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Round Robin Scheduling Visualizer

Simulate and visualize Round Robin CPU scheduling algorithm which executes processes for a fixed time slice in a circular queue.

Configuration

What is Round Robin Scheduling?

Round Robin (RR) is a CPU scheduling algorithm where each process is assigned a fixed time slot in a cyclic way. It is designed especially for time-sharing systems and is preemptive in nature. The scheduler assigns a fixed time unit per process, called a quantum or time slice, and cycles through them. Once a process is executed for the given time period, it's preempted and the next process in the queue is executed.

Key Concepts

  • Time Quantum: Fixed time period allocated to each process for execution.
  • Ready Queue: Circular queue containing all processes waiting for CPU time.
  • Context Switch: Overhead involved in switching from one process to another.
  • Turnaround Time: Time taken from submission to completion (Completion Time - Arrival Time).
  • Waiting Time: Time a process waits in the ready queue (Turnaround Time - Burst Time).

How the Algorithm Works

1. Queue Initialization

Processes are placed in a queue in the order they arrive in the system.

2. Processing

The CPU is allocated to a process for a time interval of up to one time quantum. If the process's remaining burst time is less than one time quantum, the process is executed until completion. Otherwise, the process is preempted after the time quantum expires and placed at the back of the ready queue.

3. Cyclic Execution

The scheduler picks the next process from the front of the queue and repeats step 2 until all processes are completed.

4. Completion

When all processes are executed, the algorithm calculates performance metrics like average turnaround time and average waiting time.

Advantages & Limitations

Advantages

  • ✓ Fair allocation of CPU among processes
  • ✓ Lower response time for all processes
  • ✓ Good for time-sharing environments
  • ✓ Prevents process starvation

Limitations

  • ✗ Higher context switching overhead
  • ✗ Time quantum selection is critical for performance
  • ✗ Not optimal for processes with varying burst times
  • ✗ Increased average waiting time for longer processes