VIbe-d fiber question

[Tristan Brice Velloza Kildaire]

I have a piece of server-side software I am writing using Vibed's 
web socket support.

I initially setup an HTTP server of which listens on a given 
port, with the provided `HTTPServerSettings`

```d
// Setup where to listen
this.httpSettings = new HTTPServerSettings();
httpSettings.port = bindPort;
httpSettings.bindAddresses = bindAddresses;
```

I then later continue to setup a handler for web socket 
connections using:

```d
// Setup a websocket negotiater with a handler attached
this.websocketNegotiater = handleWebSockets(&websocketHandler);
```

Then lastly I attach the web socket handler to a given route 
which must allow web socket connections to it:

```d
// Handle `/` as the web socket path
this.router = new URLRouter();
router.get("/", this.websocketNegotiater);
```

All of this is pretty stock-standard.

---

However, here is the snatch (and consequently where my question 
comes in). Because we are accepting connections by virtue of a 
web socket handler which is called on web socket connections to 
the `/` route, I can obviously handle each client by doing some 
work in a loop, then when I am done calling `this.yield()` where 
`this` is a `Connection : Fiber` (custom type of mine), this then 
saving the stack context, the instruction address etc. for later 
resumption with `conn1.call()`.

My question though, is, if there is a way to hook a 
`pre-connection-accept()` function in, because currently the only 
way I am able to propgress the other fibers is by yieling away 
from the websocket connection handler, loop through all the 
current fibers and calling `.call()` on them - this works but 
then after which I have to exit the `websocketHandler()` method 
such that the code can progress to the processing of any possible 
new connections - but in such a case where there are none I 
effectively hang on waiting for such an event instead of doing 
something along the lines of:

```d
if(noNewConnections)
{
     // Loop through all fibers and .call them
}
else
{
     // Process new connection as per `websocketHandler()`
}
```

---

I hope I made my problem/scenario clear and would be interested 
to hear what you guys have to say.