A message for data waiting at a socket?

[Doug Lerner]

I am currently polling an open socket to check for data, or checking for
data immediately after writing to the socket (to check for replies to
messages I send).

But is there a message-driven way of doing this? Like if data is waiting at
a socket (data pushed from a server) having it trigger a message, like
socketDataWaiting, or something like that?

Thanks,

Doug Lerner, Tokyo