chronOS

A scheduling simulator.

• Authors:

  • 39489 — Jorge Miguel Louro Pissarra, UBI
  • 41266 — Diogo Castanheira Simões, UBI
  • 41381 — Igor Cordeiro Bordalo Nunes, UBI

• Advisor:

  • Paul Andrew Crocker, PhD, UBI

• License: GNU-GPL 3.0

• Latest version: 1.3.0

• Last update: June 19th, 2020

• Languages:

  • English (en-us) — for code, identifiers and general output;
  • Portuguese (pt-pt) — for some comments.

What is chronOS?

chronOS is an operating system scheduling simulator. It is built around two main components:

• A process simulator;
• A memory manager.

It is able to use different algorithms — namely FCFS, SJF, PSA and round-robin — to schedule processes which are as well simulated. The processes consist of changing an unique integer variable.

The static memory manager uses a first-fit algorithm to accommodate new instructions of programs.

The dynamic memory manager uses 4 algorithms — first-fit, next-fit, best-fit and worst-fit — to test them and obtain certain comparative statistics about them.

How to compile

There are two modes to build:

• debug — outputs very extensive debugging information about the execution of chronOS:

  make debug
  

• release — produces a final version of chronOS with only the absolute essential output:

  make release
  

It is possible to clean the current directories using make clean.

Usage

How to call the program:

chronos
    [<--fcfs | --sjf | <--rr | --robin | --round-robin> | --psa>]
    [<<--no-heap-request | -n> | <--seed | -s> n>]
    [<--control | -c> <auto | stdin | file>]

Options available:

Flag                  Description
--------------------------------------------------------------------------------
--fcfs                Uses FCFS scheduling algorithm (mode by default).
--sjf                 Uses SJF scheduling algorithm.
--psa                 Uses PSA scheduling algorithm.
--rr
--robin
--round-robin         Uses round-robin scheduling algorithm.
--------------------------------------------------------------------------------
--no-heap-request
-n                    Turns off pseudorandom heap memory requests.
--seed n
-s n                  Uses the seed 'n' to generate the pseudorandom requests.
                      Time is used by default if seed is not given.
--------------------------------------------------------------------------------
--control x
-c x                  Changes the control to mode defined by X, being:
      auto            Automatic (mode by default);
      stdin           Manual (via stdin);
      file            By file (via control.txt text file).
--------------------------------------------------------------------------------

A file plan.txt with the list of programs, times to execute and optionally priorities is expected. Without it the program will not execute.

DISCLAIMER

This project is an university project. The authors and advisers are NOT responsible for anything resulting from the use of this software. USE IT AT YOUR OWN RISK!