Updated for Squeak 3.6, and registered on SqueakMap.

AioPlugin provides support for asynchronous IO event notification.
When an external IO event occurs, the event registration causes
a Smalltalk semaphore to be signaled. A process can wait on this
semaphore, thereby acting as an event handler for the external event.
Currently this works with the Unix VM (probably including OS X,
feedback on this would be appreciated).

UnixAioPlugin implements the primitives that interact with the aio
mechanism in the Unix VM. Other platform-specific subclasses could be
written to provide a compatible aio mechanism for other platforms.

AioEventHandler provides image side support for aio event notification.
An AioEventHandler is an object that waits for an external IO event
to occur, then sends #changed to itself. Any object that is interested
in the external event can register itself as a dependent of the
AioEventHandler, and take appropriate action whenever the external
event occurs.

AioEventHanderExample demonstrate asynchronous read handers for file
streams, OS pipes, standard input, and sockets. See class category
'examples'. Some examples require OSProcess.

Dave