Assigning Priorities for Fixed Priority Preemption Threshold Scheduling

Algorithm 2

Pseudo code for (a) CORRECTED-SEARCH( ) and (b) RESTORING-OPT-ASSIGN-THRESHOLD( ).

(1) CORRECTED-SEARCH (Γ: set of tasks)

(2)   return  _CORRECTED-SEARCH(1, Γ, Γ);

(3) _CORRECTED-SEARCH (prio: priority, UnAssigned: set of tasks, Γ: set of tasks)

(4)  if (UnAssigned = ) return RESTORING-OPT-ASSIGN-THRESHOLD(Γ);

(5) RefinedList ← Refine(UnAssigned); // eliminating infeasible tasks even with the highest preemption threshold

(6)  foreach ()

(7)  ;

(8)  ;

(9)  if (_SEARCH(prio + 1, UnAssigned −  , Γ) = success) return success;

(10)    // end-foreach

(11)   return  fail;

(a) CORRECTED-SEARCH( )

(1) RESTORING-OPT-ASSIGN-THRESHOLD (Γ: set of tasks)

(2)   OPT-ASSIGN-THRESHOLD(Γ);

(3)   if (ret = fail) foreach () ; // restore preemption thresholds

(4)   return  ret;

(b) RESTORING-OPT-ASSIGN-THRESHOLD( )