one step toward a live migration plugin

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

diff --git a/src/msg/msg_task.cpp b/src/msg/msg_task.cpp
index 0ad5499..ae1f59c 100644 (file)
--- a/src/msg/msg_task.cpp
+++ b/src/msg/msg_task.cpp
@@ -216,27 +216,50 @@ 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;
 }
 
 /** \ingroup m_task_management
- * \brief Returns the remaining amount of flops needed to execute a task #msg_task_t.
+ * \brief Returns a value in ]0,1[ that represent the task remaining work
+ *    to do: starts at 1 and goes to 0. Returns 0 if not started or finished.
  *
- * 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.
+ * 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_flops_amount(msg_task_t task) {
+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->remainingRatio();
+  } else {
+    // Task not started or finished
+    return 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 != 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;
   }
 }