The root IO tracker for a class of clients.
You can use different kinds of clients with a single registry. The registry generates network status
events for connections - readable & writable. Connections themselves service the events and invoke
read/writev.
You may choose to spawn this in your mixed runtime, but you should strongly consider putting
it on a dedicated thread. It uses epoll and though it tries to stay live, it can hitch for brief
moments.
To be spawned, this is the task that handles serialization, deserialization, and network readiness events.