Disruptor.NET example

Question

I am trying to learn how to use the Disruptor.NET messaging framework, and I can't find any practical examples. There are quite a few articles out there with pictures about how it works, but I can't find anywhere that actually goes and shows you how to implement the methods. What would be an example?

Answer 1

Frustrated that I couldn't find a workable 'Hello World' for Disruptor-net, I fiddled around until I got one working. See below. The Console.WriteLine lines are handy for seeing how things work. For example, the RingBuffer creates each entry instance at start-up (which makes sense).

Hopefully this helps anyone looking for help with Disruptor on .NET.

using System;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Disruptor;
using Disruptor.Dsl;

namespace DisruptorTest
{
    public sealed class ValueEntry
    {
        public long Value { get; set; }

        public ValueEntry()
        {
            Console.WriteLine("New ValueEntry created");
        }
    }

    public class ValueAdditionHandler : IEventHandler<ValueEntry>
    {
        public void OnNext(ValueEntry data, long sequence, bool endOfBatch)
        {
            Console.WriteLine("Event handled: Value = {0} (processed event {1}", data.Value, sequence);
        }
    }

    class Program
    {
        private static readonly Random _random = new Random();
        private static readonly int _ringSize = 16;  // Must be power of 2

        static void Main(string[] args)
        {
            var disruptor = new Disruptor.Dsl.Disruptor<ValueEntry>(() => new ValueEntry(), _ringSize, TaskScheduler.Default);    
            disruptor.HandleEventsWith(new ValueAdditionHandler());    
            var ringBuffer = disruptor.Start();    
            while (true)
            {
                long sequenceNo = ringBuffer.Next();    
                ValueEntry entry = ringBuffer[sequenceNo];    
                entry.Value = _random.Next();    
                ringBuffer.Publish(sequenceNo);    
                Console.WriteLine("Published entry {0}, value {1}", sequenceNo, entry.Value);    
                Thread.Sleep(250);
            }
        }
    }
}

Answer 2

There is a detailed blog post on the Disruptor pattern, The Latency Issue. It demonstrates how to get started and use the Disruptor in detail.