Round Robin Scheduling algorithm

Could anyone help me with Matlab code to find the turnaround time using the roundrobin algorithm. This is my code to find the waiting time and the total CPU time. Moreover the waiting time obtained is in negative. I wanna make sure is negative waiting time is possible in round robin?

{ numOfJobs=5

CPUTime=randperm(20)

CPUTime_copy=CPUTime;

CPUTime_copy2=CPUTime;

quantum=5;

totalCPUtime= sum(CPUTime)

total_temp=totalCPUtime;

while (total_temp ~= 0)

for i=1:1:numOfJobs

if CPUTime(i)>0

if(CPUTime(i)>quantum)

CPUTime(i)=CPUTime(i)-quantum;

total_temp=total_temp-quantum;

else CPUTime(i)=CPUTime(i)-quantum;

total_temp=total_temp-quantum;

complete_RR(i)=totalCPUtime-total_temp;

end

end

start(i)=i;

wait_time(i)=totalCPUtime-total_temp-CPUTime_copy(i);

end

break

end }

Answer 1

[Jamal Nasir]

%%% this MATLAB code for calculate Average waiting time for Round Robin CPU Scheduling %%% %%% edited by Jamal Nasir %%%%% Unversity of Almustansiryah

clc clear all close all j=3; job=randperm(10,j); jobi=job; flag=job>0; Quant=2; tw=sum(job); job1=[]; x=1:j; x1=[]; n=0; f1=[]; while tw>0 n=n+1; job1=[job1,job]; for i=1:j if flag(i)>0 if job(i)>Quant job(i)=job(i)-Quant; else job(i)=0; flag(i)=0; end end end tw=sum(job); x1=[x1,x]; f1=[f1,flag]; end

k=length(f1); for m=1:j to=0;wt=0; for i=1:k if x1(i)~=m if job1(i)>=Quant t=Quant; else t=job1(i); end wt=wt+t; else if job1(i)>=Quant t1=Quant; else t1=job1(i); end if t1<job1(i) to=to+t1; else break; end end end wait(m)=wt; end AvWaitTime=mean(wait) AvTurnAroundTime=mean(wait+jobi)

Answer 2

[Dr R SANJEEV KUMAR]

clc clear all close all j=3; job=randperm(10,j); jobi=job; flag=job>0; Quant=2; tw=sum(job); job1=[]; x=1:j; x1=[]; n=0; f1=[]; while tw>0 n=n+1; job1=[job1,job]; for i=1:j if flag(i)>0 if job(i)>Quant job(i)=job(i)-Quant; else job(i)=0; flag(i)=0; end end end tw=sum(job); x1=[x1,x]; f1=[f1,flag]; end

k=length(f1); for m=1:j to=0;wt=0; for i=1:k if x1(i)~=m if job1(i)>=Quant t=Quant; else t=job1(i); end wt=wt+t; else if job1(i)>=Quant t1=Quant; else t1=job1(i); end if t1<job1(i) to=to+t1; else break; end end end wait(m)=wt; end AvWaitTime=mean(wait) AvTurnAroundTime=mean(wait+jobi)