The Asynchronous Input/Output (I/O)
feature contains the following
POSIX P1003.4 interface functions:
cancel asynchronous read and/or write requests
retrieve Asynchronous I/O error status
asynchronously force I/O completion, and sets errno to ENOSYS
begin asynchronous read
retrieve return status of Asynchronous I/O operation
suspend until Asynchronous I/O Completes
begin asynchronous write
issue list of I/O requests
Together they provide a user application with the ability to overlap
CPU processing with I/O operations.
Additionally, Asynchronous I/O supports the aio_memlock function
for high performance database applications.
The aio_cancel and aio_suspend functions are supported
only in the thread-based implementation of
UNIX System V Release 4.2 Multiprocessor (SVR4.2 MP) and SCO OpenServer.
The lio_listio function is
supported only for raw slices of hard disks for both
SVR4.2 MP, SVR4.2, and SCO OpenServer.
These routines are more fully described in their respective manual pages.
The Asynchronous I/O feature supports UNIX System V Release 4.2
(SVR4.2), UNIX System V Release 4.2 Multiprocessor (SVR4.2 MP),
and SCO OpenServer.
Functions that can only be used on raw slices of hard disks
have been indicated in the following manner:
Functions provided for the SVR4.2 MP and SCO OpenServer threads-based
implementation only have been indicated in the following manner:
Advantages of asynchronous I/O
© 2005 The SCO Group, Inc. All rights reserved.
SCO OpenServer Release 6.0.0 -- 02 June 2005