The First Come First Serve (FCFS) CPU scheduling algorithm processes jobs in the order that they arrive in the ready queue. Newly arrived processes are added to the tail of the FIFO queue. The first process in the queue is scheduled first and removed from the queue. This is the simplest scheduling algorithm to implement but can result in long average wait times for processes as later arriving processes may have to wait for all earlier processes to complete.
First come first serve. A simple slide demonstration of FCFS regarding Operating System subject Computer Applications
Gives an overview about Process, PCB, Process States, Process Operations, Scheduling, Schedulers, Interprocess communication, shared memory and message passing systems
* Using SJF preemptive scheduling: P2 will execute from time 0 to 5 ms. P3 will execute from time 5 to 8 ms. P1 will execute from time 8 to 18 ms. P4 will execute from time 18 to 38 ms. P5 will execute from time 38 to 40 ms. Total waiting time = (10-5) + (8-5) + (18-0) + (38-5) + (40-10) = 5.6 + 3 + 18 + 33 + 30 = 90 Average waiting time = Total waiting time / Number of processes = 90/5 = 5.6 ms * Using Priority preemptive scheduling