EZSA_RTScheduler

A real-time scheduler for the M.Sc. CS subject EZSA (Realtime Systems in Automotive Computing) at TH Nuremberg

What it does:

The scheduler can be used to test task scheduling on a CPU. Current possible scheduling algorithms include:

• RMS - Rate-Monotonic Scheduling, including Liu/Layland-Test
• DMS - Deadline-Monotonic Scheduling

Preparation:

Tasks need to be provided in a .txt file within the same directory. The file structure has to look like this:

task_name, computation_time, period, deadline (optional)

Example:

A,1,3,3
B,1,6,6
C,1,5,5
D,2,10,9

How to run:

Within the main method, read the file data into a variable, then call one of the scheduling methods, currently:

• rms_from_file( /path ) or
• dms_from_file( /path )

Output:

For the above example the output looks as follows:
Hyperperiod, Utilisation, and the output array are displayed. Also a gant chart of the output is generated (Limited to 200 chars max.)

RMS:

Hyperperiode:  30
Prozessorauslastung:  0.8999999999999999 , Max:  0.7568284600108841
==> RMS-Test nicht bestanden!
['A', 'C', 'B', 'A', 'D', 'C', 'A', 'B', 'D', 'A', 'C', 'D', 'A', 'B', 
'D', 'A', 'C', 'i', 'A', 'B', 'C', 'A', 'D', 'D', 'A', 'C', 'B', 'A', 'i', 'i']
RMS Scheduling: 100%|██████████| 30/30 [00:00<00:00, 142825.33it/s]

Gant Chart:
A |█░░█░░█░░█░░█░░█░░█░░█░░█░░█░░
B |░░█░░░░█░░░░░█░░░░░█░░░░░░█░░░
C |░█░░░█░░░░█░░░░░█░░░█░░░░█░░░░
D |░░░░█░░░█░░█░░█░░░░░░░██░░░░░░

DMS:

Hyperperiode:  30
Prozessorauslastung:  0.8999999999999999
['A', 'C', 'B', 'A', 'D', 'C', 'A', 'B', 'D', 'A', 'C', 'D', 'A', 'B', 
'D', 'A', 'C', 'i', 'A', 'B', 'C', 'A', 'D', 'D', 'A', 'C', 'B', 'A', 'i', 'i']
DMS Scheduling: 100%|██████████| 30/30 [00:00<00:00, 142825.33it/s]

Gant Chart:
A |█░░█░░█░░█░░█░░█░░█░░█░░█░░█░░
B |░░█░░░░█░░░░░█░░░░░█░░░░░░█░░░
C |░█░░░█░░░░█░░░░░█░░░█░░░░█░░░░
D |░░░░█░░░█░░█░░█░░░░░░░██░░░░░░

Error Handling:

If the program is not able to schedule the given tasks, it will identify where the error occured and throw an exception:

Example:

A,1,3,3
B,1,6,6
C,1,5,5
D,2,10,8 <= Using DMS, this Task will not meet its deadline of 8 ticks

Output:

Exception: ('D', 'cannot be scheduled, because comp time', 1, 
'is longer than remaining deadline time', 0, 'on tick', 8)