invalid parameter");
  78   return task->data;
  79 }
  80
  81 /**
  82  * \brief Sets the user data of a task
  83  *
  84  * The new data can be \c NULL. The old data should have been freed first
  85  * if it was not \c NULL.
  86  *
  87  * \param task a task
  88  * \param data the new data you want to associate with this task
  89  * \see SD_task_get_data()
  90  */
  91 void SD_task_set_data(SD_task_t task, void *data)
  92 {
  93   SD_CHECK_INIT_DONE();
  94   xbt_assert0(task != NULL, "Invalid parameter");
  95   task->data = data;
  96 }
  97
  98 /**
  99  * \brief Returns the state of a task
 100  *
 101  * \param task a task
 102  * \return the current \ref e_SD_task_state_t "state" of this task:
 103  * #SD_NOT_SCHEDULED, #SD_SCHEDULED, #SD_READY, #SD_RUNNING, #SD_DONE or #SD_FAILED
 104  * \see e_SD_task_state_t
 105  */
 106 e_SD_task_state_t SD_task_get_state(SD_task_t task)
 107 {
 108   SD_CHECK_INIT_DONE();
 109   xbt_assert0(task != NULL, "Invalid parameter");
 110   return task->state;
 111 }
 112
 113 /* Changes the state of a task. Updates the swags and the flag sd_global->watch_point_reached.
 114  */
 115 void __SD_task_set_state(SD_task_t task, e_SD_task_state_t new_state)
 116 {
 117   xbt_swag_remove(task, task->state_set);
 118   switch (new_state) {
 119   case SD_NOT_SCHEDULED:
 120     task->state_set = sd_global->not_scheduled_task_set;
 121     break;
 122   case SD_SCHEDULED:
 123     task->state_set = sd_global->scheduled_task_set;
 124     break;
 125   case SD_READY:
 126     task->state_set = sd_global->ready_task_set;
 127     break;
 128   case SD_IN_FIFO:
 129     task->state_set = sd_global->in_fifo_task_set;
 130     break;
 131   case SD_RUNNING:
 132     task->state_set = sd_global->running_task_set;
 133     task->start_time =
 134       surf_workstation_model->action_get_start_time(task->surf_action);
 135     break;
 136   case SD_DONE:
 137     task->state_set = sd_global->done_task_set;
 138     task->finish_time =
 139       surf_workstation_model->action_get_finish_time(task->surf_action);
 140     task->remains = 0;
 141     break;
 142   case SD_FAILED:
 143     task->state_set = sd_global->failed_task_set;
 144     break;
 145   default:
 146     xbt_assert0(0, "Invalid state");
 147   }
 148   xbt_swag_insert(task, task->state_set);
 149   task->state = new_state;
 150
 151   if (task->watch_points & new_state) {
 152     INFO1("Watch point reached with task '%s'!", SD_task_get_name(task));
 153     sd_global->watch_point_reached = 1;
 154     SD_task_unwatch(task, new_state);   /* remove the watch point */
 155   }
 156 }
 157
 158 /**
 159  * \brief Returns the name of a task
 160  *
 161  * \param task a task
 162  * \return the name of this task (can be \c NULL)
 163  */
 164 const char *SD_task_get_name(SD_task_t task)
 165 {
 166   SD_CHECK_INIT_DONE();
 167   xbt_assert0(task != NULL, "Invalid parameter");
 168   return task->name;
 169 }
 170
 171 /** @brief Returns the dynar of the parents of a task
 172  *
 173  * \param task a task
 174  * \return a newly allocated dynar comprising the parents of this task
 175  */
 176
 177 xbt_dynar_t SD_task_get_parents(SD_task_t task)
 178 {
 179   unsigned int i;
 180   xbt_dynar_t parents;
 181   SD_dependency_t dep;
 182   SD_CHECK_INIT_DONE();
 183   xbt_assert0(task != NULL, "Invalid parameter");
 184
 185   parents = xbt_dynar_new(sizeof(SD_task_t), NULL);
 186   xbt_dynar_foreach(task->tasks_before, i, dep){
 187     xbt_dynar_push(parents, &(dep->src));
 188   }
 189   return parents;
 190 }
 191
 192 /** @brief Returns the dynar of the parents of a task
 193  *
 194  * \param task a task
 195  * \return a newly allocated dynar comprising the parents of this task
 196  */
 197 xbt_dynar_t SD_task_get_children(SD_task_t task)
 198 {
 199   unsigned int i;
 200   xbt_dynar_t children;
 201   SD_dependency_t dep;
 202   SD_CHECK_INIT_DONE();
 203   xbt_assert0(task != NULL, "Invalid parameter");
 204
 205   children = xbt_dynar_new(sizeof(SD_task_t), NULL);
 206   xbt_dynar_foreach(task->tasks_after, i, dep){
 207     xbt_dynar_push(children, &(dep->dst));
 208   }
 209   return children;
 210 }
 211
 212 /**
 213  * \brief Returns the amount of workstations involved in a task
 214  *
 215  * Only call this on already scheduled tasks!
 216  * \param task a task
 217  */
 218 int SD_task_get_workstation_count(SD_task_t task)
 219 {
 220   SD_CHECK_INIT_DONE();
 221   xbt_assert0(task != NULL, "Invalid parameter");
 222   //  xbt_assert1( task->state_set != sd_global->scheduled_task_set,
 223   //           "Unscheduled task %s", task->name);
 224   return task->workstation_nb;
 225 }
 226
 227 /**
 228  * \brief Returns the list of workstations involved in a task
 229  *
 230  * Only call this on already scheduled tasks!
 231  * \param task a task
 232  */
 233 SD_workstation_t* SD_task_get_workstation_list(SD_task_t task)
 234 {
 235   SD_CHECK_INIT_DONE();
 236   xbt_assert0(task != NULL, "Invalid parameter");
 237   //xbt_assert1( task->state_set != sd_global->scheduled_task_set,
 238   //           "Unscheduled task %s", task->name);
 239   return task->workstation_list;
 240 }
 241
 242 /**
 243  * \brief Returns the total amount of work contained in a task
 244  *
 245  * \param task a task
 246  * \return the total amount of work (computation or data transfer) for this task
 247  * \see SD_task_get_remaining_amount()
 248  */
 249 double SD_task_get_amount(SD_task_t task)
 250 {
 251   SD_CHECK_INIT_DONE();
 252   xbt_assert0(task != NULL, "Invalid parameter");
 253   return task->amount;
 254 }
 255
 256 /**
 257  * \brief Returns the remaining amount work to do till the completion of a task
 258  *
 259  * \param task a task
 260  * \return the remaining amount of work (computation or data transfer) of this task
 261  * \see SD_task_get_amount()
 262  */
 263 double SD_task_get_remaining_amount(SD_task_t task)
 264 {
 265   SD_CHECK_INIT_DONE();
 266   xbt_assert0(task != NULL, "Invalid parameter");
 267
 268   if (task->surf_action)
 269     return surf_workstation_model->get_remains(task->surf_action);
 270   else
 271     return task->remains;
 272 }
 273
 274 int SD_task_get_kind(SD_task_t task) {
 275   return task->kind;
 276 }
 277
 278 /** @brief Displays debugging informations about a task */
 279 void SD_task_dump(SD_task_t task)
 280 {
 281   unsigned int counter;
 282   SD_dependency_t dependency;
 283   char *statename;
 284
 285   INFO1("Displaying task %s",SD_task_get_name(task));
 286   statename=bprintf("%s %s %s %s %s %s %s",
 287       (task->state&SD_NOT_SCHEDULED?"not scheduled":""),
 288       (task->state&SD_SCHEDULED?"scheduled":""),
 289       (task->state&SD_READY?"ready":"not ready"),
 290       (task->state&SD_IN_FIFO?"in fifo":""),
 291       (task->state&SD_RUNNING?"running":""),
 292       (task->state&SD_DONE?"done":""),
 293       (task->state&SD_FAILED?"failed":""));
 294   INFO1("  - state: %s",statename);
 295   free(statename);
 296
 297   if (task->kind!=0) {
 298     switch(task->kind){
 299     case SD_TASK_COMM_E2E:
 300       INFO0("  - kind: end-to-end communication");
 301       break;
 302     case SD_TASK_COMP_SEQ:
 303       INFO0("  - kind: sequential computation");
 304       break;
 305     default:
 306       INFO1("  - (unknown kind %d)",task->kind);
 307     }
 308   }
 309   INFO1("  - amount: %.0f",SD_task_get_amount(task));
 310   if (xbt_dynar_length(task->tasks_before)) {
 311     INFO0("  - pre-dependencies:");
 312     xbt_dynar_foreach(task->tasks_before,counter,dependency) {
 313       INFO1("    %s",SD_task_get_name(dependency->src));
 314     }
 315   }
 316   if (xbt_dynar_length(task->tasks_after)) {
 317     INFO0("  - post-dependencies:");
 318     xbt_dynar_foreach(task->tasks_after,counter,dependency) {
 319       INFO1("    %s",SD_task_get_name(dependency->dst));
 320     }
 321   }
 322 }
 323 /** @brief Dumps the task in dotty formalism into the FILE* passed as second argument */
 324 void SD_task_dotty(SD_task_t task,void* out) {
 325   unsigned int counter;
 326   SD_dependency_t dependency;
 327   fprintf(out, "  T%p [label=\"%.20s\"",task, task->name);
 328   switch(task->kind){
 329     case SD_TASK_COMM_E2E:
 330       fprintf(out,", shape=box");
 331       break;
 332     case SD_TASK_COMP_SEQ:
 333       fprintf(out,", shape=circle");
 334       break;
 335     default:
 336       xbt_die("Unknown task type!");
 337   }
 338   fprintf(out,"];\n");
 339   xbt_dynar_foreach(task->tasks_before,counter,dependency) {
 340     fprintf(out," T%p -> T%p;\n",dependency->src, dependency->dst);
 341   }
 342 }
 343
 344 /* Destroys a dependency between two tasks.
 345  */
 346 static void __SD_task_dependency_destroy(void *dependency)
 347 {
 348   if (((SD_dependency_t) dependency)->name != NULL)
 349     xbt_free(((SD_dependency_t) dependency)->name);
 350   xbt_free(dependency);
 351 }
 352
 353 /**
 354  * \brief Adds a dependency between two tasks
 355  *
 356  * \a dst will depend on \a src, ie \a dst will not start before \a src is finished.
 357  * Their \ref e_SD_task_state_t "state" must be #SD_NOT_SCHEDULED, #SD_SCHEDULED or #SD_READY.
 358  *
 359  * \param name the name of the new dependency (can be \c NULL)
 360  * \param data the user data you want to associate with this dependency (can be \c NULL)
 361  * \param src the task which must be executed first
 362  * \param dst the task you want to make depend on \a src
 363  * \see SD_task_dependency_remove()
 364  */
 365 void SD_task_dependency_add(const char *name, void *data, SD_task_t src,
 366                             SD_task_t dst)
 367 {
 368   xbt_dynar_t dynar;
 369   int length;
 370   int found = 0;
 371   int i;
 372   SD_dependency_t dependency;
 373
 374   SD_CHECK_INIT_DONE();
 375   xbt_assert0(src != NULL && dst != NULL, "Invalid parameter");
 376
 377   dynar = src->tasks_after;
 378   length = xbt_dynar_length(dynar);
 379
 380   if (src == dst)
 381     THROW1(arg_error, 0,
 382            "Cannot add a dependency between task '%s' and itself",
 383            SD_task_get_name(src));
 384
 385   if (!__SD_task_is_not_scheduled(src)
 386       && !__SD_task_is_scheduled_or_ready(src))
 387     THROW1(arg_error, 0,
 388            "Task '%s' must be SD_NOT_SCHEDULED, SD_SCHEDULED or SD_READY",
 389            SD_task_get_name(src));
 390
 391   if (!__SD_task_is_not_scheduled(dst)
 392       && !__SD_task_is_scheduled_or_ready(dst))
 393     THROW1(arg_error, 0,
 394            "Task '%s' must be SD_NOT_SCHEDULED, SD_SCHEDULED or SD_READY",
 395            SD_task_get_name(dst));
 396
 397   DEBUG2("SD_task_dependency_add: src = %s, dst = %s", SD_task_get_name(src),
 398          SD_task_get_name(dst));
 399   for (i = 0; i < length && !found; i++) {
 400     xbt_dynar_get_cpy(dynar, i, &dependency);
 401     found = (dependency->dst == dst);
 402     DEBUG2("Dependency %d: dependency->dst = %s", i,
 403            SD_task_get_name(dependency->dst));
 404   }
 405
 406   if (found)
 407     THROW2(arg_error, 0,
 408            "A dependency already exists between task '%s' and task '%s'",
 409            SD_task_get_name(src), SD_task_get_name(dst));
 410
 411   dependency = xbt_new(s_SD_dependency_t, 1);
 412
 413   dependency->name = xbt_strdup(name); /* xbt_strdup is cleaver enough to deal with NULL args itself */
 414   dependency->data = data;
 415   dependency->src = src;
 416   dependency->dst = dst;
 417
 418   /* src must be executed before dst */
 419   xbt_dynar_push(src->tasks_after, &dependency);
 420   xbt_dynar_push(dst->tasks_before, &dependency);
 421
 422   /* if the task was ready, then dst->tasks_before is not empty anymore,
 423      so we must go back to state SD_SCHEDULED */
 424   if (__SD_task_is_ready(dst)) {
 425     DEBUG1("SD_task_dependency_add: %s was ready and becomes scheduled!",
 426            SD_task_get_name(dst));
 427     __SD_task_set_state(dst, SD_SCHEDULED);
 428   }
 429
 430   /*  __SD_print_dependencies(src);
 431      __SD_print_dependencies(dst); */
 432 }
 433
 434 /**
 435  * \brief Indacates whether there is a dependency between two tasks.
 436  *
 437  * \param src a task
 438  * \param dst a task depending on \a src
 439  *
 440  * If src is NULL, checks whether dst has any pre-dependency.
 441  * If dst is NULL, checks whether src has any post-dependency.
 442  */
 443 int SD_task_dependency_exists(SD_task_t src, SD_task_t dst)
 444 {
 445   unsigned int counter;
 446   SD_dependency_t dependency;
 447
 448   SD_CHECK_INIT_DONE();
 449   xbt_assert0(src != NULL || dst != NULL, "Invalid parameter: both src and dst are NULL");
 450
 451   if (src) {
 452     if (dst) {
 453       xbt_dynar_foreach(src->tasks_after,counter,dependency) {
 454         if (dependency->dst == dst)
 455           return 1;
 456       }
 457     } else {
 458       return xbt_dynar_length(src->tasks_after);
 459     }
 460   } else {
 461     return xbt_dynar_length(dst->tasks_before);
 462   }
 463   return 0;
 464 }
 465
 466 /**
 467  * \brief Remove a dependency between two tasks
 468  *
 469  * \param src a task
 470  * \param dst a task depending on \a src
 471  * \see SD_task_dependency_add()
 472  */
 473 void SD_task_dependency_remove(SD_task_t src, SD_task_t dst)
 474 {
 475
 476   xbt_dynar_t dynar;
 477   int length;
 478   int found = 0;
 479   int i;
 480   SD_dependency_t dependency;
 481
 482   SD_CHECK_INIT_DONE();
 483   xbt_assert0(src != NULL && dst != NULL, "Invalid parameter");
 484
 485   /* remove the dependency from src->tasks_after */
 486   dynar = src->tasks_after;
 487   length = xbt_dynar_length(dynar);
 488
 489   for (i = 0; i < length && !found; i++) {
 490     xbt_dynar_get_cpy(dynar, i, &dependency);
 491     if (dependency->dst == dst) {
 492       xbt_dynar_remove_at(dynar, i, NULL);
 493       found = 1;
 494     }
 495   }
 496   if (!found)
 497     THROW4(arg_error, 0,
 498            "No dependency found between task '%s' and '%s': task '%s' is not a successor of task '%s'",
 499            SD_task_get_name(src), SD_task_get_name(dst),
 500            SD_task_get_name(dst), SD_task_get_name(src));
 501
 502   /* remove the dependency from dst->tasks_before */
 503   dynar = dst->tasks_before;
 504   length = xbt_dynar_length(dynar);
 505   found = 0;
 506
 507   for (i = 0; i < length && !found; i++) {
 508     xbt_dynar_get_cpy(dynar, i, &dependency);
 509     if (dependency->src == src) {
 510       xbt_dynar_remove_at(dynar, i, NULL);
 511       __SD_task_dependency_destroy(dependency);
 512       found = 1;
 513     }
 514   }
 515   /* should never happen... */
 516   xbt_assert4(found,
 517               "SimDag error: task '%s' is a successor of '%s' but task '%s' is not a predecessor of task '%s'",
 518               SD_task_get_name(dst), SD_task_get_name(src),
 519               SD_task_get_name(src), SD_task_get_name(dst));
 520
 521   /* if the task was scheduled and dst->tasks_before is empty now, we can make it ready */
 522   if (xbt_dynar_length(dst->tasks_before) == 0 && __SD_task_is_scheduled(dst))
 523     __SD_task_set_state(dst, SD_READY);
 524
 525   /*  __SD_print_dependencies(src);
 526      __SD_print_dependencies(dst); */
 527 }
 528
 529 /**
 530  * \brief Returns the user data associated with a dependency between two tasks
 531  *
 532  * \param src a task
 533  * \param dst a task depending on \a src
 534  * \return the user data associated with this dependency (can be \c NULL)
 535  * \see SD_task_dependency_add()
 536  */
 537 void *SD_task_dependency_get_data(SD_task_t src, SD_task_t dst)
 538 {
 539
 540   xbt_dynar_t dynar;
 541   int length;
 542   int found = 0;
 543   int i;
 544   SD_dependency_t dependency;
 545
 546
 547   SD_CHECK_INIT_DONE();
 548   xbt_assert0(src != NULL && dst != NULL, "Invalid parameter");
 549
 550   dynar = src->tasks_after;
 551   length = xbt_dynar_length(dynar);
 552
 553   for (i = 0; i < length && !found; i++) {
 554     xbt_dynar_get_cpy(dynar, i, &dependency);
 555     found = (dependency->dst == dst);
 556   }
 557   if (!found)
 558     THROW2(arg_error, 0, "No dependency found between task '%s' and '%s'",
 559            SD_task_get_name(src), SD_task_get_name(dst));
 560   return dependency->data;
 561 }
 562
 563 /* temporary function for debugging */
 564 static void __SD_print_watch_points(SD_task_t task)
 565 {
 566   static const int state_masks[] =
 567     { SD_SCHEDULED, SD_RUNNING, SD_READY, SD_DONE, SD_FAILED };
 568   static const char *state_names[] =
 569     { "scheduled", "running", "ready", "done", "failed" };
 570   int i;
 571
 572   INFO2("Task '%s' watch points (%x): ", SD_task_get_name(task),
 573         task->watch_points);
 574
 575
 576   for (i = 0; i < 5; i++) {
 577     if (task->watch_points & state_masks[i])
 578       INFO1("%s ", state_names[i]);
 579   }
 580 }
 581
 582 /**
 583  * \brief Adds a watch point to a task
 584  *
 585  * SD_simulate() will stop as soon as the \ref e_SD_task_state_t "state" of this
 586  * task becomes the one given in argument. The
 587  * watch point is then automatically removed.
 588  *
 589  * \param task a task
 590  * \param state the \ref e_SD_task_state_t "state" you want to watch
 591  * (cannot be #SD_NOT_SCHEDULED)
 592  * \see SD_task_unwatch()
 593  */
 594 void SD_task_watch(SD_task_t task, e_SD_task_state_t state)
 595 {
 596   SD_CHECK_INIT_DONE();
 597   xbt_assert0(task != NULL, "Invalid parameter");
 598
 599   if (state & SD_NOT_SCHEDULED)
 600     THROW0(arg_error, 0,
 601            "Cannot add a watch point for state SD_NOT_SCHEDULED");
 602
 603   task->watch_points = task->watch_points | state;
 604   /*  __SD_print_watch_points(task); */
 605 }
 606
 607 /**
 608  * \brief Removes a watch point from a task
 609  *
 610  * \param task a task
 611  * \param state the \ref e_SD_task_state_t "state" you no longer want to watch
 612  * \see SD_task_watch()
 613  */
 614 void SD_task_unwatch(SD_task_t task, e_SD_task_state_t state)
 615 {
 616   SD_CHECK_INIT_DONE();
 617   xbt_assert0(task != NULL, "Invalid parameter");
 618   xbt_assert0(state != SD_NOT_SCHEDULED,
 619               "SimDag error: Cannot have a watch point for state SD_NOT_SCHEDULED");
 620
 621   task->watch_points = task->watch_points & ~state;
 622   /*  __SD_print_watch_points(task); */
 623 }
 624
 625 /**
 626  * \brief Returns an approximative estimation of the execution time of a task.
 627  *
 628  * The estimation is very approximative because the value returned is the time
 629  * the task would take if it was executed now and if it was the only task.
 630  *
 631  * \param task the task to evaluate
 632  * \param workstation_nb number of workstations on which the task would be executed
 633  * \param workstation_list the workstations on which the task would be executed
 634  * \param computation_amount computation amount for each workstation
 635  * \param communication_amount communication amount between each pair of workstations
 636  * \param rate task execution speed rate
 637  * \see SD_schedule()
 638  */
 639 double SD_task_get_execution_time(SD_task_t task,
 640                                   int workstation_nb,
 641                                   const SD_workstation_t * workstation_list,
 642                                   const double *computation_amount,
 643                                   const double *communication_amount,
 644                                   double rate)
 645 {
 646   double time, max_time = 0.0;
 647   int i, j;
 648   SD_CHECK_INIT_DONE();
 649   xbt_assert0(task != NULL && workstation_nb > 0 && workstation_list != NULL
 650               && computation_amount != NULL
 651               && communication_amount != NULL, "Invalid parameter");
 652
 653   /* the task execution time is the maximum execution time of the parallel tasks */
 654
 655   for (i = 0; i < workstation_nb; i++) {
 656     time =
 657       SD_workstation_get_computation_time(workstation_list[i],
 658                                           computation_amount[i]);
 659
 660     for (j = 0; j < workstation_nb; j++) {
 661       time +=
 662         SD_route_get_communication_time(workstation_list[i],
 663                                         workstation_list[j],
 664                                         communication_amount[i *
 665                                                              workstation_nb +
 666                                                              j]);
 667     }
 668
 669     if (time > max_time) {
 670       max_time = time;
 671     }
 672   }
 673   return max_time;
 674 }
 675 static inline void SD_task_do_schedule(SD_task_t task) {
 676   SD_CHECK_INIT_DONE();
 677
 678    if (!__SD_task_is_not_scheduled(task))
 679      THROW1(arg_error, 0, "Task '%s' has already been scheduled",
 680             SD_task_get_name(task));
 681
 682  /* update the task state */
 683   if (xbt_dynar_length(task->tasks_before) == 0)
 684     __SD_task_set_state(task, SD_READY);
 685   else
 686     __SD_task_set_state(task, SD_SCHEDULED);
 687 }
 688
 689 /**
 690  * \brief Schedules a task
 691  *
 692  * The task state must be #SD_NOT_SCHEDULED.
 693  * Once scheduled, a task will be executed as soon as possible in SD_simulate(),
 694  * i.e. when its dependencies are satisfied.
 695  *
 696  * \param task the task you want to schedule
 697  * \param workstation_nb number of workstations on which the task will be executed
 698  * \param workstation_list the workstations on which the task will be executed
 699  * \param computation_amount computation amount for each workstation
 700  * \param communication_amount communication amount between each pair of workstations
 701  * \param rate task execution speed rate
 702  * \see SD_task_unschedule()
 703  */
 704 void SD_task_schedule(SD_task_t task, int workstation_count,
 705                       const SD_workstation_t * workstation_list,
 706                       const double *computation_amount,
 707                       const double *communication_amount, double rate)
 708 {
 709   xbt_assert0(workstation_count > 0, "workstation_nb must be positive");
 710
 711   int communication_nb;
 712
 713   task->workstation_nb = workstation_count;
 714   task->rate = rate;
 715
 716   task->computation_amount = xbt_new(double, workstation_count);
 717   memcpy(task->computation_amount, computation_amount,
 718          sizeof(double) * workstation_count);
 719
 720   communication_nb = workstation_count * workstation_count;
 721   task->communication_amount = xbt_new(double, communication_nb);
 722   memcpy(task->communication_amount, communication_amount,
 723          sizeof(double) * communication_nb);
 724
 725   task->workstation_list = xbt_new(SD_workstation_t, workstation_count);
 726   memcpy(task->workstation_list, workstation_list,
 727          sizeof(SD_workstation_t) * workstation_count);
 728
 729   SD_task_do_schedule(task);
 730 }
 731 /**
 732  * \brief Unschedules a task
 733  *
 734  * The task state must be #SD_SCHEDULED, #SD_READY, #SD_RUNNING or #SD_FAILED.
 735  * If you call this function, the task state becomes #SD_NOT_SCHEDULED.
 736  * Call SD_task_schedule() to schedule it again.
 737  *
 738  * \param task the task you want to unschedule
 739  * \see SD_task_schedule()
 740  */
 741 void SD_task_unschedule(SD_task_t task)
 742 {
 743   SD_CHECK_INIT_DONE();
 744   xbt_assert0(task != NULL, "Invalid parameter");
 745
 746   if (task->state_set != sd_global->scheduled_task_set &&
 747       task->state_set != sd_global->ready_task_set &&
 748       task->state_set != sd_global->running_task_set &&
 749       task->state_set != sd_global->failed_task_set)
 750     THROW1(arg_error, 0,
 751            "Task %s: the state must be SD_SCHEDULED, SD_READY, SD_RUNNING or SD_FAILED",
 752            SD_task_get_name(task));
 753
 754   if (__SD_task_is_scheduled_or_ready(task))    /* if the task is scheduled or ready */
 755     __SD_task_destroy_scheduling_data(task);
 756
 757   if (__SD_task_is_running(task))       /* the task should become SD_FAILED */
 758     surf_workstation_model->action_cancel(task->surf_action);
 759   else
 760     __SD_task_set_state(task, SD_NOT_SCHEDULED);
 761   task->remains = task->amount;
 762   task->start_time = -1.0;
 763 }
 764
 765 /* Destroys the data memorised by SD_task_schedule. Task state must be SD_SCHEDULED or SD_READY.
 766  */
 767 static void __SD_task_destroy_scheduling_data(SD_task_t task)
 768 {
 769   SD_CHECK_INIT_DONE();
 770   if (!__SD_task_is_scheduled_or_ready(task) && !__SD_task_is_in_fifo(task))
 771     THROW1(arg_error, 0,
 772            "Task '%s' must be SD_SCHEDULED, SD_READY or SD_IN_FIFO",
 773            SD_task_get_name(task));
 774
 775   xbt_free(task->computation_amount);
 776   xbt_free(task->communication_amount);
 777   task->computation_amount = task->communication_amount = NULL;
 778 }
 779
 780 /* Runs a task. This function is directly called by __SD_task_try_to_run if the task
 781  * doesn't have to wait in fifos. Otherwise, it is called by __SD_task_just_done when
 782  * the task gets out of its fifos.
 783  */
 784 void __SD_task_really_run(SD_task_t task)
 785 {
 786
 787   int i;
 788   void **surf_workstations;
 789
 790   SD_CHECK_INIT_DONE();
 791   xbt_assert0(task != NULL, "Invalid parameter");
 792   xbt_assert2(__SD_task_is_ready_or_in_fifo(task),
 793               "Task '%s' is not ready or in a fifo! Task state: %d",
 794               SD_task_get_name(task), SD_task_get_state(task));
 795   xbt_assert1(task->workstation_list != NULL,
 796               "Task '%s': workstation_list is NULL!", SD_task_get_name(task));
 797
 798
 799
 800   DEBUG1("Really running task '%s'", SD_task_get_name(task));
 801
 802   /* set this task as current task for the workstations in sequential mode */
 803   for (i = 0; i < task->workstation_nb; i++) {
 804     if (SD_workstation_get_access_mode(task->workstation_list[i]) ==
 805         SD_WORKSTATION_SEQUENTIAL_ACCESS) {
 806       task->workstation_list[i]->current_task = task;
 807       xbt_assert0(__SD_workstation_is_busy(task->workstation_list[i]),
 808                   "The workstation should be busy now");
 809     }
 810   }
 811
 812   DEBUG1("Task '%s' set as current task for its workstations",
 813          SD_task_get_name(task));
 814
 815   /* start the task */
 816
 817   /* we have to create a Surf workstation array instead of the SimDag workstation array */
 818   surf_workstations = xbt_new(void *, task->workstation_nb);
 819
 820   for (i = 0; i < task->workstation_nb; i++) {
 821     surf_workstations[i] = task->workstation_list[i]->surf_workstation;
 822   }
 823
 824   task->surf_action = NULL;
 825   if ((task->workstation_nb == 1) && (task->communication_amount[0] == 0.0)) {
 826     task->surf_action =
 827       surf_workstation_model->extension.
 828       workstation.execute(surf_workstations[0], task->computation_amount[0]);
 829   } else if ((task->workstation_nb == 1)
 830              && (task->computation_amount[0] == 0.0)) {
 831     task->surf_action =
 832       surf_workstation_model->extension.
 833       workstation.communicate(surf_workstations[0], surf_workstations[0],
 834                               task->communication_amount[0], task->rate);
 835   } else if ((task->workstation_nb == 2)
 836              && (task->computation_amount[0] == 0.0)
 837              && (task->computation_amount[1] == 0.0)) {
 838     int nb = 0;
 839     double value = 0.0;
 840
 841     for (i = 0; i < task->workstation_nb * task->workstation_nb; i++) {
 842       if (task->communication_amount[i] > 0.0) {
 843         nb++;
 844         value = task->communication_amount[i];
 845       }
 846     }
 847     if (nb == 1) {
 848       task->surf_action =
 849         surf_workstation_model->extension.
 850         workstation.communicate(surf_workstations[0], surf_workstations[1],
 851                                 value, task->rate);
 852     }
 853   }
 854   if (!task->surf_action) {
 855     double *computation_amount = xbt_new(double, task->workstation_nb);
 856     double *communication_amount = xbt_new(double, task->workstation_nb *
 857                                            task->workstation_nb);
 858
 859     memcpy(computation_amount, task->computation_amount, sizeof(double) *
 860            task->workstation_nb);
 861     memcpy(communication_amount, task->communication_amount,
 862            sizeof(double) * task->workstation_nb * task->workstation_nb);
 863
 864     task->surf_action =
 865       surf_workstation_model->extension.
 866       workstation.execute_parallel_task(task->workstation_nb,
 867                                         surf_workstations, computation_amount,
 868                                         communication_amount, task->amount,
 869                                         task->rate);
 870   } else {
 871     xbt_free(surf_workstations);
 872   }
 873
 874   surf_workstation_model->action_data_set(task->surf_action, task);
 875
 876   DEBUG1("surf_action = %p", task->surf_action);
 877
 878   __SD_task_destroy_scheduling_data(task);      /* now the scheduling data are not useful anymore */
 879   __SD_task_set_state(task, SD_RUNNING);
 880   xbt_assert2(__SD_task_is_running(task), "Bad state of task '%s': %d",
 881               SD_task_get_name(task), SD_task_get_state(task));
 882
 883 }
 884
 885 /* Tries to run a task. This function is called by SD_simulate() when a scheduled task becomes SD_READY
 886  * (ie when its dependencies are satisfied).
 887  * If one of the workstations where the task is scheduled on is busy (in sequential mode),
 888  * the task doesn't start.
 889  * Returns whether the task has started.
 890  */
 891 int __SD_task_try_to_run(SD_task_t task)
 892 {
 893
 894   int can_start = 1;
 895   int i;
 896   SD_workstation_t workstation;
 897
 898   SD_CHECK_INIT_DONE();
 899   xbt_assert0(task != NULL, "Invalid parameter");
 900   xbt_assert2(__SD_task_is_ready(task),
 901               "Task '%s' is not ready! Task state: %d",
 902               SD_task_get_name(task), SD_task_get_state(task));
 903
 904
 905   for (i = 0; i < task->workstation_nb; i++) {
 906     can_start = !__SD_workstation_is_busy(task->workstation_list[i]);
 907   }
 908
 909   DEBUG2("Task '%s' can start: %d", SD_task_get_name(task), can_start);
 910
 911   if (!can_start) {             /* if the task cannot start and is not in the fifos yet */
 912     for (i = 0; i < task->workstation_nb; i++) {
 913       workstation = task->workstation_list[i];
 914       if (workstation->access_mode == SD_WORKSTATION_SEQUENTIAL_ACCESS) {
 915         DEBUG2("Pushing task '%s' in the fifo of workstation '%s'",
 916                SD_task_get_name(task), SD_workstation_get_name(workstation));
 917         xbt_fifo_push(workstation->task_fifo, task);
 918       }
 919     }
 920     __SD_task_set_state(task, SD_IN_FIFO);
 921     xbt_assert2(__SD_task_is_in_fifo(task), "Bad state of task '%s': %d",
 922                 SD_task_get_name(task), SD_task_get_state(task));
 923     DEBUG1("Task '%s' state is now SD_IN_FIFO", SD_task_get_name(task));
 924   } else {
 925     __SD_task_really_run(task);
 926   }
 927
 928   return can_start;
 929 }
 930
 931 /* This function is called by SD_simulate when a task is done.
 932  * It updates task->state and task->action and executes if necessary the tasks
 933  * which were waiting in fifos for the end of `task'
 934  */
 935 void __SD_task_just_done(SD_task_t task)
 936 {
 937   int i, j;
 938   SD_workstation_t workstation;
 939
 940   SD_task_t candidate;
 941   int candidate_nb = 0;
 942   int candidate_capacity = 8;
 943   SD_task_t *candidates;
 944   int can_start = 1;
 945
 946   SD_CHECK_INIT_DONE();
 947   xbt_assert0(task != NULL, "Invalid parameter");
 948   xbt_assert1(__SD_task_is_running(task),
 949               "The task must be running! Task state: %d",
 950               SD_task_get_state(task));
 951   xbt_assert1(task->workstation_list != NULL,
 952               "Task '%s': workstation_list is NULL!", SD_task_get_name(task));
 953
 954
 955   candidates = xbt_new(SD_task_t, 8);
 956
 957   __SD_task_set_state(task, SD_DONE);
 958   surf_workstation_model->action_unref(task->surf_action);
 959   task->surf_action = NULL;
 960
 961   DEBUG0("Looking for candidates");
 962
 963   /* if the task was executed on sequential workstations,
 964      maybe we can execute the next task of the fifo for each workstation */
 965   for (i = 0; i < task->workstation_nb; i++) {
 966     workstation = task->workstation_list[i];
 967     DEBUG2("Workstation '%s': access_mode = %d",
 968            SD_workstation_get_name(workstation), workstation->access_mode);
 969     if (workstation->access_mode == SD_WORKSTATION_SEQUENTIAL_ACCESS) {
 970       xbt_assert1(workstation->task_fifo != NULL,
 971                   "Workstation '%s' has sequential access but no fifo!",
 972                   SD_workstation_get_name(workstation));
 973       xbt_assert2(workstation->current_task =
 974                   task, "Workstation '%s': current task should be '%s'",
 975                   SD_workstation_get_name(workstation),
 976                   SD_task_get_name(task));
 977
 978       /* the task is over so we can release the workstation */
 979       workstation->current_task = NULL;
 980
 981       DEBUG0("Getting candidate in fifo");
 982       candidate =
 983         xbt_fifo_get_item_content(xbt_fifo_get_first_item
 984                                   (workstation->task_fifo));
 985
 986       if (candidate != NULL) {
 987         DEBUG1("Candidate: '%s'", SD_task_get_name(candidate));
 988         xbt_assert2(__SD_task_is_in_fifo(candidate),
 989                     "Bad state of candidate '%s': %d",
 990                     SD_task_get_name(candidate),
 991                     SD_task_get_state(candidate));
 992       }
 993
 994       DEBUG1("Candidate in fifo: %p", candidate);
 995
 996       /* if there was a task waiting for my place */
 997       if (candidate != NULL) {
 998         /* Unfortunately, we are not sure yet that we can execute the task now,
 999            because the task can be waiting more deeply in some other workstation's fifos...
1000            So we memorize all candidate tasks, and then we will check for each candidate
1001            whether or not all its workstations are available. */
1002
1003         /* realloc if necessary */
1004         if (candidate_nb == candidate_capacity) {
1005           candidate_capacity *= 2;
1006           candidates =
1007             xbt_realloc(candidates, sizeof(SD_task_t) * candidate_capacity);
1008         }
1009
1010         /* register the candidate */
1011         candidates[candidate_nb++] = candidate;
1012         candidate->fifo_checked = 0;
1013       }
1014     }
1015   }
1016
1017   DEBUG1("Candidates found: %d", candidate_nb);
1018
1019   /* now we check every candidate task */
1020   for (i = 0; i < candidate_nb; i++) {
1021     candidate = candidates[i];
1022
1023     if (candidate->fifo_checked) {
1024       continue;                 /* we have already evaluated that task */
1025     }
1026
1027     xbt_assert2(__SD_task_is_in_fifo(candidate),
1028                 "Bad state of candidate '%s': %d",
1029                 SD_task_get_name(candidate), SD_task_get_state(candidate));
1030
1031     for (j = 0; j < candidate->workstation_nb && can_start; j++) {
1032       workstation = candidate->workstation_list[j];
1033
1034       /* I can start on this workstation if the workstation is shared
1035          or if I am the first task in the fifo */
1036       can_start = workstation->access_mode == SD_WORKSTATION_SHARED_ACCESS ||
1037         candidate ==
1038         xbt_fifo_get_item_content(xbt_fifo_get_first_item
1039                                   (workstation->task_fifo));
1040     }
1041
1042     DEBUG2("Candidate '%s' can start: %d", SD_task_get_name(candidate),
1043            can_start);
1044
1045     /* now we are sure that I can start! */
1046     if (can_start) {
1047       for (j = 0; j < candidate->workstation_nb && can_start; j++) {
1048         workstation = candidate->workstation_list[j];
1049
1050         /* update the fifo */
1051         if (workstation->access_mode == SD_WORKSTATION_SEQUENTIAL_ACCESS) {
1052           candidate = xbt_fifo_shift(workstation->task_fifo);   /* the return value is stored just for debugging */
1053           DEBUG1("Head of the fifo: '%s'",
1054                  (candidate != NULL) ? SD_task_get_name(candidate) : "NULL");
1055           xbt_assert0(candidate == candidates[i],
1056                       "Error in __SD_task_just_done: bad first task in the fifo");
1057         }
1058       }                         /* for each workstation */
1059
1060       /* finally execute the task */
1061       DEBUG2("Task '%s' state: %d", SD_task_get_name(candidate),
1062              SD_task_get_state(candidate));
1063       __SD_task_really_run(candidate);
1064
1065       DEBUG4
1066         ("Calling __SD_task_is_running: task '%s', state set: %p, running_task_set: %p, is running: %d",
1067          SD_task_get_name(candidate), candidate->state_set,
1068          sd_global->running_task_set, __SD_task_is_running(candidate));
1069       xbt_assert2(__SD_task_is_running(candidate),
1070                   "Bad state of task '%s': %d", SD_task_get_name(candidate),
1071                   SD_task_get_state(candidate));
1072       DEBUG0("Okay, the task is running.");
1073
1074     }                           /* can start */
1075     candidate->fifo_checked = 1;
1076   }                             /* for each candidate */
1077
1078   xbt_free(candidates);
1079 }
1080
1081 /* Remove all dependencies associated with a task. This function is called when the task is destroyed.
1082  */
1083 static void __SD_task_remove_dependencies(SD_task_t task)
1084 {
1085   /* we must destroy the dependencies carefuly (with SD_dependency_remove)
1086      because each one is stored twice */
1087   SD_dependency_t dependency;
1088   while (xbt_dynar_length(task->tasks_before) > 0) {
1089     xbt_dynar_get_cpy(task->tasks_before, 0, &dependency);
1090     SD_task_dependency_remove(dependency->src, dependency->dst);
1091   }
1092
1093   while (xbt_dynar_length(task->tasks_after) > 0) {
1094     xbt_dynar_get_cpy(task->tasks_after, 0, &dependency);
1095     SD_task_dependency_remove(dependency->src, dependency->dst);
1096   }
1097 }
1098
1099 /**
1100  * \brief Returns the start time of a task
1101  *
1102  * The task state must be SD_RUNNING, SD_DONE or SD_FAILED.
1103  *
1104  * \param task: a task
1105  * \return the start time of this task
1106  */
1107 double SD_task_get_start_time(SD_task_t task)
1108 {
1109   SD_CHECK_INIT_DONE();
1110   xbt_assert0(task != NULL, "Invalid parameter");
1111   if (task->surf_action)
1112     return surf_workstation_model->action_get_start_time(task->surf_action);
1113   else
1114     return task->start_time;
1115 }
1116
1117 /**
1118  * \brief Returns the finish time of a task
1119  *
1120  * The task state must be SD_RUNNING, SD_DONE or SD_FAILED.
1121  * If the state is not completed yet, the returned value is an
1122  * estimation of the task finish time. This value can fluctuate
1123  * until the task is completed.
1124  *
1125  * \param task: a task
1126  * \return the start time of this task
1127  */
1128 double SD_task_get_finish_time(SD_task_t task)
1129 {
1130   SD_CHECK_INIT_DONE();
1131   xbt_assert0(task != NULL, "Invalid parameter");
1132
1133   if (task->surf_action)        /* should never happen as actions are destroyed right after their completion */
1134     return surf_workstation_model->action_get_finish_time(task->surf_action);
1135   else
1136     return task->finish_time;
1137 }
1138
1139 /**
1140  * \brief Destroys a task.
1141  *
1142  * The user data (if any) should have been destroyed first.
1143  *
1144  * \param task the task you want to destroy
1145  * \see SD_task_create()
1146  */
1147 void SD_task_destroy(SD_task_t task)
1148 {
1149   SD_CHECK_INIT_DONE();
1150   xbt_assert0(task != NULL, "Invalid parameter");
1151
1152   DEBUG1("Destroying task %s...", SD_task_get_name(task));
1153
1154   __SD_task_remove_dependencies(task);
1155   /* if the task was scheduled or ready we have to free the scheduling parameters */
1156   if (__SD_task_is_scheduled_or_ready(task))
1157     __SD_task_destroy_scheduling_data(task);
1158   xbt_swag_remove(task,task->state_set);
1159
1160   if (task->name != NULL)
1161     xbt_free(task->name);
1162
1163   if (task->surf_action != NULL)
1164     surf_workstation_model->action_unref(task->surf_action);
1165
1166   if (task->workstation_list != NULL)
1167     xbt_free(task->workstation_list);
1168
1169   if (task->communication_amount)
1170     xbt_free(task->communication_amount);
1171
1172   if (task->computation_amount)
1173     xbt_free(task->computation_amount);
1174
1175   xbt_dynar_free(&task->tasks_before);
1176   xbt_dynar_free(&task->tasks_after);
1177   xbt_free(task);
1178
1179   sd_global->task_number--;
1180
1181   DEBUG0("Task destroyed.");
1182 }
1183
1184
1185 static inline SD_task_t SD_task_create_sized(const char*name,void*data,double amount,int ws_count) {
1186   SD_task_t task = SD_task_create(name,data,amount);
1187   task->communication_amount = xbt_new0(double,ws_count*ws_count);
1188   task->computation_amount = xbt_new0(double,ws_count);
1189   task->workstation_nb = ws_count;
1190   task->workstation_list = xbt_new0(SD_workstation_t,ws_count);
1191   return task;
1192 }
1193 /** @brief create a end-to-end communication task that can then be auto-scheduled
1194  *
1195  * Auto-scheduling mean that the task can be used with SD_task_schedulev(). This
1196  * allows to specify the task costs at creation, and decorelate them from the
1197  * scheduling process where you just specify which resource should deliver the
1198  * mandatory power.
1199  *
1200  * A end-to-end communication must be scheduled on 2 hosts, and the amount
1201  * specified at creation is sent from hosts[0] to hosts[1].
1202  */
1203 SD_task_t SD_task_create_comm_e2e(const char*name, void *data, double amount) {
1204   SD_task_t res = SD_task_create_sized(name,data,amount,2);
1205   res->communication_amount[2] = amount;
1206   res->kind=SD_TASK_COMM_E2E;
1207   return res;
1208 }
1209 /** @brief create a sequential computation task that can then be auto-scheduled
1210  *
1211  * Auto-scheduling mean that the task can be used with SD_task_schedulev(). This
1212  * allows to specify the task costs at creation, and decorelate them from the
1213  * scheduling process where you just specify which resource should deliver the
1214  * mandatory power.
1215  *
1216  * A sequential computation must be scheduled on 1 host, and the amount
1217  * specified at creation to be run on hosts[0].
1218  */
1219 SD_task_t SD_task_create_comp_seq(const char*name, void *data, double amount) {
1220   SD_task_t res = SD_task_create_sized(name,data,amount,1);
1221   res->computation_amount[0]=amount;
1222   res->kind=SD_TASK_COMP_SEQ;
1223   return res;
1224 }
1225
1226 /** @brief Auto-schedules a task.
1227  *
1228  * Auto-scheduling mean that the task can be used with SD_task_schedulev(). This
1229  * allows to specify the task costs at creation, and decorelate them from the
1230  * scheduling process where you just specify which resource should deliver the
1231  * mandatory power.
1232  *
1233  * To be auto-schedulable, a task must be created with SD_task_create_comm_e2e() or
1234  * SD_task_create_comp_seq(). Check their definitions for the exact semantic of each
1235  * of them.
1236  *
1237  * @todo
1238  * We should create tasks kind for the following categories:
1239  *  - Point to point communication (done)
1240  *  - Sequential computation       (done)
1241  *  - group communication (redistribution, several kinds)
1242  *  - parallel tasks with no internal communication (one kind per speedup model such as amdal)
1243  *  - idem+ internal communication. Task type not enough since we cannot store comm cost alongside to comp one)
1244  */
1245 void SD_task_schedulev(SD_task_t task, int count, const SD_workstation_t*list) {
1246   int i;
1247   xbt_assert1(task->kind != 0,"Task %s is not typed. Cannot automatically schedule it.",SD_task_get_name(task));
1248   switch(task->kind) {
1249   case SD_TASK_COMM_E2E:
1250   case SD_TASK_COMP_SEQ:
1251     xbt_assert(task->workstation_nb==count);
1252     for (i=0;i<count;i++)
1253       task->workstation_list[i]=list[i];
1254     SD_task_do_schedule(task);
1255     break;
1256   default:
1257     xbt_die(bprintf("Kind of task %s not supported by SD_task_schedulev()",
1258           SD_task_get_name(task)));
1259   }
1260   if (task->kind == SD_TASK_COMM_E2E) {
1261     VERB4("Schedule comm task %s between %s -> %s. It costs %.f bytes",
1262         SD_task_get_name(task),
1263         SD_workstation_get_name(task->workstation_list[0]),SD_workstation_get_name(task->workstation_list[1]),
1264         task->communication_amount[2]);
1265
1266   }
1267   /* Iterate over all childs and parent being COMM_E2E to say where I am located (and start them if ready) */
1268   if (task->kind == SD_TASK_COMP_SEQ) {
1269     VERB3("Schedule computation task %s on %s. It costs %.f flops",
1270         SD_task_get_name(task),SD_workstation_get_name(task->workstation_list[0]),
1271         task->computation_amount[0]);
1272     SD_dependency_t dep;
1273     unsigned int cpt;
1274     xbt_dynar_foreach(task->tasks_before,cpt,dep) {
1275       SD_task_t before = dep->src;
1276       if (before->kind == SD_TASK_COMM_E2E) {
1277         before->workstation_list[1] = task->workstation_list[0];
1278         if (before->workstation_list[0] && __SD_task_is_not_scheduled(before)) {
1279           SD_task_do_schedule(before);
1280           VERB4("Auto-Schedule comm task %s between %s -> %s. It costs %.f bytes",
1281               SD_task_get_name(before),
1282               SD_workstation_get_name(before->workstation_list[0]),SD_workstation_get_name(before->workstation_list[1]),
1283               before->communication_amount[2]);
1284         }
1285       }
1286     }
1287     xbt_dynar_foreach(task->tasks_after,cpt,dep) {
1288       SD_task_t after = dep->dst;
1289       if (after->kind == SD_TASK_COMM_E2E) {
1290         after->workstation_list[0] = task->workstation_list[0];
1291         if (after->workstation_list[1] && __SD_task_is_not_scheduled(after)) {
1292           SD_task_do_schedule(after);
1293           VERB4("Auto-Schedule comm task %s between %s -> %s. It costs %.f bytes",
1294               SD_task_get_name(after),
1295               SD_workstation_get_name(after->workstation_list[0]),SD_workstation_get_name(after->workstation_list[1]),
1296               after->communication_amount[2]);
1297
1298         }
1299       }
1300     }
1301   }
1302 }
1303 /** @brief autoschedule a task on a list of workstations
1304  *
1305  * This function is very similar to SD_task_schedulev(),
1306  * but takes the list of workstations to schedule onto as separate parameters.
1307  * It builds a proper vector of workstations and then call SD_task_schedulev()
1308  */
1309 void SD_task_schedulel(SD_task_t task, int count, ...) {
1310   va_list ap;
1311   SD_workstation_t *list=xbt_new(SD_workstation_t,count);
1312   int i;
1313   va_start(ap,count);
1314   for (i=0;i<count;i++) {
1315       list[i] = va_arg(ap,SD_workstation_t);
1316   }
1317   va_end(ap);
1318   SD_task_schedulev(task,count,list);
1319   free(list);
1320 }