From e274863cda5514b22196942d3a55887499166fcf Mon Sep 17 00:00:00 2001 From: Pawan Sundargiri <67560186+pawanbuddy2000@users.noreply.github.com> Date: Fri, 3 Jul 2020 18:41:07 +0530 Subject: [PATCH] Add round_robin scheduling algorithm (#2158) * round_robin and priority cpu scheduling algorithms * Delete priority_cpu_scheduling.py * Delete round_robin_algorithm.py * [add] cpu_scheduling_algorithms * [add] Round robin cpu scheduling algorithm * Update scheduling/round_robin_scheduling_algorithm.py Co-authored-by: Christian Clauss * Update scheduling/round_robin.py Co-authored-by: Christian Clauss * Update scheduling/round_robin_scheduling.py Co-authored-by: Christian Clauss * Update scheduling/round_robin_scheduling.py Co-authored-by: Christian Clauss * Update scheduling/round_robin.py Co-authored-by: Christian Clauss * Round_Robin * Update round_robin.py * Update round_robin.py * Update round_robin.py * Update round_robin.py Co-authored-by: pawanbuddy <46370996+pawanbuddy@users.noreply.github.com> Co-authored-by: Christian Clauss --- scheduling/round_robin.py | 65 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100755 scheduling/round_robin.py diff --git a/scheduling/round_robin.py b/scheduling/round_robin.py new file mode 100755 index 000000000..10aa3ecab --- /dev/null +++ b/scheduling/round_robin.py @@ -0,0 +1,65 @@ +""" +Round Robin is a scheduling algorithm. +In Round Robin each process is assigned a fixed time slot in a cyclic way. +https://en.wikipedia.org/wiki/Round-robin_scheduling +""" +from statistics import mean +from typing import List + + +def calculate_waiting_times(burst_times: List[int]) -> List[int]: + """ + Calculate the waiting times of a list of processes that have a specified duration. + + Return: The waiting time for each process. + >>> calculate_waiting_times([10, 5, 8]) + [13, 10, 13] + >>> calculate_waiting_times([4, 6, 3, 1]) + [5, 8, 9, 6] + >>> calculate_waiting_times([12, 2, 10]) + [12, 2, 12] + """ + quantum = 2 + rem_burst_times = list(burst_times) + waiting_times = [0] * len(burst_times) + t = 0 + while 1: + done = True + for i, burst_time in enumerate(burst_times): + if rem_burst_times[i] > 0: + done = False + if rem_burst_times[i] > quantum: + t += quantum + rem_burst_times[i] -= quantum + else: + t += rem_burst_times[i] + waiting_times[i] = t - burst_times[i] + rem_burst_times[i] = 0 + if done is True: + return waiting_times + + +def calculate_turn_around_times( + burst_times: List[int], waiting_times: List[int] +) -> List[int]: + """ + >>> calculate_turn_around_times([1, 2, 3, 4], [0, 1, 3]) + [1, 3, 6] + >>> calculate_turn_around_times([10, 3, 7], [10, 6, 11]) + [20, 9, 18] + """ + return [burst + waiting for burst, waiting in zip(burst_times, waiting_times)] + + +if __name__ == "__main__": + burst_times = [3, 5, 7] + waiting_times = calculate_waiting_times(burst_times) + turn_around_times = calculate_turn_around_times(burst_times, waiting_times) + print("Process ID \tBurst Time \tWaiting Time \tTurnaround Time") + for i, burst_time in enumerate(burst_times): + print( + f" {i + 1}\t\t {burst_time}\t\t {waiting_times[i]}\t\t " + f"{turn_around_times[i]}" + ) + print(f"\nAverage waiting time = {mean(waiting_times):.5f}") + print(f"Average turn around time = {mean(turn_around_times):.5f}")