Runtime Scheduling, Allocation, and Execution of Real-Time Hardware Tasks onto Xilinx FPGAs Subject to Fault Occurrence

Algorithm 2

Schedule_FAEDF().

  input:  (a) List of R ready tasks, sorted by increasing 𝑑^∗_𝑖−𝑡_ICAP,𝑖

     (b) List of E executing tasks, sorted by increasing 𝑡_SP,𝑖+𝑡_ICAP,𝑖+𝑡_𝐸,𝑖

     (c) MER, given by the allocator

     (d) Real-time deadline tightness, ∑_{∀𝑘∈ReadyQueue}𝑡_ICAP,𝑘𝑑^∗_𝑘−𝑡

     (e) current time 𝑡_KT

  output: Scheduled Task

1   Reset tried array (set all positions equal to false);

2   𝑖← First Task in Ready Queue;

3  while  𝑖≤𝑅  do

4  if  MER≥ℎ_𝑥,𝑖⋅ℎ_𝑦,𝑖 and 𝑡𝑟𝑖𝑒𝑑[𝑖]=false  then

5   if  Allocate(i)≠ Ø  then

6    return  𝑖;

7   end if

8  end if

9  if  ∑_{∀𝑘∈ReadyQueue}𝑡_ICAP,𝑘𝑑^∗_𝑘−𝑡<Threshold  then

10  𝑗← First Task in Executing Queue;

11  𝐹←false;

12  while  𝑗≤𝐸 and 𝑡_SP,𝑗+𝑡_ICAP,𝑗+𝑡_𝐸,𝑗≤𝑑^∗_𝑖−𝑡_ICAP,𝑖 and !𝐹  do

13   if  ℎ_𝑥,𝑗≥ℎ_𝑥,𝑖 and ℎ_𝑦,𝑗≥ℎ_𝑦,𝑖  then

14    𝐹←true;

15   end if

16   𝑗← Next Task in Executing Queue;

17  end while

18  if  𝐹  then

19   𝑚← Next Task in Ready Queue after 𝑖;

20   while  𝑚≤𝑅  do

21    if  𝑡_KT+𝑡_ICAP,𝑚≤𝑑^∗_𝑖−𝑡_ICAP,𝑖  then

22     if  MER≥ℎ_𝑥,𝑚⋅ℎ_𝑦,𝑚 and tried[𝑚] = false  then

23      if  Allocate(𝑚)≠ Ø  then

24       return  𝑚;

25      else

26       tried[𝑚] ← true;

27      end if

28     end if

29    end if

30      𝑚← Next Task in Ready Queue;

31   end while

32   return  Ø;

33    end if

34  end if

35 𝑖← Next Task in Ready Queue;

36  end while

37  return  Ø;