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 = SD_TASK_NOT_TYPED;
  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  * \see SD_schedule()
 637  */
 638 double SD_task_get_execution_time(SD_task_t task,
 639                                   int workstation_nb,
 640                                   const SD_workstation_t * workstation_list,
 641                                   const double *computation_amount,
 642                                   const double *communication_amount)
 643 {
 644   double time, max_time = 0.0;
 645   int i, j;
 646   SD_CHECK_INIT_DONE();
 647   xbt_assert0(task != NULL && workstation_nb > 0 && workstation_list != NULL
 648               && computation_amount != NULL
 649               && communication_amount != NULL, "Invalid parameter");
 650
 651   /* the task execution time is the maximum execution time of the parallel tasks */
 652
 653   for (i = 0; i < workstation_nb; i++) {
 654     time =
 655       SD_workstation_get_computation_time(workstation_list[i],
 656                                           computation_amount[i]);
 657
 658     for (j = 0; j < workstation_nb; j++) {
 659       time +=
 660         SD_route_get_communication_time(workstation_list[i],
 661                                         workstation_list[j],
 662                                         communication_amount[i *
 663                                                              workstation_nb +
 664                                                              j]);
 665     }
 666
 667     if (time > max_time) {
 668       max_time = time;
 669     }
 670   }
 671   return max_time;
 672 }
 673 static inline void SD_task_do_schedule(SD_task_t task) {
 674   SD_CHECK_INIT_DONE();
 675
 676    if (!__SD_task_is_not_scheduled(task))
 677      THROW1(arg_error, 0, "Task '%s' has already been scheduled",
 678             SD_task_get_name(task));
 679
 680  /* update the task state */
 681   if (xbt_dynar_length(task->tasks_before) == 0)
 682     __SD_task_set_state(task, SD_READY);
 683   else
 684     __SD_task_set_state(task, SD_SCHEDULED);
 685 }
 686
 687 /**
 688  * \brief Schedules a task
 689  *
 690  * The task state must be #SD_NOT_SCHEDULED.
 691  * Once scheduled, a task will be executed as soon as possible in SD_simulate(),
 692  * i.e. when its dependencies are satisfied.
 693  *
 694  * \param task the task you want to schedule
 695  * \param workstation_nb number of workstations on which the task will be executed
 696  * \param workstation_list the workstations on which the task will be executed
 697  * \param computation_amount computation amount for each workstation
 698  * \param communication_amount communication amount between each pair of workstations
 699  * \param rate task execution speed rate
 700  * \see SD_task_unschedule()
 701  */
 702 void SD_task_schedule(SD_task_t task, int workstation_count,
 703                       const SD_workstation_t * workstation_list,
 704                       const double *computation_amount,
 705                       const double *communication_amount, double rate)
 706 {
 707   xbt_assert0(workstation_count > 0, "workstation_nb must be positive");
 708
 709   int communication_nb;
 710
 711   task->workstation_nb = workstation_count;
 712   task->rate = rate;
 713
 714   if (computation_amount) {
 715     task->computation_amount = xbt_new(double, workstation_count);
 716     memcpy(task->computation_amount, computation_amount,
 717         sizeof(double) * workstation_count);
 718   } else {
 719     task->computation_amount = NULL;
 720   }
 721
 722   communication_nb = workstation_count * workstation_count;
 723   if (communication_amount) {
 724     task->communication_amount = xbt_new(double, communication_nb);
 725     memcpy(task->communication_amount, communication_amount,
 726         sizeof(double) * communication_nb);
 727   } else {
 728     task->communication_amount = NULL;
 729   }
 730
 731   task->workstation_list = xbt_new(SD_workstation_t, workstation_count);
 732   memcpy(task->workstation_list, workstation_list,
 733          sizeof(SD_workstation_t) * workstation_count);
 734
 735   SD_task_do_schedule(task);
 736 }
 737 /**
 738  * \brief Unschedules a task
 739  *
 740  * The task state must be #SD_SCHEDULED, #SD_READY, #SD_RUNNING or #SD_FAILED.
 741  * If you call this function, the task state becomes #SD_NOT_SCHEDULED.
 742  * Call SD_task_schedule() to schedule it again.
 743  *
 744  * \param task the task you want to unschedule
 745  * \see SD_task_schedule()
 746  */
 747 void SD_task_unschedule(SD_task_t task)
 748 {
 749   SD_CHECK_INIT_DONE();
 750   xbt_assert0(task != NULL, "Invalid parameter");
 751
 752   if (task->state_set != sd_global->scheduled_task_set &&
 753       task->state_set != sd_global->ready_task_set &&
 754       task->state_set != sd_global->running_task_set &&
 755       task->state_set != sd_global->failed_task_set)
 756     THROW1(arg_error, 0,
 757            "Task %s: the state must be SD_SCHEDULED, SD_READY, SD_RUNNING or SD_FAILED",
 758            SD_task_get_name(task));
 759
 760   if (__SD_task_is_scheduled_or_ready(task) /* if the task is scheduled or ready */
 761       && task->kind == SD_TASK_NOT_TYPED) /* Don't free scheduling data for typed tasks */
 762     __SD_task_destroy_scheduling_data(task);
 763
 764   if (__SD_task_is_running(task))       /* the task should become SD_FAILED */
 765     surf_workstation_model->action_cancel(task->surf_action);
 766   else
 767     __SD_task_set_state(task, SD_NOT_SCHEDULED);
 768   task->remains = task->amount;
 769   task->start_time = -1.0;
 770 }
 771
 772 /* Destroys the data memorised by SD_task_schedule. Task state must be SD_SCHEDULED or SD_READY.
 773  */
 774 static void __SD_task_destroy_scheduling_data(SD_task_t task)
 775 {
 776   SD_CHECK_INIT_DONE();
 777   if (!__SD_task_is_scheduled_or_ready(task) && !__SD_task_is_in_fifo(task))
 778     THROW1(arg_error, 0,
 779            "Task '%s' must be SD_SCHEDULED, SD_READY or SD_IN_FIFO",
 780            SD_task_get_name(task));
 781
 782   xbt_free(task->computation_amount);
 783   xbt_free(task->communication_amount);
 784   task->computation_amount = task->communication_amount = NULL;
 785 }
 786
 787 /* Runs a task. This function is directly called by __SD_task_try_to_run if the task
 788  * doesn't have to wait in fifos. Otherwise, it is called by __SD_task_just_done when
 789  * the task gets out of its fifos.
 790  */
 791 void __SD_task_really_run(SD_task_t task)
 792 {
 793
 794   int i;
 795   void **surf_workstations;
 796
 797   SD_CHECK_INIT_DONE();
 798   xbt_assert0(task != NULL, "Invalid parameter");
 799   xbt_assert2(__SD_task_is_ready_or_in_fifo(task),
 800               "Task '%s' is not ready or in a fifo! Task state: %d",
 801               SD_task_get_name(task), SD_task_get_state(task));
 802   xbt_assert1(task->workstation_list != NULL,
 803               "Task '%s': workstation_list is NULL!", SD_task_get_name(task));
 804
 805
 806
 807   DEBUG1("Really running task '%s'", SD_task_get_name(task));
 808
 809   /* set this task as current task for the workstations in sequential mode */
 810   for (i = 0; i < task->workstation_nb; i++) {
 811     if (SD_workstation_get_access_mode(task->workstation_list[i]) ==
 812         SD_WORKSTATION_SEQUENTIAL_ACCESS) {
 813       task->workstation_list[i]->current_task = task;
 814       xbt_assert0(__SD_workstation_is_busy(task->workstation_list[i]),
 815                   "The workstation should be busy now");
 816     }
 817   }
 818
 819   DEBUG1("Task '%s' set as current task for its workstations",
 820          SD_task_get_name(task));
 821
 822   /* start the task */
 823
 824   /* we have to create a Surf workstation array instead of the SimDag workstation array */
 825   surf_workstations = xbt_new(void *, task->workstation_nb);
 826
 827   for (i = 0; i < task->workstation_nb; i++)
 828     surf_workstations[i] = task->workstation_list[i]->surf_workstation;
 829
 830   /* It's allowed to pass a NULL vector as cost to mean vector of 0.0 (easing user's life). Let's deal with it */
 831 #define cost_or_zero(array,pos) ((array)?(array)[pos]:0.0)
 832
 833   task->surf_action = NULL;
 834   if ((task->workstation_nb == 1) && (cost_or_zero(task->communication_amount,0) == 0.0)) {
 835     task->surf_action =
 836       surf_workstation_model->extension.
 837       workstation.execute(surf_workstations[0], cost_or_zero(task->computation_amount,0));
 838   } else if ((task->workstation_nb == 1)
 839              && (cost_or_zero(task->computation_amount,0) == 0.0)) {
 840
 841     task->surf_action =
 842       surf_workstation_model->extension.
 843       workstation.communicate(surf_workstations[0], surf_workstations[0],
 844                               cost_or_zero(task->communication_amount,0), task->rate);
 845   } else if ((task->workstation_nb == 2)
 846              && (cost_or_zero(task->computation_amount,0) == 0.0)
 847              && (cost_or_zero(task->computation_amount,1) == 0.0)) {
 848     int nb = 0;
 849     double value = 0.0;
 850
 851     for (i = 0; i < task->workstation_nb * task->workstation_nb; i++) {
 852       if (cost_or_zero(task->communication_amount,i) > 0.0) {
 853         nb++;
 854         value = cost_or_zero(task->communication_amount,i);
 855       }
 856     }
 857     if (nb == 1) {
 858       task->surf_action =
 859         surf_workstation_model->extension.
 860         workstation.communicate(surf_workstations[0], surf_workstations[1],
 861                                 value, task->rate);
 862     }
 863   }
 864 #undef cost_or_zero
 865
 866   if (!task->surf_action) {
 867     double *computation_amount = xbt_new(double, task->workstation_nb);
 868     double *communication_amount = xbt_new(double, task->workstation_nb *
 869                                            task->workstation_nb);
 870
 871     memcpy(computation_amount, task->computation_amount, sizeof(double) *
 872            task->workstation_nb);
 873     memcpy(communication_amount, task->communication_amount,
 874            sizeof(double) * task->workstation_nb * task->workstation_nb);
 875
 876     task->surf_action =
 877       surf_workstation_model->extension.
 878       workstation.execute_parallel_task(task->workstation_nb,
 879                                         surf_workstations, computation_amount,
 880                                         communication_amount, task->amount,
 881                                         task->rate);
 882   } else {
 883     xbt_free(surf_workstations);
 884   }
 885
 886   surf_workstation_model->action_data_set(task->surf_action, task);
 887
 888   DEBUG1("surf_action = %p", task->surf_action);
 889
 890   __SD_task_destroy_scheduling_data(task);      /* now the scheduling data are not useful anymore */
 891   __SD_task_set_state(task, SD_RUNNING);
 892   xbt_assert2(__SD_task_is_running(task), "Bad state of task '%s': %d",
 893               SD_task_get_name(task), SD_task_get_state(task));
 894
 895 }
 896
 897 /* Tries to run a task. This function is called by SD_simulate() when a scheduled task becomes SD_READY
 898  * (ie when its dependencies are satisfied).
 899  * If one of the workstations where the task is scheduled on is busy (in sequential mode),
 900  * the task doesn't start.
 901  * Returns whether the task has started.
 902  */
 903 int __SD_task_try_to_run(SD_task_t task)
 904 {
 905
 906   int can_start = 1;
 907   int i;
 908   SD_workstation_t workstation;
 909
 910   SD_CHECK_INIT_DONE();
 911   xbt_assert0(task != NULL, "Invalid parameter");
 912   xbt_assert2(__SD_task_is_ready(task),
 913               "Task '%s' is not ready! Task state: %d",
 914               SD_task_get_name(task), SD_task_get_state(task));
 915
 916
 917   for (i = 0; i < task->workstation_nb; i++) {
 918     can_start = !__SD_workstation_is_busy(task->workstation_list[i]);
 919   }
 920
 921   DEBUG2("Task '%s' can start: %d", SD_task_get_name(task), can_start);
 922
 923   if (!can_start) {             /* if the task cannot start and is not in the fifos yet */
 924     for (i = 0; i < task->workstation_nb; i++) {
 925       workstation = task->workstation_list[i];
 926       if (workstation->access_mode == SD_WORKSTATION_SEQUENTIAL_ACCESS) {
 927         DEBUG2("Pushing task '%s' in the fifo of workstation '%s'",
 928                SD_task_get_name(task), SD_workstation_get_name(workstation));
 929         xbt_fifo_push(workstation->task_fifo, task);
 930       }
 931     }
 932     __SD_task_set_state(task, SD_IN_FIFO);
 933     xbt_assert2(__SD_task_is_in_fifo(task), "Bad state of task '%s': %d",
 934                 SD_task_get_name(task), SD_task_get_state(task));
 935     DEBUG1("Task '%s' state is now SD_IN_FIFO", SD_task_get_name(task));
 936   } else {
 937     __SD_task_really_run(task);
 938   }
 939
 940   return can_start;
 941 }
 942
 943 /* This function is called by SD_simulate when a task is done.
 944  * It updates task->state and task->action and executes if necessary the tasks
 945  * which were waiting in fifos for the end of `task'
 946  */
 947 void __SD_task_just_done(SD_task_t task)
 948 {
 949   int i, j;
 950   SD_workstation_t workstation;
 951
 952   SD_task_t candidate;
 953   int candidate_nb = 0;
 954   int candidate_capacity = 8;
 955   SD_task_t *candidates;
 956   int can_start = 1;
 957
 958   SD_CHECK_INIT_DONE();
 959   xbt_assert0(task != NULL, "Invalid parameter");
 960   xbt_assert1(__SD_task_is_running(task),
 961               "The task must be running! Task state: %d",
 962               SD_task_get_state(task));
 963   xbt_assert1(task->workstation_list != NULL,
 964               "Task '%s': workstation_list is NULL!", SD_task_get_name(task));
 965
 966
 967   candidates = xbt_new(SD_task_t, 8);
 968
 969   __SD_task_set_state(task, SD_DONE);
 970   surf_workstation_model->action_unref(task->surf_action);
 971   task->surf_action = NULL;
 972
 973   DEBUG0("Looking for candidates");
 974
 975   /* if the task was executed on sequential workstations,
 976      maybe we can execute the next task of the fifo for each workstation */
 977   for (i = 0; i < task->workstation_nb; i++) {
 978     workstation = task->workstation_list[i];
 979     DEBUG2("Workstation '%s': access_mode = %d",
 980            SD_workstation_get_name(workstation), workstation->access_mode);
 981     if (workstation->access_mode == SD_WORKSTATION_SEQUENTIAL_ACCESS) {
 982       xbt_assert1(workstation->task_fifo != NULL,
 983                   "Workstation '%s' has sequential access but no fifo!",
 984                   SD_workstation_get_name(workstation));
 985       xbt_assert2(workstation->current_task =
 986                   task, "Workstation '%s': current task should be '%s'",
 987                   SD_workstation_get_name(workstation),
 988                   SD_task_get_name(task));
 989
 990       /* the task is over so we can release the workstation */
 991       workstation->current_task = NULL;
 992
 993       DEBUG0("Getting candidate in fifo");
 994       candidate =
 995         xbt_fifo_get_item_content(xbt_fifo_get_first_item
 996                                   (workstation->task_fifo));
 997
 998       if (candidate != NULL) {
 999         DEBUG1("Candidate: '%s'", SD_task_get_name(candidate));
1000         xbt_assert2(__SD_task_is_in_fifo(candidate),
1001                     "Bad state of candidate '%s': %d",
1002                     SD_task_get_name(candidate),
1003                     SD_task_get_state(candidate));
1004       }
1005
1006       DEBUG1("Candidate in fifo: %p", candidate);
1007
1008       /* if there was a task waiting for my place */
1009       if (candidate != NULL) {
1010         /* Unfortunately, we are not sure yet that we can execute the task now,
1011            because the task can be waiting more deeply in some other workstation's fifos...
1012            So we memorize all candidate tasks, and then we will check for each candidate
1013            whether or not all its workstations are available. */
1014
1015         /* realloc if necessary */
1016         if (candidate_nb == candidate_capacity) {
1017           candidate_capacity *= 2;
1018           candidates =
1019             xbt_realloc(candidates, sizeof(SD_task_t) * candidate_capacity);
1020         }
1021
1022         /* register the candidate */
1023         candidates[candidate_nb++] = candidate;
1024         candidate->fifo_checked = 0;
1025       }
1026     }
1027   }
1028
1029   DEBUG1("Candidates found: %d", candidate_nb);
1030
1031   /* now we check every candidate task */
1032   for (i = 0; i < candidate_nb; i++) {
1033     candidate = candidates[i];
1034
1035     if (candidate->fifo_checked) {
1036       continue;                 /* we have already evaluated that task */
1037     }
1038
1039     xbt_assert2(__SD_task_is_in_fifo(candidate),
1040                 "Bad state of candidate '%s': %d",
1041                 SD_task_get_name(candidate), SD_task_get_state(candidate));
1042
1043     for (j = 0; j < candidate->workstation_nb && can_start; j++) {
1044       workstation = candidate->workstation_list[j];
1045
1046       /* I can start on this workstation if the workstation is shared
1047          or if I am the first task in the fifo */
1048       can_start = workstation->access_mode == SD_WORKSTATION_SHARED_ACCESS ||
1049         candidate ==
1050         xbt_fifo_get_item_content(xbt_fifo_get_first_item
1051                                   (workstation->task_fifo));
1052     }
1053
1054     DEBUG2("Candidate '%s' can start: %d", SD_task_get_name(candidate),
1055            can_start);
1056
1057     /* now we are sure that I can start! */
1058     if (can_start) {
1059       for (j = 0; j < candidate->workstation_nb && can_start; j++) {
1060         workstation = candidate->workstation_list[j];
1061
1062         /* update the fifo */
1063         if (workstation->access_mode == SD_WORKSTATION_SEQUENTIAL_ACCESS) {
1064           candidate = xbt_fifo_shift(workstation->task_fifo);   /* the return value is stored just for debugging */
1065           DEBUG1("Head of the fifo: '%s'",
1066                  (candidate != NULL) ? SD_task_get_name(candidate) : "NULL");
1067           xbt_assert0(candidate == candidates[i],
1068                       "Error in __SD_task_just_done: bad first task in the fifo");
1069         }
1070       }                         /* for each workstation */
1071
1072       /* finally execute the task */
1073       DEBUG2("Task '%s' state: %d", SD_task_get_name(candidate),
1074              SD_task_get_state(candidate));
1075       __SD_task_really_run(candidate);
1076
1077       DEBUG4
1078         ("Calling __SD_task_is_running: task '%s', state set: %p, running_task_set: %p, is running: %d",
1079          SD_task_get_name(candidate), candidate->state_set,
1080          sd_global->running_task_set, __SD_task_is_running(candidate));
1081       xbt_assert2(__SD_task_is_running(candidate),
1082                   "Bad state of task '%s': %d", SD_task_get_name(candidate),
1083                   SD_task_get_state(candidate));
1084       DEBUG0("Okay, the task is running.");
1085
1086     }                           /* can start */
1087     candidate->fifo_checked = 1;
1088   }                             /* for each candidate */
1089
1090   xbt_free(candidates);
1091 }
1092
1093 /* Remove all dependencies associated with a task. This function is called when the task is destroyed.
1094  */
1095 static void __SD_task_remove_dependencies(SD_task_t task)
1096 {
1097   /* we must destroy the dependencies carefuly (with SD_dependency_remove)
1098      because each one is stored twice */
1099   SD_dependency_t dependency;
1100   while (xbt_dynar_length(task->tasks_before) > 0) {
1101     xbt_dynar_get_cpy(task->tasks_before, 0, &dependency);
1102     SD_task_dependency_remove(dependency->src, dependency->dst);
1103   }
1104
1105   while (xbt_dynar_length(task->tasks_after) > 0) {
1106     xbt_dynar_get_cpy(task->tasks_after, 0, &dependency);
1107     SD_task_dependency_remove(dependency->src, dependency->dst);
1108   }
1109 }
1110
1111 /**
1112  * \brief Returns the start time of a task
1113  *
1114  * The task state must be SD_RUNNING, SD_DONE or SD_FAILED.
1115  *
1116  * \param task: a task
1117  * \return the start time of this task
1118  */
1119 double SD_task_get_start_time(SD_task_t task)
1120 {
1121   SD_CHECK_INIT_DONE();
1122   xbt_assert0(task != NULL, "Invalid parameter");
1123   if (task->surf_action)
1124     return surf_workstation_model->action_get_start_time(task->surf_action);
1125   else
1126     return task->start_time;
1127 }
1128
1129 /**
1130  * \brief Returns the finish time of a task
1131  *
1132  * The task state must be SD_RUNNING, SD_DONE or SD_FAILED.
1133  * If the state is not completed yet, the returned value is an
1134  * estimation of the task finish time. This value can fluctuate
1135  * until the task is completed.
1136  *
1137  * \param task: a task
1138  * \return the start time of this task
1139  */
1140 double SD_task_get_finish_time(SD_task_t task)
1141 {
1142   SD_CHECK_INIT_DONE();
1143   xbt_assert0(task != NULL, "Invalid parameter");
1144
1145   if (task->surf_action)        /* should never happen as actions are destroyed right after their completion */
1146     return surf_workstation_model->action_get_finish_time(task->surf_action);
1147   else
1148     return task->finish_time;
1149 }
1150
1151 /**
1152  * \brief Destroys a task.
1153  *
1154  * The user data (if any) should have been destroyed first.
1155  *
1156  * \param task the task you want to destroy
1157  * \see SD_task_create()
1158  */
1159 void SD_task_destroy(SD_task_t task)
1160 {
1161   SD_CHECK_INIT_DONE();
1162   xbt_assert0(task != NULL, "Invalid parameter");
1163
1164   DEBUG1("Destroying task %s...", SD_task_get_name(task));
1165
1166   __SD_task_remove_dependencies(task);
1167   /* if the task was scheduled or ready we have to free the scheduling parameters */
1168   if (__SD_task_is_scheduled_or_ready(task))
1169     __SD_task_destroy_scheduling_data(task);
1170   xbt_swag_remove(task,task->state_set);
1171
1172   if (task->name != NULL)
1173     xbt_free(task->name);
1174
1175   if (task->surf_action != NULL)
1176     surf_workstation_model->action_unref(task->surf_action);
1177
1178   if (task->workstation_list != NULL)
1179     xbt_free(task->workstation_list);
1180
1181   if (task->communication_amount)
1182     xbt_free(task->communication_amount);
1183
1184   if (task->computation_amount)
1185     xbt_free(task->computation_amount);
1186
1187   xbt_dynar_free(&task->tasks_before);
1188   xbt_dynar_free(&task->tasks_after);
1189   xbt_free(task);
1190
1191   sd_global->task_number--;
1192
1193   DEBUG0("Task destroyed.");
1194 }
1195
1196
1197 static inline SD_task_t SD_task_create_sized(const char*name,void*data,double amount,int ws_count) {
1198   SD_task_t task = SD_task_create(name,data,amount);
1199   task->communication_amount = xbt_new0(double,ws_count*ws_count);
1200   task->computation_amount = xbt_new0(double,ws_count);
1201   task->workstation_nb = ws_count;
1202   task->workstation_list = xbt_new0(SD_workstation_t,ws_count);
1203   return task;
1204 }
1205 /** @brief create a end-to-end communication task that can then be auto-scheduled
1206  *
1207  * Auto-scheduling mean that the task can be used with SD_task_schedulev(). This
1208  * allows to specify the task costs at creation, and decorelate them from the
1209  * scheduling process where you just specify which resource should deliver the
1210  * mandatory power.
1211  *
1212  * A end-to-end communication must be scheduled on 2 hosts, and the amount
1213  * specified at creation is sent from hosts[0] to hosts[1].
1214  */
1215 SD_task_t SD_task_create_comm_e2e(const char*name, void *data, double amount) {
1216   SD_task_t res = SD_task_create_sized(name,data,amount,2);
1217   res->communication_amount[2] = amount;
1218   res->kind=SD_TASK_COMM_E2E;
1219   return res;
1220 }
1221 /** @brief create a sequential computation task that can then be auto-scheduled
1222  *
1223  * Auto-scheduling mean that the task can be used with SD_task_schedulev(). This
1224  * allows to specify the task costs at creation, and decorelate them from the
1225  * scheduling process where you just specify which resource should deliver the
1226  * mandatory power.
1227  *
1228  * A sequential computation must be scheduled on 1 host, and the amount
1229  * specified at creation to be run on hosts[0].
1230  */
1231 SD_task_t SD_task_create_comp_seq(const char*name, void *data, double amount) {
1232   SD_task_t res = SD_task_create_sized(name,data,amount,1);
1233   res->computation_amount[0]=amount;
1234   res->kind=SD_TASK_COMP_SEQ;
1235   return res;
1236 }
1237
1238 /** @brief Auto-schedules a task.
1239  *
1240  * Auto-scheduling mean that the task can be used with SD_task_schedulev(). This
1241  * allows to specify the task costs at creation, and decorelate them from the
1242  * scheduling process where you just specify which resource should deliver the
1243  * mandatory power.
1244  *
1245  * To be auto-schedulable, a task must be created with SD_task_create_comm_e2e() or
1246  * SD_task_create_comp_seq(). Check their definitions for the exact semantic of each
1247  * of them.
1248  *
1249  * @todo
1250  * We should create tasks kind for the following categories:
1251  *  - Point to point communication (done)
1252  *  - Sequential computation       (done)
1253  *  - group communication (redistribution, several kinds)
1254  *  - parallel tasks with no internal communication (one kind per speedup model such as amdal)
1255  *  - idem+ internal communication. Task type not enough since we cannot store comm cost alongside to comp one)
1256  */
1257 void SD_task_schedulev(SD_task_t task, int count, const SD_workstation_t*list) {
1258   int i;
1259   xbt_assert1(task->kind != 0,"Task %s is not typed. Cannot automatically schedule it.",SD_task_get_name(task));
1260   switch(task->kind) {
1261   case SD_TASK_COMM_E2E:
1262   case SD_TASK_COMP_SEQ:
1263     xbt_assert(task->workstation_nb==count);
1264     for (i=0;i<count;i++)
1265       task->workstation_list[i]=list[i];
1266     SD_task_do_schedule(task);
1267     break;
1268   default:
1269     xbt_die(bprintf("Kind of task %s not supported by SD_task_schedulev()",
1270           SD_task_get_name(task)));
1271   }
1272   if (task->kind == SD_TASK_COMM_E2E) {
1273     VERB4("Schedule comm task %s between %s -> %s. It costs %.f bytes",
1274         SD_task_get_name(task),
1275         SD_workstation_get_name(task->workstation_list[0]),SD_workstation_get_name(task->workstation_list[1]),
1276         task->communication_amount[2]);
1277
1278   }
1279   /* Iterate over all childs and parent being COMM_E2E to say where I am located (and start them if ready) */
1280   if (task->kind == SD_TASK_COMP_SEQ) {
1281     VERB3("Schedule computation task %s on %s. It costs %.f flops",
1282         SD_task_get_name(task),SD_workstation_get_name(task->workstation_list[0]),
1283         task->computation_amount[0]);
1284     SD_dependency_t dep;
1285     unsigned int cpt;
1286     xbt_dynar_foreach(task->tasks_before,cpt,dep) {
1287       SD_task_t before = dep->src;
1288       if (before->kind == SD_TASK_COMM_E2E) {
1289         before->workstation_list[1] = task->workstation_list[0];
1290         if (before->workstation_list[0] && __SD_task_is_not_scheduled(before)) {
1291           SD_task_do_schedule(before);
1292           VERB4("Auto-Schedule comm task %s between %s -> %s. It costs %.f bytes",
1293               SD_task_get_name(before),
1294               SD_workstation_get_name(before->workstation_list[0]),SD_workstation_get_name(before->workstation_list[1]),
1295               before->communication_amount[2]);
1296         }
1297       }
1298     }
1299     xbt_dynar_foreach(task->tasks_after,cpt,dep) {
1300       SD_task_t after = dep->dst;
1301       if (after->kind == SD_TASK_COMM_E2E) {
1302         after->workstation_list[0] = task->workstation_list[0];
1303         if (after->workstation_list[1] && __SD_task_is_not_scheduled(after)) {
1304           SD_task_do_schedule(after);
1305           VERB4("Auto-Schedule comm task %s between %s -> %s. It costs %.f bytes",
1306               SD_task_get_name(after),
1307               SD_workstation_get_name(after->workstation_list[0]),SD_workstation_get_name(after->workstation_list[1]),
1308               after->communication_amount[2]);
1309
1310         }
1311       }
1312     }
1313   }
1314 }
1315 /** @brief autoschedule a task on a list of workstations
1316  *
1317  * This function is very similar to SD_task_schedulev(),
1318  * but takes the list of workstations to schedule onto as separate parameters.
1319  * It builds a proper vector of workstations and then call SD_task_schedulev()
1320  */
1321 void SD_task_schedulel(SD_task_t task, int count, ...) {
1322   va_list ap;
1323   SD_workstation_t *list=xbt_new(SD_workstation_t,count);
1324   int i;
1325   va_start(ap,count);
1326   for (i=0;i<count;i++) {
1327       list[i] = va_arg(ap,SD_workstation_t);
1328   }
1329   va_end(ap);
1330   SD_task_schedulev(task,count,list);
1331   free(list);
1332 }