FCFS Algorithm with Same Arrival Time














































FCFS Algorithm with Same Arrival Time



'''
FCFS: First Come First Serve

The task is to find the Average Waiting Time and Average Turnaround Time of the given processes with their Burst Time using FCFS Scheduling Algorithm.

FCFS is the simplest Scheduling Algorithm. It simply serves a process in order that they arrive in the Ready Queue.

FCFS is a Non Pre-emptive Algorithm, hence the process which comes first will be executed first and the next process will be served only after the previous process is executed completely.

Here we are considering the arrival time of all processes to be 0.

1. Start Time: Time at which the execution of the process starts
2. Completion Time: Time at which the process completes its execution
3. Turnaround Time: Completion Time - Arrival Time
4. Waiting Time: Turnaround Time - Burst Time
'''




class FCFS:
def processData(self, no_of_processes):
process_data = []
for i in range(no_of_processes):
temporary = []
process_id =
int(input("Enter Process ID: "))

burst_time =
int(input(f"Enter Burst Time for Process {process_id}: "))

temporary.extend([process_id,
0, burst_time])
'''
0(zero) is the arrival time of the processes
'''
process_data.append(temporary)
FCFS.schedulingProcess(
self, process_data)

def schedulingProcess(self, process_data):
start_time = []
exit_time = []
s_time =
0
for i in range(len(process_data)):
start_time.append(s_time)
s_time = s_time + process_data[i][
2]
e_time = s_time
exit_time.append(e_time)
process_data[i].append(e_time)
t_time = FCFS.calculateTurnaroundTime(
self, process_data)
w_time = FCFS.calculateWaitingTime(
self, process_data)
FCFS.printData(
self, process_data, t_time, w_time)

def calculateTurnaroundTime(self, process_data):
total_turnaround_time =
0
for i in range(len(process_data)):
turnaround_time = process_data[i][
3] - process_data[i][1]
'''
turnaround_time = completion_time - arrival_time
'''
total_turnaround_time = total_turnaround_time + turnaround_time
process_data[i].append(turnaround_time)
average_turnaround_time = total_turnaround_time /
len(process_data)
'''
average_turnaround_time = total_turnaround_time / no_of_processes
'''
return average_turnaround_time

def calculateWaitingTime(self, process_data):
total_waiting_time =
0
for i in range(len(process_data)):
waiting_time = process_data[i][
4] - process_data[i][2]
'''
waiting_time = turnaround_time - burst_time
'''
total_waiting_time = total_waiting_time + waiting_time
process_data[i].append(waiting_time)
average_waiting_time = total_waiting_time /
len(process_data)
'''
average_waiting_time = total_waiting_time / no_of_processes
'''
return average_waiting_time

def printData(self, process_data, average_turnaround_time, average_waiting_time):

print("Process_ID Arrival_Time Burst_Time Completion_Time Turnaround_Time Waiting_Time")

for i in range(len(process_data)):
for j in range(len(process_data[i])):

print(process_data[i][j], end=" ")

print()

print(f'Average Turnaround Time: {average_turnaround_time}')

        print(f'Average Waiting Time: {average_waiting_time}')

if __name__ == "__main__":

no_of_processes =
int(input("Enter number of processes: "))

fcfs = FCFS()
fcfs.processData(no_of_processes)


Output:





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