NAME

aio_cancel - cancel asynchronous I/O request

SYNOPSIS

cc [ flag . . . ] file . . . -lposix4 [ library . . . ]

#include <aio.h>
int aio_cancel(int fildes, struct aiocb * aiocbp );

MT-LEVEL

MT-Safe

DESCRIPTION

aio_cancel( ) attempts to cancel either one or all outstanding asynchronous I/O requests pending on the file descriptor specified by fildes. If aiocbp is NULL, then all such outstanding cancelable requests are canceled; otherwise, the individual request referenced by aiocbp references will be canceled.

Normal completion notification occurs even for asynchronous I/O operations that are successfully canceled. If there are requests which cannot be canceled, then the normal asynchronous completion process takes place for those requests, and their associated aiocb structures are not modified.

struct aiocb {
 int               aio_fildes;         /* file descriptor * /
 volatile void     * aio_buf;         /* buffer location * /
 size_t            aio_nbytes;        /* length of transfer * /
 off_t             aio_offset;        /* file offset * /
 int               aio_reqprio;       /* request priority offset * /
 struct sigevent   aio_sigevent;      /* signal number and offset * /
 int               aio_lio_opcode;    /* listio operation * /
};

struct sigevent {

 int               sigev_notify;     /* notification mode * /
 int               sigev_signo;      /* signal number * /
 union sigval      sigev_value;      /* signal value * /
};

union sigval {

 int                sival_int;        /* integer value * /
 void               * sival_ptr;      /* pointer value * /
};

RETURN VALUES

If the requested operation(s) were canceled, aio_cancel( ) returns AIO_CANCELED. But if at least one of the requested operation(s) cannot be canceled because it is in progress, then AIO_NOTCANCELED is returned, and the application may determine the state of affairs for these operation(s) by using aio_error(3R). If all of the operation(s) had already completed, AIO_ALLDONE is returned. Otherwise, aio_cancel( ) returns -1, and sets errno to indicate the error condition.

ERRORS

EBADF

fildes is not a valid file descriptor.

ENOSYS

aio_cancel( ) is not supported by this implementation.

SEE ALSO

aio_return(3R), aio_read(3R)

BUGS

In Solaris 2.4, these functions always return -1 and set errno to ENOSYS, because this release does not support the Asynchronous Input and Output option. It is our intention to provide support for these interfaces in future releases.