Asynchronous I/O on UNIX?

[Joseph S. D. Yao]

I'm afraid this isn't a great response, but:  I've seen one or two
implementations of asynchronous I/O.  One was done by Steve Holmgren
et al at U Ill Champaign-Urbana (U-C?) maybe half a dozen years ago.
Obviously, not based on any current system, nor has it been propagated
much, especially since it was part of a version that completely changed
UNIX.

I vaguely remember an interface; and I don't remember whether this
is from Steve's implementation or not.  Basically, one opens an fd
and posts a signal routine for that fd.  Asread()'s and aswrite()'s
etc. return an object which is compared to (something, I think
retrieved by another system call) at interrupt time.  Not too far
from simple.
-- 

	Joe Yao		hadron!jsdy at seismo.{CSS.GOV,ARPA,UUCP}