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add clean-atexit test
[simgrid.git] / src / simdag / sd_task.cpp
index 63d2fe3..e57a89d 100644 (file)
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
+#include "simdag_private.hpp"
+#include "src/surf/HostImpl.hpp"
 #include "src/surf/surf_interface.hpp"
-#include "src/surf/host_interface.hpp"
-#include "src/simdag/simdag_private.h"
-#include "simgrid/simdag.h"
-#include "xbt/sysdep.h"
-#include "xbt/dynar.h"
-#include "src/instr/instr_private.h"
 
-XBT_LOG_NEW_DEFAULT_SUBCATEGORY(sd_task, sd,
-                                "Logging specific to SimDag (task)");
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(sd_task, sd, "Logging specific to SimDag (task)");
 
-static void __SD_task_remove_dependencies(SD_task_t task);
-static void __SD_task_destroy_scheduling_data(SD_task_t task);
-
-void* SD_task_new_f(void)
-{
-  SD_task_t task = xbt_new0(s_SD_task_t, 1);
-  task->tasks_before = xbt_dynar_new(sizeof(SD_dependency_t), NULL);
-  task->tasks_after = xbt_dynar_new(sizeof(SD_dependency_t), NULL);
-
-  return task;
-}
-
-void SD_task_recycle_f(void *t)
-{
-  SD_task_t task = (SD_task_t) t;
-
-  /* Reset the content */
-  task->kind = SD_TASK_NOT_TYPED;
-  task->state= SD_NOT_SCHEDULED;
-  xbt_dynar_push(sd_global->initial_task_set,&task);
-  task->return_hookup.prev = NULL;
-  task->return_hookup.next = NULL;
-
-  task->marked = 0;
-
-  task->start_time = -1.0;
-  task->finish_time = -1.0;
-  task->surf_action = NULL;
-  task->watch_points = 0;
-
-  /* dependencies */
-  xbt_dynar_reset(task->tasks_before);
-  xbt_dynar_reset(task->tasks_after);
-  task->unsatisfied_dependencies = 0;
-  task->is_not_ready = 0;
-
-  /* scheduling parameters */
-  task->workstation_nb = 0;
-  task->workstation_list = NULL;
-  task->flops_amount = NULL;
-  task->bytes_amount = NULL;
-  task->rate = -1;
-}
-
-void SD_task_free_f(void *t)
+/* Destroys the data memorized by SD_task_schedule. Task state must be SD_SCHEDULED or SD_RUNNABLE. */
+static void __SD_task_destroy_scheduling_data(SD_task_t task)
 {
-  SD_task_t task = (SD_task_t)t;
+  if (task->state != SD_SCHEDULED && task->state != SD_RUNNABLE)
+    THROWF(arg_error, 0, "Task '%s' must be SD_SCHEDULED or SD_RUNNABLE", SD_task_get_name(task));
 
-  xbt_dynar_free(&task->tasks_before);
-  xbt_dynar_free(&task->tasks_after);
-  xbt_free(task);
+  xbt_free(task->flops_amount);
+  xbt_free(task->bytes_amount);
+  task->bytes_amount = nullptr;
+  task->flops_amount = nullptr;
 }
 
 /**
  * \brief Creates a new task.
  *
- * \param name the name of the task (can be \c NULL)
- * \param data the user data you want to associate with the task (can be \c NULL)
+ * \param name the name of the task (can be \c nullptr)
+ * \param data the user data you want to associate with the task (can be \c nullptr)
  * \param amount amount of the task
  * \return the new task
  * \see SD_task_destroy()
  */
 SD_task_t SD_task_create(const char *name, void *data, double amount)
 {
-  SD_task_t task = (SD_task_t)xbt_mallocator_get(sd_global->task_mallocator);
-
-  /* general information */
-  task->data = data;            /* user data */
-  task->name = xbt_strdup(name);
-  task->amount = amount;
-  task->remains = amount;
+  SD_task_t task = xbt_new0(s_SD_task_t, 1);
+  task->kind = SD_TASK_NOT_TYPED;
+  task->state= SD_NOT_SCHEDULED;
+  sd_global->initial_tasks->insert(task);
 
-  sd_global->task_number++;
+  task->marked = 0;
+  task->start_time = -1.0;
+  task->finish_time = -1.0;
+  task->surf_action = nullptr;
+  task->watch_points = 0;
 
-  TRACE_sd_task_create(task);
+  task->inputs = new std::set<SD_task_t>();
+  task->outputs = new std::set<SD_task_t>();
+  task->predecessors = new std::set<SD_task_t>();
+  task->successors = new std::set<SD_task_t>();
 
+  task->data = data;
+  task->name = xbt_strdup(name);
+  task->amount = amount;
+  task->allocation = new std::vector<sg_host_t>();
+  task->rate = -1;
   return task;
 }
 
-static XBT_INLINE SD_task_t SD_task_create_sized(const char *name,
-                                                 void *data, double amount,
-                                                 int ws_count)
+static inline SD_task_t SD_task_create_sized(const char *name, void *data, double amount, int count)
 {
   SD_task_t task = SD_task_create(name, data, amount);
-  task->bytes_amount = xbt_new0(double, ws_count * ws_count);
-  task->flops_amount = xbt_new0(double, ws_count);
-  task->workstation_nb = ws_count;
-  task->workstation_list = xbt_new0(SD_workstation_t, ws_count);
+  task->bytes_amount = xbt_new0(double, count * count);
+  task->flops_amount = xbt_new0(double, count);
   return task;
 }
 
 /** @brief create a end-to-end communication task that can then be auto-scheduled
  *
- * Auto-scheduling mean that the task can be used with SD_task_schedulev(). This
- * allows to specify the task costs at creation, and decouple them from the
- * scheduling process where you just specify which resource should deliver the
+ * Auto-scheduling mean that the task can be used with SD_task_schedulev(). This allows to specify the task costs at
+ * creation, and decouple them from the scheduling process where you just specify which resource should deliver the
  * mandatory power.
  *
- * A end-to-end communication must be scheduled on 2 hosts, and the amount
- * specified at creation is sent from hosts[0] to hosts[1].
+ * A end-to-end communication must be scheduled on 2 hosts, and the amount specified at creation is sent from hosts[0]
+ * to hosts[1].
  */
-SD_task_t SD_task_create_comm_e2e(const char *name, void *data,
-                                  double amount)
+SD_task_t SD_task_create_comm_e2e(const char *name, void *data, double amount)
 {
   SD_task_t res = SD_task_create_sized(name, data, amount, 2);
   res->bytes_amount[2] = amount;
   res->kind = SD_TASK_COMM_E2E;
 
-  TRACE_category("COMM_E2E");
-  TRACE_sd_set_task_category(res, "COMM_E2E");
-
   return res;
 }
 
 /** @brief create a sequential computation task that can then be auto-scheduled
  *
- * Auto-scheduling mean that the task can be used with SD_task_schedulev(). This
- * allows to specify the task costs at creation, and decouple them from the
- * scheduling process where you just specify which resource should deliver the
+ * Auto-scheduling mean that the task can be used with SD_task_schedulev(). This allows to specify the task costs at
+ * creation, and decouple them from the scheduling process where you just specify which resource should deliver the
  * mandatory power.
  *
- * A sequential computation must be scheduled on 1 host, and the amount
- * specified at creation to be run on hosts[0].
+ * A sequential computation must be scheduled on 1 host, and the amount specified at creation to be run on hosts[0].
  *
- * \param name the name of the task (can be \c NULL)
- * \param data the user data you want to associate with the task (can be \c NULL)
+ * \param name the name of the task (can be \c nullptr)
+ * \param data the user data you want to associate with the task (can be \c nullptr)
  * \param flops_amount amount of compute work to be done by the task
  * \return the new SD_TASK_COMP_SEQ typed task
  */
-SD_task_t SD_task_create_comp_seq(const char *name, void *data,
-                                  double flops_amount)
+SD_task_t SD_task_create_comp_seq(const char *name, void *data, double flops_amount)
 {
   SD_task_t res = SD_task_create_sized(name, data, flops_amount, 1);
   res->flops_amount[0] = flops_amount;
   res->kind = SD_TASK_COMP_SEQ;
 
-  TRACE_category("COMP_SEQ");
-  TRACE_sd_set_task_category(res, "COMP_SEQ");
-
   return res;
 }
 
 /** @brief create a parallel computation task that can then be auto-scheduled
  *
- * Auto-scheduling mean that the task can be used with SD_task_schedulev(). This
- * allows to specify the task costs at creation, and decouple them from the
- * scheduling process where you just specify which resource should deliver the
+ * Auto-scheduling mean that the task can be used with SD_task_schedulev(). This allows to specify the task costs at
+ * creation, and decouple them from the scheduling process where you just specify which resource should deliver the
  * mandatory power.
  *
  * A parallel computation can be scheduled on any number of host.
  * The underlying speedup model is Amdahl's law.
- * To be auto-scheduled, \see SD_task_distribute_comp_amdahl has to be called
- * first.
- * \param name the name of the task (can be \c NULL)
- * \param data the user data you want to associate with the task (can be \c NULL)
+ * To be auto-scheduled, \see SD_task_distribute_comp_amdahl has to be called first.
+ * \param name the name of the task (can be \c nullptr)
+ * \param data the user data you want to associate with the task (can be \c nullptr)
  * \param flops_amount amount of compute work to be done by the task
  * \param alpha purely serial fraction of the work to be done (in [0.;1.[)
  * \return the new task
  */
-SD_task_t SD_task_create_comp_par_amdahl(const char *name, void *data,
-                                  double flops_amount, double alpha)
+SD_task_t SD_task_create_comp_par_amdahl(const char *name, void *data, double flops_amount, double alpha)
 {
-  xbt_assert(alpha < 1. && alpha >= 0.,
-              "Invalid parameter: alpha must be in [0.;1.[");
-  
+  xbt_assert(alpha < 1. && alpha >= 0., "Invalid parameter: alpha must be in [0.;1.[");
+
   SD_task_t res = SD_task_create(name, data, flops_amount);
   res->alpha = alpha;
   res->kind = SD_TASK_COMP_PAR_AMDAHL;
 
-  TRACE_category("COMP_PAR_AMDAHL");
-  TRACE_sd_set_task_category(res, "COMP_PAR_AMDAHL");
-
   return res;
 }
 
-/** @brief create a complex data redistribution task that can then be 
- * auto-scheduled
+/** @brief create a complex data redistribution task that can then be  auto-scheduled
  *
  * Auto-scheduling mean that the task can be used with SD_task_schedulev(). 
- * This allows to specify the task costs at creation, and decouple them from 
- * the scheduling process where you just specify which resource should 
- * communicate. 
+ * This allows to specify the task costs at creation, and decouple them from the scheduling process where you just
+ * specify which resource should communicate.
  *
  * A data redistribution can be scheduled on any number of host.
- * The assumed distribution is a 1D block distribution. Each host owns the same
- * share of the \see amount. 
- * To be auto-scheduled, \see SD_task_distribute_comm_mxn_1d_block has to be 
- * called first.
- * \param name the name of the task (can be \c NULL)
- * \param data the user data you want to associate with the task (can be
- * \c NULL)
+ * The assumed distribution is a 1D block distribution. Each host owns the same share of the \see amount.
+ * To be auto-scheduled, \see SD_task_distribute_comm_mxn_1d_block has to be  called first.
+ * \param name the name of the task (can be \c nullptr)
+ * \param data the user data you want to associate with the task (can be \c nullptr)
  * \param amount amount of data to redistribute by the task
  * \return the new task
  */
-SD_task_t SD_task_create_comm_par_mxn_1d_block(const char *name, void *data,
-                                               double amount)
+SD_task_t SD_task_create_comm_par_mxn_1d_block(const char *name, void *data, double amount)
 {
   SD_task_t res = SD_task_create(name, data, amount);
-  res->workstation_list=NULL;
   res->kind = SD_TASK_COMM_PAR_MXN_1D_BLOCK;
 
-  TRACE_category("COMM_PAR_MXN_1D_BLOCK");
-  TRACE_sd_set_task_category(res, "COMM_PAR_MXN_1D_BLOCK");
-
   return res;
 }
 
@@ -234,26 +165,32 @@ void SD_task_destroy(SD_task_t task)
 {
   XBT_DEBUG("Destroying task %s...", SD_task_get_name(task));
 
-  __SD_task_remove_dependencies(task);
-  /* if the task was scheduled or runnable we have to free the scheduling parameters */
-  if (__SD_task_is_scheduled_or_runnable(task))
+  /* First Remove all dependencies associated with the task. */
+  while (not task->predecessors->empty())
+    SD_task_dependency_remove(*(task->predecessors->begin()), task);
+  while (not task->inputs->empty())
+    SD_task_dependency_remove(*(task->inputs->begin()), task);
+  while (not task->successors->empty())
+    SD_task_dependency_remove(task, *(task->successors->begin()));
+  while (not task->outputs->empty())
+    SD_task_dependency_remove(task, *(task->outputs->begin()));
+
+  if (task->state == SD_SCHEDULED || task->state == SD_RUNNABLE)
     __SD_task_destroy_scheduling_data(task);
 
-  xbt_swag_remove(task, sd_global->return_set);
-
   xbt_free(task->name);
 
-  if (task->surf_action != NULL)
-       task->surf_action->unref();
+  if (task->surf_action != nullptr)
+    task->surf_action->unref();
 
-  xbt_free(task->workstation_list);
+  delete task->allocation;
   xbt_free(task->bytes_amount);
   xbt_free(task->flops_amount);
-
-  TRACE_sd_task_destroy(task);
-
-  xbt_mallocator_release(sd_global->task_mallocator,task);
-  sd_global->task_number--;
+  delete task->inputs;
+  delete task->outputs;
+  delete task->predecessors;
+  delete task->successors;
+  xbt_free(task);
 
   XBT_DEBUG("Task destroyed.");
 }
@@ -262,7 +199,7 @@ void SD_task_destroy(SD_task_t task)
  * \brief Returns the user data of a task
  *
  * \param task a task
- * \return the user data associated with this task (can be \c NULL)
+ * \return the user data associated with this task (can be \c nullptr)
  * \see SD_task_set_data()
  */
 void *SD_task_get_data(SD_task_t task)
@@ -273,8 +210,7 @@ void *SD_task_get_data(SD_task_t task)
 /**
  * \brief Sets the user data of a task
  *
- * The new data can be \c NULL. The old data should have been freed first
- * if it was not \c NULL.
+ * The new data can be \c nullptr. The old data should have been freed first, if it was not \c nullptr.
  *
  * \param task a task
  * \param data the new data you want to associate with this task
@@ -288,11 +224,9 @@ void SD_task_set_data(SD_task_t task, void *data)
 /**
  * \brief Sets the rate of a task
  *
- * This will change the network bandwidth a task can use. This rate
- * cannot be dynamically changed. Once the task has started, this call
- * is ineffective. This rate depends on both the nominal bandwidth on
- * the route onto which the task is scheduled (\see
- * SD_task_get_current_bandwidth) and the amount of data to transfer.
+ * This will change the network bandwidth a task can use. This rate  cannot be dynamically changed. Once the task has
+ * started, this call is ineffective. This rate depends on both the nominal bandwidth on the route onto which the task
+ * is scheduled (\see SD_task_get_current_bandwidth) and the amount of data to transfer.
  *
  * To divide the nominal bandwidth by 2, the rate then has to be :
  *    rate = bandwidth/(2*amount)
@@ -302,9 +236,8 @@ void SD_task_set_data(SD_task_t task, void *data)
  */
 void SD_task_set_rate(SD_task_t task, double rate)
 {
-  xbt_assert(task->kind == SD_TASK_COMM_E2E,
-             "The rate can be modified for end-to-end communications only.");
-  if(task->start_time<0) {
+  xbt_assert(task->kind == SD_TASK_COMM_E2E, "The rate can be modified for end-to-end communications only.");
+  if(task->state < SD_RUNNING) {
     task->rate = rate;
   } else {
     XBT_WARN("Task %p has started. Changing rate is ineffective.", task);
@@ -324,70 +257,53 @@ e_SD_task_state_t SD_task_get_state(SD_task_t task)
   return task->state;
 }
 
-/* Changes the state of a task. Updates the swags and the flag sd_global->watch_point_reached.
+/* Changes the state of a task. Updates the sd_global->watch_point_reached flag.
  */
 void SD_task_set_state(SD_task_t task, e_SD_task_state_t new_state)
 {
-  int idx;
-  switch (new_state) {
-  case SD_NOT_SCHEDULED:
-  case SD_SCHEDULABLE:
-    if (SD_task_get_state(task) == SD_FAILED){
-        xbt_dynar_remove_at(sd_global->completed_task_set,
-            xbt_dynar_search(sd_global->completed_task_set, &task), &task);
-        xbt_dynar_push(sd_global->initial_task_set,&task);
-    }
-    break;
-  case SD_SCHEDULED:
-    if (SD_task_get_state(task) == SD_RUNNABLE){
-      xbt_dynar_remove_at(sd_global->executable_task_set,
-          xbt_dynar_search(sd_global->executable_task_set, &task), &task);
-      xbt_dynar_push(sd_global->initial_task_set,&task);
-    }
-    break;
-  case SD_IN_FIFO:
-    xbt_dynar_remove_at(sd_global->executable_task_set,
-       xbt_dynar_search(sd_global->executable_task_set, &task), &task);
-    xbt_dynar_push(sd_global->initial_task_set,&task);
-    break;
-  case SD_RUNNABLE:
-    idx = xbt_dynar_search_or_negative(sd_global->initial_task_set, &task);
-    if (idx >= 0) {
-      xbt_dynar_remove_at(sd_global->initial_task_set, idx, &task);
-      xbt_dynar_push(sd_global->executable_task_set,&task);
-    }
-    break;
-  case SD_RUNNING:
-    if (SD_task_get_state(task) == SD_RUNNABLE){
-      xbt_dynar_remove_at(sd_global->executable_task_set,
-         xbt_dynar_search(sd_global->executable_task_set, &task), &task);
-    } else {
-      if (SD_task_get_state(task) == SD_IN_FIFO){
-        xbt_dynar_remove_at(sd_global->initial_task_set,
-            xbt_dynar_search(sd_global->initial_task_set, &task), &task);
-      }
+  std::set<SD_task_t>::iterator idx;
+  XBT_DEBUG("Set state of '%s' to %d", task->name, new_state);
+  if ((new_state == SD_NOT_SCHEDULED || new_state == SD_SCHEDULABLE) && task->state == SD_FAILED){
+    sd_global->completed_tasks->erase(task);
+    sd_global->initial_tasks->insert(task);
+  }
+
+  if (new_state == SD_SCHEDULED && task->state == SD_RUNNABLE){
+    sd_global->initial_tasks->insert(task);
+    sd_global->runnable_tasks->erase(task);
+  }
+
+  if (new_state == SD_RUNNABLE){
+    idx = sd_global->initial_tasks->find(task);
+    if (idx != sd_global->initial_tasks->end()) {
+      sd_global->runnable_tasks->insert(*idx);
+      sd_global->initial_tasks->erase(idx);
     }
-    break;
-  case SD_DONE:
-    xbt_dynar_push(sd_global->completed_task_set,&task);
-    task->finish_time = task->surf_action->getFinishTime();
-    task->remains = 0;
-#ifdef HAVE_JEDULE
-    jedule_log_sd_event(task);
+  }
+
+  if (new_state == SD_RUNNING)
+    sd_global->runnable_tasks->erase(task);
+
+  if (new_state == SD_DONE || new_state == SD_FAILED){
+    sd_global->completed_tasks->insert(task);
+    task->start_time = task->surf_action->getStartTime();
+    if (new_state == SD_DONE){
+      task->finish_time = task->surf_action->getFinishTime();
+#if SIMGRID_HAVE_JEDULE
+      jedule_log_sd_event(task);
 #endif
-    break;
-  case SD_FAILED:
-    xbt_dynar_push(sd_global->completed_task_set,&task);
-    break;
-  default:
-    xbt_die( "Invalid state");
+    } else
+      task->finish_time = surf_get_clock();
+    task->surf_action->unref();
+    task->surf_action = nullptr;
+    task->allocation->clear();
   }
 
   task->state = new_state;
 
   if (task->watch_points & new_state) {
-    XBT_VERB("Watch point reached with task '%s'!", SD_task_get_name(task));
-    sd_global->watch_point_reached = 1;
+    XBT_VERB("Watch point reached with task '%s'!", task->name);
+    sd_global->watch_point_reached = true;
     SD_task_unwatch(task, new_state);   /* remove the watch point */
   }
 }
@@ -396,7 +312,7 @@ void SD_task_set_state(SD_task_t task, e_SD_task_state_t new_state)
  * \brief Returns the name of a task
  *
  * \param task a task
- * \return the name of this task (can be \c NULL)
+ * \return the name of this task (can be \c nullptr)
  */
 const char *SD_task_get_name(SD_task_t task)
 {
@@ -418,14 +334,13 @@ void SD_task_set_name(SD_task_t task, const char *name)
 
 xbt_dynar_t SD_task_get_parents(SD_task_t task)
 {
-  unsigned int i;
-  xbt_dynar_t parents;
-  SD_dependency_t dep;
+  xbt_dynar_t parents = xbt_dynar_new(sizeof(SD_task_t), nullptr);
+
+  for (auto it : *task->predecessors)
+    xbt_dynar_push(parents, &it);
+  for (auto it : *task->inputs)
+    xbt_dynar_push(parents, &it);
 
-  parents = xbt_dynar_new(sizeof(SD_task_t), NULL);
-  xbt_dynar_foreach(task->tasks_before, i, dep) {
-    xbt_dynar_push(parents, &(dep->src));
-  }
   return parents;
 }
 
@@ -436,26 +351,25 @@ xbt_dynar_t SD_task_get_parents(SD_task_t task)
  */
 xbt_dynar_t SD_task_get_children(SD_task_t task)
 {
-  unsigned int i;
-  xbt_dynar_t children;
-  SD_dependency_t dep;
+  xbt_dynar_t children = xbt_dynar_new(sizeof(SD_task_t), nullptr);
+
+  for (auto it : *task->successors)
+    xbt_dynar_push(children, &it);
+  for (auto it : *task->outputs)
+    xbt_dynar_push(children, &it);
 
-  children = xbt_dynar_new(sizeof(SD_task_t), NULL);
-  xbt_dynar_foreach(task->tasks_after, i, dep) {
-    xbt_dynar_push(children, &(dep->dst));
-  }
   return children;
 }
 
 /**
- * \brief Returns the amount of workstations involved in a task
+ * \brief Returns the number of workstations involved in a task
  *
  * Only call this on already scheduled tasks!
  * \param task a task
  */
 int SD_task_get_workstation_count(SD_task_t task)
 {
-  return task->workstation_nb;
+  return task->allocation->size();
 }
 
 /**
@@ -464,9 +378,9 @@ int SD_task_get_workstation_count(SD_task_t task)
  * Only call this on already scheduled tasks!
  * \param task a task
  */
-SD_workstation_t *SD_task_get_workstation_list(SD_task_t task)
+sg_host_t *SD_task_get_workstation_list(SD_task_t task)
 {
-  return task->workstation_list;
+  return &(*(task->allocation))[0];
 }
 
 /**
@@ -481,13 +395,10 @@ double SD_task_get_amount(SD_task_t task)
   return task->amount;
 }
 
-/**
- * \brief Sets the total amount of work of a task
- * For sequential typed tasks (COMP_SEQ and COMM_E2E), it also sets the
- * appropriate values in the flops_amount and bytes_amount arrays
- * respectively. Nothing more than modifying task->amount is done for paralle
- * typed tasks (COMP_PAR_AMDAHL and COMM_PAR_MXN_1D_BLOCK) as the distribution
- * of the amount of work is done at scheduling time.
+/** @brief Sets the total amount of work of a task
+ * For sequential typed tasks (COMP_SEQ and COMM_E2E), it also sets the appropriate values in the flops_amount and
+ * bytes_amount arrays respectively. Nothing more than modifying task->amount is done for parallel  typed tasks
+ * (COMP_PAR_AMDAHL and COMM_PAR_MXN_1D_BLOCK) as the distribution of the amount of work is done at scheduling time.
  *
  * \param task a task
  * \param amount the new amount of work to execute
@@ -509,12 +420,10 @@ void SD_task_set_amount(SD_task_t task, double amount)
  */
 double SD_task_get_alpha(SD_task_t task)
 {
-  xbt_assert(SD_task_get_kind(task) == SD_TASK_COMP_PAR_AMDAHL,
-     "Alpha parameter is not defined for this kink of task");
+  xbt_assert(SD_task_get_kind(task) == SD_TASK_COMP_PAR_AMDAHL, "Alpha parameter is not defined for this kind of task");
   return task->alpha;
 }
 
-
 /**
  * \brief Returns the remaining amount work to do till the completion of a task
  *
@@ -525,9 +434,9 @@ double SD_task_get_alpha(SD_task_t task)
 double SD_task_get_remaining_amount(SD_task_t task)
 {
   if (task->surf_action)
-       return surf_action_get_remains(task->surf_action);
+    return task->surf_action->getRemains();
   else
-    return task->remains;
+    return (task->state == SD_DONE) ? 0 : task->amount;
 }
 
 e_SD_task_kind_t SD_task_get_kind(SD_task_t task)
@@ -535,27 +444,16 @@ e_SD_task_kind_t SD_task_get_kind(SD_task_t task)
   return task->kind;
 }
 
-/** @brief Displays debugging informations about a task */
+/** @brief Displays debugging information about a task */
 void SD_task_dump(SD_task_t task)
 {
-  unsigned int counter;
-  SD_dependency_t dependency;
-  char *statename;
-
   XBT_INFO("Displaying task %s", SD_task_get_name(task));
-  statename = bprintf("%s %s %s %s %s %s %s %s",
-                      (task->state == SD_NOT_SCHEDULED ? "not scheduled" :
-                       ""),
-                      (task->state == SD_SCHEDULABLE ? "schedulable" : ""),
-                      (task->state == SD_SCHEDULED ? "scheduled" : ""),
-                      (task->state == SD_RUNNABLE ? "runnable" :
-                       "not runnable"),
-                      (task->state == SD_IN_FIFO ? "in fifo" : ""),
-                      (task->state == SD_RUNNING ? "running" : ""),
-                      (task->state == SD_DONE ? "done" : ""),
-                      (task->state == SD_FAILED ? "failed" : ""));
-  XBT_INFO("  - state: %s", statename);
-  free(statename);
+  if (task->state == SD_RUNNABLE)
+    XBT_INFO("  - state: runnable");
+  else if (task->state < SD_RUNNABLE)
+    XBT_INFO("  - state: %s not runnable", __get_state_name(task->state));
+  else
+    XBT_INFO("  - state: not runnable %s", __get_state_name(task->state));
 
   if (task->kind != 0) {
     switch (task->kind) {
@@ -576,33 +474,32 @@ void SD_task_dump(SD_task_t task)
     }
   }
 
-  if (task->category)
-    XBT_INFO("  - tracing category: %s", task->category);
-
   XBT_INFO("  - amount: %.0f", SD_task_get_amount(task));
   if (task->kind == SD_TASK_COMP_PAR_AMDAHL)
     XBT_INFO("  - alpha: %.2f", task->alpha);
-  XBT_INFO("  - Dependencies to satisfy: %d", task->unsatisfied_dependencies);
-  if (!xbt_dynar_is_empty(task->tasks_before)) {
+  XBT_INFO("  - Dependencies to satisfy: %zu", task->inputs->size()+ task->predecessors->size());
+  if ((task->inputs->size()+ task->predecessors->size()) > 0) {
     XBT_INFO("  - pre-dependencies:");
-    xbt_dynar_foreach(task->tasks_before, counter, dependency) {
-      XBT_INFO("    %s", SD_task_get_name(dependency->src));
-    }
+    for (auto it : *task->predecessors)
+      XBT_INFO("    %s", it->name);
+
+    for (auto it: *task->inputs)
+      XBT_INFO("    %s", it->name);
   }
-  if (!xbt_dynar_is_empty(task->tasks_after)) {
+  if ((task->outputs->size() + task->successors->size()) > 0) {
     XBT_INFO("  - post-dependencies:");
-    xbt_dynar_foreach(task->tasks_after, counter, dependency) {
-      XBT_INFO("    %s", SD_task_get_name(dependency->dst));
-    }
+
+    for (auto it : *task->successors)
+      XBT_INFO("    %s", it->name);
+    for (auto it : *task->outputs)
+      XBT_INFO("    %s", it->name);
   }
 }
 
 /** @brief Dumps the task in dotty formalism into the FILE* passed as second argument */
 void SD_task_dotty(SD_task_t task, void *out)
 {
-  unsigned int counter;
-  SD_dependency_t dependency;
-  FILE *fout = (FILE*)out;
+  FILE *fout = static_cast<FILE*>(out);
   fprintf(fout, "  T%p [label=\"%.20s\"", task, task->name);
   switch (task->kind) {
   case SD_TASK_COMM_E2E:
@@ -617,17 +514,10 @@ void SD_task_dotty(SD_task_t task, void *out)
     xbt_die("Unknown task type!");
   }
   fprintf(fout, "];\n");
-  xbt_dynar_foreach(task->tasks_before, counter, dependency) {
-    fprintf(fout, " T%p -> T%p;\n", dependency->src, dependency->dst);
-  }
-}
-
-/* Destroys a dependency between two tasks.
- */
-static void __SD_task_dependency_destroy(void *dependency)
-{
-  xbt_free(((SD_dependency_t)dependency)->name);
-  xbt_free(dependency);
+  for (auto it : *task->predecessors)
+    fprintf(fout, " T%p -> T%p;\n", it, task);
+  for (auto it : *task->inputs)
+    fprintf(fout, " T%p -> T%p;\n", it, task);
 }
 
 /**
@@ -636,97 +526,50 @@ static void __SD_task_dependency_destroy(void *dependency)
  * \a dst will depend on \a src, ie \a dst will not start before \a src is finished.
  * Their \ref e_SD_task_state_t "state" must be #SD_NOT_SCHEDULED, #SD_SCHEDULED or #SD_RUNNABLE.
  *
- * \param name the name of the new dependency (can be \c NULL)
- * \param data the user data you want to associate with this dependency (can be \c NULL)
+ * \param name the name of the new dependency (can be \c nullptr)
+ * \param data the user data you want to associate with this dependency (can be \c nullptr)
  * \param src the task which must be executed first
  * \param dst the task you want to make depend on \a src
  * \see SD_task_dependency_remove()
  */
-void SD_task_dependency_add(const char *name, void *data, SD_task_t src,
-                            SD_task_t dst)
+void SD_task_dependency_add(const char *name, void *data, SD_task_t src, SD_task_t dst)
 {
-  xbt_dynar_t dynar;
-  unsigned long length;
-  int found = 0;
-  unsigned long i;
-  SD_dependency_t dependency;
-  e_SD_task_state_t state;
-
-  dynar = src->tasks_after;
-  length = xbt_dynar_length(dynar);
-
   if (src == dst)
-    THROWF(arg_error, 0,
-           "Cannot add a dependency between task '%s' and itself",
-           SD_task_get_name(src));
-
-  state = SD_task_get_state(src);
-  if (state != SD_NOT_SCHEDULED && state != SD_SCHEDULABLE &&
-      state != SD_RUNNING && !__SD_task_is_scheduled_or_runnable(src))
-    THROWF(arg_error, 0,
-           "Task '%s' must be SD_NOT_SCHEDULED, SD_SCHEDULABLE, SD_SCHEDULED,"
-           " SD_RUNNABLE or SD_RUNNING", SD_task_get_name(src));
-
-  state = SD_task_get_state(dst);
-  if (state != SD_NOT_SCHEDULED && state != SD_SCHEDULABLE &&
-      !__SD_task_is_scheduled_or_runnable(dst))
-    THROWF(arg_error, 0,
-           "Task '%s' must be SD_NOT_SCHEDULED, SD_SCHEDULABLE, SD_SCHEDULED,"
-           "or SD_RUNNABLE", SD_task_get_name(dst));
-
-  XBT_DEBUG("SD_task_dependency_add: src = %s, dst = %s",
-         SD_task_get_name(src), SD_task_get_name(dst));
-  for (i = 0; i < length && !found; i++) {
-    xbt_dynar_get_cpy(dynar, i, &dependency);
-    found = (dependency->dst == dst);
-    XBT_DEBUG("Dependency %lu: dependency->dst = %s", i,
-           SD_task_get_name(dependency->dst));
-  }
-
-  if (found)
-    THROWF(arg_error, 0,
-           "A dependency already exists between task '%s' and task '%s'",
-           SD_task_get_name(src), SD_task_get_name(dst));
+    THROWF(arg_error, 0, "Cannot add a dependency between task '%s' and itself", SD_task_get_name(src));
 
-  dependency = xbt_new(s_SD_dependency_t, 1);
+  if (src->state == SD_DONE || src->state == SD_FAILED)
+    THROWF(arg_error, 0, "Task '%s' must be SD_NOT_SCHEDULED, SD_SCHEDULABLE, SD_SCHEDULED, SD_RUNNABLE, or SD_RUNNING",
+           src->name);
 
-  dependency->name = xbt_strdup(name);  /* xbt_strdup is cleaver enough to deal with NULL args itself */
-  dependency->data = data;
-  dependency->src = src;
-  dependency->dst = dst;
+  if (dst->state == SD_DONE || dst->state == SD_FAILED || dst->state == SD_RUNNING)
+    THROWF(arg_error, 0, "Task '%s' must be SD_NOT_SCHEDULED, SD_SCHEDULABLE, SD_SCHEDULED, or SD_RUNNABLE",
+           dst->name);
 
-  /* src must be executed before dst */
-  xbt_dynar_push(src->tasks_after, &dependency);
-  xbt_dynar_push(dst->tasks_before, &dependency);
+  if (dst->inputs->find(src) != dst->inputs->end() || src->outputs->find(dst) != src->outputs->end() ||
+      src->successors->find(dst) != src->successors->end() || dst->predecessors->find(src) != dst->predecessors->end())
+    THROWF(arg_error, 0, "A dependency already exists between task '%s' and task '%s'", src->name, dst->name);
 
-  dst->unsatisfied_dependencies++;
-  dst->is_not_ready++;
+  XBT_DEBUG("SD_task_dependency_add: src = %s, dst = %s", src->name, dst->name);
 
-  /* if the task was runnable, then dst->tasks_before is not empty anymore,
-     so we must go back to state SD_SCHEDULED */
-  if (SD_task_get_state(dst) == SD_RUNNABLE) {
-    XBT_DEBUG
-        ("SD_task_dependency_add: %s was runnable and becomes scheduled!",
-         SD_task_get_name(dst));
-    SD_task_set_state(dst, SD_SCHEDULED);
+  if (src->kind == SD_TASK_COMM_E2E || src->kind == SD_TASK_COMM_PAR_MXN_1D_BLOCK){
+    if (dst->kind == SD_TASK_COMP_SEQ || dst->kind == SD_TASK_COMP_PAR_AMDAHL)
+        dst->inputs->insert(src);
+    else
+      dst->predecessors->insert(src);
+    src->successors->insert(dst);
+  } else {
+    if (dst->kind == SD_TASK_COMM_E2E|| dst->kind == SD_TASK_COMM_PAR_MXN_1D_BLOCK)
+      src->outputs->insert(dst);
+    else
+      src->successors->insert(dst);
+    dst->predecessors->insert(src);
   }
-}
-/**
- * \brief Returns the name given as input when dependency has been created..
- *
- * \param src a task
- * \param dst a task depending on \a src
- *
- */
-const char *SD_task_dependency_get_name(SD_task_t src, SD_task_t dst){
-  unsigned int i;
-  SD_dependency_t dependency;
 
-  xbt_dynar_foreach(src->tasks_after, i, dependency){
-    if (dependency->dst == dst)
-      return dependency->name;
+  /* if the task was runnable, the task goes back to SD_SCHEDULED because of the new dependency*/
+  if (dst->state == SD_RUNNABLE) {
+    XBT_DEBUG("SD_task_dependency_add: %s was runnable and becomes scheduled!", dst->name);
+    SD_task_set_state(dst, SD_SCHEDULED);
   }
-  return NULL;
 }
 
 /**
@@ -735,29 +578,21 @@ const char *SD_task_dependency_get_name(SD_task_t src, SD_task_t dst){
  * \param src a task
  * \param dst a task depending on \a src
  *
- * If src is NULL, checks whether dst has any pre-dependency.
- * If dst is NULL, checks whether src has any post-dependency.
+ * If src is nullptr, checks whether dst has any pre-dependency.
+ * If dst is nullptr, checks whether src has any post-dependency.
  */
 int SD_task_dependency_exists(SD_task_t src, SD_task_t dst)
 {
-  unsigned int counter;
-  SD_dependency_t dependency;
-
-  xbt_assert(src != NULL
-              || dst != NULL,
-              "Invalid parameter: both src and dst are NULL");
+  xbt_assert(src != nullptr || dst != nullptr, "Invalid parameter: both src and dst are nullptr");
 
   if (src) {
     if (dst) {
-      xbt_dynar_foreach(src->tasks_after, counter, dependency) {
-        if (dependency->dst == dst)
-          return 1;
-      }
+      return (src->successors->find(dst) != src->successors->end() || src->outputs->find(dst) != src->outputs->end());
     } else {
-      return xbt_dynar_length(src->tasks_after);
+      return src->successors->size() + src->outputs->size();
     }
   } else {
-    return xbt_dynar_length(dst->tasks_before);
+    return dst->predecessors->size() + dst->inputs->size();
   }
   return 0;
 }
@@ -771,114 +606,45 @@ int SD_task_dependency_exists(SD_task_t src, SD_task_t dst)
  */
 void SD_task_dependency_remove(SD_task_t src, SD_task_t dst)
 {
+  XBT_DEBUG("SD_task_dependency_remove: src = %s, dst = %s", SD_task_get_name(src), SD_task_get_name(dst));
 
-  xbt_dynar_t dynar;
-  unsigned long length;
-  int found = 0;
-  unsigned long i;
-  SD_dependency_t dependency;
-
-  /* remove the dependency from src->tasks_after */
-  dynar = src->tasks_after;
-  length = xbt_dynar_length(dynar);
-
-  for (i = 0; i < length && !found; i++) {
-    xbt_dynar_get_cpy(dynar, i, &dependency);
-    if (dependency->dst == dst) {
-      xbt_dynar_remove_at(dynar, i, NULL);
-      found = 1;
-    }
-  }
-  if (!found)
-    THROWF(arg_error, 0,
-           "No dependency found between task '%s' and '%s': task '%s' is not a successor of task '%s'",
-           SD_task_get_name(src), SD_task_get_name(dst),
-           SD_task_get_name(dst), SD_task_get_name(src));
-
-  /* remove the dependency from dst->tasks_before */
-  dynar = dst->tasks_before;
-  length = xbt_dynar_length(dynar);
-  found = 0;
-
-  for (i = 0; i < length && !found; i++) {
-    xbt_dynar_get_cpy(dynar, i, &dependency);
-    if (dependency->src == src) {
-      xbt_dynar_remove_at(dynar, i, NULL);
-      __SD_task_dependency_destroy(dependency);
-      dst->unsatisfied_dependencies--;
-      dst->is_not_ready--;
-      found = 1;
-    }
-  }
-  /* should never happen... */
-  xbt_assert(found,
-              "SimDag error: task '%s' is a successor of '%s' but task '%s' is not a predecessor of task '%s'",
-              SD_task_get_name(dst), SD_task_get_name(src),
-              SD_task_get_name(src), SD_task_get_name(dst));
-
-  /* if the task was scheduled and dst->tasks_before is empty now, we can make it runnable */
+  if (src->successors->find(dst) == src->successors->end() && src->outputs->find(dst) == src->outputs->end())
+    THROWF(arg_error, 0, "No dependency found between task '%s' and '%s': task '%s' is not a successor of task '%s'",
+           src->name, dst->name, dst->name, src->name);
 
-  if (dst->unsatisfied_dependencies == 0) {
-    if (SD_task_get_state(dst) == SD_SCHEDULED)
-      SD_task_set_state(dst, SD_RUNNABLE);
+  if (src->kind == SD_TASK_COMM_E2E || src->kind == SD_TASK_COMM_PAR_MXN_1D_BLOCK){
+    if (dst->kind == SD_TASK_COMP_SEQ || dst->kind == SD_TASK_COMP_PAR_AMDAHL)
+      dst->inputs->erase(src);
+    else
+      dst->predecessors->erase(src);
+    src->successors->erase(dst);
+  } else {
+    if (dst->kind == SD_TASK_COMM_E2E|| dst->kind == SD_TASK_COMM_PAR_MXN_1D_BLOCK)
+      src->outputs->erase(dst);
     else
-      SD_task_set_state(dst, SD_SCHEDULABLE);
+      src->successors->erase(dst);
+    dst->predecessors->erase(src);
   }
 
-  if (dst->is_not_ready == 0)
-    SD_task_set_state(dst, SD_SCHEDULABLE);
-
-  /*  __SD_print_dependencies(src);
-     __SD_print_dependencies(dst); */
-}
-
-/**
- * \brief Returns the user data associated with a dependency between two tasks
- *
- * \param src a task
- * \param dst a task depending on \a src
- * \return the user data associated with this dependency (can be \c NULL)
- * \see SD_task_dependency_add()
- */
-void *SD_task_dependency_get_data(SD_task_t src, SD_task_t dst)
-{
-
-  xbt_dynar_t dynar;
-  unsigned long length;
-  int found = 0;
-  unsigned long i;
-  SD_dependency_t dependency;
-
-  dynar = src->tasks_after;
-  length = xbt_dynar_length(dynar);
-
-  for (i = 0; i < length && !found; i++) {
-    xbt_dynar_get_cpy(dynar, i, &dependency);
-    found = (dependency->dst == dst);
-  }
-  if (!found)
-    THROWF(arg_error, 0, "No dependency found between task '%s' and '%s'",
-           SD_task_get_name(src), SD_task_get_name(dst));
-  return dependency->data;
+  /* if the task was scheduled and dependencies are satisfied, we can make it runnable */
+  if (dst->predecessors->empty() && dst->inputs->empty() && dst->state == SD_SCHEDULED)
+    SD_task_set_state(dst, SD_RUNNABLE);
 }
 
 /**
  * \brief Adds a watch point to a task
  *
- * SD_simulate() will stop as soon as the \ref e_SD_task_state_t "state" of this
- * task becomes the one given in argument. The
- * watch point is then automatically removed.
+ * SD_simulate() will stop as soon as the \ref e_SD_task_state_t "state" of this task becomes the one given in argument.
+ * The watch point is then automatically removed.
  *
  * \param task a task
- * \param state the \ref e_SD_task_state_t "state" you want to watch
- * (cannot be #SD_NOT_SCHEDULED)
+ * \param state the \ref e_SD_task_state_t "state" you want to watch (cannot be #SD_NOT_SCHEDULED)
  * \see SD_task_unwatch()
  */
 void SD_task_watch(SD_task_t task, e_SD_task_state_t state)
 {
   if (state & SD_NOT_SCHEDULED)
-    THROWF(arg_error, 0,
-           "Cannot add a watch point for state SD_NOT_SCHEDULED");
+    THROWF(arg_error, 0, "Cannot add a watch point for state SD_NOT_SCHEDULED");
 
   task->watch_points = task->watch_points | state;
 }
@@ -892,70 +658,53 @@ void SD_task_watch(SD_task_t task, e_SD_task_state_t state)
  */
 void SD_task_unwatch(SD_task_t task, e_SD_task_state_t state)
 {
-  xbt_assert(state != SD_NOT_SCHEDULED,
-              "SimDag error: Cannot have a watch point for state SD_NOT_SCHEDULED");
-
+  xbt_assert(state != SD_NOT_SCHEDULED, "SimDag error: Cannot have a watch point for state SD_NOT_SCHEDULED");
   task->watch_points = task->watch_points & ~state;
 }
 
 /**
  * \brief Returns an approximative estimation of the execution time of a task.
  *
- * The estimation is very approximative because the value returned is the time
- * the task would take if it was executed now and if it was the only task.
+ * The estimation is very approximative because the value returned is the time the task would take if it was executed
+ * now and if it was the only task.
  *
  * \param task the task to evaluate
- * \param workstation_nb number of workstations on which the task would be executed
- * \param workstation_list the workstations on which the task would be executed
- * \param flops_amount computation amount for each workstation
- * \param bytes_amount communication amount between each pair of workstations
+ * \param host_count number of hosts on which the task would be executed
+ * \param host_list the hosts on which the task would be executed
+ * \param flops_amount computation amount for each host(i.e., an array of host_count doubles)
+ * \param bytes_amount communication amount between each pair of hosts (i.e., a matrix of host_count*host_count doubles)
  * \see SD_schedule()
  */
-double SD_task_get_execution_time(SD_task_t task,
-                                  int workstation_nb,
-                                  const SD_workstation_t *
-                                  workstation_list,
-                                  const double *flops_amount,
-                                  const double *bytes_amount)
+double SD_task_get_execution_time(SD_task_t task, int host_count, const sg_host_t *host_list,
+                                  const double *flops_amount, const double *bytes_amount)
 {
-  double time, max_time = 0.0;
-  int i, j;
-  xbt_assert(workstation_nb > 0, "Invalid parameter");
+  xbt_assert(host_count > 0, "Invalid parameter");
+  double max_time = 0.0;
 
   /* the task execution time is the maximum execution time of the parallel tasks */
-
-  for (i = 0; i < workstation_nb; i++) {
-    time = 0.0;
-    if (flops_amount != NULL)
-      time =
-          SD_workstation_get_computation_time(workstation_list[i],
-                                              flops_amount[i]);
-
-    if (bytes_amount != NULL)
-      for (j = 0; j < workstation_nb; j++) {
-        time +=
-            SD_route_get_communication_time(workstation_list[i],
-                                            workstation_list[j],
-                                            bytes_amount[i *
-                                                                 workstation_nb
-                                                                 + j]);
-      }
-
-    if (time > max_time) {
+  for (int i = 0; i < host_count; i++) {
+    double time = 0.0;
+    if (flops_amount != nullptr)
+      time = flops_amount[i] / host_list[i]->speed();
+
+    if (bytes_amount != nullptr)
+      for (int j = 0; j < host_count; j++)
+        if (bytes_amount[i * host_count + j] != 0)
+          time += (sg_host_route_latency(host_list[i], host_list[j]) +
+                   bytes_amount[i * host_count + j] / sg_host_route_bandwidth(host_list[i], host_list[j]));
+
+    if (time > max_time)
       max_time = time;
-    }
   }
   return max_time;
 }
 
-static XBT_INLINE void SD_task_do_schedule(SD_task_t task)
+static inline void SD_task_do_schedule(SD_task_t task)
 {
   if (SD_task_get_state(task) > SD_SCHEDULABLE)
-    THROWF(arg_error, 0, "Task '%s' has already been scheduled",
-           SD_task_get_name(task));
+    THROWF(arg_error, 0, "Task '%s' has already been scheduled", SD_task_get_name(task));
 
-  /* update the task state */
-  if (task->unsatisfied_dependencies == 0)
+  if (task->predecessors->empty() && task->inputs->empty())
     SD_task_set_state(task, SD_RUNNABLE);
   else
     SD_task_set_state(task, SD_SCHEDULED);
@@ -965,53 +714,42 @@ static XBT_INLINE void SD_task_do_schedule(SD_task_t task)
  * \brief Schedules a task
  *
  * The task state must be #SD_NOT_SCHEDULED.
- * Once scheduled, a task will be executed as soon as possible in SD_simulate(),
- * i.e. when its dependencies are satisfied.
+ * Once scheduled, a task is executed as soon as possible in \see SD_simulate, i.e. when its dependencies are satisfied.
  *
  * \param task the task you want to schedule
- * \param workstation_count number of workstations on which the task will be executed
- * \param workstation_list the workstations on which the task will be executed
- * \param flops_amount computation amount for each workstation
- * \param bytes_amount communication amount between each pair of workstations
+ * \param host_count number of hosts on which the task will be executed
+ * \param host_list the hosts on which the task will be executed
+ * \param flops_amount computation amount for each hosts (i.e., an array of host_count doubles)
+ * \param bytes_amount communication amount between each pair of hosts (i.e., a matrix of host_count*host_count doubles)
  * \param rate task execution speed rate
  * \see SD_task_unschedule()
  */
-void SD_task_schedule(SD_task_t task, int workstation_count,
-                      const SD_workstation_t * workstation_list,
-                      const double *flops_amount,
-                      const double *bytes_amount, double rate)
+void SD_task_schedule(SD_task_t task, int host_count, const sg_host_t * host_list,
+                      const double *flops_amount, const double *bytes_amount, double rate)
 {
-  xbt_assert(workstation_count > 0, "workstation_nb must be positive");
+  xbt_assert(host_count > 0, "host_count must be positive");
 
-  task->workstation_nb = workstation_count;
   task->rate = rate;
 
   if (flops_amount) {
-    task->flops_amount = (double*)xbt_realloc(task->flops_amount,
-                                           sizeof(double) * workstation_count);
-    memcpy(task->flops_amount, flops_amount,
-           sizeof(double) * workstation_count);
+    task->flops_amount = static_cast<double*>(xbt_realloc(task->flops_amount, sizeof(double) * host_count));
+    memcpy(task->flops_amount, flops_amount, sizeof(double) * host_count);
   } else {
     xbt_free(task->flops_amount);
-    task->flops_amount = NULL;
+    task->flops_amount = nullptr;
   }
 
-  int communication_nb = workstation_count * workstation_count;
+  int communication_nb = host_count * host_count;
   if (bytes_amount) {
-    task->bytes_amount = (double*)xbt_realloc(task->bytes_amount,
-                                             sizeof(double) * communication_nb);
-    memcpy(task->bytes_amount, bytes_amount,
-           sizeof(double) * communication_nb);
+    task->bytes_amount = static_cast<double*>(xbt_realloc(task->bytes_amount, sizeof(double) * communication_nb));
+    memcpy(task->bytes_amount, bytes_amount, sizeof(double) * communication_nb);
   } else {
     xbt_free(task->bytes_amount);
-    task->bytes_amount = NULL;
+    task->bytes_amount = nullptr;
   }
 
-  task->workstation_list = (SD_workstation_t*)
-    xbt_realloc(task->workstation_list,
-                sizeof(SD_workstation_t) * workstation_count);
-  memcpy(task->workstation_list, workstation_list,
-         sizeof(SD_workstation_t) * workstation_count);
+  for(int i =0; i<host_count; i++)
+    task->allocation->push_back(host_list[i]);
 
   SD_task_do_schedule(task);
 }
@@ -1028,342 +766,62 @@ void SD_task_schedule(SD_task_t task, int workstation_count,
  */
 void SD_task_unschedule(SD_task_t task)
 {
-  if (task->state != SD_SCHEDULED &&
-      task->state != SD_RUNNABLE &&
-      task->state != SD_RUNNING &&
-      task->state != SD_FAILED)
-    THROWF(arg_error, 0,
-           "Task %s: the state must be SD_SCHEDULED, SD_RUNNABLE, SD_RUNNING or SD_FAILED",
-           SD_task_get_name(task));
-
-  if (__SD_task_is_scheduled_or_runnable(task)  /* if the task is scheduled or runnable */
-      && ((task->kind == SD_TASK_COMP_PAR_AMDAHL) ||
-          (task->kind == SD_TASK_COMM_PAR_MXN_1D_BLOCK))) { /* Don't free scheduling data for typed tasks */
+  if (task->state == SD_NOT_SCHEDULED || task->state == SD_SCHEDULABLE)
+    THROWF(arg_error, 0, "Task %s: the state must be SD_SCHEDULED, SD_RUNNABLE, SD_RUNNING or SD_FAILED", task->name);
+
+  if ((task->state == SD_SCHEDULED || task->state == SD_RUNNABLE) /* if the task is scheduled or runnable */
+      && ((task->kind == SD_TASK_COMP_PAR_AMDAHL) || (task->kind == SD_TASK_COMM_PAR_MXN_1D_BLOCK))) {
+          /* Don't free scheduling data for typed tasks */
     __SD_task_destroy_scheduling_data(task);
-    xbt_free(task->workstation_list);
-    task->workstation_list=NULL;
-    task->workstation_nb = 0;
+    task->allocation->clear();
   }
 
   if (SD_task_get_state(task) == SD_RUNNING)
     /* the task should become SD_FAILED */
     task->surf_action->cancel();
   else {
-    if (task->unsatisfied_dependencies == 0)
+    if (task->predecessors->empty() && task->inputs->empty())
       SD_task_set_state(task, SD_SCHEDULABLE);
     else
       SD_task_set_state(task, SD_NOT_SCHEDULED);
   }
-  task->remains = task->amount;
   task->start_time = -1.0;
 }
 
-/* Destroys the data memorized by SD_task_schedule.
- * Task state must be SD_SCHEDULED or SD_RUNNABLE.
- */
-static void __SD_task_destroy_scheduling_data(SD_task_t task)
-{
-  if (!__SD_task_is_scheduled_or_runnable(task)
-      && SD_task_get_state(task) != SD_IN_FIFO)
-    THROWF(arg_error, 0,
-           "Task '%s' must be SD_SCHEDULED, SD_RUNNABLE or SD_IN_FIFO",
-           SD_task_get_name(task));
-
-  xbt_free(task->flops_amount);
-  xbt_free(task->bytes_amount);
-  task->flops_amount = task->bytes_amount = NULL;
-}
-
-/* Runs a task. This function is directly called by __SD_task_try_to_run if
- * the task doesn't have to wait in FIFOs. Otherwise, it is called by
- * __SD_task_just_done when the task gets out of its FIFOs.
- */
-void __SD_task_really_run(SD_task_t task)
+/* Runs a task. */
+void SD_task_run(SD_task_t task)
 {
+  xbt_assert(task->state == SD_RUNNABLE, "Task '%s' is not runnable! Task state: %d", task->name, (int) task->state);
+  xbt_assert(task->allocation != nullptr, "Task '%s': host_list is nullptr!", task->name);
 
-  int i;
-  sg_host_t *hosts;
-
-  xbt_assert(__SD_task_is_runnable_or_in_fifo(task),
-              "Task '%s' is not runnable or in a fifo! Task state: %d",
-             SD_task_get_name(task), (int)SD_task_get_state(task));
-  xbt_assert(task->workstation_list != NULL,
-              "Task '%s': workstation_list is NULL!",
-              SD_task_get_name(task));
-
-  XBT_DEBUG("Really running task '%s'", SD_task_get_name(task));
-  int host_nb = task->workstation_nb;
-
-  /* set this task as current task for the workstations in sequential mode */
-  for (i = 0; i < host_nb; i++) {
-    if (SD_workstation_get_access_mode(task->workstation_list[i]) ==
-        SD_WORKSTATION_SEQUENTIAL_ACCESS) {
-       sg_host_sd(task->workstation_list[i])->current_task = task;
-      xbt_assert(__SD_workstation_is_busy(task->workstation_list[i]),
-                  "The workstation should be busy now");
-    }
-  }
-
-  XBT_DEBUG("Task '%s' set as current task for its workstations",
-         SD_task_get_name(task));
-
-  /* start the task */
+  XBT_VERB("Executing task '%s'", task->name);
 
   /* Copy the elements of the task into the action */
-  hosts = xbt_new(sg_host_t, host_nb);
-
-  for (i = 0; i < host_nb; i++)
-    hosts[i] =  task->workstation_list[i];
+  int host_nb = task->allocation->size();
+  sg_host_t *hosts = xbt_new(sg_host_t, host_nb);
+  int i =0;
+  for (auto host: *task->allocation){
+    hosts[i] = host;
+    i++;
+  }
 
   double *flops_amount = xbt_new0(double, host_nb);
   double *bytes_amount = xbt_new0(double, host_nb * host_nb);
 
-
   if(task->flops_amount)
-    memcpy(flops_amount, task->flops_amount, sizeof(double) *
-           host_nb);
+    memcpy(flops_amount, task->flops_amount, sizeof(double) * host_nb);
   if(task->bytes_amount)
-    memcpy(bytes_amount, task->bytes_amount,
-           sizeof(double) * host_nb * host_nb);
+    memcpy(bytes_amount, task->bytes_amount, sizeof(double) * host_nb * host_nb);
 
-  task->surf_action = surf_host_model->executeParallelTask(
-    host_nb, hosts, flops_amount, bytes_amount, task->rate);
+  task->surf_action = surf_host_model->executeParallelTask(host_nb, hosts, flops_amount, bytes_amount, task->rate);
 
   task->surf_action->setData(task);
 
   XBT_DEBUG("surf_action = %p", task->surf_action);
 
-  if (task->category)
-    TRACE_surf_action(task->surf_action, task->category);
-
   __SD_task_destroy_scheduling_data(task);      /* now the scheduling data are not useful anymore */
   SD_task_set_state(task, SD_RUNNING);
-  xbt_assert(SD_task_get_state(task) == SD_RUNNING,
-             "Bad state of task '%s': %d",
-             SD_task_get_name(task), (int)SD_task_get_state(task));
-
-}
-
-/* Tries to run a task. This function is called by SD_simulate() when a
- * scheduled task becomes SD_RUNNABLE (i.e., when its dependencies are
- * satisfied).
- * If one of the workstations where the task is scheduled on is busy (in
- * sequential mode), the task doesn't start.
- * Returns whether the task has started.
- */
-int __SD_task_try_to_run(SD_task_t task)
-{
-
-  int can_start = 1;
-  int i;
-  SD_workstation_t workstation;
-
-  xbt_assert(SD_task_get_state(task) == SD_RUNNABLE,
-              "Task '%s' is not runnable! Task state: %d",
-             SD_task_get_name(task), (int)SD_task_get_state(task));
-
-
-  for (i = 0; i < task->workstation_nb; i++) {
-    can_start = can_start &&
-        !__SD_workstation_is_busy(task->workstation_list[i]);
-  }
-
-  XBT_DEBUG("Task '%s' can start: %d", SD_task_get_name(task), can_start);
-
-  if (!can_start) {             /* if the task cannot start and is not in the FIFOs yet */
-    for (i = 0; i < task->workstation_nb; i++) {
-      workstation = task->workstation_list[i];
-      if (sg_host_sd(workstation)->access_mode == SD_WORKSTATION_SEQUENTIAL_ACCESS) {
-        XBT_DEBUG("Pushing task '%s' in the FIFO of workstation '%s'",
-               SD_task_get_name(task),
-               SD_workstation_get_name(workstation));
-        xbt_fifo_push(sg_host_sd(workstation)->task_fifo, task);
-      }
-    }
-    SD_task_set_state(task, SD_IN_FIFO);
-    XBT_DEBUG("Task '%s' state is now SD_IN_FIFO", SD_task_get_name(task));
-  } else {
-    __SD_task_really_run(task);
-  }
-
-  return can_start;
-}
-
-/* This function is called by SD_simulate when a task is done.
- * It updates task->state and task->action and executes if necessary the tasks
- * which were waiting in FIFOs for the end of `task'
- */
-void __SD_task_just_done(SD_task_t task)
-{
-  int i, j;
-  SD_workstation_t workstation;
-
-  SD_task_t candidate;
-  int candidate_nb = 0;
-  int candidate_capacity = 8;
-  SD_task_t *candidates;
-  int can_start = 1;
-
-  xbt_assert(SD_task_get_state(task)== SD_RUNNING,
-              "The task must be running! Task state: %d",
-              (int)SD_task_get_state(task));
-  xbt_assert(task->workstation_list != NULL,
-              "Task '%s': workstation_list is NULL!",
-              SD_task_get_name(task));
-
-
-  candidates = xbt_new(SD_task_t, 8);
-
-  SD_task_set_state(task, SD_DONE);
-  task->surf_action->unref();
-  task->surf_action = NULL;
-
-  XBT_DEBUG("Looking for candidates");
-
-  /* if the task was executed on sequential workstations,
-     maybe we can execute the next task of the FIFO for each workstation */
-  for (i = 0; i < task->workstation_nb; i++) {
-    workstation = task->workstation_list[i];
-    XBT_DEBUG("Workstation '%s': access_mode = %d",
-              SD_workstation_get_name(workstation),
-              (int)sg_host_sd(workstation)->access_mode);
-    if (sg_host_sd(workstation)->access_mode ==
-        SD_WORKSTATION_SEQUENTIAL_ACCESS) {
-      xbt_assert(sg_host_sd(workstation)->task_fifo != NULL,
-                  "Workstation '%s' has sequential access but no FIFO!",
-                  SD_workstation_get_name(workstation));
-      xbt_assert(sg_host_sd(workstation)->current_task =
-                  task, "Workstation '%s': current task should be '%s'",
-                  SD_workstation_get_name(workstation),
-                  SD_task_get_name(task));
-
-      /* the task is over so we can release the workstation */
-      sg_host_sd(workstation)->current_task = NULL;
-
-      XBT_DEBUG("Getting candidate in FIFO");
-      candidate = (SD_task_t)
-          xbt_fifo_get_item_content(xbt_fifo_get_first_item
-                                    (sg_host_sd(workstation)->task_fifo));
-
-      if (candidate != NULL) {
-        XBT_DEBUG("Candidate: '%s'", SD_task_get_name(candidate));
-        xbt_assert(SD_task_get_state(candidate) == SD_IN_FIFO,
-                    "Bad state of candidate '%s': %d",
-                    SD_task_get_name(candidate),
-                    (int)SD_task_get_state(candidate));
-      }
-
-      XBT_DEBUG("Candidate in fifo: %p", candidate);
-
-      /* if there was a task waiting for my place */
-      if (candidate != NULL) {
-        /* Unfortunately, we are not sure yet that we can execute the task now,
-           because the task can be waiting more deeply in some other
-           workstation's FIFOs ...
-           So we memorize all candidate tasks, and then we will check for each
-           candidate whether or not all its workstations are available. */
-
-        /* realloc if necessary */
-        if (candidate_nb == candidate_capacity) {
-          candidate_capacity *= 2;
-          candidates = (SD_task_t*)
-              xbt_realloc(candidates,
-                          sizeof(SD_task_t) * candidate_capacity);
-        }
-
-        /* register the candidate */
-        candidates[candidate_nb++] = candidate;
-        candidate->fifo_checked = 0;
-      }
-    }
-  }
-
-  XBT_DEBUG("Candidates found: %d", candidate_nb);
-
-  /* now we check every candidate task */
-  for (i = 0; i < candidate_nb; i++) {
-    candidate = candidates[i];
-
-    if (candidate->fifo_checked) {
-      continue;                 /* we have already evaluated that task */
-    }
-
-    xbt_assert(SD_task_get_state(candidate) == SD_IN_FIFO,
-                "Bad state of candidate '%s': %d",
-               SD_task_get_name(candidate), (int)SD_task_get_state(candidate));
-
-    for (j = 0; j < candidate->workstation_nb && can_start; j++) {
-      workstation = candidate->workstation_list[j];
-
-      /* I can start on this workstation if the workstation is shared
-         or if I am the first task in the FIFO */
-      can_start = sg_host_sd(workstation)->access_mode == SD_WORKSTATION_SHARED_ACCESS
-          || candidate ==
-          xbt_fifo_get_item_content(xbt_fifo_get_first_item
-                                    (sg_host_sd(workstation)->task_fifo));
-    }
-
-    XBT_DEBUG("Candidate '%s' can start: %d", SD_task_get_name(candidate),
-           can_start);
-
-    /* now we are sure that I can start! */
-    if (can_start) {
-      for (j = 0; j < candidate->workstation_nb && can_start; j++) {
-        workstation = candidate->workstation_list[j];
-
-        /* update the FIFO */
-        if (sg_host_sd(workstation)->access_mode == SD_WORKSTATION_SEQUENTIAL_ACCESS) {
-          candidate = (SD_task_t)xbt_fifo_shift(sg_host_sd(workstation)->task_fifo);   /* the return value is stored just for debugging */
-          XBT_DEBUG("Head of the FIFO: '%s' on workstation %s (%d task left)",
-                 (candidate !=
-                  NULL) ? SD_task_get_name(candidate) : "NULL",
-                  SD_workstation_get_name(workstation),
-                  xbt_fifo_size(sg_host_sd(workstation)->task_fifo));
-          xbt_assert(candidate == candidates[i],
-                      "Error in __SD_task_just_done: bad first task in the FIFO");
-
-        }
-      }                         /* for each workstation */
-
-      /* finally execute the task */
-      XBT_DEBUG("Task '%s' state: %d", SD_task_get_name(candidate),
-             (int)SD_task_get_state(candidate));
-      __SD_task_really_run(candidate);
-
-      XBT_DEBUG
-          ("Calling __SD_task_is_running: task '%s', state set: %d",
-           SD_task_get_name(candidate), candidate->state);
-      xbt_assert(SD_task_get_state(candidate) == SD_RUNNING,
-                  "Bad state of task '%s': %d",
-                  SD_task_get_name(candidate),
-                 (int)SD_task_get_state(candidate));
-      XBT_DEBUG("Okay, the task is running.");
-
-    }                           /* can start */
-    candidate->fifo_checked = 1;
-  }                             /* for each candidate */
-
-  xbt_free(candidates);
-}
-
-/* 
- * Remove all dependencies associated with a task. This function is called 
- * when the task is destroyed.
- */
-static void __SD_task_remove_dependencies(SD_task_t task)
-{
-  /* we must destroy the dependencies carefuly (with SD_dependency_remove)
-     because each one is stored twice */
-  SD_dependency_t dependency;
-  while (!xbt_dynar_is_empty(task->tasks_before)) {
-    xbt_dynar_get_cpy(task->tasks_before, 0, &dependency);
-    SD_task_dependency_remove(dependency->src, dependency->dst);
-  }
-
-  while (!xbt_dynar_is_empty(task->tasks_after)) {
-    xbt_dynar_get_cpy(task->tasks_after, 0, &dependency);
-    SD_task_dependency_remove(dependency->src, dependency->dst);
-  }
+  sd_global->return_set->insert(task);
 }
 
 /**
@@ -1386,9 +844,8 @@ double SD_task_get_start_time(SD_task_t task)
  * \brief Returns the finish time of a task
  *
  * The task state must be SD_RUNNING, SD_DONE or SD_FAILED.
- * If the state is not completed yet, the returned value is an
- * estimation of the task finish time. This value can fluctuate
- * until the task is completed.
+ * If the state is not completed yet, the returned value is an estimation of the task finish time. This value can
+ * vary until the task is completed.
  *
  * \param task: a task
  * \return the start time of this task
@@ -1400,286 +857,128 @@ double SD_task_get_finish_time(SD_task_t task)
   else
     return task->finish_time;
 }
-/** @brief Blah
- *
- */
-void SD_task_distribute_comp_amdahl(SD_task_t task, int ws_count)
+
+void SD_task_distribute_comp_amdahl(SD_task_t task, int count)
 {
-  int i;
-  xbt_assert(task->kind == SD_TASK_COMP_PAR_AMDAHL,
-              "Task %s is not a SD_TASK_COMP_PAR_AMDAHL typed task."
-              "Cannot use this function.",
-              SD_task_get_name(task));  
-  task->flops_amount = xbt_new0(double, ws_count);
-  task->bytes_amount = xbt_new0(double, ws_count * ws_count);
-  xbt_free(task->workstation_list);
-  task->workstation_nb = ws_count;
-  task->workstation_list = xbt_new0(SD_workstation_t, ws_count);
-  
-  for(i=0;i<ws_count;i++){
-    task->flops_amount[i] = 
-      (task->alpha + (1 - task->alpha)/ws_count) * task->amount;
+  xbt_assert(task->kind == SD_TASK_COMP_PAR_AMDAHL, "Task %s is not a SD_TASK_COMP_PAR_AMDAHL typed task."
+              "Cannot use this function.", task->name);
+  task->flops_amount = xbt_new0(double, count);
+  task->bytes_amount = xbt_new0(double, count * count);
+
+  for (int i=0; i<count; i++){
+    task->flops_amount[i] = (task->alpha + (1 - task->alpha)/count) * task->amount;
   }
-} 
+}
 
+void SD_task_build_MxN_1D_block_matrix(SD_task_t task, int src_nb, int dst_nb){
+  xbt_assert(task->kind == SD_TASK_COMM_PAR_MXN_1D_BLOCK, "Task %s is not a SD_TASK_COMM_PAR_MXN_1D_BLOCK typed task."
+              "Cannot use this function.", task->name);
+  xbt_free(task->bytes_amount);
+  task->bytes_amount = xbt_new0(double,task->allocation->size() * task->allocation->size());
+
+  for (int i=0; i<src_nb; i++) {
+    double src_start = i*task->amount/src_nb;
+    double src_end = src_start + task->amount/src_nb;
+    for (int j=0; j<dst_nb; j++) {
+      double dst_start = j*task->amount/dst_nb;
+      double dst_end = dst_start + task->amount/dst_nb;
+      XBT_VERB("(%d->%d): (%.2f, %.2f)-> (%.2f, %.2f)", i, j, src_start, src_end, dst_start, dst_end);
+      task->bytes_amount[i*(src_nb+dst_nb)+src_nb+j]=0.0;
+      if ((src_end > dst_start) && (dst_end > src_start)) { /* There is something to send */
+        task->bytes_amount[i*(src_nb+dst_nb)+src_nb+j] = MIN(src_end, dst_end)- MAX(src_start, dst_start);
+        XBT_VERB("==> %.2f", task->bytes_amount[i*(src_nb+dst_nb)+src_nb+j]);
+      }
+    }
+  }
+}
 
 /** @brief Auto-schedules a task.
  *
- * Auto-scheduling mean that the task can be used with SD_task_schedulev(). This
- * allows to specify the task costs at creation, and decouple them from the
- * scheduling process where you just specify which resource should deliver the
+ * Auto-scheduling mean that the task can be used with SD_task_schedulev(). This allows to specify the task costs at
+ * creation, and decouple them from the scheduling process where you just specify which resource should deliver the
  * mandatory power.
  *
- * To be auto-schedulable, a task must be created with SD_task_create_comm_e2e()
- * or SD_task_create_comp_seq(). Check their definitions for the exact semantic
- * of each of them.
- *
- * @todo
- * We should create tasks kind for the following categories:
- *  - Point to point communication (done)
- *  - Sequential computation       (done)
- *  - group communication (redistribution, several kinds)
- *  - parallel tasks with no internal communication (one kind per speedup
- *    model such as Amdahl)
- *  - idem+ internal communication. Task type not enough since we cannot store
- *    comm cost alongside to comp one)
+ * To be auto-schedulable, a task must be a typed computation SD_TASK_COMP_SEQ or SD_TASK_COMP_PAR_AMDAHL.
  */
-void SD_task_schedulev(SD_task_t task, int count,
-                       const SD_workstation_t * list)
+void SD_task_schedulev(SD_task_t task, int count, const sg_host_t * list)
 {
-  int i, j;
-  SD_dependency_t dep;
-  unsigned int cpt;
-  xbt_assert(task->kind != 0,
-              "Task %s is not typed. Cannot automatically schedule it.",
-              SD_task_get_name(task));
-  switch (task->kind) {
-  case SD_TASK_COMP_PAR_AMDAHL:
-    SD_task_distribute_comp_amdahl(task, count);
-  case SD_TASK_COMM_E2E:
-  case SD_TASK_COMP_SEQ:
-    xbt_assert(task->workstation_nb == count,
-               "Got %d locations, but were expecting %d locations",
-               count,task->workstation_nb);
-    for (i = 0; i < count; i++)
-      task->workstation_list[i] = list[i];
-    if (SD_task_get_kind(task)== SD_TASK_COMP_SEQ && !task->flops_amount){
-      /*This task has failed and is rescheduled. Reset the flops_amount*/
+  xbt_assert(task->kind == SD_TASK_COMP_SEQ || task->kind == SD_TASK_COMP_PAR_AMDAHL,
+      "Task %s is not typed. Cannot automatically schedule it.", SD_task_get_name(task));
+
+  for(int i =0; i<count; i++)
+    task->allocation->push_back(list[i]);
+
+  XBT_VERB("Schedule computation task %s on %zu host(s)", task->name, task->allocation->size());
+
+  if (task->kind == SD_TASK_COMP_SEQ) {
+    if (not task->flops_amount) { /*This task has failed and is rescheduled. Reset the flops_amount*/
       task->flops_amount = xbt_new0(double, 1);
-      task->flops_amount[0] = task->remains;
+      task->flops_amount[0] = task->amount;
     }
-    SD_task_do_schedule(task);
-    break;
-  default:
-    xbt_die("Kind of task %s not supported by SD_task_schedulev()",
-            SD_task_get_name(task));
+    XBT_VERB("It costs %.f flops", task->flops_amount[0]);
   }
-  if (task->kind == SD_TASK_COMM_E2E) {
-    XBT_VERB("Schedule comm task %s between %s -> %s. It costs %.f bytes",
-          SD_task_get_name(task),
-          SD_workstation_get_name(task->workstation_list[0]),
-          SD_workstation_get_name(task->workstation_list[1]),
-          task->bytes_amount[2]);
 
+  if (task->kind == SD_TASK_COMP_PAR_AMDAHL) {
+    SD_task_distribute_comp_amdahl(task, count);
+    XBT_VERB("%.f flops will be distributed following Amdahl's Law", task->flops_amount[0]);
   }
 
-  /* Iterate over all children and parents being COMM_E2E to say where I am
-   * located (and start them if runnable) */
-  if (task->kind == SD_TASK_COMP_SEQ) {
-    XBT_VERB("Schedule computation task %s on %s. It costs %.f flops",
-          SD_task_get_name(task),
-          SD_workstation_get_name(task->workstation_list[0]),
-          task->flops_amount[0]);
-
-    xbt_dynar_foreach(task->tasks_before, cpt, dep) {
-      SD_task_t before = dep->src;
-      if (before->kind == SD_TASK_COMM_E2E) {
-        before->workstation_list[1] = task->workstation_list[0];
-
-        if (before->workstation_list[0] &&
-            (SD_task_get_state(before)< SD_SCHEDULED)) {
-          SD_task_do_schedule(before);
-          XBT_VERB
-              ("Auto-Schedule comm task %s between %s -> %s. It costs %.f bytes",
-               SD_task_get_name(before),
-               SD_workstation_get_name(before->workstation_list[0]),
-               SD_workstation_get_name(before->workstation_list[1]),
-               before->bytes_amount[2]);
-        }
-      }
-    }
-    xbt_dynar_foreach(task->tasks_after, cpt, dep) {
-      SD_task_t after = dep->dst;
-      if (after->kind == SD_TASK_COMM_E2E) {
-        after->workstation_list[0] = task->workstation_list[0];
-        if (after->workstation_list[1]
-            && (SD_task_get_state(after)< SD_SCHEDULED)) {
-          SD_task_do_schedule(after);
-          XBT_VERB
-              ("Auto-Schedule comm task %s between %s -> %s. It costs %.f bytes",
-               SD_task_get_name(after),
-               SD_workstation_get_name(after->workstation_list[0]),
-               SD_workstation_get_name(after->workstation_list[1]),
-               after->bytes_amount[2]);
-
-        }
-      }
+  SD_task_do_schedule(task);
+
+  /* Iterate over all inputs and outputs to say where I am located (and start them if runnable) */
+  for (auto input : *task->inputs){
+    int src_nb = input->allocation->size();
+    int dst_nb = count;
+    if (input->allocation->empty())
+      XBT_VERB("Sender side of '%s' not scheduled. Set receiver side to '%s''s allocation", input->name, task->name);
+
+    for (int i=0; i<count;i++)
+      input->allocation->push_back(task->allocation->at(i));
+
+    if (input->allocation->size () > task->allocation->size()) {
+      if (task->kind == SD_TASK_COMP_PAR_AMDAHL)
+        SD_task_build_MxN_1D_block_matrix(input, src_nb, dst_nb);
+
+      SD_task_do_schedule(input);
+      XBT_VERB ("Auto-Schedule Communication task '%s'. Send %.f bytes from %d hosts to %d hosts.",
+          input->name,input->amount, src_nb, dst_nb);
     }
   }
-  /* Iterate over all children and parents being MXN_1D_BLOCK to say where I am
-   * located (and start them if runnable) */
-  if (task->kind == SD_TASK_COMP_PAR_AMDAHL) {
-    XBT_VERB("Schedule computation task %s on %d workstations. %.f flops"
-             " will be distributed following Amdahl's Law",
-          SD_task_get_name(task), task->workstation_nb,
-          task->flops_amount[0]);
-    xbt_dynar_foreach(task->tasks_before, cpt, dep) {
-      SD_task_t before = dep->src;
-      if (before->kind == SD_TASK_COMM_PAR_MXN_1D_BLOCK){
-        if (!before->workstation_list){
-          XBT_VERB("Sender side of Task %s is not scheduled yet",
-             SD_task_get_name(before));
-          before->workstation_list = xbt_new0(SD_workstation_t, count);
-          before->workstation_nb = count;
-          XBT_VERB("Fill the workstation list with list of Task '%s'",
-            SD_task_get_name(task));
-          for (i=0;i<count;i++)
-            before->workstation_list[i] = task->workstation_list[i];
-        } else {
-          XBT_VERB("Build communication matrix for task '%s'",
-             SD_task_get_name(before));
-          int src_nb, dst_nb;
-          double src_start, src_end, dst_start, dst_end;
-          src_nb = before->workstation_nb;
-          dst_nb = count;
-          before->workstation_list = (SD_workstation_t*) xbt_realloc(
-             before->workstation_list,
-             (before->workstation_nb+count)*sizeof(s_SD_workstation_t));
-          for(i=0; i<count; i++)
-            before->workstation_list[before->workstation_nb+i] =
-               task->workstation_list[i];
-
-          before->workstation_nb += count;
-          xbt_free(before->flops_amount);
-          xbt_free(before->bytes_amount);
-          before->flops_amount = xbt_new0(double,
-                                                before->workstation_nb);
-          before->bytes_amount = xbt_new0(double,
-                                                  before->workstation_nb*
-                                                  before->workstation_nb);
-
-          for(i=0;i<src_nb;i++){
-            src_start = i*before->amount/src_nb;
-            src_end = src_start + before->amount/src_nb;
-            for(j=0; j<dst_nb; j++){
-              dst_start = j*before->amount/dst_nb;
-              dst_end = dst_start + before->amount/dst_nb;
-              XBT_VERB("(%s->%s): (%.2f, %.2f)-> (%.2f, %.2f)",
-                  SD_workstation_get_name(before->workstation_list[i]),
-                  SD_workstation_get_name(before->workstation_list[src_nb+j]),
-                  src_start, src_end, dst_start, dst_end);
-              if ((src_end <= dst_start) || (dst_end <= src_start)) {
-                before->bytes_amount[i*(src_nb+dst_nb)+src_nb+j]=0.0;
-              } else {
-                before->bytes_amount[i*(src_nb+dst_nb)+src_nb+j] =
-                  MIN(src_end, dst_end) - MAX(src_start, dst_start);
-              }
-              XBT_VERB("==> %.2f",
-                 before->bytes_amount[i*(src_nb+dst_nb)+src_nb+j]);
-            }
-          }
-
-          if (SD_task_get_state(before)< SD_SCHEDULED) {
-            SD_task_do_schedule(before);
-            XBT_VERB
-              ("Auto-Schedule redistribution task %s. Send %.f bytes from %d hosts to %d hosts.",
-                  SD_task_get_name(before),before->amount, src_nb, dst_nb);
-            }
-        }
-      }
-    }
-    xbt_dynar_foreach(task->tasks_after, cpt, dep) {
-      SD_task_t after = dep->dst;
-      if (after->kind == SD_TASK_COMM_PAR_MXN_1D_BLOCK){
-        if (!after->workstation_list){
-          XBT_VERB("Receiver side of Task '%s' is not scheduled yet",
-              SD_task_get_name(after));
-          after->workstation_list = xbt_new0(SD_workstation_t, count);
-          after->workstation_nb = count;
-          XBT_VERB("Fill the workstation list with list of Task '%s'",
-            SD_task_get_name(task));
-          for (i=0;i<count;i++)
-            after->workstation_list[i] = task->workstation_list[i];
-        } else {
-          int src_nb, dst_nb;
-          double src_start, src_end, dst_start, dst_end;
-          src_nb = count;
-          dst_nb = after->workstation_nb;
-          after->workstation_list = (SD_workstation_t*) xbt_realloc(
-            after->workstation_list,
-            (after->workstation_nb+count)*sizeof(s_SD_workstation_t));
-          for(i=after->workstation_nb - 1; i>=0; i--)
-            after->workstation_list[count+i] = after->workstation_list[i];
-          for(i=0; i<count; i++)
-            after->workstation_list[i] = task->workstation_list[i];
-
-          after->workstation_nb += count;
-
-          xbt_free(after->flops_amount);
-          xbt_free(after->bytes_amount);
-
-          after->flops_amount = xbt_new0(double, after->workstation_nb);
-          after->bytes_amount = xbt_new0(double,
-                                                 after->workstation_nb*
-                                                 after->workstation_nb);
-
-          for(i=0;i<src_nb;i++){
-            src_start = i*after->amount/src_nb;
-            src_end = src_start + after->amount/src_nb;
-            for(j=0; j<dst_nb; j++){
-              dst_start = j*after->amount/dst_nb;
-              dst_end = dst_start + after->amount/dst_nb;
-              XBT_VERB("(%d->%d): (%.2f, %.2f)-> (%.2f, %.2f)",
-                  i, j, src_start, src_end, dst_start, dst_end);
-              if ((src_end <= dst_start) || (dst_end <= src_start)) {
-                after->bytes_amount[i*(src_nb+dst_nb)+src_nb+j]=0.0;
-              } else {
-                after->bytes_amount[i*(src_nb+dst_nb)+src_nb+j] =
-                   MIN(src_end, dst_end)- MAX(src_start, dst_start);
-              }
-              XBT_VERB("==> %.2f",
-                 after->bytes_amount[i*(src_nb+dst_nb)+src_nb+j]);
-            }
-          }
-
-          if (SD_task_get_state(after)< SD_SCHEDULED) {
-            SD_task_do_schedule(after);
-            XBT_VERB
-            ("Auto-Schedule redistribution task %s. Send %.f bytes from %d hosts to %d hosts.",
-              SD_task_get_name(after),after->amount, src_nb, dst_nb);
-          }
-         }
-      }
+
+  for (auto output : *task->outputs){
+    int src_nb = count;
+    int dst_nb = output->allocation->size();
+    if (output->allocation->empty())
+      XBT_VERB("Receiver side of '%s' not scheduled. Set sender side to '%s''s allocation", output->name, task->name);
+
+    for (int i=0; i<count;i++)
+      output->allocation->insert(output->allocation->begin()+i, task->allocation->at(i));
+
+    if (output->allocation->size () > task->allocation->size()) {
+      if (task->kind == SD_TASK_COMP_PAR_AMDAHL)
+        SD_task_build_MxN_1D_block_matrix(output, src_nb, dst_nb);
+
+      SD_task_do_schedule(output);
+      XBT_VERB ("Auto-Schedule Communication task %s. Send %.f bytes from %d hosts to %d hosts.",
+                output->name, output->amount, src_nb, dst_nb);
     }
   }
 }
 
-/** @brief autoschedule a task on a list of workstations
+/** @brief autoschedule a task on a list of hosts
  *
- * This function is very similar to SD_task_schedulev(),
- * but takes the list of workstations to schedule onto as separate parameters.
- * It builds a proper vector of workstations and then call SD_task_schedulev()
+ * This function is similar to SD_task_schedulev(), but takes the list of hosts to schedule onto as separate parameters.
+ * It builds a proper vector of hosts and then call SD_task_schedulev()
  */
 void SD_task_schedulel(SD_task_t task, int count, ...)
 {
   va_list ap;
-  SD_workstation_t *list = xbt_new(SD_workstation_t, count);
-  int i;
+  sg_host_t *list = xbt_new(sg_host_t, count);
   va_start(ap, count);
-  for (i = 0; i < count; i++) {
-    list[i] = va_arg(ap, SD_workstation_t);
-  }
+  for (int i=0; i<count; i++)
+    list[i] = va_arg(ap, sg_host_t);
+
   va_end(ap);
   SD_task_schedulev(task, count, list);
-  free(list);
+  xbt_free(list);
 }