AIO_CANCEL(3C) Standard C Library Functions AIO_CANCEL(3C)


NAME


aio_cancel - cancel asynchronous I/O request

SYNOPSIS


#include <aio.h>

int aio_cancel(int fildes, struct aiocb *aiocbp);


DESCRIPTION


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, then all outstanding
cancelable asynchronous I/O requests against fildes are canceled.


Normal asynchronous notification occurs for asynchronous I/O operations
that are successfully canceled. If there are requests that cannot be
canceled, then the normal asynchronous completion process takes 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, then if fildes does not have the same value as the
file descriptor with which the asynchronous operation was initiated,
unspecified results occur.

RETURN VALUES


The aio_cancel() function returns 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 the call to aio_cancel() is
not indicated by the return value of aio_cancel(). The application may
determine the state of affairs for these operations by using
aio_error(3C). The value AIO_ALLDONE is returned if all of the operations
have already completed. Otherwise, the function returns -1 and sets errno
to indicate the error.

ERRORS


The aio_cancel() function will fail if:

EBADF
The fildes argument is not a valid file descriptor.


ENOSYS
The aio_cancel() function is not supported.


USAGE


The aio_cancel() function has a transitional interface for 64-bit file
offsets. See lf64(5).

ATTRIBUTES


See attributes(5) for descriptions of the following attributes:


+--------------------+-------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------+
|Interface Stability | Committed |
+--------------------+-------------------+
|MT-Level | MT-Safe |
+--------------------+-------------------+
|Standard | See standards(5). |
+--------------------+-------------------+

SEE ALSO


aio.h(3HEAD), signal.h(3HEAD), aio_read(3C), aio_return(3C),
attributes(5), lf64(5), standards(5)

NOTES


Solaris 2.6 was the first release to support the Asynchronous Input and
Output option. Prior to this release, this function always returned -1
and set errno to ENOSYS.


February 5, 2008 AIO_CANCEL(3C)