Reentrancy

[qazwsxedckll]

Does goakt support reentrancy？A->A or A->B->C->A. All using synchronous Ask.

func (p *Pinger) Receive(ctx goakt.ReceiveContext) {
	switch ctx.Message().(type) {
	case *samplepb.Ping:
		resp := ctx.Ask(ctx.Self(), new(samplepb.Pong))
		ctx.Response(resp)
	case *samplepb.Pong:
		ctx.Response(&samplepb.Pong{
			Reply: "pong",
		})
	default:
		ctx.Unhandled()
	}
}

protoactor: A->Future(with response function)->B->C->Future
orleans: Interleaving methods
dapr: bypassing lock if it is in the same request chain

[Tochemey]

@qazwsxedckll There is no future concept in Go-Akt. Ask expects a response within a time frame.
Also one thing to be aware of the message context is only carried forward when using Forward.
I can look into that feature and see whether I would like to support it out of the box or not.
I hope it helps.

[Tochemey]

@qazwsxedckll What are the main use cases for such features?

[qazwsxedckll]

It is very common that A asks B, B asks C and C need some infomation from A to perform the action. When the chain is long, it is hard to track such loop and sometimes it is inevitable.

[Tochemey]

It is very common that A asks B, B asks C and C need some infomation from A to perform the action. When the chain is long, it is hard to track such loop and sometimes it is inevitable.

This can be easily be done using the pattern A--> Tell-->B-->Forward-->C-->Tell-->A. I will read around the use case and see. But I think a Tell and Forward combination can do the job.

[qazwsxedckll]

Someone is waiting for A's response, like a client or a user.

User -> A -> B -> A

Let me clarify. User calls A, waiting for a response. While handling the message, A need some infomation from B, so A calls B waiting a response. However, A doesn't know B also need infomation from itself and B calls A, waiting A to response.

I hope this make sense.

[Tochemey]

@qazwsxedckll I have created an issue to look into that #322. Thanks. I hope I have some bandwith to tackle that.