Assigning Priorities for Fixed Priority Preemption Threshold Scheduling

Algorithm 3

Pseudo code for the proposed PRUNED-TRAVERSE( ) algorithm.

(1) PRUNED-TRAVERSE (Γ: set of tasks)

(2)    Γ ← descendingSort(Γ, );

(3)    foreach ()

(4)     ;

(5)     ;

(6)     ;

(7)     // end-foreach

(8)    return_PRUNED-TRAVERSE(1, Γ, Γ);

(9) _PRUNED-TRAVERSE (prio: priority, UnAssigned: set of tasks, Γ: set of tasks)

(10)  foreach ()

(11)     if (prio < ) continue; // pruning this path with condition C2

(12)     ;

(13)     ;

(14)     if (prio = |Γ|)

(15)     ret = RESTORING-OPT-ASSIGN-THRESHOLD(Γ);

(16)      if (ret = fail)  ;

(17)      return ret;

(18)     // end-if

(19)     if ()

(20)      ; // restore to the highest priority

(21)      if (prio > infeasiblePrioMax _i) ;

(22)      continue; // pruning this path with condition C1

(23)     // end-if

(24)     ;

(25)     if (_PRUNED-TRAVERSE(prio + 1, UnAssigned −  , Γ) = success) return  success;

       // The following line is executed when the above _PRUNED-TRAVERSE( ) returned fail.

(26)     foreach () ; // restore to the highest priority

(27)  // end-foreach

(28) return  fail;