BroadcastBlock with guaranteed delivery in TPL Dataflow

Question

I have a stream of data that I process in several different ways... so I would like to send a copy of each message I get to multiple targets so that these targets may execut

Answer 1

It is fairly simple to build what you're asking using ActionBlock and SendAsync(), something like:

public static ITargetBlock CreateGuaranteedBroadcastBlock(
    IEnumerable> targets)
{
    var targetsList = targets.ToList();

    return new ActionBlock(
        async item =>
        {
            foreach (var target in targetsList)
            {
                await target.SendAsync(item);
            }
        }, new ExecutionDataflowBlockOptions { BoundedCapacity = 1 });
}

This is the most basic version, but extending it to support mutable list of targets, propagating completion or cloning function should be easy.