Sqrt OS is a simulation of an OS scheduler and memory manager using different scheduling algorithms including Highest Priority First (non-preemptive), Shortest Remaining Time Next, and Round Robin

OS ^ 1/2

About

A CPU scheduler determines an order for the execution of its scheduled processes; it decides which process will run according to a certain data structure that keeps track of the processes in the system and their status.

A process, upon creation, has one of the three states: Running, Ready, Blocked (doing I/O, using other resources than CPU or waiting on unavailable resource).

System Description

Consider a Computer with 1-CPU and fixed size memory (1024 ==> can be changed). Our scheduler implemented the complementary components as sketched in the following diagrams.

📌 NOTE:

We are supporting the following Scheduling algorithms:

1. HPF (Highest Priority First)
2. STRN (Shortest Time Remaining Next)
3. RR (Round Robin)

Used Data structures

Algorithm Flow

• Algo Explanation:

  1. Recieve and process all processes which come in the current second 1. In case of free space: Allocate space for it and push it in the ready queue 2. Else: Push it in the waiting list

  2. Check the running process if it finishes or not 1. True: Free its allocated space and check the waiting list 2. False: Pass (continue the code flow)

  3. Check if the ready queue is not empty:

     • True: based on the algo, we decide that we will switch or not

  4. Wait till the next second

Results

1. HPF Algorithm

2. SRTN Algorithm

3. Round Robin Algorithm

Contributors

Abdallah Hemdan

Adel Mohamed

Ahmed Sherif

Ahmed Mahboub

Licence

MIT Licence