Scheduling Simulation

Work with an LLM to write a simulation in C which analyzes CPU scheduling algorithms. Your program will simulate the following schedulers:

First Come First Serve
Preemptive Shortest Job First
Priority (preemptive)
Round Robin with quantum=20.

All time units should be an integral number of milliseconds. These milliseconds don't have to literally take a millisecond while running. Don't make things happen in "real time".

Simulate context switches between processes, each of which will require 5 ms. Context switches should not be preempted.

AI Usage

You should use AI to assist in writing this program. Take advantage of Gettysburg's Linc AI Hub.

Test your program to make sure it works as you have specified it.
Be familiar enough with your resulting code to make minor changes.
Document your development and testing in a file called README.txt.
- Describe your development process. How did you incorporate AI in the process? Did you have AI write the entire program and then modify it to fit your your needs, or did you start with a basic outline and have AI build pieces as you needed them,
- Which LLM did you use, and how did you access it? Include some important prompts you wrote while you developed and tested your code.
- Describe your testing process.

Command Line Arguments

Your program will need to specify an input file name from the command line and a single flag. The flag is optional on the command line. If it is specified, your program will produce verbose output (see below), otherwise it will produce the default output only.

Suppose you write a program called CPUSim. The command line format would be:

      CPUSim infile -v

where infile is the name of the input file and the optional -v specifies verbose output.

You can specify command line arguments in eclipse by modifying the Run Configurations for your project so you aren't stuck only running from the command line.

Input Format

Your program will read processes from a file. The first line of the file will contain n:the number of processes to simulate which will have a value between 1 and 1000.

There will then be n lines (one for each process) containing 4 integers separated by a single space:

The process ID which will be unique for each line.
The process's priority (use for the priority schedulers only). A lower number indicates a higher priority.
The process's arrival time in the ready queue.
The process's CPU burst time.

The lines will be ordered by the process's arrival time.

For example the input file might be:

Output Format

There are two output formats that your program should produce. The first is the default format, the second format will be used when your program is run with a -v on the command line. Time units in the output should be in milliseconds, but may be floating point numbers. The output described below should be all that appears on standard output (System.out, cout or stdout). Use standard error for debugging messages (System.err, cerr, stderr).

Default Output

The default output just produces the following statistics for each of the schedulers:

The name of the scheduler
The time in the simulation when the last process finished.
The percent CPU utilization (the amount of time the CPU is running the processes).
The throughput in processes per second.
The average wait time.
The average turnaround time.

Verbose Output

The verbose output will print out the default output followed by individual process statistics. For each scheduling algorithm you should output information about each process. Each of these should be on its own line which contains the following information:

The process ID
Arrival time.
Completion time.
Turnaround time.
Total wait.

The line should be just numbers separated by a space with no labels.

The file testOut.txt contains verbose output for the example input above. Your calculations may differ a bit from mine depending on your design and scheduling decisions. They do not need to match exactly.

There is an additional sample input file, procTest.txt and its verbose output procTest_output.txt. You can make other input files using ProcGen.java Java program provided.

Comments

Include thematic comments. I recommend adding these without the assistance of AI to help you understand what the program is doing. These comments will describe in general terms the activities and events surrounding the process structure and life cycle in your simulation. Document what is done to the processes, how they are manipulated, how they change. If your code tells a story, the process is the protagonist.

Thematic comments should begin with a "--", so would use //-- or /*-- to indicate the beginning of a thematic comment.

Submission

Submit the following in Moodle.

Your source code.
README.txt described above.

Hints and Suggestions

The following are suggestions, not requirements for the assignment.

Start early.
Make each iteration of an outer loop represent 1 msec. Each iteration should update each process's statistics and make any state changes necessary.
This is not an exercise in syntax and semantics, it is all about the simulation. If you find yourself getting caught up in details, stop and ask for help.
Don't run with scissors.