$Revision: 5.0.2.6 $
Package: SYSTEM
Arguments: nil
This function is called with no arguments. If the return value is t, SIGIO
signals can be received on the machine where Lisp is running. If it is nil,
SIGIO signals cannot be received because the operating system does not support it.
A SIGIO handler is a function that associated with a specific Unix file descriptor. It is called whenever Unix generates a SIGIO signal on that file descriptor. Such signals are generated whenever input is available. (SIGIO signals are also generated when output can be performed without the operating system needing to block but all output signals are filtered out by Allegro CL. We will not discuss output-generated signals further.)
See initialize-sigio-handling, set-sigio-handler and remove-sigio-handler.
The general documentation description is in introduction.htm. The index is in index.htm.
Copyright (C) 1998-1999, Franz Inc., Berkeley, CA. All Rights Reserved.