AP-IO: Asynchronous Pipeline I/O for Hiding Periodic Output Cost in CFD Simulation

Algorithm 1

A heuristic algorithm for the scheduling of fields' calculation segments in a single timestep.

INPUT: the origin order set of calculation segments in a time step 𝐹, which includes 𝑛

  calculation segments; the matrix of dependence relationship between calculation segments 𝐷;

OUTPUT: the new order set of calculation segments in a time step 𝐹_new;

(1) procedure SCHEDULING(𝐹,𝐷) // calculation segments scheduling procedure

(2)   𝐹_new=𝐹

(3)   while  𝐹_new≠𝐹_old  do

(4)     𝐹_old=𝐹_new;

(5)     for each 𝑖∈[1,𝑛]  do

(6)        if (𝐾(𝑆_𝑖)%2==0&&𝐷(𝑖,𝑖+1)==0&&𝑆_𝑖≠𝑆^first_{𝑘(𝑆𝑖)}) then // 𝑘(𝑆_𝑖) indicates

 the field number which 𝑆_𝑖 belongs to

(7)         𝑆_𝑖 exchange with 𝑆_𝑖+1;

(8)        end if

(9)        if (𝐾(𝑆_𝑖)%2==1&&𝐷(𝑖−1,𝑖)==0&&𝑆_𝑖≠𝑆^last_{𝑘(𝑆𝑖)}) then

(10)         𝑆_𝑖−1 exchange with 𝑆_𝑖;

(11)        end if

(12)     end for

(13)     if (𝐹_new==𝐹_old) then

(14)       break;

(15)     end if

(16)   end while

(17) end procedure