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@BolajiAyodeji
Last active October 25, 2022 22:18
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Python implementation of the Robin Round (RR) preemptive scheduling algorithm.
# Python3 program for implementation of RR scheduling
# Function to find the waiting time for all processes
def findWaitingTime(processes, n, bt, wt, quantum):
rem_bt = [0] * n
# Copy the burst time into rt[]
for i in range(n):
rem_bt[i] = bt[i]
t = 0 # Current time
# Keep traversing processes in round robin manner until all of them are not done.
while(1):
done = True
# Traverse all processes one by
# one repeatedly
for i in range(n):
# If burst time of a process is greater
# than 0 then only need to process further
if (rem_bt[i] > 0):
done = False # There is a pending process
if (rem_bt[i] > quantum):
# Increase the value of t i.e. shows
# how much time a process has been processed
t += quantum
# Decrease the burst_time of current process by quantum
rem_bt[i] -= quantum
# If burst time is smaller than or equal
# to quantum. Last cycle for this process
else:
# Increase the value of t i.e. shows
# how much time a process has been processed
t = t + rem_bt[i]
# Waiting time is current time minus
# time used by this process
wt[i] = t - bt[i]
# As the process gets fully executed
# make its remaining burst time = 0
rem_bt[i] = 0
# If all processes are done
if (done == True):
break
# Function to calculate turn around time
def findTurnAroundTime(processes, n, bt, wt, tat):
# Calculating turnaround time
for i in range(n):
tat[i] = bt[i] + wt[i]
# Function to calculate average waiting and turn-around times.
def findavgTime(processes, n, bt, quantum):
wt = [0] * n
tat = [0] * n
# Function to find waiting time of all processes
findWaitingTime(processes, n, bt,
wt, quantum)
# Function to find turn around time for all processes
findTurnAroundTime(processes, n, bt,
wt, tat)
# Display processes along with all details
print("Processes Burst Time Waiting",
"Time Turn-Around Time")
total_wt = 0
total_tat = 0
for i in range(n):
total_wt = total_wt + wt[i]
total_tat = total_tat + tat[i]
print(" ", i + 1, "\t\t", bt[i],
"\t\t", wt[i], "\t\t", tat[i])
print("\nAverage waiting time = %.5f " % (total_wt / n))
print("Average turn around time = %.5f " % (total_tat / n))
# Driver code
if __name__ == "__main__":
# Process id's
proc = [1, 2, 3]
n = 3
# Burst time of all processes
burst_time = [10, 5, 8]
# Time quantum
quantum = 2
findavgTime(proc, n, burst_time, quantum)
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