_____  ________      _______   
 |  __ \|  ____\ \    / / ____|  
 | |  | | |__   \ \  / / (___    
 | |  | |  __|   \ \/ / \___ \   
 | |__| | |____   \  /  ____) |  
 |_____/|______|   \/  |_____/                                      

A Discrete Event Scheduling Simulation using Python

FORMAT OF FILES:

Every Individual test should include two files "setup.txt" and "arrivals.txt" where the inputs for your simulation are defined.

I - setup.txt:

The file setup.txt consists of three parts:

• Part 1: One line (i.e., the first line in the file) which is a positive integer that sets the number of tasks "n_tasks" that the RTOS should schedule.

• Part 2: "n_tasks" lines that define the tasks that the system should schedule. Every line has the format:

   <task_id>  <frequency>
  
   Where:
   <task_id> is a positive non-zero integer  
   <frequency> is the periodicity of the task with <task_id>  
  

• Part 3: One line that contains a positive integer defining the context switching overhead. This overhead can equal zero. This overhead should be simulated when the execution of a given task is interrupted by a higher priority task

For example, "setup" of a system with 2 tasks and scheduler overhead of 1 unit will look like:

2
1 100
2 50
1

II - arrivals.txt

The input file arrivals.txt consists of 2 parts

• Part 1: One line (i.e., the first line in the file) which is a positive integer that sets the number of events "n_events" your simulator will trace.

• Part 2: "n_events" lines that define the events the simulator will trace. Every line has the format:

   <time> <task_id> <execution_time> <deadline>
  
   Where:    
   <time> is a positive integer representing the time unit when the event occurs   
   <task_id> is a positive integer that is less than or equal <n_tasks> defining the task_id for the event    
   <execution_time> is non-zero positive integer representing the time required to execute the task that associates this event  
   <deadline> is non-zero positive integer representing the time by which this event should complete execution  
  

For example, using the setupt.txt example shown above, arrivals.txt can look like:
3
0 1 20 100
1 2 10 50
60 2 10 100

III- correct-output.txt

correct-output.txt contains the simulation trace for the system defined in setup.txt and arrivals.txt.

As the simulator is implemented as a discrete events system, we are only interested in the moment when the task being executed changes.

Therefore, correct-output.txt will consist of multiple lines where every line indicates a change in the task being executed by the system.

Every line in correct-output.txt has the format:

<time> <task-id>.<task-instance>

Note: There should be a SINGLE space " " between these three fields.

Where:
<time> is the time when the simulator switches tasks. 

<task-id> is the id of task that will start execution.

<task-instance> is a non zero positive integer representing each subsequent instance for the task "task-id".  
The value of "task-instance" should start with 1, and be incremented by 1 for every task.  

Two special values of "task-id" are reserved for the context switching overhead and the idle execution. These values are: "0" for the context switching overhead and "-1" for idle execution.

For example, given the above values for setup.txt and arrivals.txt, using a RMS or EDF schedules, the correct-output.txt should be:
0 1.1
1 0.1
2 2.1
12 1.1
31 -1.1
60 2.2
70 -1.2