X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/d74b4977daa2266f5a80c90d906c01eff72b4d7d..3f17e7a2d9e727cf8ba2da354280f3afd329c8a6:/src/simdag/sd_task.c

diff --git a/src/simdag/sd_task.c b/src/simdag/sd_task.c
index ce2c2e2785..4a046fa6b9 100644
--- a/src/simdag/sd_task.c
+++ b/src/simdag/sd_task.c
@@ -3,81 +3,56 @@
 #include "xbt/sysdep.h"
 #include "xbt/dynar.h"
 
-/* Creates a task.
+/**
+ * \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 amount the computing amount necessary to do this task
+ * \return the new task
+ * \see SD_task_destroy()
  */
 SD_task_t SD_task_create(const char *name, void *data, double amount) {
   SD_CHECK_INIT_DONE();
   xbt_assert0(amount > 0, "amount must be positive");
 
-  SD_task_data_t sd_data = xbt_new0(s_SD_task_data_t, 1); /* task private data */
+  SD_task_t task = xbt_new0(s_SD_task_t, 1);
 
   /* general information */
+  task->data = data; /* user data */
   if (name != NULL)
-    sd_data->name = xbt_strdup(name);
+    task->name = xbt_strdup(name);
   else
-    sd_data->name = NULL;
+    task->name = NULL;
 
-  sd_data->state = SD_NOT_SCHEDULED;
-  sd_data->amount = amount;
-  sd_data->surf_action = NULL;
-  sd_data->watch_points = 0;
+  task->state_set = sd_global->not_scheduled_task_set;
+  xbt_swag_insert(task,task->state_set);
+
+  task->amount = amount;
+  task->surf_action = NULL;
+  task->watch_points = 0;
+  task->state_changed = 0;
 
   /* dependencies */
-  sd_data->tasks_before = xbt_dynar_new(sizeof(SD_dependency_t), NULL);
-  sd_data->tasks_after = xbt_dynar_new(sizeof(SD_dependency_t), NULL);
+  task->tasks_before = xbt_dynar_new(sizeof(SD_dependency_t), NULL);
+  task->tasks_after = xbt_dynar_new(sizeof(SD_dependency_t), NULL);
 
   /* scheduling parameters */
-  sd_data->workstation_nb = 0;
-  sd_data->workstation_list = NULL;
-  sd_data->computation_amount = NULL;
-  sd_data->communication_amount = NULL;
-  sd_data->rate = 0;
-
-  SD_task_t task = xbt_new0(s_SD_task_t, 1);
-  task->sd_data = sd_data; /* private data */
-  task->data = data; /* user data */
+  task->workstation_nb = 0;
+  task->workstation_list = NULL;
+  task->computation_amount = NULL;
+  task->communication_amount = NULL;
+  task->rate = 0;
 
   return task;
 }
 
-/* Schedules a task.
- * task: the task to schedule
- * workstation_nb: number of workstations where the task will be executed
- * workstation_list: workstations where the task will be executed
- * computation_amount: computation amount for each workstation
- * communication_amount: communication amount between each pair of workstations
- * rate: task execution speed rate
- */
-void SD_task_schedule(SD_task_t task, int workstation_nb,
-		     const SD_workstation_t *workstation_list, double *computation_amount,
-		     double *communication_amount, double rate) {
-  SD_CHECK_INIT_DONE();
-  xbt_assert0(task, "Invalid parameter");
-  xbt_assert1(SD_task_get_state(task) == SD_NOT_SCHEDULED, "Task '%s' has already been scheduled.", SD_task_get_name(task));
-  xbt_assert0(workstation_nb > 0, "workstation_nb must be positive");
-
-  SD_task_data_t sd_data = task->sd_data;
-  sd_data->workstation_nb = workstation_nb;
-  sd_data->rate = rate;
-
-  sd_data->computation_amount = xbt_new0(double, workstation_nb);
-  memcpy(sd_data->computation_amount, computation_amount, sizeof(double) * workstation_nb);
-
-  int communication_nb = workstation_nb * workstation_nb;
-  sd_data->communication_amount = xbt_new0(double, communication_nb);
-  memcpy(sd_data->communication_amount, communication_amount, sizeof(double) * communication_nb);
-
-  /* we have to create a Surf workstation array instead of the SimDag workstation array */
-  sd_data->workstation_list = xbt_new0(void*, workstation_nb);
-  int i;
-  for (i = 0; i < workstation_nb; i++) {
-    sd_data->workstation_list[i] = workstation_list[i]->sd_data->surf_workstation;
-  }
-
-  sd_data->state = SD_SCHEDULED;
-}
-
-/* Returns the data of a 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)
+ * \see SD_task_set_data()
  */
 void* SD_task_get_data(SD_task_t task) {
   SD_CHECK_INIT_DONE();
@@ -85,7 +60,15 @@ void* SD_task_get_data(SD_task_t task) {
   return task->data;
 }
 
-/* Sets the data of a 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.
+ *
+ * \param task a task
+ * \param data the new data you want to associate with this task
+ * \see SD_task_get_data()
  */
 void SD_task_set_data(SD_task_t task, void *data) {
   SD_CHECK_INIT_DONE();
@@ -93,76 +76,171 @@ void SD_task_set_data(SD_task_t task, void *data) {
   task->data = data;
 }
 
-/* Returns the name of a task. The name can be NULL.
+/**
+ * \brief Returns the state of a task
+ *
+ * \param task a task
+ * \return the current \ref e_SD_task_state_t "state" of this task:
+ * #SD_NOT_SCHEDULED, #SD_SCHEDULED, #SD_READY, #SD_RUNNING, #SD_DONE or #SD_FAILED
+ * \see e_SD_task_state_t
+ */
+e_SD_task_state_t SD_task_get_state(SD_task_t task) {
+  SD_CHECK_INIT_DONE();
+  xbt_assert0(task != NULL, "Invalid parameter");
+
+  if (task->state_set == sd_global->scheduled_task_set)
+    return SD_SCHEDULED;
+  if (task->state_set == sd_global->done_task_set)
+    return SD_DONE;
+  if (task->state_set == sd_global->running_task_set)
+    return SD_RUNNING;
+  if (task->state_set == sd_global->ready_task_set)
+    return SD_READY;
+  if (task->state_set == sd_global->not_scheduled_task_set)
+    return SD_NOT_SCHEDULED;
+  return SD_FAILED;
+}
+
+/* Changes the state of a task. Updates the swags and the flag sd_global->watch_point_reached.
+ */
+void __SD_task_set_state(SD_task_t task, e_SD_task_state_t new_state) {
+  xbt_swag_remove(task, task->state_set);
+  switch (new_state) {
+  case SD_NOT_SCHEDULED:
+    task->state_set = sd_global->not_scheduled_task_set;
+    break;
+  case SD_SCHEDULED:
+    task->state_set = sd_global->scheduled_task_set;
+    break;
+  case SD_READY:
+    task->state_set = sd_global->ready_task_set;
+    break;
+  case SD_RUNNING:
+    task->state_set = sd_global->running_task_set;
+    break;
+  case SD_DONE:
+    task->state_set = sd_global->done_task_set;
+    break;
+  case SD_FAILED:
+    task->state_set = sd_global->failed_task_set;
+    break;
+  default:
+    xbt_assert0(0, "Invalid state");
+  }
+  xbt_swag_insert(task, task->state_set);
+
+  if (task->watch_points & new_state) {
+    printf("Watch point reached with task '%s' in state %d!\n", SD_task_get_name(task), new_state);
+    sd_global->watch_point_reached = 1;
+    SD_task_unwatch(task, new_state); /* remove the watch point */
+  }
+}
+
+/**
+ * \brief Returns the name of a task
+ *
+ * \param task a task
+ * \return the name of this task (can be \c NULL)
  */
 const char* SD_task_get_name(SD_task_t task) {
   SD_CHECK_INIT_DONE();
   xbt_assert0(task != NULL, "Invalid parameter");
-  return task->sd_data->name;
+  return task->name;
 }
 
-/* Returns the computing amount of a task.
+/**
+ * \brief Returns the computing amount of a task
+ *
+ * \param task a task
+ * \return the total computing amount of this task
+ * \see SD_task_get_remaining_amount()
  */
 double SD_task_get_amount(SD_task_t task) {
   SD_CHECK_INIT_DONE();
   xbt_assert0(task != NULL, "Invalid parameter");
-  return task->sd_data->amount;
+  return task->amount;
 }
 
-/* Returns the remaining computing amount of a task.
+/**
+ * \brief Returns the remaining computing amount of a task
+ *
+ * \param task a task
+ * \return the remaining computing amount of this task
+ * \see SD_task_get_amount()
  */
 double SD_task_get_remaining_amount(SD_task_t task) {
   SD_CHECK_INIT_DONE();
   xbt_assert0(task != NULL, "Invalid parameter");
-  SD_task_data_t sd_data = task->sd_data;
-  if (sd_data->surf_action)
-    return sd_data->amount;
+  
+  if (task->surf_action)
+    return task->amount;
   else
-    return sd_data->surf_action->remains;
+    return task->surf_action->remains;
 }
 
 /* temporary function for debbuging */
-void __SD_print_dependencies(SD_task_t task) {
+static void __SD_print_dependencies(SD_task_t task) {
   printf("The following tasks must be executed before %s:", SD_task_get_name(task));
-  xbt_dynar_t dynar = task->sd_data->tasks_before;
+  xbt_dynar_t dynar = task->tasks_before;
   int length = xbt_dynar_length(dynar);
   int i;
   SD_dependency_t dependency;
   for (i = 0; i < length; i++) {
-    dependency = *((SD_dependency_t*) xbt_dynar_get_ptr(dynar, i));
+    xbt_dynar_get_cpy(dynar, i, &dependency);
     printf(" %s", SD_task_get_name(dependency->src));
   }
 
   printf("\nThe following tasks must be executed after %s:", SD_task_get_name(task));
 
-  dynar = task->sd_data->tasks_after;
+  dynar = task->tasks_after;
   length = xbt_dynar_length(dynar);
   for (i = 0; i < length; i++) {
-    dependency = *((SD_dependency_t*) xbt_dynar_get_ptr(dynar, i));
+    xbt_dynar_get_cpy(dynar, i, &dependency);
     printf(" %s", SD_task_get_name(dependency->dst));
   }
   printf("\n----------------------------\n");
 }
 
-/* Adds a dependency between two tasks.
+/* Destroys a dependency between two tasks.
+ */
+static void __SD_task_dependency_destroy(void *dependency) {
+  if (((SD_dependency_t) dependency)->name != NULL)
+    xbt_free(((SD_dependency_t) dependency)->name);
+  xbt_free(dependency);
+}
+
+/**
+ * \brief Adds a dependency between two tasks
+ *
+ * \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_READY.
+ *
+ * \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 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) {
   SD_CHECK_INIT_DONE();
   xbt_assert0(src != NULL && dst != NULL, "Invalid parameter");
   xbt_assert1(src != dst, "Cannot add a dependency between task '%s' and itself", SD_task_get_name(src));
+  xbt_assert1(__SD_task_is_not_scheduled(src) || __SD_task_is_scheduled_or_ready(src),
+	      "Task '%s' must be SD_NOT_SCHEDULED, SD_SCHEDULED or SD_READY", SD_task_get_name(src));
+  xbt_assert1(__SD_task_is_not_scheduled(dst) || __SD_task_is_scheduled_or_ready(dst),
+	      "Task '%s' must be SD_NOT_SCHEDULED, SD_SCHEDULED or SD_READY", SD_task_get_name(dst));
 
-  xbt_dynar_t dynar = src->sd_data->tasks_after;
+  xbt_dynar_t dynar = src->tasks_after;
   int length = xbt_dynar_length(dynar);
   int found = 0;
   int i;
   SD_dependency_t dependency;
   for (i = 0; i < length && !found; i++) {
-    dependency = *((SD_dependency_t*) xbt_dynar_get_ptr(dynar, i));
-    if (dependency->src == src && dependency->dst == dst) {
-      found = 1;
-    }
+    xbt_dynar_get_cpy(dynar, i, &dependency);
+    found = (dependency->dst == dst);
   }
-  xbt_assert2(!found, "A dependency already exists between task '%s' and task '%s'", src->sd_data->name, dst->sd_data->name);
+  xbt_assert2(!found, "A dependency already exists between task '%s' and task '%s'",
+	      SD_task_get_name(src), SD_task_get_name(dst));
 
   dependency = xbt_new0(s_SD_dependency_t, 1);
 
@@ -173,188 +251,299 @@ void SD_task_dependency_add(const char *name, void *data, SD_task_t src, SD_task
   dependency->dst = dst;
 
   /* src must be executed before dst */
-  xbt_dynar_push(src->sd_data->tasks_after, &dependency);
-  xbt_dynar_push(dst->sd_data->tasks_before, &dependency);
+  xbt_dynar_push(src->tasks_after, &dependency);
+  xbt_dynar_push(dst->tasks_before, &dependency);
+
+  /* if the task was ready, then dst->tasks_before is not empty anymore,
+     so we must go back to state SD_SCHEDULED */
+  if (__SD_task_is_ready(dst)) {
+    printf("SD_task_dependency_add: %s was ready and becomes scheduled!\n", SD_task_get_name(dst));
+    __SD_task_set_state(dst, SD_SCHEDULED);
+  }
 
   /*  __SD_print_dependencies(src);
-      __SD_print_dependencies(dst);*/
+      __SD_print_dependencies(dst); */
 }
 
-/* Removes a dependency between two tasks.
+/**
+ * \brief Remove a dependency between two tasks
+ *
+ * \param src a task
+ * \param dst a task depending on \a src
+ * \see SD_task_dependency_add()
  */
 void SD_task_dependency_remove(SD_task_t src, SD_task_t dst) {
   SD_CHECK_INIT_DONE();
   xbt_assert0(src != NULL && dst != NULL, "Invalid parameter");
-  xbt_assert1(src != dst, "Cannot remove a dependency between task '%s' and itself", SD_task_get_name(src));
 
-  xbt_dynar_t dynar = src->sd_data->tasks_after;
+  /* remove the dependency from src->tasks_after */
+  xbt_dynar_t dynar = src->tasks_after;
   int length = xbt_dynar_length(dynar);
   int found = 0;
   int i;
   SD_dependency_t dependency;
   for (i = 0; i < length && !found; i++) {
-    dependency = *((SD_dependency_t*) xbt_dynar_get_ptr(dynar, i));
-    if (dependency->src == src && dependency->dst == dst) {
+    xbt_dynar_get_cpy(dynar, i, &dependency);
+    if (dependency->dst == dst) {
       xbt_dynar_remove_at(dynar, i, NULL);
       found = 1;
     }
   }
   xbt_assert4(found, "No dependency found between task '%s' and '%s': task '%s' is not a successor of task '%s'",
-	      src->sd_data->name, dst->sd_data->name, dst->sd_data->name, src->sd_data->name);
+	      SD_task_get_name(src), SD_task_get_name(dst), SD_task_get_name(dst), SD_task_get_name(src));
 
-  dynar = dst->sd_data->tasks_before;
+  /* 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++) {
-    dependency = *((SD_dependency_t*) xbt_dynar_get_ptr(dynar, i));
-    if (dependency->src == src && dependency->dst == dst) {
+    xbt_dynar_get_cpy(dynar, i, &dependency);
+    if (dependency->src == src) {
       xbt_dynar_remove_at(dynar, i, NULL);
-      __SD_task_destroy_dependency(dependency);
+      __SD_task_dependency_destroy(dependency);
       found = 1;
     }
   }
   xbt_assert4(found, "SimDag error: task '%s' is a successor of '%s' but task '%s' is not a predecessor of task '%s'",
-	      dst->sd_data->name, src->sd_data->name, src->sd_data->name, dst->sd_data->name); /* should never happen... */
+	      SD_task_get_name(dst), SD_task_get_name(src), SD_task_get_name(src), SD_task_get_name(dst)); /* should never happen... */
 
-  /*  __SD_print_dependencies(src);
+  /* if the task was scheduled and dst->tasks_before is empty now, we can make it ready */
+  if (xbt_dynar_length(dst->tasks_before) == 0 && __SD_task_is_scheduled(dst))
+    __SD_task_set_state(dst, SD_READY);
+
+  /*  __SD_print_dependencies(src); 
       __SD_print_dependencies(dst);*/
 }
 
-/* Returns the state of a task: SD_NOT_SCHEDULED, SD_SCHEDULED, SD_RUNNING, SD_DONE or SD_FAILED.
+/**
+ * \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()
  */
-SD_task_state_t SD_task_get_state(SD_task_t task) {
+void *SD_task_dependency_get_data(SD_task_t src, SD_task_t dst) {
   SD_CHECK_INIT_DONE();
-  xbt_assert0(task != NULL, "Invalid parameter");
-  return task->sd_data->state;
+  xbt_assert0(src != NULL && dst != NULL, "Invalid parameter");
+
+  xbt_dynar_t dynar = src->tasks_after;
+  int length = xbt_dynar_length(dynar);
+  int found = 0;
+  int i;
+  SD_dependency_t dependency;
+  for (i = 0; i < length && !found; i++) {
+    xbt_dynar_get_cpy(dynar, i, &dependency);
+    found = (dependency->dst == dst);
+  }
+  xbt_assert2(found, "No dependency found between task '%s' and '%s'", SD_task_get_name(src), SD_task_get_name(dst));
+  return dependency->data;
 }
 
 /* temporary function for debugging */
-void __SD_print_watch_points(SD_task_t task) {
-  static const int state_masks[] = {SD_SCHEDULED, SD_RUNNING, SD_DONE, SD_FAILED};
-  static const char* state_names[] = {"scheduled", "running", "done", "failed"};
+static void __SD_print_watch_points(SD_task_t task) {
+  static const int state_masks[] = {SD_SCHEDULED, SD_RUNNING, SD_READY, SD_DONE, SD_FAILED};
+  static const char* state_names[] = {"scheduled", "running", "ready", "done", "failed"};
 
-  printf("Task '%s' watch points (%x): ", task->sd_data->name, task->sd_data->watch_points);
+  printf("Task '%s' watch points (%x): ", SD_task_get_name(task), task->watch_points);
 
   int i;
-  for (i = 0; i < 4; i++) {
-    if (task->sd_data->watch_points & state_masks[i])
+  for (i = 0; i < 5; i++) {
+    if (task->watch_points & state_masks[i])
       printf("%s ", state_names[i]);
   }
   printf("\n");
 }
 
-/* Adds a watch point to a task.
-   SD_simulate will stop as soon as the state of this task is the one given in argument.
-   Watch point is then automatically removed.
+/**
+ * \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.
+ * 
+ * \param task a task
+ * \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, SD_task_state_t state) {
+void SD_task_watch(SD_task_t task, e_SD_task_state_t state) {
   SD_CHECK_INIT_DONE();
   xbt_assert0(task != NULL, "Invalid parameter");
+  xbt_assert0(state != SD_NOT_SCHEDULED, "Cannot add a watch point for state SD_NOT_SCHEDULED");
 
-  task->sd_data->watch_points = task->sd_data->watch_points | state;
-  __SD_print_watch_points(task);
+  task->watch_points = task->watch_points | state;
+  /*  __SD_print_watch_points(task);*/
 }
 
-/* Removes a watch point from a task.
+/**
+ * \brief Removes a watch point from a task
+ * 
+ * \param task a task
+ * \param state the \ref e_SD_task_state_t "state" you no longer want to watch
+ * \see SD_task_watch()
  */
-void SD_task_unwatch(SD_task_t task, SD_task_state_t state) {
+void SD_task_unwatch(SD_task_t task, e_SD_task_state_t state) {
   SD_CHECK_INIT_DONE();
   xbt_assert0(task != NULL, "Invalid parameter");
+  xbt_assert0(state != SD_NOT_SCHEDULED, "Cannot have a watch point for state SD_NOT_SCHEDULED");
   
-  task->sd_data->watch_points = task->sd_data->watch_points & ~state;
-  __SD_print_watch_points(task);
+  task->watch_points = task->watch_points & ~state;
+  /*  __SD_print_watch_points(task);*/
+}
+
+/* Destroys the data memorised by SD_task_schedule. Task state must be SD_SCHEDULED or SD_READY.
+ */
+static void __SD_task_destroy_scheduling_data(SD_task_t task) {
+  SD_CHECK_INIT_DONE();
+  xbt_assert1(__SD_task_is_scheduled_or_ready(task),
+	      "Task '%s' must be SD_SCHEDULED or SD_READY", SD_task_get_name(task));
+  xbt_free(task->workstation_list);
+  xbt_free(task->computation_amount);
+  xbt_free(task->communication_amount);
+}
+
+/**
+ * \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.
+ * 
+ * \param task the task you want to schedule
+ * \param workstation_nb number of workstations on which the task will be executed
+ * \param workstation_list the workstations on which the task will be executed
+ * \param computation_amount computation amount for each workstation
+ * \param communication_amount communication amount between each pair of workstations
+ * \param rate task execution speed rate
+ * \see SD_task_unschedule()
+ */
+void SD_task_schedule(SD_task_t task, int workstation_nb,
+		     const SD_workstation_t *workstation_list, double *computation_amount,
+		     double *communication_amount, double rate) {
+  SD_CHECK_INIT_DONE();
+  xbt_assert0(task, "Invalid parameter");
+  xbt_assert1(__SD_task_is_not_scheduled(task), "Task '%s' has already been scheduled.", SD_task_get_name(task));
+  xbt_assert0(workstation_nb > 0, "workstation_nb must be positive");
+
+  task->workstation_nb = workstation_nb;
+  task->rate = rate;
+
+  task->computation_amount = xbt_new0(double, workstation_nb);
+  memcpy(task->computation_amount, computation_amount, sizeof(double) * workstation_nb);
+
+  int communication_nb = workstation_nb * workstation_nb;
+  task->communication_amount = xbt_new0(double, communication_nb);
+  memcpy(task->communication_amount, communication_amount, sizeof(double) * communication_nb);
+
+  /* we have to create a Surf workstation array instead of the SimDag workstation array */
+  task->workstation_list = xbt_new0(void*, workstation_nb);
+  int i;
+  for (i = 0; i < workstation_nb; i++) {
+    task->workstation_list[i] = workstation_list[i]->surf_workstation;
+  }
+
+  /* update the task state */
+  if (xbt_dynar_length(task->tasks_before) == 0)
+    __SD_task_set_state(task, SD_READY);
+  else
+    __SD_task_set_state(task, SD_SCHEDULED);
 }
 
-/* Unschedules a task. The state must be SD_SCHEDULED, SD_RUNNING or SD_FAILED.
- * The task is reinitialised and its state becomes SD_NOT_SCHEDULED.
- * Call SD_task_schedule to schedule it again.
+/**
+ * \brief Unschedules a task
+ *
+ * The task state must be #SD_SCHEDULED, #SD_READY, #SD_RUNNING or #SD_FAILED.
+ * If you call this function, the task state becomes #SD_NOT_SCHEDULED.
+ * Call SD_task_schedule() to schedule it again.
+ *
+ * \param task the task you want to unschedule
+ * \see SD_task_schedule()
  */
 void SD_task_unschedule(SD_task_t task) {
   SD_CHECK_INIT_DONE();
   xbt_assert0(task != NULL, "Invalid parameter");
-  xbt_assert1(task->sd_data->state == SD_SCHEDULED ||
-	      task->sd_data->state == SD_RUNNING ||
-	      task->sd_data->state == SD_FAILED,
-	      "Task %s: the state must be SD_SCHEDULED, SD_RUNNING or SD_FAILED", task->sd_data->name);
-
-  if (task->sd_data->state == SD_SCHEDULED)
+  xbt_assert1(task->state_set == sd_global->scheduled_task_set ||
+	      task->state_set == sd_global->ready_task_set ||
+	      task->state_set == sd_global->running_task_set ||
+	      task->state_set == sd_global->failed_task_set,
+	      "Task %s: the state must be SD_SCHEDULED, SD_READY, SD_RUNNING or SD_FAILED",
+	      SD_task_get_name(task));
+
+  if (__SD_task_is_scheduled_or_ready(task)) /* if the task is scheduled or ready */
     __SD_task_destroy_scheduling_data(task);
 
-  task->sd_data->state = SD_NOT_SCHEDULED;
+  if (__SD_task_is_running(task)) /* the task should become SD_FAILED */
+    surf_workstation_resource->common_public->action_cancel(task->surf_action);
+  else
+    __SD_task_set_state(task, SD_NOT_SCHEDULED);
 }
 
 /* Runs a task. This function is called by SD_simulate when a scheduled task can start
  * (ie when its dependencies are satisfied).
  */
-void __SD_task_run(SD_task_t task) {
+surf_action_t __SD_task_run(SD_task_t task) {
   SD_CHECK_INIT_DONE();
   xbt_assert0(task != NULL, "Invalid parameter");
+  xbt_assert2(__SD_task_is_ready(task), "Task '%s' is not ready! Task state: %d",
+	      SD_task_get_name(task), SD_task_get_state(task));
 
-  SD_task_data_t sd_data = task->sd_data;
-  surf_workstation_resource->extension_public->
-    execute_parallel_task(sd_data->workstation_nb,
-			  sd_data->workstation_list,
-			  sd_data->computation_amount,
-			  sd_data->communication_amount,
-			  sd_data->amount,
-			  sd_data->rate);
-  task->sd_data->state = SD_RUNNING;
+  surf_action_t surf_action = surf_workstation_resource->extension_public->
+    execute_parallel_task(task->workstation_nb,
+			  task->workstation_list,
+			  task->computation_amount,
+			  task->communication_amount,
+			  task->amount,
+			  task->rate);
 
   __SD_task_destroy_scheduling_data(task); /* now the scheduling data are not useful anymore */
-}
+  __SD_task_set_state(task, SD_RUNNING);
 
+  return surf_action;
+}
 
-/* Destroys a task. The user data (if any) should have been destroyed first.
+/* Remove all dependencies associated with a task. This function is called when the task is done.
  */
-void SD_task_destroy(SD_task_t task) {
-  SD_CHECK_INIT_DONE();
-  xbt_assert0(task != NULL, "Invalid parameter");
-
-  /*  printf("Destroying task %s...\n", SD_task_get_name(task));*/
-
+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_length(task->sd_data->tasks_before) > 0) {
-    xbt_dynar_get_cpy(task->sd_data->tasks_before, 0, &dependency);
+  while (xbt_dynar_length(task->tasks_before) > 0) {
+    xbt_dynar_get_cpy(task->tasks_before, 0, &dependency);
     SD_task_dependency_remove(dependency->src, dependency->dst);
   }
 
-  while (xbt_dynar_length(task->sd_data->tasks_after) > 0) {
-    xbt_dynar_get_cpy(task->sd_data->tasks_after, 0, &dependency);
+  while (xbt_dynar_length(task->tasks_after) > 0) {
+    xbt_dynar_get_cpy(task->tasks_after, 0, &dependency);
     SD_task_dependency_remove(dependency->src, dependency->dst);
   }
+}
 
-  if (task->sd_data->state == SD_SCHEDULED)
-    __SD_task_destroy_scheduling_data(task);
+/**
+ * \brief Destroys a task.
+ *
+ * The user data (if any) should have been destroyed first.
+ *
+ * \param task the task you want to destroy
+ * \see SD_task_create()
+ */
+void SD_task_destroy(SD_task_t task) {
+  SD_CHECK_INIT_DONE();
+  xbt_assert0(task != NULL, "Invalid parameter");
 
-  if (task->sd_data->name != NULL)
-    xbt_free(task->sd_data->name);
+  /*printf("Destroying task %s...\n", SD_task_get_name(task));*/
 
-  xbt_dynar_free(&task->sd_data->tasks_before);
-  xbt_dynar_free(&task->sd_data->tasks_after);
-  xbt_free(task->sd_data);
-  xbt_free(task);
+  __SD_task_remove_dependencies(task);
 
-  /*printf("Task destroyed.\n");*/
+  /* if the task was scheduled or ready we have to free the scheduling parameters */
+  if (__SD_task_is_scheduled_or_ready(task))
+    __SD_task_destroy_scheduling_data(task);
 
-}
+  if (task->name != NULL)
+    xbt_free(task->name);
 
-/* Destroys the data memorised by SD_task_schedule. Task state must be SD_SCHEDULED.
- */
-void __SD_task_destroy_scheduling_data(SD_task_t task) {
-  xbt_free(task->sd_data->workstation_list);
-  xbt_free(task->sd_data->computation_amount);
-  xbt_free(task->sd_data->communication_amount);
-}
+  xbt_dynar_free(&task->tasks_before);
+  xbt_dynar_free(&task->tasks_after);
+  xbt_free(task);
 
-/* Destroys a dependency between two tasks.
- */
-void __SD_task_destroy_dependency(void *dependency) {
-  if (((SD_dependency_t) dependency)->name != NULL)
-    xbt_free(((SD_dependency_t) dependency)->name);
-  /*printf("destroying dependency between %s and %s\n", ((SD_dependency_t) dependency)->src->sd_data->name, ((SD_dependency_t) dependency)->dst->sd_data->name);*/
-  xbt_free(dependency);
-  /*printf("destroyed.\n");*/
+  /*printf("Task destroyed.\n");*/
 }