Readevents on a socket. Windows calls this an
GetQueuedCompletionStatuswhich only returns one event at a time. The
Exversion can return multiple events that has been completed, and we'll use that since we there is no point for us to only handle one and one event at a time.
WSA_IO_PENDINGwhich we most likely will get when calling
WSARecv. This specific error simply means that the action we're waiting for is not ready immediately, and can be waited on by calling
Poll::poll()when the timeout event has completed, and we need this syscall will let us register such an interest to our completion port.