refac: add a specific variable _priority_job_expected_start_time to stop...

refac: add a specific variable _priority_job_expected_start_time to stop storing that info in _priority_job->completion_time

src/algo/easy_bf_fast.cpp

@@ -3,7 +3,6 @@
 //#include <loguru.hpp>
 
 #include "../pempek_assert.hpp"
-#include <cstddef>
 
 EasyBackfillingFast::EasyBackfillingFast(Workload *workload,
     SchedulingDecision *decision, Queue *queue, ResourceSelector *selector,
@@ -50,9 +49,6 @@ void EasyBackfillingFast::make_decisions(double date,
     // - only handles one priority job (the first of the queue)
     // - only handles time as floating-point (-> precision errors).
 
-    // Hacks:
-    // - uses priority job's completion time to store its expected starting time
-
     bool job_ended = false;
 
     // Handle newly finished jobs
@@ -122,7 +118,7 @@ void EasyBackfillingFast::make_decisions(double date,
                     {
                         // The job becomes priority!
                         _priority_job = pending_job;
-                        _priority_job->completion_time = compute_priority_job_expected_earliest_starting_time();
+                        update_priority_job_expected_earliest_start_time();
                         _pending_jobs.erase(job_it);
 
                         // Stop first queue traversal.
@@ -137,7 +133,7 @@ void EasyBackfillingFast::make_decisions(double date,
                 // Update priority job expected starting time (might have changed if a recently ended job 
                 // completed before its walltime)
                 if (_priority_job != nullptr)
-                    _priority_job->completion_time = compute_priority_job_expected_earliest_starting_time();
+                    update_priority_job_expected_earliest_start_time();
 
                 for (auto job_it = _pending_jobs.begin();
                      job_it != _pending_jobs.end(); )
@@ -145,7 +141,7 @@ void EasyBackfillingFast::make_decisions(double date,
                     const Job * pending_job = *job_it;
                     // Can the job be executed now ?
                     if (pending_job->nb_requested_resources <= _nb_available_machines &&
-                        date + pending_job->walltime <= _priority_job->completion_time)
+                        date + pending_job->walltime <= _priority_job_expected_start_time)
                     {
                         // Yes, it can be backfilled!
                         alloc.machines = _available_machines.left(
@@ -198,7 +194,7 @@ void EasyBackfillingFast::make_decisions(double date,
             //LOG_F(INFO, "There are enough available resources (%d) to execute job %s", _nb_available_machines, new_job->id.c_str());
             // Can it be executed now (without hindering priority job?)
             if (_priority_job == nullptr ||
-                date + new_job->walltime <= _priority_job->completion_time)
+                date + new_job->walltime <= _priority_job_expected_start_time)
             {
                 //LOG_F(INFO, "Job %s can be started right away!", new_job->id.c_str());
                 // Yes, the job can be executed right away!
@@ -222,7 +218,7 @@ void EasyBackfillingFast::make_decisions(double date,
             {
                 // No, the job cannot be executed (hinders priority job.)
                 /*LOG_F(INFO, "Not enough time to execute job %s (walltime=%g, priority job expected starting time=%g)",
-                      new_job->id.c_str(), (double)new_job->walltime, _priority_job->completion_time);*/
+                      new_job->id.c_str(), (double)new_job->walltime, _priority_job_expected_start_time);*/
                 _pending_jobs.push_back(new_job);
             }
         }
@@ -234,7 +230,7 @@ void EasyBackfillingFast::make_decisions(double date,
             {
                 // The job becomes priority.
                 _priority_job = new_job;
-                _priority_job->completion_time = compute_priority_job_expected_earliest_starting_time();
+                update_priority_job_expected_earliest_start_time();
             }
             else
             {
@@ -245,7 +241,7 @@ void EasyBackfillingFast::make_decisions(double date,
     }
 }
 
-double EasyBackfillingFast::compute_priority_job_expected_earliest_starting_time()
+void EasyBackfillingFast::update_priority_job_expected_earliest_start_time()
 {
     int nb_available = _nb_available_machines;
     int required = _priority_job->nb_requested_resources;
@@ -256,12 +252,14 @@ double EasyBackfillingFast::compute_priority_job_expected_earliest_starting_time
 
         if (nb_available >= required)
         {
-            return it->date;
+            _priority_job_expected_start_time = it->date;
+            _remaining_resources_at_priority_job_start = nb_available - required;
+            return;
         }
     }
 
     PPK_ASSERT_ERROR(false, "The job will never be executable.");
-    return 0;
+    return;
 }
 
 std::list<EasyBackfillingFast::FinishedHorizonPoint>::iterator EasyBackfillingFast::insert_horizon_point(const EasyBackfillingFast::FinishedHorizonPoint &point)

src/algo/easy_bf_fast.hpp

@@ -39,7 +39,7 @@ private:
     };
 
 private:
-    double compute_priority_job_expected_earliest_starting_time();
+    void update_priority_job_expected_earliest_start_time();
     std::list<FinishedHorizonPoint>::iterator insert_horizon_point(const FinishedHorizonPoint & point);
 
 private:
@@ -59,4 +59,6 @@ private:
 
     // At any time, null if there is no priority job (no waiting job)
     Job * _priority_job = nullptr;
+    double _priority_job_expected_start_time = -1;
+    int _remaining_resources_at_priority_job_start = -1;
 };