On-Line Real-Time Service-Oriented Task Scheduling Using TUF

Algorithm 2

Generating the speculated execution order and the expected utility for task in the ready queue.

1: Input: Let Γ={𝜏₁,𝜏₂,…,𝜏_𝑘} be the accepted tasks in the

 ready queue, and let 𝑟_𝑖, 𝐶_𝑖 represent the arrival time and

 expected execution time of 𝜏_𝑖. Let the current time be 𝑡

2: Output: The new list Γ′={𝜏^1,𝜏^2,…,𝜏^𝑘} with the speculated

 execution order and their corresponding expected

 utility density 𝜌̂^𝑗 for 𝜏^𝑗,1≤𝑗≤𝑘.

3: If A task 𝜏₀ is being executed then

4:    𝑇=𝑟₀+𝐶₀;

5: else

6:    𝑇=𝑡;

7: end if

8: While Γ is not empty do

9:  For Each task 𝑖 in Γ  do

10:  Calculate 𝜌_𝑖(𝑇) based on (3), (4), (5), and

   (6);

11:  end for

12:  Select 𝜏_𝑗 with the highest 𝜌_𝑗(𝑇);

13:  Add 𝜏_𝑗 to the end of Γ′;

14∶𝜌̂_𝑗=𝜌_𝑗(𝑇);

15:  𝑇=𝑇+𝐶_𝑗;

16:  Remove 𝜏_𝑗 from Γ;

17: end while