lio_listio(2)

NAME

lio_listio - list directed I/O (REALTIME)

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <aio.h>
int
lio_listio(int mode, struct aiocb * const [] list, int nent,
        struct sigevent *sig);

DESCRIPTION

The lio_listio() function initiates a list of I/O requests

with a single
function call. The list argument is an array of pointers to

aiocb structures describing each operation to perform, with nent ele

ments. NULL
elements are ignored.

The aio_lio_opcode field of each aiocb specifies the opera

tion to be performed. The following operations are supported:

LIO_READ Read data as if by a call to aio_read(2).

LIO_NOP No operation.

LIO_WRITE Write data as if by a call to aio_write(2).

If the mode argument is LIO_WAIT, lio_listio() does not re

turn until all
the requested operations have been completed. If mode is

LIO_NOWAIT, the
requests are processed asynchronously, and the signal speci

fied by sig is
sent when all operations have completed. If sig is NULL,

the calling
process is not notified of I/O completion.

The order in which the requests are carried out is not spec

ified; in particular, there is no guarantee that they will be executed in

the order 0,
1, ..., nent-1.

RETURN VALUES

If mode is LIO_WAIT, the lio_listio() function returns 0 if

the operations completed successfully, otherwise -1.

If mode is LIO_NOWAIT, the lio_listio() function 0 if the

operations are
successfully queued, otherwise -1.

ERRORS

The lio_listio() function will fail if:

[EAGAIN] There are not enough resources to enqueue

the

requests.

[EAGAIN] The request would cause the system-wide

limit AIO_MAX

to be exceeded.

[EINVAL] The mode argument is neither LIO_WAIT nor

LIO_NOWAIT,

or nent is greater than AIO_LISTIO_MAX.

[EINTR] A signal interrupted the system call be

fore it could

be completed.

[EIO] One or more requests failed.

In addition, the lio_listio() function may fail for any of

the reasons
listed for aio_read(2) and aio_write(2).

If lio_listio() succeeds, or fails with an error code of EA

GAIN, EINTR,
or EIO, some of the requests may have been initiated. The

caller should
check the error status of each aiocb structure individually

by calling
aio_error(2).

SEE ALSO

aio_error(2), aio_read(2), aio_write(2), read(2), write(2),

aio(4)

STANDARDS

The lio_listio() function is expected to conform to .

BSD January 12, 2003

BSD