[ENet-discuss] Questions -- select, peer numbers, connects

[Casey Marshall]

Hi!

I'm writing a new software project, and am using enet for part of the transport protocol, and had a few questions.

The biggest question I have is how to use enet in a select-based (or, more likely, epoll-based) loop: waiting for events via an interface like epoll, and on activity, drive the enet connections.

Now, it makes sense that I can run a selection on a ENetHost's socket for readability, and invoke enet_host_service then. What I'm missing, though, is when to call enet_host_service for writable events: I assume, from looking a bit at the code, that enet_host_service needs to be called regularly to dispatch both incoming and outgoing messages, but I don't think you want to call enet_host_service on *every* writable event, if there is nothing going out, because that would lead to a busy-loop, which I want to avoid (the idea here is that I would call enet_host_service with a very small timeout, probably zero). Is there a way to tell from an ENetHost or a bunch of ENetPeers whether or not there is pending outgoing messages?

The short answer to why I want to do this is because I want to write an addon for Node that wraps enet, and Node has its fairly specific way of doing things. I suppose this can also be accomplished by doing the enet service calls in a separate thread, but I was hoping to avoid that.

A related question is how many simultaneous peers can enet support? 100? 1,000? 10,000?

And lastly, any idea what the behavior should be for a "simultaneous connect"? That is, two peers attempt to connect to one another at the same time, on the same ports? Would the ENetPeer objects returned by enet_host_connect both be valid?

Thanks!