OS Schedulers

Files

• main.py : Contains main section of the program
• task.py : Illustrates class "Task". This class contains attributes such as:
  • name
  • type (X, Y, Z)
  • duration (CPU burst-time)
  • cpu_time (how much time CPU has assigned time to this task)
  • priority
  • required resources: X: (A,B), Y: (B,C), Z: (A,C)
• cpuCore.py : Illustrates class "CPUCore". This class contains attributes such as:
  • name
  • idle_time (how much time this core has been busy)
  • state (busy, idle, running)
  • running_task (indicates he task that is processing by this CPU-core)
  • process_task() process the input task preemptive/none-preemptive
• schedulers.py : Contains different scheduling algorithms and also needed functions to run them
• globals.py : Contains globals variables and functions used in different files

Algorithms

In this project I was supposed to implement some well-known OS scheduler algorithms. The implemented algorithms are as follows:

• FCFS : First Come First Service
• SJF : Shortest Job First
• RR : Round Robin
• MLFQ : Multilevel feedback queue
• MLQ : Multilevel Queue (based on priorities)

How to run?

1. First of all you should run main.py with python 3.xx:

python3 main.py 

2. Choose the desired scheduler algorithm by typing its abbreviation: FCFS, SJF, RR, MLFQ, MLQ 3.Specify the number of resources that are available in this system. You should enter the number of resources A , B, C respectively.
3. Enter the number of tasks that need to be processed
4. Enter the information about tasks (line-by-line) in the following format: <name> <type> <duration>
5. Enter the intended number of CPU-cores
6. In case that selected scheduler algorithm needs more parameters to be specified such as time-quantum or number of queues, you'll be asked to enter them at this step, otherwise algorithm starts working!

Extra information

• In this program, tasks are fed to system at the first step which means tasks will not be added to system while CPU is processing
• One of the main advantages of this program is multithreading! It allows tasks to be processed by different CPU-cores simultaneously. So to be able to run this program you should have installed threading module
• To be able to use advantages of multi-threading, I used different Semaphores
• This project was done as my final project of Operating Systems course in semester 5