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* Pyupgrade to Python 3.9
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109 lines
3.7 KiB
Python
109 lines
3.7 KiB
Python
# Implementation of First Come First Served scheduling algorithm
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# In this Algorithm we just care about the order that the processes arrived
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# without carring about their duration time
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# https://en.wikipedia.org/wiki/Scheduling_(computing)#First_come,_first_served
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from __future__ import annotations
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def calculate_waiting_times(duration_times: list[int]) -> list[int]:
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"""
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This function calculates the waiting time of some processes that have a
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specified duration time.
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Return: The waiting time for each process.
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>>> calculate_waiting_times([5, 10, 15])
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[0, 5, 15]
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>>> calculate_waiting_times([1, 2, 3, 4, 5])
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[0, 1, 3, 6, 10]
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>>> calculate_waiting_times([10, 3])
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[0, 10]
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"""
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waiting_times = [0] * len(duration_times)
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for i in range(1, len(duration_times)):
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waiting_times[i] = duration_times[i - 1] + waiting_times[i - 1]
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return waiting_times
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def calculate_turnaround_times(
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duration_times: list[int], waiting_times: list[int]
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) -> list[int]:
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"""
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This function calculates the turnaround time of some processes.
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Return: The time difference between the completion time and the
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arrival time.
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Practically waiting_time + duration_time
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>>> calculate_turnaround_times([5, 10, 15], [0, 5, 15])
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[5, 15, 30]
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>>> calculate_turnaround_times([1, 2, 3, 4, 5], [0, 1, 3, 6, 10])
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[1, 3, 6, 10, 15]
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>>> calculate_turnaround_times([10, 3], [0, 10])
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[10, 13]
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"""
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return [
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duration_time + waiting_times[i]
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for i, duration_time in enumerate(duration_times)
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]
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def calculate_average_turnaround_time(turnaround_times: list[int]) -> float:
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"""
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This function calculates the average of the turnaround times
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Return: The average of the turnaround times.
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>>> calculate_average_turnaround_time([0, 5, 16])
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7.0
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>>> calculate_average_turnaround_time([1, 5, 8, 12])
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6.5
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>>> calculate_average_turnaround_time([10, 24])
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17.0
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"""
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return sum(turnaround_times) / len(turnaround_times)
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def calculate_average_waiting_time(waiting_times: list[int]) -> float:
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"""
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This function calculates the average of the waiting times
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Return: The average of the waiting times.
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>>> calculate_average_waiting_time([0, 5, 16])
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7.0
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>>> calculate_average_waiting_time([1, 5, 8, 12])
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6.5
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>>> calculate_average_waiting_time([10, 24])
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17.0
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"""
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return sum(waiting_times) / len(waiting_times)
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if __name__ == "__main__":
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# process id's
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processes = [1, 2, 3]
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# ensure that we actually have processes
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if len(processes) == 0:
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print("Zero amount of processes")
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exit()
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# duration time of all processes
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duration_times = [19, 8, 9]
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# ensure we can match each id to a duration time
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if len(duration_times) != len(processes):
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print("Unable to match all id's with their duration time")
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exit()
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# get the waiting times and the turnaround times
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waiting_times = calculate_waiting_times(duration_times)
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turnaround_times = calculate_turnaround_times(duration_times, waiting_times)
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# get the average times
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average_waiting_time = calculate_average_waiting_time(waiting_times)
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average_turnaround_time = calculate_average_turnaround_time(turnaround_times)
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# print all the results
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print("Process ID\tDuration Time\tWaiting Time\tTurnaround Time")
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for i, process in enumerate(processes):
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print(
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f"{process}\t\t{duration_times[i]}\t\t{waiting_times[i]}\t\t"
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f"{turnaround_times[i]}"
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)
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print(f"Average waiting time = {average_waiting_time}")
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print(f"Average turn around time = {average_turnaround_time}")
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