FIRST COME FIRST SERVE
F.C.F.S.
Basic Theory :
First Come First Serve (FCFS) is an operating system
scheduling algorithm that automatically executes queued requests
and processes in order of their arrival.
It is non-preemptive algorithm. It is the easiest and simplest CPU scheduling algorithm. In this type of algorithm, processes which requests the CPU first get the CPU allocation first. This is managed with a FIFO queue. As the process enters the ready queue, its PCB (Process Control Block) is linked with the tail of the queue and, when the CPU becomes free, it should be assigned to the process at the beginning of the queue. FCFS also suffers from starvation which arise if the first process has larger burst time.
It is non-preemptive algorithm. It is the easiest and simplest CPU scheduling algorithm. In this type of algorithm, processes which requests the CPU first get the CPU allocation first. This is managed with a FIFO queue. As the process enters the ready queue, its PCB (Process Control Block) is linked with the tail of the queue and, when the CPU becomes free, it should be assigned to the process at the beginning of the queue. FCFS also suffers from starvation which arise if the first process has larger burst time.
- Input the number of processes required to be scheduled using FCFS, burst time for each process and its arrival time.
- Using enhanced bubble sort technique, sort the all given processes in ascending order according to arrival time in a ready queue.
- Calculate the Finish Time, Turn Around Time and Waiting Time for each process which in turn help to calculate Average Waiting Time and Average Turn Around Time required by CPU to schedule given set of process using FCFS.