AIO_CANCEL(3)              POSIX Programmer's Manual             AIO_CANCEL(3)



PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NAME
       aio_cancel -- cancel an asynchronous I/O request

SYNOPSIS
       #include <aio.h>

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

DESCRIPTION
       The aio__cancel() function shall attempt 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
       shall be canceled.

       Normal asynchronous notification shall occur for asynchronous I/O
       operations that are successfully canceled. If there are requests that
       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 shall be set to [ECANCELED] and the return status shall be
       -1. For requested operations that are not successfully canceled, the
       aiocbp shall not be 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.

       Which operations are cancelable is implementation-defined.

RETURN VALUE
       The aio__cancel() function shall return the value AIO_CANCELED if the
       requested operation(s) were canceled.  The value AIO_NOTCANCELED shall
       be 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().  The value AIO_ALLDONE is returned if all of the
       operations have already completed.  Otherwise, the function shall
       return -1 and set errno to indicate the error.

ERRORS
       The aio__cancel() function shall fail if:

       EBADF  The fildes argument is not a valid file descriptor.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       aio__read(), aio__write()

       The Base Definitions volume of POSIX.1-2017, <aio.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  In the event of any discrepancy between this version and the
       original IEEE and The Open Group Standard, the original IEEE and The
       Open Group Standard is the referee document. The original Standard can
       be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017                        AIO_CANCEL(3)
