py-common-scheduling-algorithms

Common scheduling algorithms implemented in Python 2.7

AUTHOR

Diego Perini, Istanbul Technical University, May 2013

INTRODUCTION

This folder contains Python 2.7 implementations of the following scheduling algorithms.

• RM: Rate Monotonic
• DM: Deadline Monotonic
• EDF: Earliest Deadline First
• LLF: Least Laxity First
• Deferrable: Deferrable Server
• Sporadic: Sporadic Server

Task execution is simulated via verbose messages. Prepare your tasks using the input files and modify relevant print lines with your code to apply scheduling.

FILE STRUCTURE

Each folder contains one main program named after its corresponding algorithm.

prime.py is a utility library provided by third parties for mathematical operations.

tasks.txt is the input file for RM, DM, EDF and LLF implementations. Its structure is explained below.

deferrable_inputs.txt and sporadic_inputs.txt files are special input files. They can only contain a single server named after their corresponding algorithm. Tasks which set their period as 0 (zero) are considered aperiodic and are only executed once. Their structure is explained below.

tasks.txt

Period1 ReleaseTime1 ExecutionTime1 Deadline1 Taskname1
Period2 ReleaseTime2 ExecutionTime2 Deadline2 Taskname2
Period3 ReleaseTime3 ExecutionTime3 Deadline3 Taskname3
..

deferrable_inputs.txt

Period1 ReleaseTime1 ExecutionTime1 Deadline1 Taskname1
Period2 ReleaseTime2 ExecutionTime2 Deadline2 Taskname2
Period3 ReleaseTime3 ExecutionTime3 Deadline3 Taskname3
ServerPeriod ServerRelease ServerExecution ServerDeadline Deferrable=Budget
..

sporadic_inputs.txt

Period1 ReleaseTime1 ExecutionTime1 Deadline1 Taskname1
Period2 ReleaseTime2 ExecutionTime2 Deadline2 Taskname2
Period3 ReleaseTime3 ExecutionTime3 Deadline3 Taskname3
ServerPeriod ServerRelease ServerExecution ServerDeadline Sporadic=Budget
..

HOW TO RUN

In order to run the project, execute the following command in a terminal. Replace algorithm name with one of the given implementations (i.e rm.py)

python path/algorithm_name.py

The result will be shown on standard output. A visual representation will also be rendered in html. Look for output.html file in your project folder after each execution.

LICENSE

Public Domain

Noob info: Public Domain means you are free to decide what to do with this code. There are absolutely no restrictions regarding copyright, distribution and commercial appliances. Use it as if you have written it.