mxjones / redbus Goto Github PK

There's a concurrency issue in EventBus.Publish. When enumerating allSubscriptions for publishing, it's possible that a subscription has unsubscribed since allSubscriptions was assigned. This will result in an IndexOutOfBoundsException.

Related to #1.

I want to use your library (.NET Standard 2.0) but it adds some dependencies that are not necessary and I don't want them in my project.

https://github.com/mxjones/RedBus/blob/master/src/Redbus/Redbus/Redbus.csproj

You can remove this block and it will compile fine.

  <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
    <PackageReference Include="System.Reflection.Emit.LightWeight" Version="4.3.0" />
    <PackageReference Include="System.Dynamic.Runtime" Version="4.3.0" />
    <PackageReference Include="Microsoft.CSharp" Version="4.3.0" />
  </ItemGroup>
  <ItemGroup Condition=" '$(TargetFramework)' == 'net45' ">
    <Reference Include="System" />
    <Reference Include="System.Configuration" />
    <Reference Include="System.Core" />
    <Reference Include="Microsoft.CSharp" />
  </ItemGroup>

I think that doing this it's dangerous, you shouldn't do this:

https://github.com/mxjones/RedBus/blob/master/src/Redbus/Redbus/EventBus.cs#L86

Hi, I found an issue that if you have for example this wrapper:

private static readonly IEventBus EventBus;

public static void Publish(EventBase message)
{
      EventBus.Publish(message);
}

// in another class

EventBusWrapper.Publish(new Payload(payload))

EventBus cannot find any event except EventBase.

But if you declare the method as below, everything works as should:

public static void Publish<T>(T message) where T : EventBase
{
      EventBus.Publish(message);
}

I spent a few hours to find a root cause. Maybe it saves time for others.

It does nothing, it doesn't have any body. Instead of an abstract class it would be nice if it was an interface 'IEvent' or similar.

https://github.com/mxjones/RedBus/blob/master/src/Redbus/Redbus/Events/EventBase.cs

It would be great to have a separate package for Interfaces (e.g. Redbus.Abstractions). The main need I have for this is that I want my domain project to have a reference to Redbus.Abstractions package but don't want it to have a reference to concrete implementation of the event bus so that it prevents direct coupling to the implementation.

I am happy to contribute this but wanted to check with you first to see if this would be something you are up to having.

Hi,

Thanks for your work, but there is an issue in EventBus, where you use a for-each to alter a collection.
I have fixed it by using a normal for instead:

    `public void Publish<TEventBase>(TEventBase eventItem) where TEventBase : EventBase
    {
        if (eventItem == null)
            throw new ArgumentNullException("eventItem");

        List<ISubscription> allSubscriptions = new List<ISubscription>();
        lock (SubscriptionsLock)
        {
            if (_subscriptions.ContainsKey(typeof(TEventBase)))
                allSubscriptions = _subscriptions[typeof(TEventBase)];
        }

        for (int listIndex = allSubscriptions.Count - 1; listIndex >= 0; listIndex--)
        {
            try
            {
                allSubscriptions[listIndex].Publish(eventItem);
            }
            catch (Exception exception)
            {
            }
        }
    }`

Regards :)