Move forward declaration in simgrid/forward.h.

[simgrid.git] / src / msg / msg_task.cpp

diff --git a/src/msg/msg_task.cpp b/src/msg/msg_task.cpp
index 86ece99..3e1d68b 100644 (file)
--- a/src/msg/msg_task.cpp
+++ b/src/msg/msg_task.cpp
@@ -86,7 +86,9 @@ msg_task_t MSG_task_create(const char *name, double flop_amount, double message_
 msg_task_t MSG_parallel_task_create(const char *name, int host_nb, const msg_host_t * host_list,
                                     double *flops_amount, double *bytes_amount, void *data)
 {
-  msg_task_t task = MSG_task_create(name, 0, 0, data);
+  // Task's flops amount is set to an arbitrary value > 0.0 to be able to distinguish, in
+  // MSG_task_get_remaining_work_ratio(), a finished task and a task that has not started yet.
+  msg_task_t task        = MSG_task_create(name, 1.0, 0, data);
   simdata_task_t simdata = task->simdata;
 
   /* Simulator Data specific to parallel tasks */
@@ -216,14 +218,13 @@ msg_error_t MSG_task_cancel(msg_task_t task)
 {
   xbt_assert((task != nullptr), "Cannot cancel a nullptr task");
 
-  if (task->simdata->compute) {
-    simcall_execution_cancel(task->simdata->compute);
-  }
-  else if (task->simdata->comm) {
-    simdata_task_t simdata = task->simdata;
+  simdata_task_t simdata = task->simdata;
+  if (simdata->compute) {
+    simcall_execution_cancel(simdata->compute);
+  } else if (simdata->comm) {
     simcall_comm_cancel(simdata->comm);
-    simdata->setNotUsed();
   }
+  simdata->setNotUsed();
   return MSG_OK;
 }
 
@@ -232,45 +233,38 @@ msg_error_t MSG_task_cancel(msg_task_t task)
  *    to do: starts at 1 and goes to 0. Returns 0 if not started or finished.
  *
  * It works for either parallel or sequential tasks.
- * TODO: Improve this function by returning 1 if the task has not started
  */
 double MSG_task_get_remaining_work_ratio(msg_task_t task) {
 
   xbt_assert((task != nullptr), "Cannot get information from a nullptr task");
   if (task->simdata->compute) {
     // Task in progress
-    return task->simdata->compute->remains();
-
-  //} else if ((MSG_task_get_flops_amount(task) == 0 and task->simdata->flops_parallel_amount == nullptr) //this is a sequential task
-  //    or (task->simdata->flops_parallel_amount != nullptr and task->simdata->flops_parallel_amount == 0)) {
-  //  // Task finished
-  //  return 1;
+    return task->simdata->compute->remainingRatio();
   } else {
-    // Task not started or finished
-    return 0;
+    // Task not started (flops_amount is > 0.0) or finished (flops_amount is set to 0.0)
+    return task->simdata->flops_amount > 0.0 ? 1.0 : 0.0;
   }
 }
 
+/** \ingroup m_task_management
+ * \brief Returns the amount of flops that remain to be computed
+ *
+ * The returned value is initially the cost that you defined for the task, then it decreases until it reaches 0
+ *
+ * It works for sequential tasks, but the remaining amount of work is not a scalar value for parallel tasks.
+ * So you will get an exception if you call this function on parallel tasks. Just don't do it.
+ */
 double MSG_task_get_flops_amount(msg_task_t task) {
-  if (task->simdata->compute) {
+  if (task->simdata->compute != nullptr) {
     return task->simdata->compute->remains();
   } else {
+    // Not started or already done.
+    // - Before starting, flops_amount is initially the task cost
+    // - After execution, flops_amount is set to 0 (until someone uses MSG_task_set_flops_amount, if any)
     return task->simdata->flops_amount;
   }
 }
 
-/** \ingroup m_task_management
- * \brief Returns the initial amount of flops needed to execute a task #msg_task_t.
- *
- * Once a task has been processed, this amount is set to 0. If you want, you can reset this value with
- * #MSG_task_set_flops_amount before restarting the task.
- *
- * Warning: Only work for simple task, not parallel task.
- */
-double MSG_task_get_initial_flops_amount(msg_task_t task) {
-  return task->simdata->flops_amount;
-}
-
 /** \ingroup m_task_management
  * \brief set the computation amount needed to process a task #msg_task_t.
  *