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



NAME
       aio_cancel - cancel an outstanding asynchronous I/O request

SYNOPSIS
       #include <aio.h>

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

       Link with -lrt.

DESCRIPTION
       The aio_cancel() function attempts to cancel outstanding asynchronous I/O requests for the
       file descriptor fd.  If aiocbp is NULL, all such requests are canceled.   Otherwise,  only
       the  request described by the control block pointed to by aiocbp is canceled.  (See aio(7)
       for a description of the aiocb structure.)

       Normal  asynchronous  notification  occurs  for  canceled   requests   (see   aio(7)   and
       sigevent(7)).   The  request  return  status (aio_return(3)) is set to -1, and the request
       error status (aio_error(3)) is set to ECANCELED.  The control block of requests that  can‐
       not be canceled is not changed.

       If  the  request could not be canceled, then it will terminate in the usual way after per‐
       forming the I/O operation.  (In this case, aio_error(3) will  return  the  status  EINPRO‐
       GRESSS.)

       If aiocbp is not NULL, and fd differs from 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 returns one of the following values:

       AIO_CANCELED
              All requests were successfully canceled.

       AIO_NOTCANCELED
              At least one of the requests specified was not canceled because it was in progress.
              In this case, one may check the status of individual requests using aio_error(3).

       AIO_ALLDONE
              All requests had already been completed before the call.

       -1     An error occurred.  The cause of the error can be found by inspecting errno.

ERRORS
       EBADF  fd is not a valid file descriptor.

       ENOSYS aio_cancel() is not implemented.

VERSIONS
       The aio_cancel() function is available since glibc 2.1.

CONFORMING TO
       POSIX.1-2001, POSIX.1-2008.

EXAMPLE
       See aio(7).

SEE ALSO
       aio_error(3),  aio_fsync(3),  aio_read(3),  aio_return(3),  aio_suspend(3),  aio_write(3),
       lio_listio(3), aio(7)

COLOPHON
       This page is part of release 3.74 of the Linux man-pages project.  A  description  of  the
       project,  information  about  reporting  bugs, and the latest version of this page, can be
       found at http://www.kernel.org/doc/man-pages/.



                                            2012-05-08                              AIO_CANCEL(3)