aio_cancel, aio_cancel64 --
cc [options] -Kthread file
struct aiocb *aio_cancel(int fildes, struct aiocb *aiocbp);
struct aiocb64 *aio_cancel64(int fildes, struct aiocb64 *aiocbp);
aio_cancel allows you to cancel
one or more outstanding asynchronous I/O requests.
fildes and key
are used to identify the asynchronous I/O requests that
should be canceled.
The aio_cancel function attempts to cancel one or more asynchronous I/O
requests currently outstanding against file descriptor fildes.
The aiocbp argument points to the asynchronous I/O control block
for a particular request to be canceled. If aiocbp is
NULL, all outstanding cancelable asynchronous I/O requests agains fildes
Normal notification occurs for asynchronous I/O operations that
are successfully canceled.
If there are requests which cannot be canceled, then
the normal asynchronous completion process shall take place for those
requests when they are completed.
For requested operations that are successfully canceled, the associated error
status is set to ECANCELED
and the return status is -1.
For requested operations that are not successfully canceled, the aiocbp
is not modified by aio_cancel.
If aiocbp is not NULL,
and fildes does not have the same value as the file
descriptor with which the asynchronous operation was initiated,
unspecified results occur.
functions return the value
AIO_CANCELED to the calling process if
the requested operation(s) were canceled.
The value AIO_NOTCANCELED
is returned if at least one of the
requested operation(s) cannot be canceled
because it is in progress.
In this case, the state of the other operations, if any, referenced in
a call to aio_cancel or aio_cancel64 is not indicated by the return value of
aio_cancel or aio_cancel64.
The application may determine the state of affairs
for these operations by using aio_error or aio_error64.
The value AIO_ALLDONE is returned if all of the operations have
Otherwise, the functions return -1, and set errno to indicate
Under the following conditions, aio_cancel and aio_cancel64
fail and set errno to:
fildes is not a valid file descriptor.
No asynchronous I/O has ever been requested for fildes.
There were no internal kernal aio control blocks available to service
the request (number of kernel aio control blocks is tunable via
the NUMAIO kernel parameter; see
``Miscellaneous parameters'' in Monitoring and tuning the system).
aio_cancel called on SVR4.2.
Considerations for large file support
aio_cancel64 supports large files, but is otherwise identical
For details on programming for large file capable applications, see
``Large File Support''
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004