Kernel Scheduler

Kernel Scheduler is a simulation of various CPU scheduling algorithms typically used within an operating system kernel. This project demonstrates different scheduling strategies including:

• Shortest Job First (SJF)
• Earliest Deadline First (EDF)
• First-Come, First-Served (FCFS)
• Round Robin (RR)
• Priority Scheduling
• Priority Round Robin (Priority RR)

Each scheduler considers job attributes such as name, priority, burst time, start time, and (optionally) a deadline. The simulation calculates key metrics like average waiting time, turnaround time, and response time for performance analysis.

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Features

• Job Structure:
  Each job has:

  • job_name: A string identifier.
  • priority: Numerical priority.
  • burst: CPU burst time.
  • start_time: Time when the job becomes eligible.
  • deadline: Optional deadline for EDF scheduling (set to -1 if unused).

• Multiple Scheduling Algorithms:

  • SJF: Non-preemptive execution of the shortest job first.
  • EDF: Non-preemptive Earliest Deadline First for jobs with deadlines.
  • FCFS: Simple first-come, first-served ordering.
  • RR: Round Robin scheduling with a configurable time quantum.
  • Priority: Non-preemptive scheduling based on job priority.
  • Priority RR: A hybrid approach combining priority scheduling with round robin time slicing.

• Metrics Calculation:
  The system computes average waiting time, turnaround time, and response time for each scheduler.

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Directory Structure

Kernel-Scheduler/
├── include/
│   ├── job.h                # Defines the Job data structure.
│   ├── scheduler.h          # Scheduler function prototypes.
│   ├── list.h               # Linked list structure for job queues.
│   └── cpu.h                # CPU simulation interface.
├── src/
│   ├── cpu.c                # Implements the CPU simulation.
│   ├── list.c               # Implements linked list operations.
│   ├── scheduler_sjf.c      # SJF scheduler implementation.
│   ├── scheduler_edf.c      # EDF scheduler implementation.
│   ├── scheduler_fcfs.c     # FCFS scheduler implementation.
│   ├── scheduler_rr.c       # Round Robin scheduler implementation.
│   ├── scheduler_priority.c # Priority scheduler implementation.
│   ├── scheduler_priority_rr.c  # Priority Round Robin scheduler implementation.
│   └── main.c               # Main driver: reads input and runs the selected scheduler.
├── jobs.txt                 # Sample input file (CSV format).
└── README.md                # This file.

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Getting Started

• Prerequisites

1. C Compiler: You need a C compiler such as GCC. On Windows, using MinGW or MinGW-W64 is recommended. Ensure that the compiler's bin directory is added to your system PATH.

• Installation

1. Clone the Repository:

git clone https://github.com/yourusername/Kernel-Scheduler.git
cd Kernel-Scheduler

2. Compile the Project:

gcc -Iinclude src/*.c -o scheduler

Usage

Input File Format

The input file (e.g., jobs.txt) should be in CSV format:

job_name,priority,burst,start_time,deadline

For example:

JobA,5,10,0,-1
JobB,3,5,2,20
JobC,4,8,4,18

Note: For schedulers that do not use deadlines (e.g., SJF or FCFS), set deadline to -1.

Running the Simulation

The program accepts two command-line arguments:

1. The input file (e.g., jobs.txt)
2. The scheduler type

Valid scheduler types are:

• sjf
• edf
• fcfs
• rr
• priority
• priority_rr

Examples:

./scheduler jobs.txt sjf
./scheduler jobs.txt edf
./scheduler jobs.txt fcfs
./scheduler jobs.txt rr
./scheduler jobs.txt priority
./scheduler jobs.txt priority_rr