Efficiency of detecting input FD after SIGIO?

[Bob Lenk]

> If there is more than one fd just use select().
> ...
> But if you can't resist optimizing things,
> do a (non-blocking) read of the fd you think has the data.
> If it indeed has data you avoid the overhead of the select().

If there's more than one socket, you should always do a select,
since there may be data on more than one socket.  Remember that
SIGIO signals are not queued.

		Bob Lenk
		{ihnp4, hplabs}!hpfcla!rml